Apparatus for dehydrating and drying a wet article

Abstract: An article to be dried (1) is transferred, being pressed and held between a wire endless conveyor (8) and a "cushion" conveyor (7). The wire endless conveyor (8) is placed between a nozzle (20), comprising a suction nozzle (20a) and a blowing nozzle (20b), and the cushion conveyor (7) in order to press, hold and transfer the article (1) to be dried, and the nozzle (20) being operative to dehydrate/dry the article to be dried. When an article (1) narrower than the width of the nozzle (20) is to be dried, the exposed zone where the article to be dried is not placed is automatically shut by the "cushion" conveyor (7). The article to be dried is dehydrated/dried while it is pressed, held and transferred in the closed state so that high speed air jet stream R and high speed negative pressure air stream Q do not flow out/in to outer air. While the article to be dried is transferred, being pressed and held by the "cushion" conveyor (7), water adhering to it is transformed into minute water drops by the high speed air jet stream R and the high speed negative pressure air stream. The minute water drops are sucked out and removed on the high speed negative pressure air stream Q. Thus dehydrating/drying can be performed continuously without water evaporation heat, in a short time and efficiently with a little energy for articles to be dried of various sizes and of irregular shape.

Description: The present invention relates to a rapid dehydrating/drying device usable at low temperature which can perform extremely efficient and energy-saving dehydration/drying by high speed fluid used for drying sheet-type articles such as a mat, a carpet, fabrics, clothes, non-woven fabrics, synthetic resin film, glass, cardboard and printed articles or tubes or hoses. For drying a mat, a carpet, a sheet and clothes, natural drying, ventilation drying, heating drying, high frequency heating drying, centrifugal dehydration drying, dehydrating/drying by pressurizing, heating drying by a rotary drum and vacuum drying by pressure decrease have all been used. These drying methods have the defects of requiring a substantial amount of heat and energy, and a long time. Especially a flat mat such as a household foot mat, a business-use door mat or a carpet has various fibers implanted on a sheet surface of usually reinforcing rubber, or the like, or has fabrics adhered onto the surface of a rubber sheet. They are extremely hard to dry as they have no possibility of passage of air through such an article in the direction of the thickness thereof. For articles mentioned above to be dried, natural drying and hot air drying need a long time. In heating drying by a rotary drum, an article to be dried is put in a drum which is rotated, hot air being admitted for drying. Fibers of the mat were damaged by friction and cracks were generated in the rubber sheet base material comprising the back or rear of the mat. As a high temperature air draught was used, substantial heat energy was required and at the same time fibers of the mat were deteriorated by the heat, which had the effect of shortening their lives remarkably. In vacuum drying by pressure decrease, vapour pressure in a vacuum vessel is decreased to evaporate the humidity contained in an article to be dried. As the article to be dried is dried by taking away heat of evaporation, that article is cooled and sometimes it is frozen. Then it must be heated. Thus this heating method has a defect that a substantial amount of heat energy and motive power for a vacuum pump are needed and at the same time its drying time is long. United States patent number US-A-4 625 433 shows a dehydrating/drying device comprising a nozzle having a blowing nozzle part and a suction nozzle part. In order to eliminate the above defects, the applicants of the present invention proposed a rapid dehydrating/drying device low temperature in usable at EP-A-0 679 849 which forms a state of the art according to Art.54(3) EPC. EP-A-0 679 849 describes a method to dehydrate/dry an article to be dried by forming the water adhering to a wet mat into minute droplets by using only a negative pressure air stream or both a negative pressure air stream and a high speed air jet stream, which minute water droplets are sucked out and removed. The device can continuously dehydrate/dry at low temperature in a short time by providing flanges in circumferential parts of a suction opening and/or a blowing opening to prevent fluid from flowing into both nozzles by a short circuit or cut, thus making the high