JP2010042342A - Device and method for treating evacuated vapor containing exhaust gas and organic waste treatment system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for treating evacuated vapor containing an exhaust gas which enable the evacuated vapor and the exhaust gas to be discharged from a reaction container and turned to a condensate in a short time, and also performing treatment in a comparatively lower cooling capacity for a discharge amount per given time of the evacuated vapor and the exhaust gas. <P>SOLUTION: This device for treating the evacuated vapor containing the exhaust gas includes the following components: a mixing condenser 51 which condenses the evacuated vapor accompanied by the exhaust gas to be discharged from a batch-wise reaction can through direct contact with cooling water, a cooling tank 52 which stores the cooling water and receives the inflow of the cooling water containing the condensate to be discharged from the mixing condenser 51, a cooling water circulation system 54 which supplies the cooling water from the cooling tank 52 to the mixing condenser 51, and a cooling tower 56 which cools the cooling water through a heat exchanger 55 installed halfway of the cooling water circulation system 54. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is an organic material that thermally denaturizes organic waste including general waste such as paper, plastic, food waste, combustible waste, pruned branches, construction waste wood, etc., and livestock excreta, livestock excreta containing waste straw and sewage treatment sludge. The present invention relates to a processing apparatus and a processing method for exhaust steam including exhaust gas.

Conventionally, this type of technology includes, for example, one described in Patent Document 1. This is as shown in FIG.
The reaction apparatus 1 performs a solid organic waste treatment process, and has a double structure including an outer container 2 and a reaction container 3 stored in the outer container 2.

  In the reaction apparatus 1, organic waste such as solid organic waste such as garbage and plastic is introduced into the reaction vessel 3 from the inlet 4 as a raw material, and saturated into the reaction vessel 3 from the first steam supply port 5. Supply steam. Inside the reaction vessel 3, a stirring blade 7 that is rotationally driven by a motor 6 stirs the raw material under high temperature and high pressure.

  Inside the reaction vessel 3, the solid organic waste is heat-denatured by hydrothermal reaction under the operating conditions of normal temperature to 235 ° C., normal pressure to 3 MPa, and elevated temperature and pressure increase time of 1 to 3 hours, and steam indirect Dry powder by heating. At this time, the reaction vessel 3 is kept at a predetermined temperature or higher by saturated water vapor supplied from the second vapor supply port 9 to the mantle vessel 2. The produced desiccant 10 is taken out from the outlet 8 and the exhaust steam and the exhaust gas 11 are taken out from the outlet 12 to the outside.

  Exhaust steam and exhaust gas 11 containing steam-containing components generated during the reaction condensate treated water from the water treatment facility 13 as cooling water 14, and use the exhaust steam absorption circulating liquid 15 as a water treatment facility 13 such as a sludge regeneration treatment center. And processed as an organic nutrient (BOD source).

As a method for treating the exhaust steam and the exhaust gas 11, there is, for example, the one shown in FIG. As shown in FIG. 3, in the reaction vessel 31, the waste 33 is decomposed and dried by hydrothermal reaction with saturated steam supplied from the boiler 32, detoxified, and discharged as a processed product 34. Wet steam discharged from the reaction vessel 31 is supplied to the condenser 35, condensed in the condenser 35, and discharged through the septic tank 36. The exhaust gas emitted from the condenser 35 is processed by the activated adsorption charcoal deodorizing device 38 through the vacuum pump 37a and the collecting fan 37b. Cooling water is circulated between the condenser 35 and the cooling tower 39. Prior art documents include the following.
JP 2007-136312 A JP 2007-7622 A Japanese Patent No. 3832587 Japanese Patent No. 3898918 JP 2007-7555 A Japanese Patent No. 3579417 Japanese Patent No. 3613567

  By the way, in the equipment which processes organic waste by a hydrothermal reaction as mentioned above, since it is on condition of high temperature and high pressure, it is common to process it batchwise. For this reason, in order to increase the processing efficiency, it is required to exhaust the exhaust steam and the exhaust gas from the reaction vessel and to condense the water in a short time in the interval from the end of the reaction to the start of the next processing.

