Source: https://russianpatents.com/patent/217/2173437.html
Timestamp: 2020-02-24 23:42:40
Document Index: 401516736

Matched Legal Cases: ['art 23', 'arts 12', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 12', 'art 12', 'arts 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 28']

Heat exchanger and method of heat transfer
The invention is intended for use in the methods and devices must be substantial relative thermal expansion between the tubes and the tube Board. The heat exchanger includes a feed area of process fluid and the area of release of process fluid, separated from the zone of heat exchange boundary means, such as a tube sheet or manifold pipe. The multiple heat exchanging tubes for the fluid extends through a zone of heat transfer from one edge of the funds and is in sliding engagement on the other edge of the tool with the sealing tube attached to the other edge of the tool. Inside the inner one of the tubes of the sealing tube and the associated heat pipe is provided narrowing of reduced cross-sectional area, forming a region of low pressure downstream from the constriction, expansion area with the cross-sectional area greater than the cross-sectional area narrowing downstream from the narrowing and one or more passages through the wall of this inner pipe connecting area of low pressure with the outside of wny with the to ensure the flow path of the leakage of the coolant from the heat exchange zone through the overlapping region and the passages in the area of low pressure. The method includes a process fluid that contains the feeding process fluid in the feeding zone of the process fluid, transmission fluids from the zone of process fluid through the multiple heat exchanging tubes extending through the heat transfer area, while the process liquid is subjected to heat exchange with the coolant in the area of heat transfer, transmission of process fluid from the heat exchange tubes in the area of drainage of the fluid separated from the zone of heat exchange second boundary means the process liquid from the zone allocation process fluid is subjected to process and transmit the resulting processed process fluid through a zone of heat transfer as the heat carrier, moreover, the tubes are attached to one of the edge means. 2 C. and 8 C.p. f-crystals, 3 tab., 6 Il.
The invention relates to a heat exchanger and method of heat exchange and, in particular, to a method and device, which must be substantial relative tallesim border zone, through which the heat medium in the heat exchange process with the process fluid passing through the pipe.
In the heat exchanger of the above type of process fluid passes from the zone of process fluid through the tubes (tubes forming the heating surface) located within the zone of the heat exchanger defined by the housing, through which the coolant, and then in the area of drainage of the fluid. Thus, the tube sheet may separate the area of heat exchange, through which passes the fluid from the zone, such as the discharge chamber, soamsawali with inside heat exchanger pipes for the supply of process liquid to the pipe or drain the fluid from the pipes. An alternative device includes the use of collector pipes located inside the heat exchange zone to determine the zone of process fluid: the process liquid is fed to manifold pipe, whence it flows and passes through the tubes. Similarly can be provided with a collector pipe for draining of process fluid from the pipes. An alternative may be a combination of tube plates is through the camera, separated from the zone of heat exchange pipe Board, while provided with collector pipes located within the zone of heat to drain the fluid from the pipes. Such tube sheets or headers, hereafter referred to as boundary tool, as they define the boundaries between the heat transfer area and the areas of the inlet and outlet process fluid.
In some applications, such as steam reforming of hydrocarbons, the tubes are of considerable length, typically a few meters, and in this case there is a large temperature difference, often reaching several hundred degrees Celsius, for example from 500 to 1000oC or more, between the cold, that is, the surrounding condition, and the normal working condition. In the pipes get when extending in the longitudinal direction a considerable elongation, often amounting to 10 cm or more, relative to the housing to which is attached the boundary tool. It is common practice to install one or both ends of flexible pipe shank to allow such relative expansion, so to the boundary means attached to the shank, not the pipe. An alternative often used of silk devices capable of adjustment relative expansion of the order of 10 cm or more, presents practical difficulties.
