CHANGE-OVER VALVE, AND REGENERATIVE COMBUSTION APPARATUS AND REGENERATIVE HEAT EXCHANGER USING SAME

Abstract: In order to realize in a continuous operation efficient heat decomposition and purification of a gas to be treated, which contains bad-smelling substances, with a large-sized and heavy heat reserving material (53) in a stationary condition, the gas to be treated is supplied to a chamber (65) of a change-over valve (51) to be conducted from a guide space (91) through first moving valve ports (86, 87) of a moving valve member (69) and a stationary valve port (82) of a stationary valve member (71) to a plurality of passages (84, 113-120), which are compartmented by partition plates (55) in a housing (52) and contain therein the heat reserving material (53), a pretreatment material (141) and a catalyst (54), to undergo endothermic reaction for heat decomposition of the bad-smelling substances by means of the catalyst (54) and a burner (59), the gas being treated then having its heat reserved through the heat reserving material (53), so that a purified gas is taken out from the stationary valve port (82) and second moving valve ports (88, 89) through a chamber (66). A third moving valve port (90) is provided to prevent the gas being treated from being mixed with the purified gas. A change-over section (138) is provided to instantaneously perform change-over of gas flows through the plurality of passages (84, 113-120), thereby improving an efficiency of operation.

Description: The invention relates to a rotary distribution valve for changing over and guiding a fluid such as gas according to the first part of claim 1, a regenerative combustion apparatus using the rotary distribution valve, and its operating method, and a regenerative heat exchanger using the rotary distribution valve. Such a rotary distribution value is known from US-A-5 016 547. A direct combustion apparatus hitherto employed for removing malodorous substances discharged from a paint plant and other various plants is designed to heat an polluted gas to about 800°C, oxidize the malodorous substances, and decompose into odorless carbon dioxide and water, and is known as a deodorizing apparatus of a wide scope of application capable of treating all of malodorous substances that are oxidized and decomposed at high temperature. A drawback of this direct combustion apparatus is its high fuel cost. In other words, the combustion heat of the malodorous substances is lowered as the concentration of the malodorous substances is lowered, which leads to increase of the fuel amount, thereby increasing the cost. A prior art reduced in the fuel amount and substantially enhanced in the heat recovery rate is disclosed in Fig. 22. First, second, and third columns 1, 2, 3 filled with a heat reserve material such as ceramics are provided, and burners 4, 5 are disposed so that the temperature of the top of each column reaches about 800°C. The polluted gas containing malodorous substances is guided into a duct 6, which is linked to the lower part of each column 1, 2, 3 through valves 7, 8, 9, and the gas purified through valves 10, 11, 12 is discharged through a duct 13. During operation, the polluted gas from the duct 6 is raised, for example, from the lower part of the second column 2 through the valve 8, and is heat-exchanged, the malodorous substances are oxidized and decomposed by the burner 5, a heat reserve material 14 in the third column 3 is heated to reserve heat, and the purified gas is discharged from the duct 13 through the valve 12, and exhausted to the atmosphere. The valves are changed over by a timer, and air for purge is supplied from a duct 15 into the lower part of the second column 2 to conduct the malodorous gas in the second column 2 into the first column 1, and the polluted gas to be processed next is guided into the lower part of the third column 3 through the valve 9 from the duct 6, and heated by the heat reserve material 14, and the malodorous substances are oxidized and decomposed by the burner 4, and the heat reserve material in the first column 1 is heated to exchange heat, and the purified gas is conducted into the duct 13. Afterwards, the air for purge is further supplied into the lower part of the third column 3 from the duct 15, and is conducted into the second column 2 through the burner 5, and the objective gas is supplied into the lower part of the first column 1 through the valve 7 from the duct 6, and heated by the heat reserve material, and the malodorous substances are oxidized and decomposed by the burner 4, and the purified gas through the valve 11 from the second column 2 is discharged from the duct 13 together with the air for purge. In this way, sequentially in time by the timer, the polluted gas rises through the first to third columns 1, 2, 3, and absorbs the heat from the heat reserve material 14, and the gas heated by the burners 4, 5 descends through the first, second and third columns 1, 2, 3 to heat the heat reserve material 14, so that the heat recovery rate may be enhanced greatly. A problem of the prior art shown in Fig. 22 is that it requires a total of three large-sized columns 1, 2, 3 for the purpose of purging. Before changing from the heat absorption process of the polluted gas into the heat release process, the malodorous gas remaining in the columns 1, 2, 3 without being decomposed must be purged, and although the amount of air necessary for this purge is substantially smaller as compared with the flow rate of the polluted gas, the prior art shown in Fig. 22 requires the columns in the same volume as the columns for heat absorption-release, and the facility cost is high, and a wider area for installation is needed. Moreover, it requires a total of six changeover valves 7, 8, 9; 10, 11, 12, and also three changeover valves for purge, and therefore the construction is complicated and expensive. Moreover, in the prior art shown in Fig. 22, the changeover operation of the valves 7, 8, 9; 10, 11, 12 is a so-called semi-batch operation, and the changeover operation is done, generally, in every two minutes or so. The required amount of heat reserve material is determined by this changeover time, and as compared with the heat reserve material required for changeover operation in every two minutes, that for changeover operation in every one minute is about 1/2, and the required amount of heat reserve material is about 1/4 when changing over in every 30 seconds, but the prior art shown in Fig. 22 requires the operation time of the valves 7, 8, 9; 10, 11, 12, and the time required for purging a massive volume of air is long, and hence it is difficult to shorten the changeover time of the valves 7, 8, 9; 10, 11, 12, and thereby, as mentioned above, the required amount of the heat reserve material increases. Fig. 23 shows other prior art enhanced in the heat recovery efficiency and capable of saving the fuel consumption for the purpose of downsizing the constitution. In this prior art, the polluted gas containing malodorous substances is supplied from a duct 17, and is conducted into an upper space 20 of a housing 19 from a changeover valve 18, and when flowing through the heat reserve material 21, when it is heated by a heat reserve material 21 to absorb heat, and is further heated by an electric heater 22 to about 1000°C, and the heat is released to a heat reserve material 23 beneath, and as a result heat is accumulated in the heat reserve material 23, and then it is discharged through a changeover valve 18 and a duct 25 from a lower space 24. Then the changeover valve 18 is changed over, and the polluted gas from the duct 17 passes through the space 24 from the changeover valve 18 and is heated by the heat reserve material 23, and is further heated by the electric heater 22, and the heat is released to the heat reserve material 21 to accumulate heat, and it is discharged from the duct 25 through the changeover valve 18 from the space 20. Such operation is repeated. In the prior art shown in Fig. 23, immediately after changeover operation of the changeover valve 18, purging is not carried out, and hence the polluted gas containing malodorous substances is partly discharged through the duct 25. A different prior art for solving this problem is disclosed in Fig. 24. In this prior art, the corresponding parts similar to those of the prior art shown in Fig. 23 are denoted with the same reference numerals. This prior art has further changeover valves 27, 28, and also has a tank 30 communicating with the atmosphere for purge. In this prior art, the polluted gas containing malodorous substances is passed through the changeover valve 18 from the duct 17, and is heated by the heat reserve material 21 from the space 20 in the housing 19, and is further heated by the electric heater 22, and the heat is reserved in the heat reserve material 23, then a purified gas is discharged through the valve 27 from the changeover valve 18 and the duct 25. At this time, the changeover valve 28 is closed. Immediately after the changeover valve 18 is changed over, the changeover valve 27 is closed, the changeover valve 28 is opened, and from the duct 17 through the changeover valve 18 and from the space 24 in the housing 19 through the space 20, and further through the changeover valves 18, 28, the exhaust gas is stored in the tank 30, and after storing a necessary amount for purge, the changeover valve 28 is closed, the changeover valve 27 is opened, and the exhaust gas is exhausted through the changeover valve 27. The air containing malodorous substances stored in the tank 30 immediately after the changeover stored in the tank 30 is later passed gradually into the duct 17 through the duct 31, and is mixed into the polluted gas. This prior art shown in Fig. 24 has problems that the tank 30 of a large column tank for purge is also required, and time for changeover operation of the changeover valves 18, 27, and 28 is necessary, and a large amount of heat reserve material is required, and such problems are the same as experienced in the prior art mentioned in Fig. 22. In an other prior art disclosed in the US-A-5,016,547 heat reserve materials are disposed in plural segments partitioned in a housing in the peripheral direction, and a changeover valve of which disc valve is rotated is disposed beneath the housing, and the polluted gas is elevated and heated by the heat reserve materials. Flammable components of the polluted gas are burnt in a combustion chamber above the housing, and a purified gas containing no flammable component passes through the heat reserve materials and descends while heating the heat reserve materials, and is discharged outside through the changeover valve, and the changeover valve sequentially changes over each of such segments in