  However, in the configuration described above, heat is exchanged between the exhaust steam and exhaust gas and the cooling medium in the condenser, and the cooling medium is cooled by the cooling tower. For this reason, the capacity | capacitance used for the condenser and cooling tower used for the condensate is so large that the discharge | emission amount per unit time of the waste steam discharged | emitted from reaction container and exhaust gas is large.

  The condenser serves as both a condenser and a heat exchanger, and is a shell-and-tube type indirect cooling type from the viewpoint of easy cleaning of attached dust. This configuration is larger and more expensive than the direct heat transfer type mixing condenser.

  The present invention solves the above-described problems, and can exhaust and condense exhaust steam and exhaust gas from the reaction vessel in a short time, and can reduce exhaust steam and exhaust gas per hour. An object of the present invention is to provide a processing apparatus and processing method for exhaust steam containing exhaust gas that can be processed with a relatively small cooling capacity, and an organic waste processing system.

  In order to solve the above-described problems, the exhaust steam treatment apparatus including exhaust gas according to the present invention is a mixing condenser that condenses exhaust steam accompanying exhaust gas discharged from a batch reactor by direct contact with a cooling medium. A cooling tank for storing a cooling medium and containing a cooling medium including condensate discharged from the mixing condenser, a cooling medium circulation system for supplying the cooling medium from the cooling tank to the mixing condenser, and a cooling medium circulation A cooling medium cooling means for cooling the cooling medium of the system is provided.

In the exhaust steam processing apparatus including exhaust gas according to the present invention, the cooling medium cooling means cools the cooling medium via a heat exchanger provided in the middle of the cooling medium circulation system.
Moreover, in the processing apparatus for exhaust steam containing exhaust gas of the present invention, the cooling medium cooling means cools the cooling medium via a heat exchanger that communicates with the cooling tank separately from the cooling medium circulation system. .

  Further, in the processing apparatus for exhaust steam containing exhaust gas according to the present invention, the cooling tank stores a predetermined amount of cooling medium necessary for condensing exhaust steam accompanied by at least one exhaust gas discharged from the batch reactor. It is characterized by doing.

  Moreover, in the processing apparatus of the exhaust steam containing the exhaust gas of the present invention, it is provided with a second cooling tank that communicates with the cooling tank and is interposed in the cooling medium circulation system, and the second cooling tank also serves as a precipitation tank. Features.

Moreover, in the processing apparatus for exhaust steam containing exhaust gas of the present invention, the heat exchanger has a plate-type structure.
The method for treating exhaust steam containing exhaust gas according to the present invention comprises condensing exhaust steam accompanying exhaust gas discharged from a batch reactor by direct contact with a cooling medium sprayed in a mixing condenser, and mixing condenser The cooling medium containing the condensate discharged from the refrigerant flows into the cooling tank, the heat of the cooling medium containing the condensate is absorbed by the cooling medium stored in the cooling tank, and the cooling medium stored in the cooling tank is absorbed into the mixing condenser. The cooling medium is circulated and supplied through a cooling medium circulation system, and the cooling medium in the cooling medium circulation system is cooled by a cooling medium cooling means.

In the method for treating exhaust steam containing exhaust gas according to the present invention, the cooling medium cooling means cools the cooling medium via a heat exchanger provided in the middle of the cooling medium circulation system.
In the method for treating exhaust steam containing exhaust gas of the present invention, the cooling medium cooling means cools the cooling medium via a heat exchanger that communicates with the cooling tank separately from the cooling medium circulation system. .

In the method for treating exhaust steam containing exhaust gas of the present invention, the exhaust gas in the gas phase of the cooling tank is subjected to combustion deodorization treatment or combustion deodorization treatment using an oxidation catalyst.
Further, in the method for treating exhaust steam containing exhaust gas of the present invention, the exhaust gas in the gas phase of the cooling tank is subjected to biological deodorization treatment and activated carbon adsorption treatment.