In some types of heat exchangers the heat transfer medium is a process liquid, which has passed through the pipe, but which was subjected to further processing before use as a coolant. For example, tubes can be filled with the reforming catalyst vapor and passes through pipes hydrocarbons that are being processed, mixed with steam: the last heated coolant to supply the necessary heat for the endothermic reaction of the primary reforming steam to produce a primary reforming gas. Then the resulting primary reforming gas is subjected to partial oxidation, where it is subjected to partial combustion with oxygen or air and, in some cases, the process is known as secondary reforming, in which the primary gas is passed through the catalyst bed of the secondary reformer. Then the resulting incompletely burned gas, which is called the secondary reformer gas, is used as the coolant, a heating pipe. An example of this type of process and heat exchanger DL the process eliminates edge means at the output end of the heat exchange tubes. Pipes open in the zone into which is introduced a gas such as air or oxygen, so that is incomplete combustion of the primary reforming gas and the resulting incompletely burned gas passes back past the tubes, thereby heating the latter. Examples of the method and device of this type is described in U.S. patent N 2579843 and N 4919844 and the United Kingdom patent N 2181740. While the device of this type avoids the problems associated with the relative thermal expansion of the pipes, however, there are problems associated with the transmission of incompletely burnt gas through the catalyst bed of the secondary reformer before using this gas for heating pipes. Also known proposals presented, for example, in U.S. patent N 4337170 and N 5264202, to use this type of furnace for reforming, where the tubes are "open" at the output end, so that the reforming gas coming out of the pipe communicates with the heat transfer area for the implementation of the reforming raw material by passing it and steam through pipes that are heated primary reforming gas obtained in conventional oven for reforming. In the above U.S. patent N 4337170 also serves to expose the secondary to the primary reforming the reforming gas from conventional p�cs is the quality of the coolant.
Also known heat exchanger that includes a feed area of process fluid, the heat transfer area and the area draining of process fluid and boundary means separating these areas from each other, the multiple heat exchanging tubes attached to one of the specified boundary means and extending through the zone heat and process fluid may flow from the zone of process fluid through the tubes in the area draining of process fluid (SU 659878A, F 28 D 7/10, 30.04.1979, 2 pages). In the same device is the way of the heat exchanger, which consists in applying the process liquid in the feeding zone of the process fluid that is separated from the heat exchange zone boundary means, transmission of process fluid from the zone of process fluid through the multiple heat exchanging tubes extending through the heat transfer area, while the process liquid is subjected to heat exchange with the coolant in the area of heat transfer, transmission of process fluid from the heat exchange tubes in the area of drainage of the fluid separated from the zone of heat exchange second edge means, and the tubes are attached to one of the faces is on the boundary of funds sealing pipes, which engages with the heat exchange tubes, but they are not attached, so that the sealing tubes provide positional placement for heat-exchanger tubes, at the same time allowing sliding movement between the sealing and heat-pipes to accommodate relative expansion. However, in this case necessarily with the path leakage between zones on either side of the boundary funds through the gap between the sealing pipes and heat exchanger tubes for the possibility of such sliding movement. Because of the high temperatures, which are usually dealing in use, a problem creating a moving, solid, gas-tight seal for the gap. The leakage pathway allows process fluid, for example a primary reforming gas to pass into the environment of the heat carrier, for example, incompletely burned gas, or Vice versa. Of course, the direction of leakage will depend on the relative pressure of process fluid and coolant. Usually, when a carrier is a product of further processing of the process fluid, the process fluid must be pre passing the process fluid through the further processing before use as a coolant. This means that the dominant leakage must be a leak of process fluid in the fluid, which, in turn, means that a certain amount of process fluid will bypass further processing. Such bypassing further processing is usually undesirable. Thus, when the product of the primary steam reforming of hydrocarbons in the pipes is a process gas, the methane content in the technological reforming gas is usually 10% vol. or more, whereas the product of the secondary steam reforming primary reforming gas typically has a methane content of less than 1 vol.%, usually less than 0.5 vol.%. If the area of heat exchange is moving 5% of the process gas, bypassing the secondary stage of the reformer, the resultant mixture of the secondary reformer gas and leaked the primary reforming gas shall be methane, usually 2 times higher than its content in the secondary reforming gas. This not only means that it was not subjected to reforming a significant amount of methane, but also that this "prosultiamine methane usually acts as an inert gas in the subsequent processes such as ammonia synthesis, thus making the latter less effective is located at some lower pressure, than the process liquid coming out of the pipes, the predominant leak is a leak of coolant into the process liquid.