speed air jet stream and the high speed negative pressure air stream act on the surface and to pass to the roots of the fibres of the wet mat, and combining a high speed air jet stream and a high speed negative pressure air stream in a multiplication effect not to decrease the flowing velocity in the fibers. The rapid dehydrating/drying device mentioned above can dehydrate/dry at an extremely high efficiency when the width of the mat is almost the same as the widths of the suction nozzle and of the blowing nozzle. But, when the width of the mat is narrower than the widths of both nozzles (the blowing nozzle and the suction nozzle), the air jet streams and a negative pressure air stream can freely flow in and flow out in the part where the mat is not touching both nozzles, i.e. an open or exposed part of both nozzles where the that is not contacting both nozzles (called hereinafter the open part). Therefore, when air flow volume increases according to the P-Q curve (P is pressure [mmAq], Q is flow volume [m 3 /hr.]), blowing pressure and suction pressure remarkably decrease to make it impossible to secure a high speed air jet stream and a high speed negative pressure air stream necessary for drying the mat, making the time for drying the mat very long, which is a defect. According to the invention there is provided a rapid dehydrating/drying device usable at low temperature, comprising a nozzle having a blowing nozzle part and a suction nozzle part to provide a high speed air jet stream from the blowing nozzle part and a high speed negative pressure air stream from the suction nozzle part a deformable conveyor adapted to close automatically the air jet stream and/or the negative pressure air stream from the nozzle in case the width of the article to be dried being narrower than the width of the nozzle parts and a transferring conveyor, the article to be dried being transferred by being pressed and held between the deformable conveyor and the transferring conveyor, in use the article to be dried being adjacent to or in sliding contact with both nozzle parts to dehydrate/dry the article to be dried by a cumulative effect of both high speed streams, thus preventing decrease of blowing pressure and/or sucking-out negative pressure by preventing leakage of the air jet stream and the negative pressure air stream. Using the invention it is possible to provide a rapid dehydrating/drying device at low temperature which eliminates the defects mentioned above and in which there is installed a pressing conveying device that can efficiently dehydrate/dry even a mat narrower than the widths of the blowing nozzle and of the suction nozzle, regardless of the size of the mat. A method and apparatus embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings. Fig. 1 is a cross-sectional view of a dehydrating/drying device showing a first embodiment according to the invention; Fig. 2 is an enlarged view of part of Fig. 1; Fig. 3 is a plan view of an endless conveyor provided with wires; Fig. 4 is a perspective view of a pressurizing system; Fig. 5 is a top view of a nozzle; Fig. 6 is a flowing volume/pressure characteristic curve of a blower; Fig. 7 is a plan view of a net-type endless conveyor; Fig. 8 is a perspective view of the pressurizing system used in a second embodiment of the device according to the invention; Fig. 9 is a plan view of a modified example of the cushion endless belt used in the second embodiment; Fig. 10 is a cross-sectional view of a dehydrating/drying device showing a third embodiment according to the invention; Fig. 11 is an enlarged view of part of Fig. 10; Fig. 12 is a perspective view showing a modified example of a cushion roller used in the third embodiment; Fig. 13 is a cross-sectional view of a dehydrating/drying device showing a fourth embodiment according to the invention. Fig. 14 is an enlarged view of part of Fig. 13; Fig. 15 is a perspective view showing an open part of both nozzles on which a mat is not placed; and Fig. 16 is an enlarged view of part of a dehydrating/drying device when an article to be dried is a blanket. Referring to the drawings (in which like parts are indicated by like reference numerals), and in the following Examples: Example 1 The structure and the drying principle of a rapid dehydrating/drying device at low temperature embodying the invention are explained referring to Figs. 1 & 2. There is a low temperature rapid dehydrating/drying device comprising an air jet stream blowing pipe 14 at an initial stage or upstream stage for treating a wet mat 1, an article to be dried, which is held