  The organic waste treatment system of the present invention comprises a batch type reaction can for treating organic waste, and a treatment device for exhaust steam containing exhaust gas discharged from the batch reaction can, A condensing unit that condenses exhaust steam accompanying exhaust gas discharged from a batch reactor by direct contact with the cooling medium, and a condensate that stores the cooling medium and discharges it from the mixing condenser A cooling tank into which the cooling medium flows, a cooling medium circulation system for supplying the cooling medium in the cooling tank to the mixing condenser, and a cooling medium cooling means for cooling the cooling medium in the cooling medium circulation system. To do.

  As described above, according to the present invention, the heat of the cooling medium containing the condensate discharged from the batch reactor is absorbed by the cooling medium stored in the cooling tank, and the cooling medium stored in the cooling tank is mixed with the condenser. By circulating and supplying the refrigerant through the cooling medium circulation system, a predetermined amount of the cooling medium stored in the cooling tank temporarily heats the exhaust steam accompanying the exhaust gas for one time discharged from the batch reactor while gradually raising the temperature. Absorb.

  Therefore, the exhaust steam accompanying the exhaust gas for one time discharged from the batch reactor is only limited by the cooling capacity of the cooling medium stored in the cooling tank, without being limited to the cooling capacity of the cooling medium cooling means for cooling the cooling medium. Condensation can be performed within a short time, and the batch processing interval in the batch reactor can be shortened.

  In addition, a predetermined amount of the cooling medium stored in the cooling tank is heated up to a predetermined upper temperature by supplying it to the condensate of the exhaust steam discharged from the batch reactor, and the cooling medium cooling means is set to the upper temperature. The reached cooling medium is cooled through a heat exchanger provided in the middle of the cooling medium circulation system, and gradually cooled to a predetermined lower temperature.

  In this case, the cooling medium cooling means is not required to reduce the temperature of the cooling medium to a predetermined lower temperature within the time interval of the batch processing in the batch type reaction can, specifically, in the steam discharge process. What is necessary is just to reduce the temperature of the cooling medium to a predetermined lower temperature before the exhaust steam is discharged from the can next time. Therefore, the cooling capacity of the cooling medium cooling unit is smaller than that required for condensing the exhaust steam discharged from the batch reactor per unit time.

  The exhaust gas discharged from the batch reactor is suitable for combustion deodorization because the amount of gas is small even if the odor component is high in concentration, and the exhaust gas accompanying the exhaust gas discharged from the batch reactor is mixed with a condenser. In the case of condensate by direct contact with the cooling medium sprayed, the exhaust gas is wet-cleaned, the halogen in the exhaust gas is transferred to the condensate and the cooling medium, and the exhaust gas in the gas phase of the cooling tank is catalyst poison Therefore, it is suitable for catalyst deodorization treatment.

  And the odor component in the exhaust gas discharged from the batch reactor can be obtained by condensing exhaust steam accompanied by the exhaust gas discharged from the batch reactor by direct contact with the cooling medium sprayed in the mixing condenser. Transition to condensate and cooling media. Since the concentration of the odor component is reduced by this transfer, the exhaust gas in the gas phase of the cooling tank can be efficiently removed by performing the biological deodorization treatment and the activated carbon adsorption treatment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the exhaust steam processing apparatus processes exhaust steam accompanied by exhaust gas discharged from a batch type reaction can of the organic waste processing system, and the organic waste processing system and the batch type reaction can are described above. Thus, the description is omitted here. The present invention is not necessarily based on the conventional organic waste treatment system described above, and can be used for various types of exhaust steam treatment.

  The processing apparatus for exhaust steam including exhaust gas mainly includes a mixed condenser 51, a first cooling tank 52, a second cooling tank 53, a cooling water circulation system 54, a heat exchanger 55, and cooling medium cooling. A cooling tower 56, a regulating tank 57, a wastewater treatment facility 58, and an activated carbon deodorizing tower 59 are provided.

The mixing condenser 51 sprays cooling water as a cooling medium, and condenses it by direct contact between the exhaust steam 50 accompanied by exhaust gas discharged from a batch-type reaction can (not shown) and the cooling water. .
The first cooling tank 52 stores a predetermined amount of cooling water necessary for condensing the exhaust steam 50 with one exhaust gas discharged from a batch reactor (not shown). Cooling water including condensate to be discharged flows in, and the second cooling tank 53 is for maintaining the water level of the first cooling tank 52 at a predetermined level, and can also serve as a precipitation tank. The first cooling tank 52 and the second cooling tank 53 do not need to be provided independently, and one tank may be divided and used by a wall body.