Features a heat exchanger that includes a feed area of process fluid, the heat transfer area and the area draining of process fluid, the first and second edge means separating these areas from each other, the multiple heat exchanging tubes attached to one of the specified boundary means and extending through the zone heat and process fluid may leak from the area of supply of process fluid through the tubes in the area of drainage of the fluid in which according to the invention, each pipe has a sealing tube mounted to the other of the edge means, and each of the sealing tube is essentially coaxial with the associated heat exchange tube so each sealing tube is in sliding engagement with the associated heat exchanger tube, thereby defining an overlapping region in which the heat exchange tubes and sealing pipe overlap each other, and thermal expansion of heat exchanger tubes may be provided within the overlapped region of the inner narrowing of reduced cross-sectional area, forming an area of low pressure, expansion area, having a large cross-sectional area than the cross-sectional area of constriction downstream in the direction of the flow of process fluid specified area of low pressure, and one or more passages through the wall of the inner pipe connecting area of low pressure with the outside of the inner tube, and the passages are located within the overlapping region, thereby providing a flow path for fluid from the heat exchange zone through the overlapping region in an area of low pressure within the inner tube. Preferably another edge tool made in the form of a tube plate, through which pipes, and contains manifold pipe connected to the exhaust tube of process fluid.
Each heat pipe is located inside the associated sealing pipes. The tubes are attached to the boundary means between the feeding zone of the process fluid and the heat transfer area.
Heat exchanger in the form of furnace for heat exchange reforming unit, operatively connected to the means incomplete combustion, intended for realization of the incomplete combustion of MSW combustion, in the heat exchange furnace reformer as a heat carrier, and the means of incomplete combustion includes the catalyst layer of the secondary reforming, which passes through incompletely burned gas before feeding it into heat oven to hydrogen as a coolant.
Also enjoy the way in which the process liquid is subjected to the process containing the feeding process fluid in the feeding zone of the process fluid that is separated from the heat exchange zone boundary means, transmission of process fluid from the zone of process fluid through the multiple heat exchanging tubes extending through the heat transfer area, while the process liquid is subjected to heat exchange with the coolant in the area of heat transfer, transmission of process fluid from the heat exchange tubes in the area of drainage of the fluid separated from the zone of heat exchange second edge means, the process liquid from the zone allocation process fluid is subjected to desired processing, and transmit the resulting processed process fluid through a zone of heat transfer as the heat carrier, and teploobmennye pipe is provided sealing the pipe, attached to the other of these boundary means, each sealing tube is essentially coaxial with the associated heat exchange tube so that each sealing tube is in sliding engagement with the associated heat exchanger tube, thereby defining an overlapping region in which the heat exchange tubes and sealing pipe overlap each other, and thermal expansion of heat exchanger tubes may be provided within the overlapping region, while the inner pipe of the specified heat exchange tubes and associated sealing tube has an internal narrowing of reduced cross-sectional area, forming an area of low pressure, expansion area, having a greater cross sectional area than the cross-sectional area of constriction downstream in the direction of the flow of process fluid specified area of low pressure, and one or more passages through the wall of the inner pipe connecting area of low pressure with the outside of the inner tube, and the passages are located within the overlapping region, thereby providing a flow path for fluid from the heat exchange zone through overlapping opinie treated process fluid, supplied to the heat transfer area, more pressure in the area of low pressure, thereby a portion of the treated process fluid supplied to the heat transfer area, passes through the gap and passes into the region of low pressure.
For steam reforming of hydrocarbons, in which process fluid fed to the feeding zone of the process fluid contains a mixture of hydrocarbons and steam, the tubes are attached to the boundary means between the feeding zone of the process fluid and the heat transfer area, and they contain the steam reforming catalyst, the sealing tube is attached to the boundary means that separates the area of heat transfer from areas draining of process fluid, thereby the mixture is subjected to steam reforming in the heat transfer tubes for receiving the stream of primary reforming gas flow stream of primary reforming gas from these heat exchange tubes in the area of drainage of the fluid subjected to primary reforming gas from the zone allocation process fluid incomplete combustion gas containing oxygen, and pass the resulting incompletely burnt gas through a zone of heat exchange to heat the tubes, while n is obmana.