the peripheral direction. Such fundamental constitution is similar to the principle of the invention, but in the prior art, in addition, a pair of purge gas passages are formed at positions deviated from each other by 180 degrees in the peripheral direction in order to prevent the polluted gas remaining in the segment from entering into the purified gas and being discharged at the time the segments of the heat reserve materials heated by the polluted gas elevated are changed over by the changeover valve so that the purified gas may descend. A problem of this prior art is that a pair of gas passages for purge are formed, thereby decreasing the heat reserve materials, i.e. the effective volume for passing of the polluted gas of segments and clean gas. Moreover, the structure of the changeover valve for forming two gas passages for purge becomes complicated. In this prior art, still more, since gas for purge is supplied into the pair of gas passages for purge, the required flow rate of gas for purge is increased. It is an object of the invention to provide a rotary distribution valve to be used preferably in a regenerative combustion apparatus capable of enhancing notably the heat recovery efficiency, decreasing the fuel consumption by lowering the oxidation reaction temperature, and reducing the size. The rotary distribution valve according to the invention is defined in claim 1. Advantageous features of the rotary distribution value according to the invention are claimed in the claims 2 to 7. The invention also provides a regenerative combustion apparatus as claimed in claim 8. A method of operating such a combustion apparatus is defined in claim 15. The invention further provides a regenerative heat exchanger as claimed in claim 16. In the rotary distribution valve according to the invention, the pair of chambers 65, 66 are formed in the axial direction in the valve box, and when fluid such as the polluted gas is supplied, for example, from the connection port 61 of the other chamber 65, it is conducted from the guide space 91 partitioned by the partition wall of the valve disc, through the first moving valve ports 86, 87, and further through the passages 84, 113 to 120 of every stationary valve port 82 through the stationary valve port 82 of the passage forming means 71, 52, 55. On the other hand, the fluid such as clean gas from a passage provided so as to communicate with the other stationary valve port 82 is conducted from the other stationary valve port 82 through the second moving valve ports 88, 89 of the moving valve disc 69, and from the one chamber 66 of the valve box 64 through the connection port 62 of the one chamber 66. In this way, by rotating the valve member 67 about its axis, the passage of the fluid can be sequentially changed over by sequentially changing over the plural stationary valve ports 82 formed in the passage forming means 71, 52, 55. Moreover, in the rotary distribution valve 51 according to the invention, in the valve member 67, the third moving valve port 90 is formed either between the first and second moving valve ports 86; 89 or between the first and second moving valve ports 87; 88 along the peripheral direction, and the communicating passage 111 to communicate with the third moving valve port 90 through the auxiliary partition wall 110 is formed, and the fluid such as purging air guided into the shaft hole 106 through the rotary tube joint 107 can be passed through the stationary valve port 82 of the passage forming means 71, 52, 55 through the third moving valve port 90 from the communicating passage 111 formed by the auxiliary partition wall 110. In particular, in the rotary distribution valve 51 according to the invention, the third moving valve port 90 is thus formed either between the first and second moving valve ports 86, 87; 89 or between the first and second moving valve ports 87; 88 along the peripheral direction, the changeover part 138 is formed between the other first and second moving valve ports 86, 87; 88, 89 along the peripheral direction, the changeover part 138 being expanded in the peripheral direction, so that at least one of the plural stationary valve ports 82 can be closed, and therefore during rotation of the valve member 67, it is only for a short time that the rotary distribution valve 138 of the valve member 67 closes the fixed valve port 82 hermetically, and as the peripheral positions of the changeover part 138 and stationary valve port 82 are deviated each other, the fluid such as the polluted gas through the first moving valve ports 86, 87 or while the fluid such as purified gas through the second moving valve ports 88, 89 flows into the passages 84, 113 to 120 individually communicating with the closed stationary valve port 82, and thus the fluid such as gas is almost always flowing in the plural passages 84, 113 to 120 formed in the passage forming means 71, 52, 55, that is, none of the passages 84, 113 to 120 is at rest, so that the operation efficiency is enhanced. This is particularly advantageous when the invention is applied to the regenerative combustion apparatus or regenerative heat exchanger and so forth as described below in relation to the passage forming means 71, 52, 55. Further according to the invention, the second angle  2 in the peripheral direction of the stationary valve port 82 in the rotary distribution valve 51 is equal to the first angle  1 in the peripheral direction of the seal members 97, 98 at both sides in the peripheral direction of the third moving valve port 90 or less, and is also equal to the third angle  3 which is the interval in the peripheral direction of the mutually adjacent stationary valve ports 82, or less so that mixing of the objective gas, purging air, and purified gas can be eliminated or sufficiently decreased. The first angle  1 is defined to be equal to or less than the third angle  3, and hence the third moving valve port 90 does not unexpectedly communicate with two stationary valve ports 82 which are adjacent to both sides in the peripheral direction of one stationary valve port 82 communicating with the third moving valve port 90 out of the plurality of stationary valve ports 82, and therefore airtightness is achieved. Also according to the invention, the second angle  2 is selected to be less than the third angle  3, that is, the porosity of the stationary valve member 71 is less than 50%, so that leak of the three gases may be prevented more securely. According to the invention, the peripheral angle  5 of the pair of auxiliary seal members 99, 100 disposed at both sides in the peripheral direction further from the pair of seal members 97, 98 disposed at both sides of the third moving valve port 90 is defined to be equal to or more than the angle  2 in the peripheral direction of the stationary valve port 82 and is also defined to be equal or less than (  2 +  3), and therefore the third moving valve port 90 is more securely prevented from communicating with the two stationary valve ports 82 which are adjacent to both sides of the one stationary valve port 82 communicating with the third moving valve port 90, so that the airtightness may be further enhanced. Further according to the invention, one stationary valve port 82a is high in airtightness by means of the seal members 101, 102 of the changeover part 138, out of the seal members 97, 98, 101, 102, and without communicating with the first and second moving valve ports 87, 88 adjacent to the changeover part 138, the airtightness can be achieved. In particular, by selecting the angle  4 of the seal members 101, 102 of the changeover part 138 nearly equal to the angle  2 of the stationary valve port 82a, one stationary valve port 82a closed by the changeover part 138 may be closed for a very short time during the rotation of the valve disc 67, and therefore the first, second, and third moving valve ports 86, 87; 88, 98; 90 may almost always communicate with the passages 84, 113 to 120 of each one of the stationary valve ports 82, 82a, and hence the operation efficiency of the passages 84, 113 to 120 may be enhanced. To prevent leak of gas, aside from the seal members 97, 98 at both sides in the peripheral direction of the third moving valve port 90 and seal members 99, 100, the changeover part 138 as the so-called changeover zone, and seal members 101, 102 for the changeover parts 138 are further provided, and therefore mutual leak of three gases can be prevented further securely. According to the invention, the rotary distribution valve above mentioned is provided beneath the housing accommodating the heat exchanger column, and above the heat exchanger column in the housing, the catalyst for burning, oxidizing and decomposing the malodorous substances in the objective gas is disposed, and the passages 84, 113 to 120 containing the heat exchanger column and catalysts are formed in every stationary valve port of the stationary valve member by the partition boards 55 in the housing, and by rotating and driving the rotary shaft, the objective gas containing the malodorous substances is supplied into the other chamber 65 of the valve box, the heat reserved in the heat exchanger column is absorbed in the objective gas, and the malodorous substances are oxidized and decomposed by the catalyst, and more preferably, the oxidation and decomposition may be done securely by heating by means of heating means such as a burner or an electric heater, and the purified gas at high temperature is conducted into the heat exchanger column to heat the heat exchanger column to accumulate heat, and the purified gas is cooled, and discharged from one chamber 66, thereby enabling continuous operation of gas treatment. In the communicating passage 111, purging gas is supplied in the same flow direction as the objective gas (for example, upward in the embodiment described below), the valve disc 67 is rotated by rotary drive sources 79, 80, and its rotating direction is determined in the direction of the purging gas being changed over and passed in the passages 84, 113 to 120 in which the objective gas flows, and therefore in the flowing state of the objective gas in the passages 84, 113 to 120, when the purging gas is supplied next in the same flow direction as the objective gas, the objective gas flows in the changed passages 84, 113 to 120 without leaving any remainder, thereby securely preventing the objective gas in the passages 84, 113 to 120 from mixing into the purified gas. When it is constituted so that the objective gas is supplied into the one chamber 66 while purified gas is discharged from the other chamber 65, the rotating direction of the valve disc 67 is reverse to the above rotating direction, and in any rotating direction, the rotating direction of the valve disc 