between an endless transfer conveyor 8 of a transferring device 4 and a "cushion" or deformable endless belt 7 of a pressing transferring device 3, the pressing transferring device 3 and the transferring device 4 that transfer the mat 1 in pressing it by the transferring endless conveyor 8 and the endless belt 7, a pressing system 5 that presses/holds/transports the mat 1 between the transferring endless conveyor 8 and the endless belt 7, a heater 9 installed near the upper surface of the endless belt 7, and nozzle 20 which consists of a suction nozzle 20a and a blowing nozzle 20b installed in a counter position to (or opposite) the pressurizing part of the endless belt 7 with the transferring endless conveyor 8 in-between. As shown in Fig. 1, the blowing pipe 14 mounts the blowing nozzle for passing a heated air jet stream to remove water adhering to the back of the wet mat 1 before holding it between the transferring endless conveyor 8 and the endless belt 7. This blowing pipe 14 is connected to the exhaust opening of the blower Fc. The transferring device 4 comprises the transferring endless conveyor 8 consisting of a plurality of wires 8a, 8a ... for transferring the mat 1 as shown in Fig, 3, which is trained round driving pulley 10c, driven pulleys 10d, 10e, 10f, and tension pulley 10g as shown in Fig. 1, and is moved by driving motor Mb in the direction shown by the arrow P. In this case the driving pulley 10c, the driven pulleys 10d, 10e, 10f and the tension pulley 10g are provided with numerous groves to guide the wires 8a. The width of the transferring endless conveyor 8 is 1.8m. The endless belt 7 of the pressing transferring device 3 is in the form of foamed polyurethane (20-40mm thick and 1.8m wide) with a tough or strong driving belt 7a secured on the inner surface. This endless belt 7 is rotated by the driving motor Ma using the driving pulley 10a and the driven pulley 10b. The surface velocity of the wires endless conveyor 8 of the transferring device 4 and that of the foamed polyurethane endless belt 7 of the pressing transferring device 3 are the same. In order to dry the back of the wet mat 1, a heater 9 is installed near the upper surface of the endless belt 7 for heating the surface of the endless belt 7. In the pressurizing system 5 as shown in Fig. 4, one or several roller(s) 5a are placed in parallel with the width direction of the foamed polyurethane endless belt 7 and are rotatably mounted on bearings carried by a bearing bar 6. Pressurizing force is controlled by bolts 12 provided with external springs S and nuts 11. Fig. 2 is an enlarged drawing of part of Fig. 1 and Fig. 5 is a plan view of the nozzle 20. As shown in both drawings, the wires of endless conveyor 8 of the transferring device 4 are mounted on the nozzle 20 so that it touches and can move thereover by sliding, the nozzle 20 comprising a flange 20e at the circumferential part of the suction nozzle 20a, and the blowing nozzle 20b having flanges 20f, 20h in the circumferential part which is situated on each side of the suction nozzle 20a, to provide an integral unit. A suction pipe 20c mounting the suction nozzle 20a is connected to a suction opening of the blower Fa with a water drop separating device B in between. A pipe 20d mounting the blowing nozzle 20b is connected to the exhaust opening of the blower Fb. A heater H 1 is mounted between the blower Fb and said blowing pipe 20d. The action of dehydration/drying will now be explained. As shown in Fig. 1, the wet mat 1 (0.9m X 0.9m and 10mm thick) is placed on the wire endless conveyor 8 (1.8m wide) of the transferring device 4 with fibers la facing downwardly as shown (Fig.1). By activation of the motors Mb, Ma the wire endless conveyor 8 and the foamed polyurethane endless belt 7 are moved at the same velocity of 50mm/sec. in the direction shown by the arrow P in Fig. 1. In the position preceding the entry of the mat 1 between the wire endless conveyor 8 and the foamed polyurethane endless belt 7, the blower Fc is operated to send a high pressure air stream into the blowing pipe 14. This high pressure air stream passes through the heater H 2 and flows out as a heated jet stream from the blowing pipe 14 at the surface of the mat base material 1b at an angle opposite to the direction of movement of the mat 1 to blow away water on the surface of the mat base material 1b to dry it. The mat 1 is then held between the wire endless conveyor 8 and the foamed polyurethane endless belt 7. The mat 1 held between the conveyor 8 and belt 7 is transferred through the device, being pressed and held