The narrowing of the inner one of the heat exchanger and the sealing tube is formed an area of low pressure within the inner tube. By appropriately selecting the size of the constriction, the pressure in the low pressure during normal operation can be made lower than the pressure in the zone of heat exchange, so that there is a flow of coolant, for example, the product of the secondary reforming process fluid taken from areas draining of process fluid from the heat exchange zone through the gap and through the passage in the area of low pressure. Downstream from the low pressure process fluid expands in the expansion area, with its pressure becomes greater than the pressure in the low pressure. Consequently, there will also be a reverse flow or recirculation of process liquid from the output end of the inner tube through the gap to the aisles and in the area of low pressure.
Preferably in boundary tool provides a seal between the zone heat transfer and area draining of process fluid. Thus, the sealing tubes are attached to this edge of the tool, while the tubes are attached to Gran is BMENA. This, in particular, it is preferable in the case when the fluid is the result of further processing of process fluid from the zone drain the fluid and process fluid undergoes a pressure drop when passing through the heat exchanger tubes, for example, when the latter contain the catalyst. In such cases, it may be difficult to make the reduction of pressure by narrowing exceeded the pressure drop, endure with the passage of process fluid through the tubes plus any pressure drop, which is undergoing a process fluid in the process of further processing before it can be used as a coolant. However, maintaining the seal in the boundary means between the feeding zone of the process fluid and the heat transfer area can in some cases be of advantage. For example, when the process liquid enters a chemical reaction while passing through the tubes, it is at the inlet end of the heat exchange tubes may have a different density, enabling greater pressure reduction by narrowing, and/or the composition may be such that the process liquid Alemannic pipes may be lower so that the seal operates at lower temperatures.
The sealing tube can be positioned in such a way that the tubes slide inside the sealing tube. In this case, the tubes are inner tubes and have a narrowing inside the pipes. In this case, the sealing tube can act in the area of heat transfer from the boundary funds or to extend back from the edge tools in the area, i.e. the area of the feed or drain the process liquid on the other side of the boundary means. The tubes may extend from the boundary funds to which they are attached, through a zone of heat exchange and through the sealing tube attached to the other edge tool, and can be in the area, i.e. the area of the feed or drain the process liquid on the other side of the boundary means is attached to the sealing of the tube. Alternative sealing tube can be positioned so that they slide inside the heat exchanger tubes. In this case, the sealing tubes are inner tubes and have inside the constriction. In this case, the sealing of the tubes extend into the area of heat transfer from the boundary funds to Kotorovych:
Fig. 1 depicts a schematic cross section of a heat exchanger according to the first embodiment of the invention, in which the boundary means are tube sheets,
Fig. 2 depicts a cross-section of the lower end of one of the tubes of the first embodiment of the invention showing the associated pipe Board, and a sealing tube
Fig. 3 depicts a schematic cross-section similar to those shown in Fig. 1, the second embodiment of the invention, in which the boundary by means of a bearing sealing tube is manifold,
Fig. 4-6 depict schematic cross-sectional various sealing devices.
In Fig. 1 shows a heat exchanger such as heat exchanger furnace for reforming, with an external, stand-alone, working under pressure housing 10, having four zones 11, 12, 13, 14, bounded by the walls of the shell and tube boards 15, 16, 17.
Zone 11, zone supply the process liquid is limited by the walls of the casing and pipe Board 15 and provided with a feed pipe 18 and has plenty of heat exchange tubes, such as tubes for the implementation of the reforming 19, attached to the tube plate 15 and extending down from it. The number of pipes will be Satinato or more. For steam reforming tube 19 must be filled with a suitable steam reforming catalyst such as Nickel on a substrate of refractory material such as alumina, zirconium dioxide or cement from calcium aluminate. The reforming catalyst is usually in the form of shaped elements, randomly laid in pipes. Usually shaped elements have a maximum size of less than about 1/5 of the diameter of the pipe for reforming and can be in the form of a cylinder having a channel or preferably several channels extending longitudinally through the cylinder.
