JP4899159B2 - Fabric processing method and apparatus using ammonia - Google Patents

Description

  The present invention relates to a cloth processing method and apparatus using ammonia that modifies a cloth by immersing a natural fiber cloth in an ammonia solution, and reduces the discharge amount of ammonia to the outside and increases the reuse rate. It is an improvement.

  Originally, cotton fibers are excellent fibers with a natural texture and high hygroscopicity, but have the disadvantage that they tend to wrinkle and shrink easily. Cotton fiber has a hollow shape and retains moisture inside the hollow, creating a highly hygroscopic property, but natural cotton fibers are not stable and contain water. The cross-section has different characteristics between the dry state and the dry state.

  In other words, the cotton fiber has a characteristic that it has a cross section like a hollow circular tube in a state of containing water, whereas it has a cross section like a collapsed circular tube in a dry state. Due to this characteristic, the shape of the cross section of the cotton fibers changes when they are in a dry state, and the cotton fibers are pulled together, so that the fabric is easily shrunk and wrinkled, and the tear strength is reduced.

  Cotton fibers, on the other hand, have a hollow circular cross section that contains water when they come into contact with an alkaline substance, and have the property of maintaining the shape of the hollow circular tube even when dried. Even with processing with caustic soda (called mercerization processing), a certain degree of reforming effect can be obtained, but liquid ammonia has less surface tension than caustic soda and can penetrate uniformly into the inside of the cellulose, so the reforming effect is high and the touch is good. Very high reforming effects such as softness, increased tear strength, dimensional stability after washing, and wrinkle recovery are observed.

In the following, the previously proposed invention will be introduced with respect to processing technology for fabric modification using liquid ammonia.
Patent Document 1 (Japanese Patent Laid-Open No. 52-128494) discloses a method and apparatus for recovering and reusing ammonia in an apparatus for treating cloth with liquid ammonia. In the present invention, after the ammonia gas generated from the processing chamber is cooled by a heat exchanger that performs non-contact heat exchange with cooling water, it is further cooled by contact heat exchange with liquid ammonia in a superheat reduction container. Thereafter, the ammonia gas is compressed by a compressor, liquefied by a condenser, and stored in an ammonia tank. This system is called a high pressure method because it uses high pressure gas compressed by a compressor.

  In addition, the gas containing ammonia gas discharged from the processing chamber and the steam chamber for steam cleaning of the cloth provided at the outlet of the processing chamber is cooled by non-contact heat exchange with liquid ammonia in the cleaning tower, and the contained ammonia is It is condensed and separated as liquid ammonia, and the uncondensed gas is sent to an incinerator or other disposal facility for processing.

  Patent Document 2 (Japanese Patent Laid-Open No. 04-308267) is a reforming technique that employs the same high-pressure method as Patent Document 1. In the present invention, after the work cloth is immersed in liquid ammonia in the working chamber, the work cloth impregnated with ammonia is heated to volatilize the ammonia attached to the work cloth. Thereafter, the work cloth is guided to a volatilization chamber, and high-temperature water vapor is applied to the work cloth in the volatilization chamber to evaporate ammonia gas attached to the work cloth.

  Moreover, after compressing the ammonia gas collect | recovered from the processing chamber with the compressor, liquid ammonia is produced | generated with a condenser and the produced | generated liquid ammonia is stored in a storage tank. The liquid ammonia stored in the storage tank is cooled by a cooler and then returned to the liquid ammonia tank in the processing chamber. Ammonia gas generated in the volatilization chamber is absorbed by absorbed water with a scrubber and then treated with wastewater treatment equipment provided outside the system.

  Next, in Patent Document 3 (Japanese Patent Application Laid-Open No. 08-245217), after the ammonia gas generated in the processing chamber is cooled by a cooler, liquid ammonia is generated by a condenser, and the liquid ammonia is transferred to a liquid ammonia tank in the processing chamber. It is returning. That is, a low pressure method that does not use a compressor is adopted. Since this method requires a cooling medium having a predetermined temperature difference with respect to ammonia gas, the system efficiency is inferior to that of the high-pressure method. In addition, the ammonia gas generated from the volatilization chamber is absorbed into water by a water absorption device, the treated water that has absorbed the ammonia gas is separated by an ammonia separation device equipped with a distillation device, and the ammonia gas is returned to the cooler. ing.

  Patent Document 4 (Japanese Patent Application Laid-Open No. 08-60525) discloses that treated water in which both ammonia gas generated from a processing chamber and ammonia gas generated from a volatilization chamber are absorbed in water by a water absorption device and then the ammonia gas is absorbed. The ammonia gas is separated in the rectification column. The separated ammonia gas is compressed by a compressor, liquid ammonia is generated by a condenser, and the generated liquid ammonia is returned to the processing chamber. Then, low-concentration ammonia gas that has not been absorbed by the absorption tower is sent to an air purger to be separated from air.

JP-A-52-128494 Japanese Patent Laid-Open No. 04-308267 Japanese Patent Laid-Open No. 08-245217 Japanese Patent Laid-Open No. 08-60525

In this type of cloth processing technology, ammonia is toxic, so it is necessary to eliminate leakage outside the apparatus system. From the economical aspect, it is desirable to reduce the consumption of ammonia as much as possible and to recycle it.
In the invention disclosed in Patent Document 1, condensed water containing ammonia is discharged from a non-contact type heat exchanger. Moreover, since the non-condensable gas that is not liquefied in the washing tower is discharged to an external incinerator or other disposal facility, the ammonia recovery rate is considered to be low.