The cooling water circulation system 54 includes a circulation pump 54 a and supplies cooling water to the mixing condenser 51 through the primary side of the heat exchanger 55. The heat exchanger 55 has a plate structure.
The cooling tower 56 includes a secondary cooling water circulation system 56 a and a secondary cooling water circulation pump 56 b between the secondary side of the heat exchanger 55 provided in the middle of the cooling medium circulation system 54, and the cooling water is passed through the heat exchanger 55. Cool down. A configuration including the cooling tower 56 and the heat exchanger 55 forms a cooling medium cooling means. The cooling medium cooling means can also be realized by providing a heat exchanger for cooling the cooling medium in a system communicating with the first cooling tank 52 and the second cooling tank 53 separately from the cooling medium circulation system 54.

  The second cooling tank 53 communicates with the adjustment tank 57 via the transfer pump 53a, and the adjustment tank 57 communicates with the wastewater treatment facility 58 via the input pump 57a. The wastewater treatment facility 58 has a sealed structure including a denitrification tank 58a, a nitrification tank 58b, and a membrane separation device 58c immersed in the nitrification tank 58b, and a gas phase region communicates with the activated carbon deodorization tower 59. The denitrification tank 58a and the nitrification tank 58b have an air diffuser 58d. The air diffuser 58d communicates with the gas phase region of the first cooling tank 52 through the suction fan 60a and the aeration blower 60b.

Moreover, in FIG. 1, 71 is a water collector, 72 is a measuring tank, 73 is a defoaming agent injection apparatus, 74 is a surplus sludge tank, 75 is open | released to air | atmosphere, 76 shows sewer discharge.
With the above-described configuration, the exhaust steam accompanying the exhaust gas discharged from the batch reactor (not shown) is introduced into the mixing condenser 51 that sprays the cooling water, and the mixing condenser 51 is directly connected to the cooling water. Condensate by contact. Therefore, compared to the conventional shell-and-tube indirect cooling type, by using the direct heat transfer type mixing condenser 51, the heat transfer efficiency can be increased and the apparatus can be downsized, and there is no adhesion of dust. So management becomes easy.

  The cooling water containing the condensate of hot water condensed in the mixing condenser 51 flows into the first cooling tank 52, and the exhaust gas is also guided to the first cooling tank 52. In the first cooling tank 52, the heat of the cooling water including the condensate discharged from the batch reactor can be absorbed by a predetermined amount of cooling water stored in the first cooling tank 52. The cooling water stored in the first cooling tank 52 is circulated and supplied to the mixing condenser 51 through the second cooling tank 53, the cooling water circulation system 54 and the heat exchanger 55.

  In this way, the batch type reactor can be used while the cooling water stored in the first cooling tank 52 is circulated and supplied to the mixing condenser 51 and the predetermined amount of cooling water stored in the first cooling tank 52 is gradually heated. Temporarily absorbs the heat of the exhaust steam accompanying the exhaust gas discharged once.

  Therefore, without being limited to the cooling capacity of the cooling tower 56, the exhaust steam accompanying the exhaust gas for one time discharged from the batch reactor can be reduced within a short time only by the cooling capacity of the cooling water stored in the first cooling tank 52. It is possible to condense the water into a batch reactor and shorten the batch processing interval in the batch reactor.

A predetermined amount of cooling water stored in the first cooling tank 52 is heated up to a predetermined upper temperature, for example, 80 ° C., by being supplied to condensate of exhaust steam for one discharge discharged from the batch reactor.
On the other hand, the cooling water is cooled by the cooling tower 56 via the heat exchanger 55 provided in the middle of the cooling water circulation system 54. The cooling tower 56 gradually reduces the cooling water that has reached the upper temperature to a predetermined lower temperature, for example, 30 ° C. to 40 ° C.