Area 12, area drain coolant form a second minor portion of the area of heat exchange, and is restricted by the walls of the shell and tube boards 15 and 16. A pipe 19 extends through the zone 12 and through the tube Board 16. Each pipe 19 provided with a surrounding annular nozzle 20 attached to the tube plate 16 and extending down from it. The inside of the pipe 20 communicates with the zone 12 so that the fluid passing upward between the inner surface of the pipe 20 and the outer surface of the pipe 19, associated with the nozzle, can be carried out in zone 12. Area 12 is also provided with an outlet pipe 21 for coolant.
the AMI 16 and 17. At the lower end of zone 13 is provided by the intake manifold for coolant. Each tube 20 is open at the lower end and ends in the lower part of zone 13, so that the coolant supplied to the zone 13 to the pipe 22 can enter the annular space between the inner surface of the pipe 20 and the outer surface of the associated pipe 19. Each of the pipe 19 has a portion 23 of reduced cross-section at the lower ends of the nozzles 20 through pipe Board 17.
Area 14, area of drainage of the fluid is limited by the walls of the casing 10 and pipe Board 17 and is provided with an outlet pipe 24 for the fluid. The lower part 23 of tube 19 passes through the tube Board 17 and open at their lower ends 25 (see Fig. 2), thus allowing the fluid to pass from the pipe 19 into the zone 14 and thence out through the pipe 24.
Therefore, it is seen that considering the two parts 12, 13 of the heat exchange zone as a single zone heat exchange zone to supply the process liquid 11 is separated from the zone of the tubular heat exchange Board 15, forming the boundary means, attached to the tubes 19, and the area is separated from the heat exchange zone allocation is As shown in Fig. 2, the lower part 23 of tube 19 is not attached to the tube plate 17, so that thermal expansion of the tube 19 relative to the housing 10 can be ensured. Each piece of pipe 23 extends into the sealing tube 26 attached to the tube plate 17 and extending into the zone 14. Part 23 of tube 19 extending in sealing tube 26 forms an overlapping region having a small gap 27 between the outer surface 28 of the lower part 23 of tube 19 and the inner surface 29 of the sealing tube 26 associated with it. Typically, this gap is of the order of 0.05-3 mm Inside the overlapping region, where the portion of the pipe 23 is located inside the sealing tube 26, the inside of the lower part 23 of tube 19 has a conical section 30, leading to a constricted cylindrical region 31 of reduced cross-sectional area. Typically, the cross-sectional area of this constricted region 31 is about 15-50% of the cross-sectional area of the lower part 23 of tube 19. Downstream from the constricted region 31 is provided a cylindrical area of low pressure 32, the cross-sectional area which is greater than the cross sectional area of the constricted region 31, but less than the cross-sectional area of the lower part 23 of tube 19. The lower portion 23 of tube 19 terminates in p the lower part 23 of tube 19, communicating with the area of low pressure 32, downstream from the constricted region 31.
Provided that the pressure of process fluid flowing down through the pipes 19, at the entrance to the conical region 30 is not too much more pressure coolant entering the zone 13 to the pipe 22 by a suitable choice of the dimensions of the constricted region 31 and the low pressure 32, it is possible to arrange so that during normal operation the pressure in the low pressure 32, which is a consequence of the flow of process fluid through a narrowed region 31 in the area of low pressure 32, less than the pressure of the coolant entering the heat transfer area 13 through the pipeline 22. Therefore, should take place during fluid from the zone 13 through the gap 27 in the overlapping region and through the passages 34 in the area of low pressure 32. The pressure at the output end 25 of the tube 19 must be greater than the pressure in the low pressure 32 and so there must also be recirculated within the process liquid from the output end of the heat pipe 19 through the gap 27 and the passages 34 in the area of low pressure 32.
It should be clear that as Pets leakage of fluid past the pipe is it part 23 of the heat exchange tubes 19 can be used a larger gap with a simple mechanical seal, allowing sliding movement. Failure of the seal will thus allow flow of the fluid past the seal in the area of low pressure 32. Thus, at the upper end of the sealing tube 26 in the gap 27 between the outer surface 28 of the lower part 23 of tube 19 and the inner surface of the sealing tube 26 may be provided with a suitable gasket, allowing sliding movement, to further reduce leakage of fluid from the zone 13 zone 14.
Although insignificant is the fact that the tubes 19 have a lower portion 23 of reduced cross-section, i.e. the pipe 19 could be a normal cross-section passing through the tube Board 17 with a corresponding change in the dimensions of the sealing tube 26, the provision of the lower part 23 of a smaller cross-section facilitates the calculation and create a leak.