  In the invention disclosed in Patent Document 2, the ammonia gas generated in the volatilization chamber is absorbed into the absorption water by the scrubber, and is then processed by the wastewater treatment facility provided outside the system. Not very expensive.

  Moreover, since the invention disclosed in Patent Document 3 employs the low pressure method, the thermal efficiency of the system is originally not good. Moreover, since the system is composed of many devices that require a cold heat source and a heating source, the thermal efficiency of the entire system is further reduced.

  Although the invention disclosed in Patent Document 4 can obtain a high recycling rate of ammonia, there is a problem that the entire system becomes complicated and large, and the equipment and maintenance costs are expensive.

  In view of the problems of the prior art, the present invention increases the ammonia recovery rate in a processing technique for fabric modification using ammonia, that is, enables a recovery rate of 96% or more, and the entire system. It is intended to increase the thermal efficiency of the compressor and prevent damage to the compressor due to moisture contained in the gas to be treated.

In order to achieve this object, the cloth processing method using ammonia of the present invention,
In the cloth processing method using ammonia, after the work cloth is immersed in liquid ammonia, the ammonia-impregnated work cloth is heated to volatilize ammonia.
After immersing the work cloth in a liquid ammonia tank in the processing chamber, heating the ammonia-impregnated work cloth to evaporate ammonia from the work cloth; and
A washing step of washing the work cloth by evaporating ammonia by blowing steam to the work cloth sent from the working chamber to the volatilization chamber;
A dehumidification step of cooling and dehumidifying the gas to be treated containing high-concentration ammonia gas recovered from the processing chamber;
A liquefaction refeeding step of generating liquid ammonia in a condenser after the dehumidified gas to be processed is at a high pressure with a compressor, and supplying the generated liquid ammonia to the processing chamber;
An absorption step of introducing the gas to be treated containing the low-concentration ammonia gas recovered from the volatilization chamber to the absorption tower and absorbing the ammonia gas in the absorption liquid;
A distillation step of producing a high concentration ammonia gas by distilling the absorption liquid having absorbed ammonia in the absorption tower in a distillation tower, and returning the high concentration ammonia gas to the dehumidification step;
A cleaning neutralization step of neutralizing ammonia gas contained in the gas to be treated by washing the gas to be treated that has come out of the absorption tower with a cleaning solution containing an acid, and
The ammonia gas decompressed from the condenser to the vicinity of the suction pressure of the compressor via the pressure reducing valve on the upstream side of the compressor is added to the gas to be collected collected from the processing chamber to reduce the suction amount of the compressor. By adjusting, the suction pressure of the compressor is adjusted and the inside of the processing chamber is adjusted to a slight negative pressure.

As an apparatus for carrying out the method of the present invention, the apparatus of the present invention is:
In a cloth processing apparatus using ammonia for evaporating ammonia by heating the ammonia-impregnated work cloth after immersing the work cloth in liquid ammonia,
A processing chamber equipped with a liquid ammonia tank for immersing the work cloth and a heating chamber for heating the ammonia-impregnated work cloth to volatilize ammonia from the work cloth;
A volatilization chamber for cleaning ammonia by spraying steam on the work cloth sent from the processing chamber;
Means for cooling and dehumidifying the gas to be treated containing high-concentration ammonia gas recovered from the processing chamber;
A compressor for compressing the dehumidified gas to be processed to a high pressure, and a condenser for condensing the compressed gas to be processed to generate liquid ammonia;
A supply path for supplying the liquid ammonia generated by the condenser to the liquid ammonia tank of the processing chamber via the liquid ammonia storage tank;
An absorption tower that absorbs a gas to be treated containing low-concentration ammonia gas recovered from the volatilization chamber into an absorption liquid;
A distillation column for distilling the absorption liquid that has absorbed ammonia in the absorption tower to produce a high concentration ammonia gas, and a recovery path for supplying the high concentration ammonia gas to the cooling and dehumidifying means;
A cleaning tower for neutralizing ammonia gas contained in the gas to be treated by washing the gas to be treated that has come out of the absorption tower with a cleaning liquid containing an acid;
Ammonia depressurized from the condenser to the vicinity of the suction pressure of the compressor through the pressure reducing valve on the upstream side of the cooling and dehumidifying means in the flow path of the gas to be processed containing the high concentration ammonia gas recovered from the processing chamber And a pressure adjusting path for adding gas.

  In order to prevent leakage of ammonia gas in the processing chamber, it is necessary to connect to a slight negative pressure of −40 to −80 Pa (gauge pressure). Therefore, in the present invention, the ammonia gas is supplied from the condenser via the pressure adjustment path upstream of the cooling and dehumidifying means with respect to the gas to be processed containing the high concentration ammonia gas recovered from the processing chamber. Since the flow path of the gas to be treated is in communication with the suction port of the compressor, when the pressure reducing valve provided in the pressure adjusting path is opened, the ammonia gas whose pressure has been reduced to the vicinity of the suction pressure of the compressor is Added to the gas flow path.

  Thus, the suction pressure of the compressor can be controlled, and the pressure in the processing chamber can be controlled with high accuracy. When the suction pressure of the compressor or the pressure in the processing chamber is high, the pressure reducing valve is closed, and when the pressure is low, the pressure reducing valve is opened. Thereby, the amount by which the compressor collects the gas to be processed from the processing chamber can be adjusted, and the pressure in the processing chamber is kept constant.

  The to-be-processed gas recovered from the processing chamber is then cooled and dehumidified on the upstream side of the compressor. By causing the compressor to suck the dehumidified gas to be processed, damage to the compressor due to moisture contained in the gas can be prevented. Moreover, since the weight per unit volume of the gas to be processed can be increased by cooling the gas to be processed sucked into the compressor in advance, the system efficiency can be improved.