between the foamed polyurethane endless belt 7, which is pressurized from the inside (side remote from the mat 1) by the pressurizing device 5, and the wire endless conveyor 8. The nozzle 20 is placed so that it touches and slides on the surface of the mat fibers la with the wire endless conveyor 8 in between to dry the fibers la of the mat 1 and at the same time the remaining water on the surface of the mat base material 1b is removed by heating the outer surface T of the foamed polyurethane endless belt 7 by the heater 9 installed near the upper surface of the foamed polyurethane endless belt 7. The heater 9 used to dry the surface of the mat base material 1b can be selected from heaters such as a planar heater, a sheath or parabolic heater and a far infrared ray heater, providing the surface temperature of the foamed polyurethane endless belt 7 is raised to around 50-80°C by the heater. In drying the fibers la of the wet mat, as the mat 1 width is half the width of the nozzle 20, the open parts of the nozzles 20a, 20b are automatically closed by using a cushion or "moulding" characteristic of the foamed polyurethane endless belt 7 to prevent a decrease in the flowing velocity of the air jet stream and the negative pressure air stream that work on the mat 1. As shown in Fig. 6, the flowing volume pressure characteristic curve of a blower generally exhibits the characteristic that the pressure P decreases according to an increase in the flowing volume Q. Pressurizing force is controlled by the bolts 12 which are provided with external springs S and nuts 11 (Figs. 2, 4) so that the open parts of the nozzles 20 are completely closed by the foamed polyurethane endless belt 7, which are pressed from the inside by the rollers 5a of the pressurizing system 5. The mat 1 is held pressed between the wire endless conveyor 8 and the foamed polyurethane endless belt 7 and moved in the direction showed by the arrow P in Figs. 1 and 2. At the same time the blowers Fa, Fb are operated and air passes from the exhaust opening of the blower Fb to the blowing pipe 20d of the nozzle 20. High speed air jet stream R is blown from the blowing nozzle 20b and high speed negative pressure air stream Q from the suction nozzle 20a is applied to the fibers la of the mat 1 by the blower Fa. As the suction nozzle 20a and the blowing nozzle 20b are provided with flanges 20e, 20f respectively in their circumferential parts, the air jet stream is prevented from flowing into the negative pressure air stream directly in short circuit and the air jet stream does not flow out directly into the atmosphere, thus flowing to the roots of the fibers of the mat, to be sucked into the suction nozzle and uniting in the negative pressure air stream zone. A more detailed description follows. Water adhering to the fibers of the mat 1 is formed into minute water drops in the high speed negative pressure air stream by the multiplication or cumulative effect of the high speed air jet stream and the high speed negative pressure air stream, and the minute water drops are sucked and exhausted by the suction nozzle. In the experiment, negative pressure in the suction pipe 20c was -1200mmAq and pressure in the blowing pipe 20d was +1000mmAq. The temperature of the air jet stream is 40°C. The drying time of the wet mat (0.9mm X 0.9mm, 10mm thick, in which implanted fibers were 7mm long, and transfer velocity of the wet mat 4cm/sec.) is 22.5 seconds in this case. Electricity consumption for drying was 0.25kwH. It will be understood that "drying" of a wet mat means the condition that 95% of the water content of the mat soaked in water is removed. That drying time is several times as long when the blowing pressure (+500mmAq) and suction pressure (-500mmAq) are decreased and the drying temperature is 40°C. As a modified embodiment of the present Example, a drying device may be used in which the pressing transferring device 3 and the transferring device 4 of the present example are replaced, the wet mat 1 is put on the cushion foamed polyurethane endless belt 7 of the pressing transferring device 3 with fibers 1a facing upwardly and the nozzle 20 is installed inside the wire endless conveyor of the transferring device 4. Example 2 In the embodiment, a net-type endless conveyor 18 was used as shown in Fig. 7 instead of the wire endless conveyor of the transferring device 4 in Example 1. The net-type endless conveyor 18 used has a large opening ratio, for example, with a mesh of 10mm by 10mm. Material of the net-type endless conveyor 18 may be stainless steel wire, or a relatively strong, perforated, belt