In an alternative device, the nozzles 20 and tube sheet 16 are eliminated, so that the heat transfer area is not divided into a core part and a built-in output part for coolant, but simply represents one area through which the heat transfer medium flows from the inlet pipe 22 and exits through the exhaust pipe 21.
In Fig. 4, 5 and 6 shows an alternative device with a seal at the top, the feed process fluid end of the heat exchange tubes. The direction of the flow of process fluid indicated by arrow A. In these devices, not shown in Fig. 4-6, the tubes 19 are attached to the boundary means, for example, the tube plate or collector pipes that separates the area of heat transfer from areas draining of process fluid. In the embodiments shown in Fig. 4 and 5, the sealing tube 37 attached is corestates part of the 12 zones of the heat exchanger. In Fig. 4 sealing pipes extend downward from the tube plate 15 in part 12 of the heat exchange zone, while in Fig. 5 sealing pipes extend upward from the tube plate 15 in the feeding zone of the process fluid 11. In the apparatus shown in Fig. 6, the sealing tube 37 is located inside the upper end of the tubes 19. In each of these devices inside the inner pipe, i.e. the pipe 19 in Fig. 4 and 5, and the sealing of the pipe 37 in Fig. 6, are provided with the tapered region, the area of low pressure, expanding the area and passes through the wall of the inner tube in the same way as described above with respect to Fig. 2. In these devices, the coolant can flow from the part 12 of the heat exchange zone through the gap between the heat exchange pipe 19 and the sealing tube 37, through the passages in the area of low pressure located downstream from the constricted region inside the inner one of the tubes.
In the calculated example using the embodiment shown in Fig. 1 and 2, natural gas obeserved by adding a small amount of the mixture of hydrogen and nitrogen recovered from the purified ammonium gas and passed through a catalyst bed desulfurization and a layer of zinc oxide, deistvujushsaja to 406oC, is supplied to the feeding zone of the process fluid 11 furnace for reforming the pipeline 18 and carried out primary reforming in the heat exchange tubes 19 having an inner diameter of 125 mm and a length of 10 m, containing randomly laid the steam reforming catalyst of Nickel on a substrate of cement from calcium aluminate in the form of a cylinder of length 17.6 mm and a diameter of 14 mm, with stretching in the axial direction through four cylindrical channel with a diameter of 4.0 mm, the Catalyst was maintained at bounding the grid at the upper end of the transition region, where the pipe 19 is reduced in diameter for forming the lower parts 23, so the bottom part 23, which had an inner diameter of 25 mm, were free from catalyst. The temperature and pressure of the process gas after reforming (thread B) included in the lower portion 23 of tube 19, there were 722oC and 4 MPa abs. respectively. The resulting reforming gas that has passed through a narrowed region 31 and an area of low pressure 32, has led to increased pressure to 3.86 MPa abs. in the area of low pressure and pressure 3,93 MPa abs. at the output end 25 of the pipe 19. As described below, there was a thread C leakage of gas from the heat exchange zone 13 zone allocation process fluid 14 is the seer of stream B and stream C leakage, moved by pipeline 24 to the second reforming furnace, in which it has been subjected to partial combustion with air flow E, which was preheated to 650oC and subjected to secondary reforming by passing the partially burned mixture through a randomly Packed bed of the catalyst in the secondary reforming of Nickel supported on cylinders of cement aluminium calcium. The cylinders of the secondary catalyst of the reformer had a length of 17.6 mm, the diameter of 14.0 mm and had a extending in the axial direction of the four cylindrical through-channel having a diameter of 4.0 mm, a Secondary reformer gas (stream F) at a pressure 3,88 MPa abs. and a temperature of 970oC was then submitted to a heat transfer area 13 through the pipeline 22. Part (flow C) flow F secondary reformer gas flowed from the zone 13 zone through the passages 34 and an area of low pressure 32, while the remainder (stream C) was used as the coolant, a heating pipe 19 when passing upward flow Q through the annular space inside the nozzle 20 to the zone 12. Temperature is obtained as a gas product (stream H), leaving the area 12 through the pipeline 21, was 530oC.