  In the method of the present invention, preferably, a screw compressor is used as the compressor, and in the liquefaction refeeding step, a part of the liquid ammonia generated by the condenser is taken out through the pressure reducing valve to the reduced pressure region, and the reduced liquid ammonia The liquid ammonia supplied from the condenser to the liquid ammonia storage tank is indirectly heat-exchanged by a liquid cooler, and the ammonia gas evaporated in the reduced pressure region is sucked into the intermediate stage portion of the screw compressor, whereby the liquid ammonia The liquid ammonia supplied to the storage tank may be supercooled.

  Thus, since the liquid ammonia stored in the liquid ammonia storage tank can be supercooled, the liquid ammonia is prevented from being gasified inside the liquid ammonia storage tank or the supply path for supplying liquid ammonia to the liquid ammonia tank in the processing chamber, Liquid ammonia can be supplied efficiently. By utilizing the pressure of the intermediate stage of the screw compressor in this way, a part of the liquid ammonia in the condenser is decompressed and expanded to the pressure of the intermediate stage so that it can be used as a cold heat source. The liquid ammonia supplied from the vessel to the liquid ammonia storage tank can be cooled without requiring another cold heat source. Therefore, the thermal efficiency of the system can be improved.

  In addition, liquid ammonia generated in the condenser in the liquefaction refeeding process is supplied to the processing chamber via the liquid ammonia storage tank, and the gas to be processed recovered from the processing chamber in the previous stage of the dehumidification process is upstream of the compressor. The pressure in the liquid ammonia storage tank may be adjusted by adding ammonia gas decompressed and expanded from the liquid ammonia storage tank to the vicinity of the suction pressure of the compressor via a pressure reducing valve.

  In the device of the present invention, a liquid ammonia storage tank is provided on the downstream side of the condenser, and the liquid ammonia generated by the condenser is temporarily stored in the liquid ammonia storage tank, whereby the behavior of the liquid ammonia can be stabilized.

  The supply of liquid ammonia from the liquid ammonia storage tank to the liquid ammonia tank in the processing chamber is usually performed by setting the liquid ammonia storage tank at a higher position than the processing chamber, and by the difference in height and the pressure difference between the two. Therefore, the required amount of liquid ammonia can be stably supplied by adjusting the pressure of the liquid ammonia storage tank as described above in consideration of the pressure loss of the supply path for supplying liquid ammonia from the liquid ammonia storage tank to the processing chamber. .

  In this invention, the to-be-processed gas containing the low concentration ammonia gas collect | recovered from the volatilization chamber is made to absorb in an absorption liquid with an absorption tower. And the absorption liquid which absorbed ammonia from the to-be-treated gas in the absorption tower is distilled in the distillation tower to produce high concentration ammonia gas, and the high concentration ammonia gas is returned to the dehumidification step performed upstream of the compressor. Therefore, the recycling rate of ammonia can be increased.

  Leakage of ammonia gas to the outside can be prevented by setting the inside of the processing chamber and the volatilization chamber to a pressure slightly lower than atmospheric pressure. In the present invention, since the processing chamber communicates with the suction port of the compressor, the processing chamber can be held at a negative pressure by the suction pressure of the compressor. If a suction means for sucking the gas to be treated from which the ammonia component is substantially removed is provided downstream of the absorption tower, the suction means and the volatilization chamber communicate with each other through the absorption tower. Negative pressure can be set. Thus, in the apparatus of the present invention, the processing chamber and the volatilization chamber can be easily set to a negative pressure by the suction pressure of the compressor and the suction means provided on the downstream side of the absorption tower.

  Furthermore, it is preferable to provide an outside air inlet capable of adjusting the flow rate upstream of the suction means. By adjusting the flow rate of the outside air inlet, the degree of negative pressure in the volatilization chamber can be appropriately adjusted.

  In the apparatus of the present invention, preferably, a seal box provided at the entrance and exit of the work cloth in the processing chamber and the volatilization chamber, and a second recovery path for supplying a gas containing ammonia gas in the seal box to the absorption tower. A bypass passage with a shut-off valve that guides the gas to be treated containing the low-concentration ammonia gas derived from the volatilization chamber and the gas containing the ammonia gas in the seal box to the upstream side of the suction means by bypassing the absorption tower; It is advisable to provide

  Thus, by providing the seal box, the ammonia gas leaking from the entrance and exit of the work cloth in the processing chamber and the volatilization chamber is received in the seal box, and the gas containing the ammonia gas in the seal box is taken into the absorption tower. By this, it can prevent that ammonia gas leaks outside from a processing chamber or a volatilization chamber. Further, by providing the bypass passage, the ammonia-containing gas led out from the volatilization chamber at the time of failure of the absorption tower and the ammonia-containing gas in the seal box can be directly sent to the washing tower by bypassing the absorption tower.

  According to the present invention, the ammonia component is removed from the gas to be treated containing high-concentration ammonia gas generated in the processing chamber, supplied to the processing chamber as liquid ammonia, and low-concentration generated in the volatilization chamber and the seal box. By treating the gas to be treated containing ammonia gas with an absorption tower and a distillation tower, the ammonia content contained in the gas to be treated can be removed and supplied to the processing chamber, so that the ammonia recycling rate is 96%. This can be improved.