67 is determined so that, after the objective gas is flowed into the passages 84, 113 to 120, the purging gas is changed over to pass, being followed by the purified gas to flow. High temperature gas does not contact with the rotary distribution valve, and hence the manufacture of the rotary distribution valve may be easy. Moreover, for example, by supplying purging air through the communicating passage 111 from the shaft hole 106 through the rotary tube joint 107, the objective gas in the passage containing the heat exchanger column and catalyst in which the objective gas is remaining can be purged by a slight amount of gas such as purging air, and be purified. Therefore, only a slight region is needed in the peripheral direction of the third moving valve port for purge, and hence the required amount of heat reserve material is less, and an excellent effect that the structure may be reduced in size is also achieved. In the regenerative catalytic combustion apparatus of the invention, the space partition wall 56 is fixed in the upper part of the housing 52, and the space 57 common to the plural passages 84, 113 to 120 is formed, and the heating means is provided in the space 57 as mentioned above, and the communicating holes 58 for individually communicating with the passages 84, 113 to 120 partitioned by the partition boards 55 are further formed in the space partition wall 56, and thus the climbing objective gas and purging air through the passages 84, 113 to 120 are conducted securely into the space 57, and therefore the objective gas and purging air are prevented from being short-circuited and short-passed to flow same as the purified gas, and the purified gas discharged from this space 57 is discharged from the space 57 as a descending flow of uniform temperature distribution by means of the heating means. Consequently, the malodorous substances in the objective gas are oxidized and decomposed securely. According to the invention, these communicating holes 58 are disposed above at a clearance from the upper part of the catalyst 54 and are realized by a porous plate such as punching metal, and multiple pores are formed discretely, and therefore a proper pressure loss is caused when the objective gas and purging gas flow into the common space 57, and the objective gas and purging gas flow through the space 57 at about 5 to 20 m/sec, and the distribution of the flow velocity is nearly uniform in every one of the multiple pores, and hence the gas is mixed sufficiently in the space 57, and mixing and heating of gas and oxidation and decomposition of malodorous substances may be done securely by the heating means. If the flow velocity of the objective gas and purging gas into the space 57 is less than about 5 m/sec, gas mixing in the space 57 becomes suddenly insufficient, and the distribution of gas temperature when discharged as purified gas from the space 57 is increased, that is, the temperature difference between maximum temperature and minimum temperature of the gas discharged from the space 57 is too large. If the flow velocity exceeds about 20 m/sec, on the other hand, the pressure loss in the communicating holes 58 of multiple pores suddenly becomes excessive, and larger power is required for the fan for forcing out the objective gas and purging gas. Moreover, in the regenerative catalytic combustion apparatus of the invention, between the heat exchanger column and the catalysts, a pretreatment material for removing the catalyst deteriorating substances contained in the objective gas by oxidizing or other processes is interposed, and the catalyst is in a structure having a honeycomb base material, that is, a honeycomb carrier, and the pretreatment material is selected at a specific heat of about 0.1 kcal/°C-liter or less, and therefore when the temperature in the space 57 provided with the heating means is kept at, for example, around 350°C, the temperature of the pretreatment material and catalyst contacting with the objective gas and purging gas can be maintained at a temperature efficient for their action, for example, above 250°C or preferably over 300°C. The catalyst of honeycomb base, that is, the honeycomb catalyst has the space velocity (SV) valve of 40000, and at this time the specific heat of the pretreatment material is about 0.1 kcal/°C-liter, and by using the pretreatment material mainly composed of, for example, the corrugated base, its heat capacity can be decreased. Therefore, the purified gas from the space 57 heated by the heating means is prevented from being lowered in temperature as the heat is absorbed by the catalyst and pretreatment material, and the object can be treated while keeping above a temperature suited to achieve a sufficient action of the catalyst and pretreatment material. Moreover, according to the invention, by using the catalyst mainly composed of foamed metal, and the pretreatment material in corrugated or honeycomb structure, the catalyst made of the foamed metal has the SV value of 60000, and the greater the SV value is, the smaller the filling amount of the catalyst is, and the heating action is decreased, and therefore the objective gas can be treated, while the temperature of the catalyst and pretreatment material is set to high temperature by the purified gas from the space 57. According to the invention, the heating means is controlled by control means, and the heat generation by the heating means is controlled by the fuel flow rate or electric power supplied to the heating means so that the temperature of the pretreatment material may be 250°C or more, and hence the catalyst deteriorating substances in the objective gas are sufficiently removed by the pretreatment material, and hence heating and oxidation by the catalyst may be done. The invention also realizes a regenerative heat exchanger of parallel flow or counter flow type, by installing a pair of rotary distribution valves above and beneath the housing accommodating the heat exchanger column. The rotary distribution valve of the invention may be applied not only in the regenerative combustion apparatus and regenerative heat exchanger, but also in other uses widely. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal sectional view simplifying the general structure of a regenerative catalytic combustion apparatus 50; Fig. 2 is a longitudinal sectional view near the rotary distribution valve 51 in the regenerative catalytic combustion apparatus 50 of an embodiment of the invention; Fig. 3 is a perspective view simplifying the internal structure of the regenerative catalytic combustion apparatus 50; Fig. 4 is a horizontal sectional view seen from the section line IV-IV in Fig. 2; Fig. 5 is a perspective view simplifying a partial structure of the valve disc 67; Fig. 6 is a plan view of the valve disc 67; Fig. 7 is a bottom view of the valve disc 67; Fig. 8 is a sectional view of the seal member 97; Fig. 9 is a sectional view showing part of the valve disc 67 taken on line IX-IX in Fig. 2; Fig. 10 is a simplified sectional view of the housing 52 in Fig. 1 taken on line X-X; Fig. 11 is a sectional view for explaining the operation of the moving valve member 69 and stationary valve member 71 developed in the peripheral direction for describing the operation of the rotary distribution valve 51; Fig. 12 is a sectional view for showing the structure having a seal member 124 in other embodiment of the invention; Fig. 13 is a simplified horizontal sectional view taken on line XIII-XIII in Fig. 1; Fig. 14 is a developed diagram in the peripheral direction of the partition wall 56 for the space 57; Fig. 15 is a simplified developed diagram in the peripheral direction of the partition wall 56 corresponding to Fig. 14 in a different embodiment of the invention; Fig. 16 is a graph showing the relation between the wind velocity and pressure loss relating to the communicating holes 58; Fig. 17 is a graph showing the relation between the wind velocity relating to the communicating holes 58 and the temperature difference between the maximum temperature and minimum temperature in the distribution of the purified gas discharged from the space 57; Fig. 18 is a graph showing the relation between the concentration of organic solvent contained in the objective gas, and the corresponding temperature rise portion ΔT; Fig. 19 is a graph showing the heat exchange efficiency  of the regenerative catalytic combustion apparatus 50; Fig. 20 is a perspective view showing the pellet shape, honeycomb shape, and foamed metal shape of the catalyst 54; Fig. 21 is a simplified sectional view of a regenerative heat exchanger 128 of a different embodiment of the invention; Fig. 22 is a partially cut-away perspective view of a prior art; Fig. 23 is a sectional view of other prior art; and Fig. 24 is a sectional view showing a different prior art modified from the prior art shown in Fig. 23. BEST MODES OF CARRYING OUT THE INVENTION Fig. 1 is a simplified sectional view showing a general structure of a regenerative catalytic combustion apparatus 50 of an embodiment of the invention, Fig. 2 is a sectional view showing the rotary distribution valve 51 near the lower part of the regenerative catalytic combustion apparatus 50, and Fig. 3 is a perspective view simplifying the internal structure of the regenerative catalytic combustion apparatus 50. Referring to these diagrams, in the housing 52 of a nearly right circular cylindrical form extending vertically, a heat exchanger column 53 of ceramic particles or Raschig rings is accommodated, and a catalyst 54 for thermally decomposing the malodorous substances of the objective gas is disposed above the heat exchanger column 53. Between the heat exchanger column 53 and catalyst 54 is interposed a pretreatment material 141 for removing the catalyst deteriorating substances contained in the objective gas by oxidizing or other process. The catalyst 54 may have the base surface coated with platinum or palladium, and the pretreatment material may be γ-alumina or zeolite. In the housing 52, there are plural (eight in this embodiment) partition boards 55 extending vertically for forming passages 84 (see Fig. 4) extending vertically by separating the heat exchanger column 53 and catalyst 54 at equal intervals in the peripheral direction. The upper parts of the partition boards 55 are fixed to a combustion chamber 57 which is formed by a partition wall 56 in a, for example, hollow inverted circular truncated conical form attached to the upper part of the housing 52 and which is a space common to the passages 84 so as to communicate through each communicating hole 58. A bottom plate 139 for forming the bottom of the space 57 is provided in the lower part of the partition wall 56. An electric heater or a burner 59 is provided