  At this time, the cooling tower 56 does not need to reduce the cooling water to a predetermined lower temperature within the batch processing interval in the batch reactor, specifically, in the steam discharge process. The cooling water may be reduced to a predetermined lower temperature before the exhaust steam is discharged next time.

  Therefore, the cooling capacity required per unit time of the heat exchanger 55 and the cooling tower 56 is smaller than the cooling capacity required for condensing the exhaust steam discharged from the batch reactor per unit time.

  The second cooling tank 53 precipitates and removes foreign matters such as dust, and a part of the cooling water is supplied to the waste water treatment facility 58 through the adjustment tank 57 for processing. The exhaust gas in the gas phase region of the first cooling tank 52 is subjected to biological deodorization treatment by aeration from the diffuser 58d of the waste water treatment facility 58 to the denitrification tank 58a and the nitrification tank 58b. Activated carbon adsorption treatment is performed in the activated carbon deodorization tower 59. Odor components in the exhaust gas discharged from the batch reactor can be transferred to condensate and cooling medium to reduce the concentration. Therefore, the exhaust gas in the gas phase region of the first cooling tank 52 is subjected to biological deodorization treatment and activated carbon adsorption treatment. Can be removed efficiently.

  Biological deodorization decomposes and removes odors by the action of aerobic microorganisms, such as a system in which odors are blown into an aeration tank, a system in which activated sludge is sprayed on a scrubber tower, a odor-contacting ceramic, etc. There is a packed tower system packed with a carrier.

  Biological deodorization is recognized to be effective in removing various odors such as ammonia, hydrogen sulfide, methyl mercaptan, and aldehydes. It is considered that odor is dissolved in water and then absorbed and decomposed by aerobic microorganisms, which is an effective method mainly for hydrophilic odor components.

  On the other hand, activated carbon adsorption is a method in which odorous gas is removed by contact adsorption to an adsorption tower filled with activated carbon. Activated carbon exhibits effective adsorptivity for hydrophobic neutralizing substances, but it has low adsorptivity for low-molecular polar substances such as ammonia and hydrogen sulfide.

Therefore, the exhaust gas can be efficiently removed by performing the biological deodorization treatment and the activated carbon adsorption treatment.
In this embodiment, a method of blowing odor into the aeration tank is adopted. This is because the aeration tank for water treatment is equipped with a device for injecting aerated air, so it is not necessary to add new equipment for deodorization, and it is possible to remove odor at low cost. it can. Moreover, since the bad odor cannot be sufficiently suppressed below the emission standard by biological deodorization alone, an activated carbon adsorption tower is provided as a finishing treatment.

  The exhaust gas in the gas phase region of the first cooling tank 52 can be subjected to combustion deodorization treatment or catalyst deodorization treatment. The exhaust gas discharged from the batch reaction can is suitable for combustion deodorization because the amount of gas is small even if the odor component is high in concentration. Further, the exhaust gas discharged from the batch reactor can be wet-cleaned by the cooling water sprayed in the mixing condenser 51, and the halogen in the exhaust gas is transferred to the condensate and the cooling water. Since the exhaust gas is in a state in which the halogen that becomes the catalyst poison is removed, it is suitable for the catalyst deodorization treatment.

  In the present embodiment, the cooling water is cooled via a heat exchanger 55 provided in the middle of the cooling medium circulation system 54, but via a heat exchanger that communicates with the cooling tank separately from the cooling medium system. The cooling medium may be cooled. In this case, the required water amount of the condenser and the required water amount of the heat exchanger can be set individually. Moreover, it is also possible to carry out heat exchange between cooling water and air instead of heat exchange between cooling water and cooling water in the heat exchanger as in the present embodiment. In this case, since the temperature of the cooling water is considerably higher than the air temperature of the outside air, it is effective.