  Moreover, the thermal efficiency of the system can be increased by removing the ammonia component from the gas to be processed generated in the processing chamber by a high-pressure method using a compressor. In addition, by pre-cooling and dehumidifying the gas to be supplied to the suction port of the compressor, the compressor can be prevented from being damaged, and the gas to be processed is cooled to increase the weight per unit volume. Therefore, the thermal efficiency of the system can be further improved.

  In addition, the ammonia gas decompressed from the condenser to the vicinity of the suction pressure of the compressor through the pressure reducing valve on the upstream side of the compressor is added to the gas to be processed collected from the processing chamber to adjust the suction amount of the compressor Thus, the suction pressure of the compressor can be adjusted, and the processing chamber can be adjusted to a slight negative pressure with high accuracy.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.
(Embodiment 1)

  Next, a first embodiment in which the present invention is applied to cotton fabric processing will be described with reference to FIGS. FIG. 1 is a schematic diagram showing the overall configuration of the present embodiment. In FIG. 1, the processing system of the present embodiment mainly includes a processing chamber 1 and a volatilization chamber 2, an ammonia recovery system 3, and an absorption processing system 4. The cotton cloth c is introduced into the processing chamber 1 after the dust attached to the surface is removed by the air cleaner 5. In the processing chamber 1, the cotton cloth c is first immersed in liquid ammonia in the liquid ammonia tank 6. The cotton cloth c impregnated with liquid ammonia in the liquid ammonia tank 6 is wound around the heating cylinder 7. Heating steam is supplied to the inside of the heating cylinder 7, and the cotton cloth c is heated by the heating cylinder 7, whereby most of the ammonia impregnated in the cotton cloth c is evaporated.

  Thereafter, the cotton cloth c is transferred to the volatilization chamber 2 through the seal box 12. In the volatilization chamber 2, the cotton cloth c is cleaned by spraying high-temperature (for example, 98 ° C.) water vapor, and the liquid ammonia remaining on the cotton cloth c is blown off together with the vapor to be gasified. The cotton cloth c from which ammonia has been sufficiently removed in the volatilization chamber 2 exits the volatilization chamber 2 and is then washed in the washing tank 8. After that, the product is wound around a number of drying cylinders 9 in order and dried to obtain a processed product.

  The to-be-treated gas a containing high-concentration ammonia gas generated in the heating cylinder 7 is separated in the ammonia recovery system 3 and returned to the liquid ammonia tank 6 in the processing chamber 1 as liquid ammonia f. Further, the gas to be processed b containing the low concentration ammonia gas generated in the volatilization chamber 2 is processed by the absorption processing system 4. Moreover, seal boxes 11 to 13 are provided at the entrances and exits of the cotton cloth c in the processing chamber 1 and the volatilization chamber 2 to prevent leakage of ammonia. Seal gas in these seal boxes is sucked into the absorption processing system 4. As a result, the inside of the seal box is maintained at a slightly lower negative pressure than the atmosphere.

  Next, the configuration of the ammonia recovery system 3 will be described with reference to FIG. In FIG. 2, the low-pressure (0.05 to 0.07 MPa) and medium temperature (−20 to + 25 ° C.) liquid ammonia stored in the liquid ammonia storage tank 21 passes through the pipe line 22, and reaches the liquid surface of the liquid ammonia tank 6. Through the controlled expansion valve 23, the pressure is reduced to a low pressure (−60 Pa; gauge pressure) and a low temperature (−33.4 ° C.) and supplied to the liquid ammonia tank 6 disposed in the processing chamber 1. In the processing chamber 1, the ammonia gas evaporated by contact with the cotton cloth c in the liquid ammonia tank 6 and the ammonia gas evaporated from the cotton cloth c heated by the heating cylinder 7 are filled at a high concentration under low temperature and low pressure.

  The low-pressure gas to be processed a leaves the processing chamber 1, passes through the recovery path 24, and is sent to the suction port of the compressor 28 via the cold water cooler 25, the brine cooler 26, and the drain separator 27 in order. The temperature of the gas to be processed a is 70 to 80 ° C. at the outlet of the processing chamber, and the medium temperature and low pressure gas a to be processed at 30 to 40 ° C. flows at −60 Pa (gauge pressure) in the recovery path 24. The gas to be treated a is moist due to the moisture contained in the cotton cloth c.

  When the gas to be treated a is sucked into the compressor 28 in this state, the possibility of damage to the compressor increases. Accordingly, the gas to be treated a passes through the cold water cooler 25 and the brine cooler 26 on the upstream side of the compressor 28, and is cooled with cold water (7 ° C.) and ethylene glycol brine (−15 ° C.) in the respective coolers. As a result, the gas to be treated a is cooled to, for example, 15 ° C. at the outlet of the cold water cooler 25 and is cooled to about −10 ° C. at the outlet of the brine cooler 26 to dehumidify the gas to be treated a. The cold water cooler 25 and the brine cooler 26 are provided with a refrigerator (not shown) for cooling the cold water and the brine. The drain water d separated from the gas to be treated a by the cold water cooler 25, the brine cooler 26 and the drain separator 27 is sent to the first absorption tower 44a of the absorption treatment system 4 described later.

  The compressor 28 includes a low-pressure screw compressor 28a and a high-pressure screw compressor 28b, and includes a single-shaft two-stage screw compressor driven by an electric motor 28c. The to-be-processed gas a having been dehumidified is sucked into the suction port of the low-pressure screw compressor 28a, compressed in two stages, and pressurized to a high pressure (about 1.7 MPa) and a high temperature (70 ° C.) to increase the pressure. It discharges from the discharge port. Since the gas to be treated a that has become high temperature and pressure contains the lubricating oil used in the compressor 28, the lubricating oil is removed by the oil separator 29. The degassed gas a is heat-exchanged with the cooling water w in the condenser 30 and becomes high-temperature and high-pressure liquid ammonia.