in the top of the housing 52 as heating means, and gas or liquid fuel burns in the burner 59. A hollow tubular body 60 is fixed in the lower part of the partition wall 56. The objective gas containing malodorous substances is supplied from a connection port 61 of a rotary distribution valve 51 provided in the lower part of the housing 52, and a purified gas is conducted out from a connection port 62. In the rotary distribution valve 51, a valve box 64 of a nearly right circular cylindrical form is provided coaxially to a perpendicular rotational axial line 63 extending vertically. A pair of chambers 65, 66 communicating respectively with the connection ports 61, 62 are formed in the valve box 64. A valve disc 67 rotated and driven about the axial line 63 is accommodated in the valve box 64. The valve disc 67 basically comprises a rotary shaft 68, a disc-shaped moving valve member 69, and a partition wall 70, and a stationary valve member 71 which is a constituent element of the rotary distribution valve 51 is fixed to a panel board 72 at the lower part of the housing 52. The rotary shaft 68 is supported by a bearing 74 which can receive a thrust force on an end plate 73 of the valve box 64, and is rotatably supported by a bearing 76 on a support body 75 in the housing 52 fixed integrally with the panel board 72. The rotary shaft 68 is fixed to a sprocket wheel 77, and a chain 78 is applied, and a sprocket wheel 79 is rotated and driven by a drive source 80. Fig. 4 is a sectional view as seen from the section line IV-IV in Fig. 2. The stationary valve member 71 is divided equally in plural (eight in this embodiment) sections in the peripheral direction, and plural, for example, eight stationary valve ports 82 are formed at an angle  2. The interval of the mutually adjacent stationary valve ports 82 is formed by a third angle  3 in the peripheral direction. In this embodiment, the angle relation is  2 =  3 = 22.5° . The partition boards 55 are fixed at an interval of 45° in the peripheral direction on the top of the stationary valve member 71 between mutual stationary valve ports 82, and passages 84 extending vertically in eight divisions are formed in the housing 52, and each passage 84 is individually communicating with the stationary valve ports 82. Fig. 5 is a simplified perspective view of the valve disc 67, Fig. 6 is a plan view of the valve disc 67, and Fig. 7 is a bottom view of the valve disc 67. Referring now to these diagrams, the moving valve member 69 is a disc-shaped, and is vertically fixed to the rotary shaft 68 at a position facing to the chamber 66. In the moving valve member 69, first moving valve ports 86, 87 and second moving valve ports 88, 89 are formed in the peripheral direction around the axial line 63, and a third moving valve port 90 is formed at an interval in the peripheral direction from these first and second moving valve ports 86, 87; 88, 89. The third moving valve port 90 is formed at one side between the first and second moving valve ports 86, 89 along the peripheral direction of the valve disc 67, and the other side between the first and second moving valve ports 87; 88 along the peripheral direction is a changeover part 138. In Fig. 6, in the first moving valve ports 86, 87, the objective gas climbs up and passes as indicated by reference numeral 142 as described later, in the second moving valve ports 88, 89, as indicated by reference numeral 143, purified gas flows down, and in the third moving valve port 90, as indicated by reference numeral 144, a clean purging air climbs up. The changeover part 138 spreads in the peripheral direction so as to divide and change over at least one (one in this embodiment) stationary valve port 82, on the other side along the peripheral direction between the first and second moving valve ports 87, 88 as mentioned above and its angle is indicated by reference numeral  4 between the seal members 101 and 102 in Fig. 6. The changeover part 138 is to change over the gas upward flow and downward flow as mentioned later in relation to the operation, and in the plural passages 84, 113 to 120, the gas is always flowing upward or downward, only momentarily settling in the state in Fig. 11 (1), and in the passage 82a in Fig. 11 (1), the gas flow direction is changed instantly from downward to upward. The partition wall 70 specifically comprises an arcuate partition wall 70a, and flat partition walls 70b, 70c, 70d, 70e, and comprehensively it may be indicated by reference numeral 70. The partition wall 70a approximately has a shape for forming part of a hollow circular truncated cone, and its upper part is fixed to the lower side of the moving valve member 69, and similarly the flat partition walls 70b, 70c are also fixed to the lower side of the moving valve member 69, and the partition walls 70b, 70c are further fixed to the outer circumference of the rotary shaft 68 along the axial direction, thereby forming a guide space 91 communicating between the chamber 65 and the first moving valve ports 86, 87. This guide space 91 is hermetically partitioned from the other chamber 66 by means of the partition walls 70a, 70b, 70c. The partition walls 70d, 70e are used for reinforcing the moving valve member 69. In the lower part of the partition wall 70a, another partition wall 92 is fixed, and a communicating hole 93 for communicating between the guide space 91 and the chamber 65 is formed in this partition wall 92. The partition wall 92 also partitions the chambers 65, 66 at the outside of the guide space 91. A short tubular part 94 is fixed to the outer circumference of the partition wall 92, and a seal member 96 is provided between the outer circumference of the short tubular part 94 and a partition wall 95 formed in the valve box 64, so that airtightness is achieved. Above the moving valve member 69, an annular inner seal member 104a and an annular outer seal member 104b are provided concentrically about the axial line 63, and further seal members 97, 98 extending in the radial direction and auxiliary seal members 99, 100 are provided, and moreover seal members 101, 102 are provided. As shown in a sectional view in Fig. 8, the seal member 97 is embodied and fixed in an accommodating hole 103 formed in the moving valve member 69. The upper part of the seal member 97 elastically contacts with the lower side of the stationary valve member 71, and therefore airtightness can be achieved. The seal member 97 may be O-ring or other structure. The peripheral angle between the seal members 97, 98 at both sides in the peripheral direction of the third moving valve port 90 is  1, and it is  1 = 22.5° in this embodiment. Moreover, at an angle of  5 at both sides in the peripheral direction of the seal members 97, 98, the auxiliary seal members 99, 100 are provided. Furthermore, with respect to the seal members 97, 98, the seal members 101, 102 are, respectively, provided symmetrically around the axial line 63. The peripheral angle  4 between the seal members 101, 102 is 22.5° in this embodiment. In this way, the seal members 104a, 104b; 97, 98; 99, 100; 101, 102 are disposed symmetrically with respect to a plane of symmetry 105. In this embodiment,  1 =  2 =  3 =  4 =  5 . Referring back to Fig. 1, a shaft hole 106 along the axial line 63 is formed on the rotary shaft 68, and a rotary tube joint 107 is connected to its lower part. Purging air is force-fed into the rotary tube joint 107 through a duct 108. The upper connection hole 109 of the rotary shaft 68 communicates with the third moving valve port 90 through a communicating passage 111 formed by an auxiliary partition wall 110. Fig. 9 is a sectional view showing part of the valve disc 67 seen from the sectional line IX-IX in Fig. 2. The auxiliary partition wall 110 is fixed from the partition wall 70c to the lower side of the moving valve member 69, and the communicating passage 111 communicates between the third moving valve port 90 and shaft hole 106 through a connection hole 109. Fig. 10 is a horizontal sectional view of the lower part of the housing 52 seen from the section line X-X in Fig. 1. In the regions 113 to 120 formed by a total of eight passages 84 partitioned by the partition boards 55 in the housing 52, the heat exchanger column 53 and catalyst 54 thereabove are accommodated as mentioned above, and by the function of the rotary distribution valve 51, the objective gas absorbs the heat accumulated in the heat exchanger column 53 and ascends in the regions 113 to 115, it is purged by air in the region 116, the purified gas in which the malodorous substances are oxidized and decomposed descends, and the heat is released and accumulated in the heat exchanger column 53 in the regions 117 to 119, and the airtightness is achieved in the region 120 which is so-called changeover zone 120. For example, when the valve disc 67 of the rotary distribution valve 51 rotates in the direction of an arrow 121, a certain region 115 in the housing 52 is changed over, as indicated by an arrow 137, in the sequence of the objective gas elevating period (see Fig. 11 (1)), air purging period (Fig. 11 (4)), and purified gas descending period. As a result, in the period when the objective gas remaining in the region 115 in which the objective gas containing malodorous substances has been supplied and elevated is purged, the purging air is elevated and the region 115 is purified, and then the purified gas after oxidation and decomposition of the malodorous substances is conducted in, thereby preventing the objective gas containing malodorous substances from mixing into the chamber 66 and connection port 62. Fig. 11 is a development diagram in the peripheral 71 in the rotary distribution valve 51. In Fig. 11 (1), in the region 116, for example, which is one of the regions 113 to 120 which are passages 84 partitioned by the partition boards 55 in the housing 52, the purging air is ascending through the third moving valve port 90 and the stationary valve port 82. The stationary valve port 82a, indicated by reference numeral 82a, which is one of the plural (eight in this embodiment) stationary valve ports 82 is kept airtight by the seal members 101, 102, and therefore the objective gas and purified gas will not mix into the region 120 which is the changeover zone. Next, as shown in Fig. 11 (2), in the process of continuous move of the moving valve member 69, the purging air is continuously supplied into the region 116. Thus the objective gas remaining in the region 116 is moved to the upper part of the housing 52 by the purging air, and after oxidation and decomposition of the malodorous substances is terminated, as shown in Fig. 11 (3), the seal members 97, 98 contact with the portion 123 of the stationary valve member 71 adjacent to the stationary