The schematic diagram which shows the organic waste processing system in embodiment of this invention Schematic diagram showing a conventional organic waste treatment system Schematic diagram showing a conventional organic waste treatment system

Explanation of symbols

50 Exhaust Steam with Exhaust Gas 51 Mixing Condenser 52 First Cooling Tank 53 Second Cooling Tank 53a Transfer Pump 54 Cooling Water Circulation System 54a Circulation Pump 55 Heat Exchanger 56 Cooling Tower 56a Secondary Cooling Water Circulation System 56b Secondary Cooling Water Circulation Pump 57 Adjustment tank 57a Input pump 58 Waste water treatment equipment 58a Denitrification tank 58b Nitrification tank 58c Membrane separation device 58d Aeration device 59 Activated carbon deodorization tower 60a Suction fan 60b Aeration blower 71 Water taker 72 Metering tank 73 Defoaming agent injection device 74 Excess sludge tank 75 Open to the atmosphere 76 Sewer discharge

Claims (12)

  A condensing condenser that condenses exhaust steam accompanying exhaust gas discharged from a batch reactor by direct contact with the cooling medium, and a cooling medium containing condensate that stores the cooling medium and discharges it from the mixing condenser Including exhaust gas, comprising: a cooling tank into which the refrigerant flows, a cooling medium circulation system that supplies the cooling medium of the cooling tank to the mixing condenser, and a cooling medium cooling means that cools the cooling medium of the cooling medium circulation system Waste steam treatment equipment.   The apparatus for processing exhaust steam containing exhaust gas according to claim 1, wherein the cooling medium cooling means cools the cooling medium via a heat exchanger provided in the middle of the cooling medium circulation system.   The apparatus for processing exhaust steam containing exhaust gas according to claim 1, wherein the cooling medium cooling means cools the cooling medium via a heat exchanger that communicates with the cooling tank separately from the cooling medium circulation system.   The cooling tank stores a predetermined amount of a cooling medium necessary for condensing exhaust steam accompanied by at least one exhaust gas discharged from a batch reactor. A processing apparatus for exhaust steam containing the exhaust gas according to Item.   5. The apparatus according to claim 1, further comprising a second cooling tank communicating with the cooling tank and interposed in the cooling medium circulation system, wherein the second cooling tank also serves as a precipitation tank. Of exhaust steam containing exhaust gas of   The apparatus for treating exhaust steam containing exhaust gas according to any one of claims 1 to 5, wherein the heat exchanger has a plate-type structure.   The exhaust steam accompanying the exhaust gas discharged from the batch reactor can be condensed by direct contact with the cooling medium sprayed in the mixing condenser, and the cooling medium containing the condensed water discharged from the mixing condenser is sent to the cooling tank. The cooling medium stored in the cooling tank is absorbed by the cooling medium stored in the cooling tank, and the cooling medium stored in the cooling tank is circulated and supplied to the mixing condenser through the cooling medium circulation system. A method for treating exhaust steam containing exhaust gas, wherein the coolant is cooled by a coolant cooling means.   The method for processing exhaust steam containing exhaust gas according to claim 7, wherein the cooling medium cooling means cools the cooling medium through a heat exchanger provided in the middle of the cooling medium circulation system.   The method for processing exhaust steam containing exhaust gas according to claim 7, wherein the cooling medium cooling means cools the cooling medium via a heat exchanger that communicates with the cooling tank separately from the cooling medium circulation system.   The exhaust gas containing exhaust gas according to any one of claims 7 to 9, wherein the exhaust gas in the gas phase of the cooling tank is subjected to combustion deodorization treatment or combustion deodorization treatment using an oxidation catalyst.   The method for treating exhaust gas containing exhaust gas according to any one of claims 7 to 10, wherein the exhaust gas in the gas phase of the cooling tank is subjected to biological deodorization treatment and activated carbon adsorption treatment.   A batch type reaction can for treating organic waste and a waste steam treatment device containing exhaust gas discharged from the batch type reaction can, wherein the waste steam treatment device containing the exhaust gas is discharged from the batch reaction can A condensing condenser for condensing exhaust steam accompanying exhaust gas by direct contact with the cooling medium, a cooling tank for storing a cooling medium and storing a cooling medium containing condensate discharged from the mixing condenser; An organic waste treatment system comprising: a cooling medium circulation system that supplies a cooling medium in a cooling tank to a mixing condenser; and a cooling medium cooling unit that cools the cooling medium in the cooling medium circulation system.