of synthetic resin such as polyethylene, etc. For the endless belt 7 of the pressing transferring device 3, expanded rubber with independent air cells and without a capacity to absorb water was used. For the pressurizing system 5, a conduit body 15 was used, as shown in Fig. 8, whose bottom is coated with polytetrafluoroethylene so that it slides smoothly on the driving belt 7a on the expanded rubber endless belt 7 mentioned above. The expanded rubber used for the cushion endless belt in the present embodiment is either natural rubber or synthetic rubbers, and soft, organic high polymers such as polyethylene, with a foamed body of these, and cushion or deformable hollow body belt 7b are used. The belt 7b is formed of rubber-coated cloth as shown in Fig. 9. The inside of the hollow body is divided by a plurality of reinforcing walls 7c. The belt 7b is trained between pulleys 10a, 10b and is rotated by driving a driving pulley 10a. Example 3 In the present embodiment, a cushion roller 30 (called rubber roller 30 hereinafter) is used instead of endless belt 7 (cf. Fig. 1) in the pressing transferring device 3 in Example 1 as shown in Figs. 10 and 11. The rubber roller 30 is driven by a driving motor Ma through a pulley 10m of a shaft 30a, a pulley 10n of the motor Ma and a belt V. The outer or circumferential velocity of the rubber roller 30 on rotation is the same as the linear velocity of the wire endless conveyor 8, and the wet mat 1 is held pressed between the rubber roller 30 and the surface of the nozzle 20 through the wire endless conveyor 8, and thus transferred and dried. A pressurizing device 60 of the rubber roller 30 comprises a bearing holder 31, which holds a bearing 30b that fits in a shaft 30a, and a rotatable frame 32 that holds it. Bolts 12a, 12b are installed at both ends of the rotatable frame 32 so that it can rotate freely. Pressurizing force to press the rollers 30 is controlled by springs S 1 , S 2 by controlling nuts and bolts 11a, 12a, and 11b, 12b. The rubber roller 30 is pressurized by compressing the pressurizing spring S by the nuts 12a, 12b of the pressurizing device 60. Owing to its elasticity, the rubber roller 30 is pressed against the open part of the nozzle 20 with the wire endless conveyor 8 in between to press the mat 1 against the nozzle 20 and at the same time to close up uniformly the surface of the open part of the nozzle 20 except the part where the mat 1 is located therebetween. Therefore the trapped part of the mat 1 comes into engagement with the surface of both nozzles, and the air jet stream and the negative pressure air stream work completely on the trapped part of the mat 1 to dehydrate/dry it. As the diameter of the wires 8a used in the wire endless conveyor 8 is small (0.5 - 1.0 mm ⊘), the air jet stream and the negative pressure air stream can pass between the nozzle 20 and the rubber roller 30, even when the mat is in position to dehydrate/dry the mat 1 without impeding the air jet stream and the negative pressure air stream. The air jet stream from the blowing pipe 14 (cf. Fig. 10) dries the back of the mat by strongly blowing away humidity and water drops at the back of the mat. In the drawing, H 2 is a heater. As heater 9 is installed near the outer circumference of the rubber roller 30 as shown in Fig. 10, it heats the surface of the rubber roller 30 which touches the back of the mat 1 and dries it. As the roller 34 filled with air comprises rubber coated cloth and is supported by a reinforcing frame 35 as shown in Fig. 12, it keeps an almost cylindrical shape around the shaft 33 substantially over all its length. The roller 34 is used similarly to the rubber roller 30 mentioned above. Example 4 A drying device of this embodiment which does not use a wire conveyor as a transferring conveyor in the dehydrating/drying part is explained referring to Figs. 13 and 14. In a downstream transferring device 4B, transferring rollers 10c are used in Fig. 13 and a transferring conveyor 8b is used in Fig. 14. It is a rapid dehydrating/drying device at low temperature comprising a pressing transferring device 3, which transfers a mat 1 by pressing and holding it between several transferring rollers 16a, 16a ... installed between an upstream transferring device 4A and a downstream transferring device 4B and a cushion or deformable endless belt 7, a pressurizing system 5 installed inside the endless belt 7 of said pressing transferring device 3, blowing nozzles 40a, 40b and suction nozzle 50 each installed between the transferring rollers 16a. The numbers of the blowing nozzles 