valve ports 82 through which the purging air has been passing, so that the purified gas can descend and flow in the region 116. As the moving valve member 69 further rotates, as shown in Fig. 11 (4), the purge region is shifted to the region 115 where the objective gas has been ascending. Thus, the direct leak from the objective gas ascending region 115 into the purified gas descending region 117 does not occur. The effect is the same in the changeover zone 120 by the function of the seal members 101, 102. In the foregoing embodiment, the objective gas is supplied into one chamber 65, and purified gas is conducted into the other chamber 66 and discharged, but in another embodiment of the invention, contrary to the above embodiment, the objective gas may be supplied into the chamber 66, and purified gas may be conducted into the chamber 65 and discharged. One important constitution of the invention is that, by the working of the rotary distribution valve 51 in the region 120 serving as changeover zone in Fig. 11 (1), at the next moment, the objective gas ascends as shown in Fig. 11 (2), and at the next moment after the state in Fig. 11 (3) in which the objective gas is ascending, the purified gas descends. Immediately before Fig. 11 (1), the purified gas is descending in the region 120 through the second moving interrupted in the state in Fig. 11 (1), the objective gas ascends in the state in Fig. 11 (2) as mentioned above. Therefore, while the valve disc 67 of the rotary distribution valve 51 is rotating, out of the regions 113 to 120 consisting of a total of eight passages 84 in the housing 52 the region in which objective gas and purified gas are not flowing for purge is substantially only one region 116 in Fig. 11. Therefore, the time for using the heat exchanger column 53, catalyst 54 and pretreatment material 141 is extended, and the operation efficiency is enhanced. This is one of the important advantages of the invention. In this embodiment, as mentioned above, the angle relation is selected as  1 =  2 =  3 =  4 =  5 , but according to the invention, by selecting  2 +  3 ≧  1 ≧  2, and  3 ≧  2, mutual leak of gas can be prevented. Further according to the invention, by defining  3 >  2, the porosity of the stationary valve member 71 may be set less than 50%, and gas leak may be prevented more securely. An angle  6 between the auxiliary seal members 99, 100 is selected as  2 + 2 ·  3 ≧  6 ≧  2, so that the mutual leak of gas can be prevented. The angle  4 between the a pair of seal members 101, 102 provided at both sides in the peripheral direction of the changeover part 138 is selected as  4 ≒  2. Hence, in the embodiment by the changeover part 138, the single stationary valve port 82a can be securely enclosed hermetically. In other embodiment of the invention, instead of the seal member 97 mentioned in relation to Fig. 8, when high temperature gas is used, in particular, as shown in Fig. 12, an elastic force may be given to a seal member 124 made of ceramic or similar material by using a spring 125, and the seal member 124 may contact with the lower surface of the stationary valve member 71, so that airtightness may be achieved. The seal member 124 and spring 125 are fitted into a recess 126 formed opposite to above the moving valve member 69. This constitution shown in Fig. 12 may be realized similarly in relation to all other remaining seal members 104a, 104b, 98 to 102. Fig. 13 is a simplified horizontal sectional view taken on line XIII-XIII in Fig. 1. The upper parts of the partition boards 55 are fixed to the partition wall 56 hermetically and also hermetically fixed to a tubular body 60 consecutive below, and the lower part of the partition boards 55 is fixed hermetically to the stationary valve member 84 as shown in Fig. 4. The partition wall 56 is hermetically fixed to the panel board of the upper part of the housing 52. The partition wall 56 has communicating holes 58 which individually communicate with the passages 84, 113 to 120 partitioned by the partition boards 55. Fig. 14 is a developed diagram in the peripheral direction of part of the partition wall 56. The communicating holes 58 are realized by multiple pores formed in a porous plate 143 such as so-called punching metal. The pores 58 are disposed discretely. The communicating holes 58 are discretely formed slightly upward at a clearance of h1 above from the upper surface of the bottom plate 139. The communicating holes 58 may be circular as shown in Fig. 14, but in other embodiment shown in Fig. 15, the communicating holes 58 may be slender in the peripheral direction, so to speak, oval shape as indicated by reference numeral 144, or in other shape. These communicating holes 58, 144 are provided at a distance of h1 from the upper surface of the bottom plate 139 as mentioned above, and are formed at a nearly same distance h1 above from the upper part of the catalyst 54. Therefore, the objective gas flows into the chamber 65 from the connection port 61 as stated above, ascends in the housing 52, and securely gets into the space 57 through the communicating holes 58, and hence it is securely prevented from mixing with the purified gas and short-circuiting in the chamber 66 side. The operating condition is determined so that the wind velocity of the ascending objective gas blown into the chamber 57 through the communicating holes 58 may be, for example, about 5 to 20 m/sec, and in other words, the inside diameter and number of communicating holes 58 are determined, and the supply flow rate of the objective gas is also defined. This range of wind velocity is for making uniform temperature distribution by gas mixing in the chamber 50. This is described in detail by referring to Fig. 16 and Fig. 17. According to the results of an experiment by the present inventor disclosed in Fig. 16 and Fig. 17, the inside diameter of the housing 52 is 1.2  , the flow rate of the objective gas from the connection port 61 is 20 Nm 3 /min, and the space 56 is kept constantly at 350°C by the burner 59 or electric heater. Fig. 16 is a graph showing the relation between the wind velocity and the pressure loss of the objective gas passing through the communicating holes 58. When the wind velocity of the objective gas passing through the communicating holes 58 exceeds about 20 m/sec, it is known that the pressure loss increases suddenly. In the invention, therefore, the wind velocity is defined 20 m/sec or less in the communicating holes 58. Fig. 17 is a graph showing the relation between the wind velocity when the purified gas descends from the space 57 through the communicating holes 58, and the temperature difference between the maximum temperature and minimum temperature of the temperature of the gas distributed immediately before being discharged in the space 57. The higher the wind velocity, the more the gas is mixed sufficiently in the space 57 to decrease the temperature difference, and the temperature distribution becomes uniform, but, to the contrary, as mentioned by reference to Fig. 16, the pressure loss increases abruptly. Or if the wind velocity is too small when the purified gas is discharged from the space 57 through the communicating holes 58, the pressure loss is sufficiently small, but, to the contrary, the temperature difference of the temperature distribution of the purified gas is too large, and the gas is not mixed sufficiently, and the objective gas is not heated, and therefore discharged while the oxidation is insufficient. Hence, in the invention, the wind velocity of the objective gas blown into the space 57 is determined approximately 5 m/sec or more. By burning the objective gas containing organic solvent by using the catalyst 54 and further by using the burner 59, the temperature of the objective gas rises climbs up as shown in Fig. 18 by the combustion heat of the organic solvent contained in the objective gas. In the regenerative catalytic combustion apparatus 50 of the above embodiment, the reaction temperature in the stationary state is generally about 300 to 350°C, and the heat resisting temperature of the catalyst 54 and pretreatment material 141 is about 550°C. The performance of the regenerative catalytic combustion apparatus is expressed by the heat exchange efficiency  defined in formula 1.  = ( t c 2* - t c 1) / (t h 1 - t c 1 ) where t is the gas temperature [°C], subscripts c and h respectively denote cold side and hot side, 1 and 2 indicate the inlet and outlet, and tc2* represents the outlet mean temperature of the cold side gas. Fig. 19 is a graph showing the heat exchange efficiency of the regenerative catalytic combustion apparatus 50. The value of the heat exchange efficiency  is calculated by assuming that the specific heat and heat transfer coefficient of gas are constant regardless time and position, and that there is no loss due to leak or carryover. In the diagram, NTUo is a dimensionless number called NTU or Overall Number of Transfer Unit, which is defined in formula 2. NTU 0 = 1 Wc [ 1 (1/hA) c+ (1/hA) h ] where h is heat transfer coefficient [kcal/m 2 .Hr.°C], A is heating area [m 2 ], and Hr is hour. Moreover, Wc is water equivalent of one gas, that is, the objective gas or purified gas, and Wr is water equivalent of the heat exchanger column 53, which are respectively given in formulas 3 and 4. Wc = G·cp [kcal/°C·Hr] Wr = n · Mr · cr [kcal/°C · Hr] where n is the rotating speed of the valve disc 67 of the rotary distribution valve 51, that is, the changeover speed [rpHr], G and cp are weight flow rate [kgf/Hr] and specific heat at constant pressure [kcal/kgf.°C] of one gas, and Mr and cr are total weight [kgf] and specific heat of the heat exchanger column 53. Table 1 shows the running statuses 1 to 4 of the regenerative catalytic combustion apparatus 50. When the regenerative catalytic combustion apparatus 50 is designed at the changeover speed of the rotary distribution valve 51 of 60 rpHr, water equivalent ratio Wr/Wc = 5 , and heat exchange efficiency  = 90%, when the inlet temperature tc1 of the objective gas at the connection port 61 is 20°C and the temperature in the combustion chamber 57 is controlled at 300°C by the burner 59, the outlet temperature th2 of the purified gas from the connection port 62 is 48°C as shown in formula 5. t h 2 = 2 0 + (3 0 0 - 2 0) × 0. 