  Non-condensable gas (air) is also carried into the processing chamber 1 by adhering to the cotton cloth c. Since the ammonia gas is flammable, the inert gas (nitrogen gas) is filled from the supply pipe 14 with the on-off valve 15 shown in FIG. The gas g containing the inert gas is discharged from the condenser 30 during operation of the present processing system to the first absorption tower 44a of the absorption processing system 4 through the pipe line 31 provided with the purge valve 31a.

  A liquid cooler 32 is provided on the downstream side of the condenser 30, and the liquid ammonia discharged from the condenser 30 is sent to the liquid cooler 32 to be cooled and then supplied to the liquid ammonia storage tank. That is, a part of the liquid ammonia in the condenser 30 is sent to the liquid cooler 32 through the pipe line 34 and the pressure reducing valve 34a. In the liquid cooler 32, the part of the liquid ammonia is indirectly heat exchanged with the other liquid ammonia sent from the condenser 30, evaporates by removing latent heat of evaporation from the other liquid ammonia, and then passes through the pipe 35. Then, it is sent to the suction port of the high-pressure screw compressor 28b of the compressor 28.

  On the other hand, the other liquid ammonia is supercooled and supplied to the liquid ammonia storage tank 21 via the pipe line 36. In this way, a part of the liquid ammonia in the condenser 30 is decompressed and expanded using the pressure at the suction port of the high-pressure screw compressor 28b (the pressure at the intermediate stage of the compressor 28), thereby forming a cold heat source. The other liquid ammonia in it can be supercooled.

  The pressure in the processing chamber 1 is maintained at a negative pressure slightly lower than the atmospheric pressure by being connected to the suction port of the compressor 28. Incidentally, the pressure in the processing chamber 1 during normal operation is controlled to −40 to −80 Pa (gauge pressure). Leakage of ammonia from the processing chamber 1 is prevented by setting the inside of the processing chamber 1 to a negative pressure.

  The condenser 30 is provided with a pressure reducing valve 37a, and a bypass pipe 37 is provided to connect the condenser 30 and the recovery passage 24 through which the gas to be processed a flows. The liquid ammonia storage tank 21 is provided with a pressure reducing valve 38a. A bypass line 38 connecting the liquid ammonia storage tank 21 and the recovery path 24 is provided. The gas to be processed a having a reduced pressure is supplied from the condenser 30 through the pipe 37 to the recovery passage 24 through the pressure reducing valve 37a. At this time, the gas to be treated a expands under reduced pressure near the suction pressure of the low-pressure screw compressor 28a.

  Ammonia gas is also supplied from the liquid ammonia storage tank 21 to the recovery path 24 through the bypass line 38 and the pressure reducing valve 38a. By adjusting the amount of ammonia gas supplied from the condenser 30 and the liquid ammonia storage tank 21 to the recovery path 24, the pressure in the liquid ammonia storage tank 21 can be made constant. In consideration of the pressure loss of the supply path for supplying liquid ammonia from the liquid ammonia storage tank 21 to the processing chamber 1, the liquid ammonia is disposed in the processing chamber 21 by adjusting the pressure of the liquid ammonia storage tank in this way. A necessary amount can be stably supplied to the ammonia tank 6.

  Next, the configuration of the absorption processing system 4 will be described with reference to FIG. In FIG. 3, the dilution water stored in the dilution tank 43 passes through the second absorption tower 44 b and the first absorption tower 44 a in this order, absorbs ammonia from the gas to be treated in the absorption tower, and the low water storage tank 41. Stored as ammonia water. The dilution water stored in the cold water storage tank 41 is supplied to the distillation column 51 by the pump 46, and the low concentration ammonia gas after the high concentration ammonia gas is distilled in the distillation column 51 returns to the dilution tank 43.

The gas b to be treated in the volatilization chamber 2 is composed of about 10 to 20% by weight of ammonia and about 80 to 90% by weight of steam. Since the gas to be treated b contains only low-concentration ammonia gas, treatment with the ammonia recovery system 3 is inefficient. Therefore, the gas to be treated b is guided to the absorption treatment system 4, the ammonia gas is absorbed into water by the absorption treatment system 4, and high concentration ammonia is separated and regenerated from the generated ammonia water.

  The pipe 16 to which the gas to be treated b generated in the volatilization chamber 2 is supplied, the pipe 17 to which the seal gas e supplied from the seal boxes 11 to 13 is supplied, and the condenser 30 are sent at the initial stage of operation. The pipe line 31 to which the gas g containing the inert gas is supplied joins the pipe line 40. And it cools by indirect heat exchange with the cooling water c in the cooler 42. Next, these gases to be treated are first supplied from the pipe line 40 to the first absorption tower 44a. In the first absorption tower 44a and the second absorption tower 44b, a circulation path for dilution water is formed by circulation pipes 47a and 47b provided with pumps 48a and 48b. And while dilution water forms a downward flow, to-be-processed gas forms an upward flow and mutually countercurrent-contacts, absorption efficiency is improved.

  The gases to be treated b, e, and g are absorbed in diluted water by the first absorption tower 44a and then sent to the second absorption tower 44b, where the ammonia content is again absorbed in the diluted water. On the other hand, since the dilution water is sent to the first absorption tower 44a after passing through the second absorption tower 44b, in the first absorption tower 44a, the gas to be treated having the highest ammonia concentration in the absorption treatment system 4 and the highest By contacting an aqueous ammonia solution having an ammonia concentration, a high concentration aqueous ammonia solution (about 10% by weight) is generated.