40a, 40b, and the suction nozzles 50 can be selected as desired. As shown in Fig. 14, a mat 1 is placed with its fiber la side down and water on the upper surface of the mat base material 1b is blown away. This wet mat 1 is transferred by a transferring belt 8a, being pressed by a "cushion" or deformable endless belt 7, onto blowing nozzles 40a, 40b and suction nozzle 50 through transferring rollers 16a. An air jet stream blows from the blowing nozzles 40a, 40b to the mat fibers 1a, and at the same time water in the mat fibers and water adhering to the fiber roots is strongly extracted as water drops together with the jet stream, by the negative pressure air stream of the suction nozzle 50, which is adjacent to the blowing nozzles 40a, 40b. Thus the mat is dehydrated/dried and is transferred to the transferring rollers 10c or the transferring belt 8b of the downstream transferring device 4B. The transferring rollers 16a, flanges 20f of the blowing nozzles 40a, 40b and a flange 20e of the suction nozzle 50 are closely spaced. The mat 1 is pressed from above (as viewed) and held by the pressed endless belt 7 to close the open part of both nozzles (i.e. the open part of both nozzles which the mat does not cover (Fig. 15)) to prevent flowing out and flowing in of the jet stream and the exhaust stream from both nozzles. For this purpose, decrease of the blowing pressure and exhaust negative pressure is completely prevented in the part which the mat covers, i.e. the part where the blowing stream and the exhaust stream directly work on the wet fibers, and the strong air stream passes through the fibers as the flanges 20e, 20f prevent the air jet stream from flowing into the negative pressure air stream directly in a short circuit, exhausting humidity and water drops. Thus dehydration/drying is continuously performed. An endless belt of foamed polyurethane was used for an impact absorbing cushion, or deformable endless belt. The velocities of the foamed polyurethane endless belt 7, the transferring belts and the transferring rollers 16a, 16a... of the upstream and downstream stages transferring devices are identical. the transferring rollers 16a, 16a... are driven by the motor Mc. Example 5 As shown in Fig. 16, this embodiment is for use in drying a blanket, or an article to be dried without a lining of rubber, etc. i.e., with air passages in the direction of its thickness. The drying device is identical to that described in Example 1. A wet blanket is placed on an endless conveyor 8, comprising a plurality of wires. The endless conveyor 8 and a foamed polyurethane endless belt 7 with discrete air bubbles and without the ability to absorb water are moved at the velocity of 50mm/sec. in the direction shown by the arrow P in the drawing, and the wet blanket 1 is placed between the endless conveyor 8 and the foamed polyurethane endless belt 7. Nozzle 20 comprises a blowing nozzle 20b and a suction nozzle 20a. As the foamed polyurethane endless belt 7 presses the blanket 1 from the inside (from above as viewed in Fig. 16) it presses the blanket 1 all over the length of the nozzle 20 and closes even the open part of the nozzle 20 over which the blanket 1 does not extend. The belt 7 is transferred in the direction of the arrow P, pressing and holding the blanket, to perform dehydration/drying. The wet blanket 1 being transferred touches and slides on both nozzles 20a, 20b as shown in the drawing. A high speed air jet stream R from the blowing nozzle 20b blows strongly onto the surface of the wet mat 1 and at the same time high speed negative pressure air stream Q from the adjacent suction nozzle 20a acts on the blanket 1. Water in the blanket is transformed into minute water drops by the cumulative effect of the air jet stream and the high speed negative pressure air stream and is exhausted in a large volume by the suction nozzle 20a, and then exhausted to atmosphere. As the suction nozzle 20a and the blowing nozzle 20b are each provided with circumferential flanges, the air jet stream and the negative pressure air stream do not flow in a short circuit nor do they flow in/out directly to the atmosphere, but pass through the blanket to reach the level K of the foamed polyurethane endless belt 7. They then unite with the negative pressure air stream flowing zone and are sucked into the suction nozzle 20a as shown by the arrow in the drawing. Meanwhile water adhered to the inside of the blanket becomes minute water drops in the high speed negative pressure air stream and is exhausted by the suction nozzle 20a. In the experiment about 90% of water