1 = 4 8 Therefore, the temperature difference Δ T (= th2 - tc1) at the connection ports 61, 62 is 28°C, and when the concentration of the organic solvent is equivalent to the heat generation corresponding to this temperature difference Δ T = 28°C , it is not necessary to operate the burner 59, and the objective gas burns by itself. For example, when the organic solvent is toluene, it is known from Fig. 18 that the concentration corresponding to the objective gas temperature rise of 28°C is 230 ppm. Therefore, in the objective gas containing toluene by 230 ppm, the temperature difference Δ T = 28°C . Such action is indicated as running status 1 in Table 1. Running status 2 is described below. When the concentration of toluene used as the organic solvent in the objective gas is high and the reaction temperature indicated by the temperature tc2, th1 is 550°C, the temperature of the purified gas at the connection port 62 is 73°C as indicated in formula 6, and the temperature difference Δ T is = 53°C.. t h 2 = 2 0 + ( 5 5 0 - 2 0 ) × 0. 1 = 7 3 The toluene concentration corresponding to this temperature difference Δ T is 430 ppm as seen from Fig. 18. Therefore, when the toluene concentration exceeds 430 ppm, the catalyst 54 and pretreatment material 141 exceed the heat resisting temperature, and hence the running status 2 cannot be continued. The inventor, accordingly, noticing that the heat exchange efficiency  is changed by varying the water equivalent ratio Wr/Wc, succeeded in prevention of abnormal temperature rise of the catalyst 54 and pretreatment material 141 by changing the changeover speed n of the rotary distribution valve 51 to vary the water equivalent ratio Wr/Wc, so as to lower the heat exchange efficiency  when the concentration of the organic solvent rises. Thus, in the running statuses 3, 4 where the toluene concentration is raised as compared with the running status 2 in Table 1, as the toluene concentration rises, the changeover speed n of the rotary distribution valve 51 is lowered, and the temperature of the catalyst 54 is controlled about suppressed around 550°C. To operate automatically in the running statuses 1 to 4, the invention is constituted as follows. Referring back to Fig. 1, temperature detecting means 131, 132 for detecting the temperature of purified gas are provided in the combustion chamber 57. The output of one temperature detecting means 131 is given to one control circuit 134 of control means 133, and the opening and closing action of a flow rate control valve 129 or flow rate is controlled by the output of the control circuit 134. The output of the other temperature detecting means 132 is given to a control circuit 135 provided in the control means 133, and the control circuit 135 controls the rotating speed of the motor 80, and accordingly the rotating speed of the valve disk 67, hence the changeover speed of the rotary distribution valve 51 is set to a speed corresponding to the detected temperature. In the invention, instead of the rotary distribution valve 51 having above-mentioned structure, a rotary distribution valve of other structure may be employed, and, for example, the rotary distribution valve may be designed to change over the plural passages partitioned by the partition boards 55 by means of an opening and closing valve, or it may be designed in other structure. To remove the organic solvent of the objective gas containing the organic solvent, that is, malodorous substances discharged from paint factory or other various factories, as known widely hitherto, the objective gas is preheated by means of the heat reserve material by passing through the heat reserve material in the axial direction partially in the peripheral direction, and is burnt by catalyst, and the further organic solvent is burnt additionally by a burner, and after passing through the catalyst, the purified gas is passed through the remaining portion in the peripheral direction of the heat reserve material in the axial direction through the catalyst to heat the heat reserve material, and is discharged. When the temperature becomes, for example, 550°C or more after the organic solvent of the objective gas is burnt by the catalyst, the catalyst deteriorates. To prevent this, in a certain prior art, the purified gas at high temperature is partially released to the atmosphere without conducting again into the heat reserve material. In such prior art, the purified gas at high temperature is released to the atmosphere, and it hence requires preventive measures of direct fire and expensive automatic valve for high temperature. In a different prior art, when the temperature of the gas burnt by the catalyst of the objective gas becomes high, it is designed to cool by sprinkling water, and this prior art is disclosed, for example, in Japanese Unexamined Patent Publication JPA 1-127811(1989). In this prior art, the inorganic dissolved matter contained in the sprinkling water deposits on the catalyst and the heat reserve material in the form of scales, and continuous operation for a long period is difficult. According to this embodiment, by realizing the regenerative catalytic combustion apparatus in which the gas is conducted by sequentially changing over the passages formed by the partition boards in the peripheral direction by means of the rotary distribution valve, the continuous operation for purification of the objective gas containing the organic solvent of malodorous substance is realized by executing the changeover action of the rotary distribution valve without moving the heat reserve material, and particularly in the invention, when the temperature of the space of the upper part of above the plural passages is high, the changeover speed is lowered, or, to the contrary, when the space temperature is low, the changeover speed is raised, and thus the heat efficiency can be changed largely in accordance with the changeover speed, with the water equivalent ratio Wr/Wc at, for example, less than 5, and continuous operation is possible for a long period without causing heat loss. In particular, according to the above embodiment, when the temperature of the common space of the upper part of the plural passages formed by partition boards is high, the changeover speed of the rotary distribution valve is lowered, and hence the ratio Wr/Wc of the water equivalent Wr of the heat reserve material to the water equivalent Wc of the objective gas is decreased, and the heat exchange efficiency is lowered. Therefore, the temperature in the common space is lowered, and the temperature in the space is kept less than the heat resisting temperature of the catalyst 53 and pretreatment material 141, so that continuous operation is realized. Therefore, according to the embodiment, if the organic solvent of high concentration is contained in the objective gas, purification of the objective gas is achieved without deterioration of the catalyst by heat. Also according to the embodiment, by keeping the water equivalent ratio Wr/Wc less than about 5, it is possible, as clear from Fig. 19, to change the heat exchange efficiency of the heat reserve material largely in accordance with the changeover speed of the rotary distribution valve, and therefore if the concentration of the organic solvent contained in the objective gas changes in a wide range, the objective gas can be purified easily. Further according to the embodiment, heating means is provided in the common space, and if less than a predetermined first temperature, for example, 300°C, the heating means is operated to heat the objective gas to oxidize and burn the organic solvent securely, and when exceeding the first temperature, the heating means is stopped, and the organic solvent contained in the objective gas is burnt by itself and purified, and further if less than a predetermined second temperature, for example, 450°C which is below the heat resisting temperature of the catalyst, for example, 550°C, the changeover speed of the rotary distribution valve is kept at a predetermined constant valve, and when exceeding the second temperature, the changeover speed is lowered to a value less than the predetermined constant value as the detection temperature in the common space becomes higher, keeping less than the heat resisting temperature. The heating means is operated at less than the predetermined first temperature, and the organic solvent is heated to be oxidized and decomposed securely, but above the first temperature, the heating means is stopped, and wasteful consumption of fuel or electric power is prevented, and the elevation of the space temperature is suppressed, and at less than the second temperature which is below the heat resisting temperature of the catalyst exceeding the first temperature, the changeover speed of the rotary distribution valve is kept at a constant value, and above the second temperature, as the detection temperature becomes higher, the changeover speed is lowered to the value less than the predetermined constant value, thus preventing the space temperature from reaching the heat resisting temperature of the catalyst, so that deterioration of the catalyst 53 and pretreatment material 141 is prevented. Moreover, according to the embodiment, if the concentration of the organic solvent contained in the objective gas varies in a wide range, or if an organic solvent of high concentration is contained, such objective gas can be securely purified very easily. Also according to the embodiment, by detecting the temperature of such common space by temperature detecting means, and by controlling the changeover speed of the rotary distribution valve by the control means, automatic continnous operation is possible. The oxidation recovery temperature and complete decomposition temperature of the malodorous substance contained in the objective gas supplied from the connection port 61 vary depending on the malodorous substance, and in particular when the malodorous substance is acetic ester or tar, the temperature is high. Therefore, in order to decompose such malodorous substances by oxidizing, the temperature of the pretreatment material 141 and catalyst 54 contacting with the objective gas is required to be 250°C or more, preferably 300°C or more. The catalyst 54 and pretreatment material 141 heated by heat exchange with gas from the space 57 have heat exchange action, and when the catalyst 54 and pretreatment material 141 have a greater heat exchange action as compared with the heat exchanger column 53, the temperature drop is larger in the catalysts 54 and pretreatment material 141, that is, the temperature difference (= th1 - th3) between the temperature th1 in the upper part of the catalyst 54 and the temperature th3 in the lower part of the pretreatment material 141 becomes larger. Therefore, the temperature of the catalyst 54 and pretreatment material 141 is lowered too much, its action is lowered, the decomposition efficiency of the malodorous substance drops, and hence the removal action for removing the catalyst 54 deteriorating substances by pretreatment material 141 becomes insufficient. There are many factors affecting the heat transfer in the regenerative combustion apparatus of the invention, but