The lower part 23 of the tubes had an inner diameter of 25, and they come back to su the second diameter of 18 mm and a length of 108 mm The open end of the pipe, a hole which extends from a diameter of 18 mm low pressure 32 to the outer diameter of 32 mm of the lower part 23 of the pipe 19 on the length of 78 mm Between the area of low pressure 32 and annular gap 27 has been provided 12 recirculation passages 34, having a diameter of 3 mm Annular gap 27 between the sealing tube 26 and the outer surface 28 of the lower part 23 of tube 19 had a width of 0.2 mm of the Lower part 28 of the pipe 19 and the sealing tube 26 may have a sufficient length, to the passages 34 and the open end 25 of the pipe 19 was inside the sealing tube 26 by starting at ambient temperature and at normal operating temperature. It was estimated that at normal operating temperatures, despite the fact that the pressure of the stream at the entrance to the conical region 30 at 0.12 MPa higher than the pressure of the secondary reforming process gas into the stream F, which is included in zone 13, about 3% technological reforming gas, leaving open ends 25 of the pipe 19, recycled through the gap 27 and the passages 34 and about 3% of the secondary reformer gas (stream F) included in zone 13, similarly passed as stream leakage C1through pipe Board 17 in the area of low pressure 32 through the gap 27 and the passages 34.
In table I are given the velocity of flow (about the s in the threads.
It was assumed that in the calculation of the comparative example, the lower part of the pipe 23 had narrowed the field or area of low pressure and no recirculation passages, and throughout its length had an inner diameter of 25 mm, the Reforming gas discharged from the end 25 of the pipe, thus, had a pressure of 4.0 MPa abs., so there was a gas leak from the area draining of process fluid 14 through the annular gap 27 in the area of heat transfer 13.
In table II are given the velocity of flow (rounded to the nearest value in 0.1 KMOL/h) component of the various threads together with temperature and pressure flows.
The above-described processes, including primary and secondary reforming with air, are designed to obtain the reforming gas for use in the production of ammonia. As the plant for the production of ammonia reforming gas is usually subjected to a shift reaction, in which virtually all of the carbon monoxide reacts with steam to produce carbon dioxide and hydrogen, the amount of hydrogen that could be produced (hydrogen equivalent), which, in turn, determines the amount of ammonia that can be obtained is equal to the sum of the contents of hydrogen and Omena 13 in the comparative example, the temperature of the gas, used as the coolant decreases. Also, comparing the flow rate to a second furnace for reforming decreases and thus should be used less air to obtain the outlet temperature of the furnace to the secondary reformer. In turn, this means that the amount of gas (flow F) leaving the kiln for the secondary reformer, and so despite the increase rather than decrease due to the flow of leakage C amount of gas (stream G) available for use as a coolant decreases. This decrease in the amount and temperature of the fluid stream F, means that to obtain the same amount of the reforming gas in the heat exchange tubes 19 flow temperature H gas as a final product leaving the kiln for reforming through the pipeline 21, below, thus reducing the amount of heat that can be recovered from this gas stream.
Characteristic points (parameters), which is the result of the above comparison, we can see in table III.
From table III it is seen that the hydrogen equivalent and, therefore, the potential production of ammonia according to the invention about to 2.65% more than in sravnitelnim-gas, because methane is an inert material in the subsequent ammonia synthesis: the increase in the content of methane in the reforming gas, as in the comparative case, means that the amount of cleaning required in the subsequent synthesis of ammonia, should be increased with a consequent reduction in the number of derived ammonia. Therefore, the amount of ammonia that could be obtained in the case of use of the invention should be significantly larger than the 2.6% increase for the comparative case.
Although the above described invention relates primarily to the heat exchange reformer, it should be clear that it can be used in other applications of heat transfer, where should be significant relative thermal expansion and leakage of fluid into the process liquid is acceptable. Examples are heat exchangers with flow and outflow of fluid, where, for example, the feed material to technological operations, such as exothermic reactions such as the synthesis of methanol or ammonia, is heated by heat exchange with the resulting end product manufacturing operations. In such cases, the tubes can be free from catalyst, the and the fluid at that time, when it is subjected to heat exchange.