  Since water generates heat by absorbing ammonia, the water sprayed in the absorption tower is cooled by indirect heat exchange with the cooling water w by the cold water coolers 49a and 49b. The dilution water in the dilution tank 43 is stored with an ammonia concentration of 1 to 3% by weight. That is, as a result of the evaporation of the ammonia gas in the distillation column 51, the concentration of the ammonia water accumulated in the lower portion of the distillation column 51 becomes 1 to 3 wt%, and it is sent to the dilution tank 43.

  Diluted water that has absorbed ammonia and stored in the safe water storage tank 41 is sent from the safe water storage tank 41 to the distillation column 51, and before that, heat exchange is performed with the high-temperature diluted water output from the distillation column 51 by the preheater 52. After being preheated, it is put into the distillation column 51. In the distillation column 51, a circulation flow path is formed in which a part of the dilution water introduced into the distillation column 51 is supplied to the reboiler 53 and heated by the reboiler 53 and then returned to the distillation column 51. Dilution water charged into the distillation column 51 is distilled and separated into vaporized high-concentration ammonia gas and low-concentration aqueous ammonia solution.

  The high-concentration ammonia gas vaporized in the distillation column 51 is sent from the upper outlet of the distillation column 51 to the partial condenser 53, and is cooled and liquefied by a cooler (not shown) provided in the partial condenser 53. After the liquid is removed by the partial condenser 53, it is sent to the brine cooler 26 of the ammonia recovery system 3 through the pipe 55. The high-concentration ammonia gas sent to the brine cooler 26 is cooled by the brine cooler 26, after which moisture is removed by the drain separator 27, and then sucked into the compressor 28. The liquid component separated from the ammonia gas by the partial condenser 53 is returned to the distillation column 51.

  On the other hand, the low-concentration aqueous ammonia solution from which ammonia has been removed by distillation is cooled by indirect heat exchange with the dilution water before being fed into the distillation column 51 by the preheater 52 by the pump 54, and further indirect heat exchange with the cooling water w. After cooling through the drainage cooler 56, it is returned to the dilution tank 43. The low-concentration aqueous ammonia solution returned to the dilution tank 43 is sent again to the second absorption tower 44b and is used for absorption of ammonia from the gas to be treated.

  The gas to be processed that has come out from the upper part of the second absorption tower 44 b is sucked into the blower 61 shown in FIG. 4 through the pipe line 60 and sent to the cleaning tower 62 through the blower 61. FIG. 4 is a block diagram showing an abatement system downstream of the absorption tower. In FIG. 4, the washing tower 62 is supplied with sulfuric acid from a sulfuric acid storage tank 63 by a pump 64 and supplied with makeup water from a pipe 68. In the cleaning tower 62, a circulation flow of an aqueous solution containing sulfuric acid is formed by a circulation flow path 70 provided with a pump 70a.

  The gas to be treated forms a flow that opposes the aqueous solution containing sulfuric acid in the cleaning tower 62, thereby improving the contact efficiency with the aqueous solution. And the trace amount ammonia content contained in to-be-processed gas is absorbed by this aqueous solution. The aqueous solution that has absorbed the ammonia component is sent to a neutralization tank 65 equipped with a stirrer 66 and neutralized with sulfuric acid in the neutralization tank 65 to be detoxified. Thereafter, the aqueous solution is sent by a pump 67 to a wastewater treatment facility (not shown).

  Further, the pipeline 40 is provided with a bypass pipeline 72 that bypasses the absorption towers 44 a and 44 b on the upstream side of the first absorption tower 44 a and is connected to the pipeline 60, and is blocked by the bypass pipeline 72. A valve 73 is interposed. Accordingly, when an abnormality or failure occurs in the system of the first absorption tower 44a, the second absorption tower 44b, or the distillation tower 51, the shutoff valve 73 can be opened to bypass the gas to be processed in the absorption system. Therefore, it is possible to prevent the ammonia component from leaking from the absorption processing system 4 in which an abnormality has occurred.

  In the system of this embodiment, ammonia gas released from a safety valve or the like is sent to the dilution tank 43 and reused in the ammonia absorption process. Therefore, in this embodiment, the ammonia discharged out of the system includes only a small amount of ammonia contained in the gas to be treated sent to the cleaning tower 62 and only the ammonia remaining in the cotton cloth c cleaned in the volatilization chamber 2. Become. Therefore, according to this embodiment, 96% or more of ammonia can be recovered and reused.

  In the present embodiment, the pressure control of the volatilization chamber 2 and the seal boxes 11 to 13 is performed by suctioning the gas to be processed using a blower 61 made of a corrosion-resistant material. In this case, a pipe line 69 that is open to the atmosphere and capable of introducing the atmosphere is connected to the pipe line 60, and by adjusting the opening of the pressure regulating valve 71 interposed in the pipe line 69, the inlet side of the blower 61 is connected. The negative pressure in the pipe line 60 can be adjusted. That is, even if the blower 61 is rotated with constant power, the negative pressure in the pipe line 60 can be controlled by the pressure adjusting valve 71. By adjusting the negative pressure of the pipeline 60 to −400 Pa, the pressure of the volatilization chamber 2 is controlled to be −80 Pa (−70 Pa to −90 Pa during system operation). Further, the pressure of the seal boxes 11 to 13 is controlled to be −100 Pa (−90 Pa to −110 Pa during system operation).