principal factors are the water equivalent ratio Wr/Wc and heating area of the heat exchanger column 54. To keep the catalyst 54 and pretreatment material 141 at 250 °C or more, or preferably 300 °C or more, as stated above, the heat transfer elements of the catalyst 54 and pretreatment material 141 must be decreased as much as possible, and the heat transfer element of the heat exchanger column 53 must be increased as much as possible. On the basis of the deodorizing performance of the catalyst 54 and the performance for removing the catalyst 54 deteriorating substances by the pretreatment material 141, a filling volume (in liters) over a specific value for the flow rate of the objective gas is determined by the space velocity (SV value) of the catalyst 54 and pretreatment material 141. This SV value depends on the shape of the base material for carrying the catalyst 54 as shown in Table 2. SV value = air flow per hour [m3/hr] volume of catalyst 54 [m3] In Table 2 and Table 3 given below, Emb refers to embodiment and Comp represents comparative example. The shape of pellets in Table 2 is granular as shown in Fig. 20 (1). The shape of honeycomb is nearly hexagonal in the section of multiple passages through which gas flows as shown in Fig. 20 (2). The shape of foamed metal is a porous shape by combining multiple metal wire elements as shown in Fig. 20 (3), and the metal may be either iron or other metal. The catalyst of which SV value is large requires a smaller filling volume, and hence the heat transfer action is smaller, and it is advantageous because the temperature drop is smaller when the purified gas from the space 57 passes through the catalyst 54 and pretreatment material 141. The catalyst 54 has the structure that the surface of the base material composed of pellets, honeycomb or foamed metal is coated with platinum or palladium. The pellet shape and honeycomb shape structure of the catalyst 54 is, for example, composed of ceramic, and the honeycomb shape may be obtained by manufacturing by means of extrusion molding. The base material having the corrugated shape of the pretreatment material 141 is a structure of zigzag bent thin sheet of, for example, ceramic, and flat plate of, for example, ceramic being disposed and fixed in the thickness direction. The honeycomb shape of the base material of the pretreatment material 141 may be manufactured, same as the honeycomb shape of the catalyst 54, by extrusion molding of, for example, ceramic, and it may be manufactured by molding a cordierite. The specific heat, specific gravity, and heat capacity of each shape of the pretreatment material 141 are as shown in Table 2. In Table 2, the changeover time of the regenerative combustion apparatus 50 is 30 sec, that is, each of the passages 84, 113 to 120 contacts with the objective gas for 30 sec., and then it contacts with the purified gas from the space 57 for 30 sec., and is changed over. As the heat exchanger column 53, using 21 kg of Intalox Saddles (tradename), the inventor conducted an experiment at the water equivalent ratio Wr/Wc of 12 about the heat exchanger column 53, and the results are shown in Table 3. SHAPE OF CATALYST SHAPE OF PRETREATMENT MATERIAL TEMPERATURE EMBODIMENT/COMP. EXAMPLE t57 th1 tc3 tc1 th2 PELLET CORRUGATE 350 342 220 25 63 COMP. 1 HONEYCOMB 350 343 205 25 59 COMP. 2 HONEYCOMB CORRUGATE 350 348 262 25 48 EMB. 1 HONEYCOMB 350 348 228 25 46 COMP. 3 FOAMED METAL CORRUGATE 350 345 285 25 51 EMB. 2 HONEYCOMB 350 345 262 25 48 EMB. 3 In Table 3, temperature t57 refers to the temperature in the space 57, and an electric heater is used as heating means in this embodiment, and the temperature t57 is kept at 350°C. According to the experiment, when the objective gas is supplied, it was in embodiment 1, embodiment 2, and embodiment 3, that the temperature tc3 in the lower part of the pretreatment material 141 was kept at least at 250°C or more and that the action of the pretreatment material 141 and catalyst 54 was sufficiently achieved, whereas the temperature tc3 was less than 250°C in comparative examples 1, 2, and 3. That is, in embodiment 1, the catalyst 54 has a shape of the honeycomb base material, and the heat capacity of the pretreatment material 141 is about less than 0.1 kcal/°C-liter as evident from Table 2, and this pretreatment material 141 has a base material of corrugated shape. When the shape of the catalyst 54 is foamed metal, whether the pretreatment material 141 is in corrugated shape or honeycomb shape, the temperature tc3 could be kept at 250°C or more. Fig. 21 is a simplified sectional view of a regenerative heat exchanger 128 of a different embodiment of the invention. Beneath a housing 129 accommodating a heat exchanger column, a rotary distribution valve 51 is provided, and a rotary distribution valve 51g inverting the rotary distribution valve 51 upside down is disposed above the housing 129 so as to be composed symmetrically up and down with respect to a horizontal plane of symmetry 131. The parts of the rotary distribution valve 51g corresponding to those of the rotary distribution valve 51 are indicated by adding a suffix g to the same reference numerals. The high temperature gas is supplied from a duct 61, and is conducted into the housing 129 to heat a heat exchanger column (heat reserve material) 130 to accumulate heat, and is discharged from a connection port 61g. Valve discs 67, 67g cooperate in synchronism, and are integrally rotated and driven by motors 80, 80g. From a connection port 62g, the gas to be heated is supplied, and is heated by the heat exchanger column 130 in which heat is accumulated, and is discharged from a connection port 62. Thus, high temperature gas and low temperature gas flow countercurrently and exchange their heat through the heat exchanger column 130. The housing 129 is partitioned at equal intervals in the peripheral direction by the partition boards the same as in the foregoing embodiments, and the other constitution is the same as in the foregoing embodiments. The shaft holes 106, 106g, auxiliary partition walls 110, 110g, and rotary tube joints 107, 107g may be omitted. The invention is applied not only in the regenerative catalytic combustion apparatus and regenerative heat exchanger, but also in other uses in a wide range. In the embodiments shown in Fig. 1 through Fig. 20, the catalyst 54 and pretreatment material 141 may be omitted. In other embodiments, only the pretreatment material 141 may be omitted. The flow directions of the objective gas and clean gas may be opposite to the directions as shown in the above embodiments. TECHNICAL APPLICABILITY Thus, according to the invention, the fluid passing through the pair of chambers formed in the valve box may be continuously changed over and may flow into the passage of each stationary valve port formed by the passage forming means including the partition boards at the stationary valve member side. Especially, according to the invention, the third moving valve port is formed at one side between the first and second moving valve ports along the peripheral direction, and hence undesired mixing of gas between the first and second moving valve ports can be prevented by purging gas or the like. Further, according to the invention, at the other side between the first and second moving valve ports along the peripheral direction, the changeover part 138 extending in the peripheral direction so as to close at least one stationary valve port is provided in the valve disc, and hence fluid such as gas is smoothly changed over in the passage of each stationary valve port respectively communicating with the first and second moving valve ports, so that the fluid can be passed in all passages, and the operation efficiency is excellent. Another excellent effect of the invention is that the sealing between of the moving valve member and stationary valve member can be composed easily. By realizing the regenerative combustion apparatus by using such rotary distribution valve, the fluid such as objective gas containing malodorous substances can be operated continuously by rotating and driving the valve disk of the rotary distribution valve without moving the heat reserve material. Hence, all advantage of the rotary type regenerative combustion apparatus can be exhibited, that is, the purging area is essentially minimized, the structure may be reduced in size, and the heat reserve material is substantially decreased, which also contributes to reduction of the structural size. Also according to the invention, the structure of the rotary distribution valve is simple, and the high temperature gas does not pass away, and adverse effects of thermal distortion can be eliminated. In the invention, it is not necessary to rotate and drive a heavy heat exchanger column, but only a light valve disc may be rotated and driven, and the structure is simplified and reduced in size, and hence the facility cost can be saved. The same effects are obtained when the rotary distribution valve is applied in the regenerative heat exchanger. According to the invention, moreover, the temperature of the catalyst and the pretreatment material for removing the catalyst deteriorating substances is prevented from becoming too low, so that the action of the catalyst and the pretreatment material may be exhibited sufficiently. Further according to the invention, communicating holes consisting of a porous plate having multiple pores opposite to the space in which the heating means is provided are formed, and hence the gas is mixed sufficiently in the space, and uniform temperature distribution is achieved, and thus obtained purified gas having uniform temperature is conducted into the catalyst, pretreatment material, and heat exchanger column, and the heat is accumulated. In the invention, since the purging gas can pass only through one of the passages 84, 113 to 120 partitioned by the partition boards 55 in the housing 52, the remaining passages 84, 113 to 120 can be used effectively for passing the objective gas or passing the purified gas, and the effective volume of the heat reserve material, catalyst, and pretreatment material can be increased, and hence the efficiency is high. Moreover, since the purging gas is supplied into one of the passages 84, 113 to 120, the structure of the rotary distribution valve 51 can be simplified. Furthermore, since the purging gas is supplied only in to one of the passages 84, 113 to 120, the required flow rate of purging gas can be reduced. In addition, this purging gas is, for example, a clean air at ordinary temperature, and by allowing the purging gas to pass only in one of the passages 84, 113 to 120, it is possible to restrain undesired cooling of the heat exchanger column 53 and hence drop of temperature.