adhering to the insider of the blanket can be removed during dehydration/drying while the blowing pressure is 700mmAq, exhaust negative pressure is -1000mmAq and the blanket is transferred at the transferring velocity of 30mm/sec.. In this case one blowing nozzle and one suction nozzle are combined as shown in Fig. 16. Drying velocity can be further increased by increasing blowing pressure and exhaust pressure and by increasing the number of nozzles. The above examples have been explained using a mat or a blanket as an article to be dried. The invention can it will be understood, be used for drying, besides these items, wide carpets, garments, clothes such as fabrics, non-woven fabrics, glass fiber sheet, long size sheets such as synthetic fiber sheet, artificial grass, a thin mat of rush, a surface covering of a mat made of rush, papers, printed articles and fire hoses, including drying during manufacture of these articles. In the invention various mats narrower than the width W of the nozzle (cf. Fig. 11) provided with an exhaust opening and/or a blowing opening or mats of irregular shapes can be uniformly and, what is more, continuously rapidly dehydrated/dried at low temperature. When the width of a mat, an article to be dried, is narrower than the width W of the nozzle, a cushion conveyor closes the open part of the nozzle by distorting itself by its elasticity or deformability and transfers the mat. Therefore the air jet stream and the negative pressure air stream that contribute to drying of the wet mat do not decrease in their pressures and yet act on the mat strongly, sending in high speed dry air from the surface to deep inside the article to the fiber roots; the dry air unites with the negative pressure air stream and changes all the water adhered to the fiber surface, fiber gaps and fiber roots into minute water drops, which are exhausted by the suction nozzle, thus dehydrating/drying the mat: therefore the drying time can be greatly shortened and uniform dehydration/drying at low temperature can be performed without uneven drying nor damaging fibers and with wrinkles of the article to be dried smoothed out. The rapid dehydrating/drying device of the invention can largely decrease the consumption of water evaporation heat and prevent temperature decrease of the article to be dried. Therefore heating energy for drying can be greatly saved, thereby providing a great energy saving effect. What is more, the method and apparatus can perform drying at low temperature (below 50°C) and prevent heat deterioration of the material of the article to be dried. Compared with prior methods of dehydration by centrifugal force or of heating using a rotary drum, there is no damage of the article to be dried by friction of the article to be dried itself and by friction with the drying container, thus remarkably prolonging the life of the article to be dried. Moreover, dust adhering to the article to be dried, especially ticks, vermin and other injurious insects and their eggs, can be completely sucked up and removed in the high speed negative pressure air stream along with water drops; thus a cleaning and sanitizing effect can be obtained. It will be understood that the invention described herein with reference to the drawings is for drying a wet article to be dried such as a mat and/or a carpet, especially mats of various sizes with an impermeable rubber sheet lining or backing by making water, adhering to fiber gaps and fibers themselves of the mat and to the fiber implanted rubber sheet surface, into minute water drops using the effect of multiplication and combining a high speed air jet stream and a high speed negative pressure air stream so as not to decrease dry air flow in the fibers, using a suction nozzle and a blowing nozzle, holding under pressure the mat, the article to be dried, between a transfer conveyor and a cushion conveyor for transfer in pressing, and transferring the open part, where the mat is not situated, by pressurizing this using a cushioning characteristic of the cushion conveyor in an automatically closed condition. Minute water drops are sucked from the suction nozzle and exhausted without taking away water evaporation heat, thus rapid dehydration/drying at a low temperature is continuously performed. Efficiency of drying of an article to be dried is further increased when water adhering to the back of the mat where there are no implanted fibers is blown away using an air jet stream of a blowing nozzle and then the back of the mat is dried by contacting the heated cushion conveyor and the wet back of the mat.