1. The heat exchanger includes a feed area of process fluid, the heat transfer area and the area draining of process fluid, the first and second edge means separating these areas from each other, the multiple heat exchanging tubes attached to one of the specified boundary means and extending through the zone heat and process fluid may leak from the area of supply of process fluid through the tubes in the area of drainage of the fluid, characterized in that each tube has a sealing tube attached to the other of the edge means, and each of the sealing tube is essentially coaxial with the associated heat exchange tube so each sealing tube is in sliding engagement with the associated heat exchanger tube, thereby defining an overlapping region in which the heat exchange tubes and sealing pipe overlap each other, and thermal expansion of heat exchanger tubes may be provided within the overlapping region, while the inner pipe of the specified heat exchange tubes and associated sealing pipe kasserine, having a greater cross sectional area than the cross-sectional area of constriction downstream in the direction of the flow of process fluid specified area of low pressure and one or more passages through the wall of the inner pipe connecting area of low pressure with the outside of the inner tube, and the passages are located within the overlapping region, thereby providing a flow path for fluid from the heat exchange zone through the overlapping region in an area of low pressure within the inner tube.
2. The heat exchanger under item 1, characterized in that the other edge tool made in the form of a tube plate, through which the pipe.
3. The heat exchanger under item 1, characterized in that the other edge tool contains manifold pipe connected to the exhaust tube of process fluid.
4. Heat exchanger according to any one of paragraphs.1 to 3, characterized in that each heat pipe is located inside the associated sealing pipes.
5. Heat exchanger according to any one of paragraphs.1 to 4, characterized in that the heat pipe is attached to the boundary means between the feeding zone of the process fluid and the area Teploobmennik furnace for reforming, operatively connected with the tool of incomplete combustion, intended for realization of the incomplete combustion of process fluid after passing the latter through a pipe for gas supply after the specified incomplete combustion in heat oven to hydrogen as a coolant.
7. Heat exchanger according to p. 6, characterized in that the means incomplete combustion includes the catalyst layer of the secondary reforming, which passes through incompletely burned gas before feeding it into heat oven to hydrogen as a coolant.
8. The way in which the process liquid is subjected to the process containing the feeding process fluid in the feeding zone of the process fluid that is separated from the heat exchange zone boundary means, transmission of process fluid from the zone of process fluid through the multiple heat exchanging tubes extending through the heat transfer area, while the process liquid is subjected to heat exchange with the coolant in the area of heat transfer, transmission of process fluid from the heat exchange tubes in the area of drainage of the fluid separated from the zone of heat exchange of the second granese processing and transmit the resulting processed process fluid through a zone of heat transfer as the heat carrier, moreover, the tubes are attached to one of the edge means, characterized in that each heat pipe is provided the sealing tube mounted to the other of these boundary means, each sealing tube is essentially coaxial with the associated heat exchange tube so that each sealing tube is in sliding engagement with the associated heat exchanger tube, thereby defining an overlapping region in which the heat exchange tubes and sealing pipe overlap each other, and thermal expansion of heat exchanger tubes may be provided within the overlapping region, when this inner tube of the above heat-exchange tubes and associated sealing tube has an internal narrowing of reduced cross-sectional area, forming an area of low pressure, expansion area, having a large cross-sectional area than the cross-sectional area of constriction downstream in the direction of the current process fluid specified area of low pressure, and one or more passages through the wall of the inner pipe connecting area of low pressure with the outside of the inner the fluid from the heat exchange zone through the overlapping region in an area of low pressure within the inner tube, moreover, the method is carried out so that the pressure of the treated process fluid supplied to the heat transfer area, more pressure in the area of low pressure, thereby a portion of the treated process fluid supplied to the heat transfer area, passes through the gap and passes into the region of low pressure.
9. The method according to p. 8, characterized in that for the steam reforming of hydrocarbons, in which process fluid fed to the feeding zone of the process fluid contains a mixture of hydrocarbons and steam, the tubes are attached to the boundary means between the feeding zone of the process fluid and the heat transfer area and they contain the steam reforming catalyst, the sealing tube is attached to the boundary means that separates the area of heat transfer from the area of process fluid, thereby the mixture is subjected to steam reforming in the heat transfer tubes for receiving the stream of primary reforming gas, let the stream of primary reforming gas from these heat exchange tubes in the area of drainage of the fluid is subjected to a primary reforming gas from areas draining of process fluid incomplete combustion gas containing oxygen, and prop the pipe.
10. The method according to p. 9, characterized in that the incompletely burned gas is passed through the catalyst bed of the secondary reformer before serving in the area of heat transfer.