Claims: Rotary distribution valve comprising: a valve box (64) including a first and a second chamber (65, 66) superposed in the axial direction, each chamber (65, 66) being provided with a connection port (61, 62), respectively, a rotatory valve member (67) accommodated in the valve box (64) so as to be rotated about the axis (63), wherein first (86, 87) and second (88, 89) moving valve ports (86, 87; 88, 89) are formed at positions facing the second chamber (66) on the one end of the valve box (64) in the axial direction at intervals in the peripheral direction about the axis (63), and a third moving valve port (90) is formed either between the first (86) and second (89) moving valve ports or between the first (87) and second (88) moving valve ports in the peripheral direction. a guide space (91) for communicating the first chamber (65) with the first moving valve ports (86, 87) is formed by partition walls (70) provided in the second chamber (66), the guide space (91) is partitioned from the upper chamber (66) which communicates with the second moving valve ports (88, 89), a communicating passage (111) which communicates with the third moving valve ports (90) is formed by an auxiliary partition wall (110), and said rotatory valve member (67) has a changeover part (138) expanding in the peripheral direction between the other first (86, 87) and second (88, 89) moving valve ports, so that at least one of the stationary valve ports (82) may be changed over distinctively, characterized in that the rotatory valve member (67) comprises a first valve disc (69), a second valve disc (92) and the partition walls (70) connecting the first valve disc (69) with the second valve disc (92), said first valve disc (69) is provided with the first (86, 87) and the second (88, 89) valve ports and the third valve port (90) is formed in said first valve disc (69) either between the first (86) and the second (89) valve port or between the first (87) and the second (88) valve port, a stationary valve member (71) is disposed at the one end of the box (64) adjacent the first valve disc (69) and provided with a plurality of stationary valve ports (82) disposed in the peripheral direction around the axis (63) and the guide space (91) for communicating the first chamber (65) with the first valve ports (86, 87) in the first valve disc (69) is formed by a part of said partition walls (70a, 70c) and by said second valve disc (92) which is provided with communicating holes (93), whereby first gases are fed through the connection port (61) into the chamber (65), through the passages (86, 87) in the rotatory valve member (67) and through the corresponding passages in the stationary valve member (71) and the second gases are fed through the remaining passages in the stationary valve member to the corresponding passages (88, 89) in the rotatory valve member (67). Rotary distribution valve according to claim 1, characterized in that the rotary valve member (67) has a rotary shaft (68) rotating about the central axis (63), the rotary shaft (68) has a shaft hole 106, which communicates with the communicating passage (111) and with a rotary tube joint (107). Rotary distribution valve according to claim 1 or 2, characterized in that the first valve disc (69) is vertical to the central axis (63) and comprises a changeover part (138) and seal members (97, 98, 101, 102) sliding on the opposite surface of the stationary valve member (71) and extending in the radial direction among the first, second, and third moving valve ports (86, 87; 88, 89; 90). Rotary distribution valve according to claim 3, characterized in that a first angle in the peripheral direction of the pair of seal members (97, 98) at both sides in the peripheral direction of the third moving valve port (90) is supposed to be 1, each stationary valve port (82) is formed by a second angle 2 in the peripheral direction, the interval of the mutually adjacent stationary valve ports is formed by a third angle 3 in the peripheral direction, and these angles have the relations of 2 + 3 ≧ 1 ≧ 2, and 3 ≧ 2. Rotary distribution valve according to claim 4, characterized in that the relation of 3 > 2 is satisfied. Rotary distribution valve according to claim 4, characterized in that a pair of auxiliary seal members (99, 100) are provided at both sides in the peripheral direction of the seal members (97, 98) and the angle 6 of these auxiliary seal members (99, 100) is selected to satisfy the relation of: 2 + 2 3 ≧ 6 ≧ 2. Rotary distribution valve according to claim 4, characterized in that the seal members (101, 102) provided between the other first and second moving valve holes (86, 87; 88, 89) along the peripheral direction, out of the seal members (97, 98, 101, 102) are disposed in the changeover part (138) at an angle 4, being selected in the relation of 4 ≒ 2. A regenerative combustion apparatus comprising: (a) a housing (52), (b) a heat exchanger column (53) accommodated in the housing (52), (c) a catalyst (54) for burning polluted gas, provided above the heat exchanger column in the housing (52), (d) partition boards(55), extending vertically in the housing (52), for forming plural passages (84, 113 to 120) by partitioning the heat exchanger column (53) and the catalyst (54) at intervals in the peripheral direction, and communicating with a common space in the upper part of the housing, and (e) a rotary distribution valve (51) according to one of the claims 1 to 7 provided beneath the housing (52), (f) the lower part of the rotary distribution valve (51) is fixed to the stationary valve member (71), (g) the polluted gas is supplied into either one of the chambers (65), and purified gas is conducted in from the remaining chamber (66), (h) a clean purging gas is supplied into the communicating passage (111) in the same flow direction as that of the polluted gas, and (i) the rotatory valve member 67 is rotated by a rotation drive source in a direction of the purging gas being changed over and passed, in the plural passages (84, 113 to 120) through which the polluted gas passes. Combustion apparatus according to claim 8, characterized in that a heating means (59) is provided in the upper space of the housing, a space partition wall (56) for forming the space (57) is fixed in the upper part of the housing, communicating holes (58) for individually communicating with the plural passages (84, 113 to 120) partitioned by the partition boards (55) are formed in the space partition wall (56), and the communicating holes (58) are disposed above at a clearance from the upper part of the catalyst (54), and are formed by a porous plate having multiple discrete pores. Combustion apparatus according to claim 8 or 9, characterized in that a pretreatment material (141) is interposed between the heat exchanger column (53) and the catalyst (54) in order to remove the catalyst (54) deteriorating substances contained in the polluted gas, and the catalyst (54) mainly composed of a base of honeycomb material, and the pretreatment material (141) has a specific heat of about 0.1 kcal/°C or less. Combustion apparatus according to claim 10, characterized in that the pretreatment material (141) is composed of a corrugated base. Combustion apparatus according to claim 9, characterized in that a pretreatment material (141) is interposed between the heat exchanger column (53) and the catalyst (54) in order to remove the catalyst (54) deteriorating substances contained in the polluted gas, and the catalyst (54) mainly composed of a foamed metal material and the pretreatment material (141) are combined. Combustion apparatus of any one of claims 10 to 12, characterized in that means for controlling the heating means (59) is provided so that the temperature of the pretreatment material (141) may be 250 °C or more. Combustion apparatus according to claim 8, characterized in that, the passage forming means (71, 52, 55) comprise the stationary valve member (71) fixed to the valve box (64) opposite to the rotary valve disc (69), the stationary valve member possessing the stationary valve ports (82) overlaying on the first, second, and third moving valve ports (86, 87; 88, 89; 90) and means (52, 55) for forming the plural passages (84, 113 to 120) by individually communicating with the stationary valve ports (82) of the stationary valve member (71). A method of operating a regenerative combustion apparatus according to one of the claims 8 to 14, characterized in that, the polluted gas is supplied into either one chambers (65), and purified gas is conducted in from the remaining chamber (66), a clean purging gas is supplied into the communicating passage 111 in the same flow direction as the polluted gas, the valve disc (67) is rotated by a rotation drive source in a direction of the purging gas being changed over and passed, in the passages (84, 113 to 120) through which the polluted gas passes, and the polluted gas passes through the communicating hole (58) at about 5 to 20 m/sec. A regenerative heat exchanger comprising: (a) a housing (52), (b) a heat exchanger column (53) accommodated in the housing (52), (c) partition boards (55), extending vertically in the housing (52), for forming passages by partitioning the heat exchanger column (53) at intervals in the peripheral direction, and (d) first and second rotary distribution valves (51, 51g) provided above and beneath the housing (52), each one of the rotary distribution valves (51, 51g) being according to one of the claims 1 to 7 (e) both ends in the axial direction of the partition boards (55, 55g) are fixed to stationary valve members (71, 71g), (f) rotary shafts (68, 68g) of the rotary distribution valves (51, 51g) are driven in cooperation, (g) high pressure gas is supplied into either chamber (65) of the first rotary distribution valve (51), and is conducted into either chamber (65g) of the second rotary distribution valve through heat exchanger column (130), and (h) low temperature gas is supplied into the remaining chamber (66g) of either the first or second rotary distribution valve (51g), and is conducted into the remaining chamber (66) of the other first or second rotary distribution valve (51).

Inventors: IZUMO MASANORI, MORI HIROSHI, WATANABE MORIMASA, IZUMO, MASANORI, MORI, HIROSHI, WATANABE, MORIMASA, MORI, HIROSHI DAIKIN INDUSTRIES, LTD., WATANABE, MORIMASA DAIKIN INDUSTRIES, LTD.
Applicants: DAIKIN IND LTD, DAIKIN INDUSTRIES, LIMITED
Application year: 1995
Main classification: F23L15
IPC codes: F23G7