  In this embodiment, a liquid ammonia storage tank 21 is provided, and the liquid ammonia storage tank 21 is replenished with liquid ammonia from the outside. Further, nitrogen gas is supplied from the pipeline 14 to the processing chamber 1 at the start of operation, and the processing chamber 1 is filled with nitrogen gas to prevent combustion of high-concentration ammonia gas. It is preferable to provide a sensor for detecting the ammonia concentration and oxygen concentration of the ammonia and to constantly monitor the ammonia concentration and oxygen concentration.

  In the present embodiment, the cold water cooler 25 of the ammonia recovery system 3, the cold water coolers 49 a and 49 b of the first absorption tower 44 a and the second absorption tower 44 b, the other coolers 42 and 56, and the coolers provided in the condenser 53. In the cooling tower, the cooling water for the refrigerator and the cooling water for producing the brine used in the brine cooler 26 are manufactured by a cooling tower and supplied by a pump.

Further, since the gas to be processed a containing the high-concentration ammonia gas generated in the processing chamber 1 is directly compressed by the compressor 28 and condensed by the condenser 30, the liquid ammonia is generated, so that the system can be simplified. At the same time, the thermal efficiency of the system can be improved.
Further, a part of the liquid ammonia in the condenser 30 is supplied to the intermediate stage part of the compressor (the suction port of the high-pressure screw compressor 28b) via the pipe line 34 provided with the pressure reducing valve 34a. The system is further expanded by reducing the pressure using the pressure, and the other liquid ammonia in the condenser 30 is supercooled by using the ammonia gas expanded under reduced pressure as a cold heat source.

  Further, a part of the ammonia gas in the condenser 30 is added to the recovery passage 24 via the bypass conduit 37 provided with the pressure reducing valve 37a, thereby adjusting the suction pressure of the screw compressor 28, and thus in the processing chamber 1. The atmosphere can be accurately adjusted to a slight negative pressure.

  In addition, by adding a part of the ammonia gas in the liquid ammonia storage tank 21 to the recovery path 24 via the bypass line 38 provided with the pressure reducing valve 38a, the pressure in the liquid ammonia storage tank 21 can also be adjusted. The pressure difference between the pressure chamber 21 and the processing chamber 1 is maintained at a predetermined pressure, so that liquid ammonia can be stably supplied from the liquid ammonia storage tank 21 to the processing chamber 1.

  The to-be-processed gas a flowing through the recovery path 24 is further cooled by the cold water cooler 25 and the brine cooler 26, and the moisture is removed and supplied to the compressor 28. Therefore, there is no possibility of causing damage to the compressor. Further, in the present embodiment, since the liquid level adjustment valve 36a is provided in the pipe line 36 that sends the liquid ammonia generated in the condenser 30 to the liquid ammonia storage tank 1, the amount of liquid ammonia in the condenser 30 increases. Then, the liquid level adjustment valve 36 a can be automatically opened to supply liquid ammonia to the liquid ammonia storage tank 21. Further, since the liquid ammonia storage tank 21 is maintained at a low pressure, liquid ammonia can be continuously supplied to the liquid ammonia storage tank 21 from the outside. Accordingly, the cotton cloth c can be processed efficiently.

In addition, the cotton fiber ammonia processing machine is a casing exceeding 100 m ³ , and the armor is weak, so fine pressure control is required. In the present embodiment, the processing chamber 1 is communicated with the suction port of the compressor 28, and the amount of gas recovered from the processing chamber 1 is adjusted by the pressure reducing valve 37a, thereby facilitating the slight negative pressure control of the processing chamber 1. In addition, the volatilization chamber 2 and the seal boxes 11 to 13 are communicated with the blower 61, and the fine negative pressure control of the volatilization chamber 2 and the seal boxes 11 to 13 is facilitated by the pressure adjustment valve 71 provided on the inlet side of the blower 61. Yes.

  According to the present invention, it is possible to improve the recovery rate of ammonia and improve the thermal efficiency of the system when performing processing for reforming a work cloth such as cotton cloth using ammonia, thereby simplifying the system configuration. It is what.

It is a block diagram which shows the whole structure of 1st Embodiment of this invention. It is a systematic diagram which shows the structure of the ammonia collection | recovery system | strain 3 of the said 1st Embodiment. It is a systematic diagram which shows the upstream of the absorption processing system | strain 4 of the said 1st Embodiment. It is a systematic diagram which shows the downstream from the absorption tower of the absorption processing system | strain 4 of the said 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Volatilization chamber 3 Ammonia recovery system 4 Absorption processing system 6 Liquid ammonia tank 7 Heating cylinder 11, 12, 13 Seal box 17 Seal gas pipe line (2nd recovery path)
21 Liquid ammonia storage tank 22 Pipe line (supply line)
23 Expansion valve (pressure regulating valve)
24 Recovery path 25 Chilled water cooler 26 Brine cooler 28 Compressor 28a Low pressure screw compressor 28b High pressure screw compressor 30 Condenser 32 Liquid cooler 34, 35 Pipe line 34a, 36a, 37a, 38a Pressure reducing valve 37 Bypass line (pressure adjustment) Road)
38 Bypass line 44a First absorption tower 44b Second absorption tower 51 Distillation tower 55 Pipe line (first recovery line)
61 Blower (suction means)
62 Washing tower 65 Neutralization tank 69 Pipe line (outside air inlet)
71 Pressure regulating valve 72 Bypass line 73 Shut-off valve a, b Processed gas c Cotton cloth (work cloth)
w Cooling water

Claims (8)