Claims: A rapid dehydrating/drying device usable at low temperature, comprising a nozzle (20) having a blowing nozzle part (20b) and a suction nozzle part (20a) to provide a high speed air jet stream from the blowing nozzle part (20b) and a high speed negative pressure air stream from the suction nozzle part (20a), a deformable conveyor (7) adapted to close automatically the air jet stream and/or the negative pressure air stream from the nozzle (20) in case the width of the article to be dried is narrower than the width of both nozzle parts, and a transferring conveyor (8), the article (1) to be dried being transferred by being pressed and held between the deformable conveyor (7) and the transferring conveyor (8), in use the article to be dried being adjacent to or in sliding contact with both nozzle parts to dehydrate/dry the article to be dried by a cumulative effect of both high speed streams, thus preventing decrease of blowing pressure and/or sucking-out negative pressure by preventing leakage of the air jet stream and the negative pressure air stream. A rapid dehydrating/drying device according to Claim 1 characterised in that the deformable conveyor (7) that presses and transfers the article to be dried comprises an endless belt with a cushion-like effect or at least one elastic roller (30) whose resilience can be controlled. A rapid dehydrating/drying device according to Claim 2, characterised in that the endless belt (7), that presses and transfers the article to be dried, or the elastic roller(s) (30), are made of soft organic high polymers such as natural rubber, synthetic rubbers, polyurethane, silicone rubber, polyethylene, soft polyvinyl chloride or sponges made thereof or is respectively a belt-type cushion hollow body filled with air or a roller-type elastic hollow body (34). A rapid dehydrating/drying device according to claims 2 or 3, characterised by a pressurizing system which, in transferring the article (1) to he dried by pressing and holding it between the transferring conveyor (8) and the pressing transferring endless belt (7) for drying, by pressurizing and compressing at the pressing and holding part the endless belt (7) from the inside against the suction nozzle part (20a) and the blowing nozzle part (20b), automatically and continuously shuts the open part of both nozzle parts using the deformable property of the endless belt (7) to transfer and dry. A rapid dehydrating/drying device according to Claim 4, characterised in that in the pressurizing system comprises one or more rotary roller(s) (5a) mounted inside the endless belt (7) in the direction of its width whereby pressurizing can be controlled. A rapid dehydrating/drying device according to Claim 5, characterised in that the pressurizing system comprises a plate-type body (15) placed so that it presses and slides on the inner side of the endless helt (7). A rapid dehydrating/drying device according to Claim 4, characterised in that the pressurizing system provides a pressing force by fluid present on the pressing part of the inside of the endless belt (7) using pressurized air. A rapid dehydrating/drying device according to any preceding claim, characterised in that the transfer conveyor (8, 18) that transfers the article to be dried comprises respectively a plurality of wires (8a), or a net-type conveyor, or a porous belt, or a plurality of rollers (16). A rapid dehydrating/drying device according to any preceding claim, characterised in that a heating means (9) heats the endless belt (7) or the elastic roller (30) and in that one surface of the article (1) to be dried is dried by heating the endless belt (7) or the elastic roller (30). A rapid dehydrating/drying device according to any preceding claim, characterised in that there is a blowing nozzle (14) for drying the back of the wet article to be dried before being passed between the deformable conveyor (7) for pressing and the transferring conveyor (8) in order to blow away water adhering to the back of the article to be dried by an air jet stream or a heated air jet stream for drying.

Inventors: KUMA TOSHIMI, MASUZAKI TOSHIHIRO, KUMA, TOSHIMI, MASUZAKI, TOSHIHIRO
Applicants: KUMA TOSHIMI, SEIBU GIKEN KK, KABUSHIKI KAISHA SEIBU GIKEN, KUMA, TOSHIMI
Application year: 1995
Main classification: F26B5
IPC codes: F26B15, F26B5, F26B13