In the cloth processing method using ammonia, after the work cloth is immersed in liquid ammonia, the ammonia-impregnated work cloth is heated to volatilize ammonia.
After immersing the work cloth in a liquid ammonia tank in the processing chamber, heating the ammonia-impregnated work cloth to evaporate ammonia from the work cloth; and
A washing step of washing the work cloth by evaporating ammonia by blowing steam to the work cloth sent from the working chamber to the volatilization chamber;
A dehumidification step of cooling and dehumidifying the gas to be treated containing the high-concentration ammonia gas recovered from the processing chamber;
A liquefaction refeeding step of liquefying the dehumidified gas to be processed with a compressor and then liquefying with a condenser and supplying the generated liquid ammonia to a liquid ammonia tank of the processing chamber;
An absorption step of introducing the gas to be treated containing the low-concentration ammonia gas recovered from the volatilization chamber to the absorption tower and absorbing the ammonia gas in the absorption liquid;
A distillation step of producing a high concentration ammonia gas by distilling the absorption liquid having absorbed ammonia in the absorption tower in a distillation tower, and returning the high concentration ammonia gas to the dehumidification step;
A cleaning neutralization step of neutralizing ammonia gas contained in the gas to be treated by washing the gas to be treated that has come out of the absorption tower with a cleaning solution containing an acid, and
The ammonia gas decompressed to the vicinity of the suction pressure of the compressor from the condenser via the pressure reducing valve on the upstream side of the compressor is added to the gas to be processed collected from the processing chamber to reduce the suction amount of the compressor. A fabric processing method using ammonia, characterized by adjusting the suction pressure of the compressor and adjusting the processing chamber to a slight negative pressure by adjusting.   The compressor is a screw compressor, and in the liquefaction refeeding step, a part of the liquid ammonia generated by the condenser is taken out through a pressure reducing valve to a reduced pressure region, and the reduced pressure from the liquid ammonia and the condenser Liquid that is supplied to the liquid ammonia storage tank by indirect heat exchange with liquid ammonia supplied to the liquid ammonia storage tank, and sucking the ammonia gas evaporated in the reduced pressure region into the intermediate stage of the screw compressor. The method for processing cloth using ammonia according to claim 1, wherein ammonia is supercooled. Supplying liquid ammonia produced by the condenser in the liquefaction refeeding step to the processing chamber via a liquid ammonia storage tank;
Ammonia gas decompressed and expanded from the liquid ammonia storage tank to the vicinity of the suction pressure of the compressor through the pressure reducing valve on the upstream side of the compressor to the gas to be treated recovered from the processing chamber in the previous stage of the dehumidifying step The cloth processing method using ammonia according to claim 1 or 2, wherein the pressure in the liquid ammonia storage tank is adjusted by adding the pressure.   The working chamber is set to a negative pressure by the suction pressure of the compressor, and the volatilization chamber is set to a negative pressure by suction means provided in a gas flow path on the downstream side of the absorption tower. A cloth processing method using ammonia according to claim 1.   A gas containing ammonia gas in a seal box provided at the entrance and exit of the cloth to be processed in the processing chamber and the volatilization chamber is supplied to the absorption tower to absorb the ammonia gas by the absorption tower, and the seal is sealed by the suction means. The cloth processing method using ammonia according to claim 4, wherein the inside of the box is held at a negative pressure. In a cloth processing apparatus using ammonia for evaporating ammonia by heating the ammonia-impregnated work cloth after immersing the work cloth in liquid ammonia,
A processing chamber equipped with a liquid ammonia tank for immersing the work cloth and a heating chamber for heating the work cloth impregnated with ammonia to evaporate ammonia from the work cloth;
A volatilization chamber for cleaning ammonia by spraying steam on the work cloth sent from the processing chamber;
Means for cooling and dehumidifying the gas to be treated containing high-concentration ammonia gas recovered from the processing chamber;
A compressor that compresses the dehumidified gas to be treated to a high pressure, and a condenser that condenses the compressed gas to produce liquid ammonia;
A supply path for supplying the liquid ammonia generated by the condenser to the liquid ammonia tank of the processing chamber via the liquid ammonia storage tank;
An absorption tower that absorbs a gas to be treated containing low-concentration ammonia gas recovered from the volatilization chamber into an absorption liquid;
A distillation column that distills the absorbing solution that has absorbed ammonia in the absorption tower to produce a high concentration ammonia gas, and a first recovery path that supplies the high concentration ammonia gas to the cooling and dehumidifying means;
A washing tower for neutralizing ammonia gas contained in the gas by washing the gas emitted from the absorption tower with a washing solution containing an acid;
Ammonia depressurized from the condenser to the vicinity of the suction pressure of the compressor through the pressure reducing valve on the upstream side of the cooling and dehumidifying means in the flow path of the gas to be processed containing the high concentration ammonia gas recovered from the processing chamber A cloth processing apparatus using ammonia, comprising: a pressure adjusting path for adding gas.   The ammonia according to claim 6, wherein a suction means for sucking the gas to be treated is provided on the downstream side of the absorption tower, and an outside air inlet whose flow rate is adjustable is provided on the upstream side of the suction means. Cloth processing equipment. A seal box provided at the entrance and exit of the work cloth in the processing chamber and the volatilization chamber;
A second recovery path for supplying a gas containing ammonia gas in the seal box to the absorption tower;
A bypass passage with a shut-off valve that guides the gas to be treated containing the low-concentration ammonia gas derived from the volatilization chamber and the gas containing the ammonia gas in the seal box to the upstream side of the suction means by bypassing the absorption tower; The cloth processing apparatus using ammonia according to claim 7, comprising:

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