JP2006116457A - Deodorization apparatus for sludge drier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deodorization apparatus for a sludge drier whose running cost is low and which is friendly to the global environment. <P>SOLUTION: This deodorization apparatus is provided with a wet scrubber 8 cooling and dehumidifying exhaust gas by showering it with a coolant; a bio-deodorizing column 9 introducing exhaust gas cooled and dehumidified in the wet scrubber 8 and with condensate of the vaporized steam removed therefrom, and deodorizing the odor included in the exhaust gas biochemically with microorganisms; and a cooling means 19 cooling the coolant used for showering the exhaust gas in the wet scrubber 8 to maintain the temperature of the exhaust gas introduced into the bio-deodorizing column 9 from the wet scrubber 8, at an optimum temperature for the activity of the microorganisms in the bio-deodorizing column 9, regardless of the atmospheric temperature or the temperature of the vaporized steam produced in the sludge drier. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a deodorizing apparatus for a sludge dryer that performs drying treatment in order to reduce or recycle sludge.

  Generally, sludge generated by sewage and wastewater treatment is discharged as dehydrated sludge having a reduced water content by dehydration. Such dewatered sludge has been reduced in volume and disposed of in landfills or oceans. More recently, recycling has progressed and attempts have been made to make sludge into slabs for effective use as construction materials.

  As a pre-process for final disposal of these sludges, it is necessary to dry the dewatered sludge. 2. Description of the Related Art Conventionally, as an apparatus for drying dewatered sludge, a sludge dryer as shown in FIG. 2 is known. This sludge dryer is provided with two drum dryers 2 and 2 that rotate inward (inner rotation) in the housing 1, and a steam source (not shown) such as a boiler in the drum dryers 2 and 2. The heated water vapor supplied and discharged from the water is fed into the drum dryer 2 and 2, and the dehydrated sludge is supplied from the dehydrated sludge supply mechanism 3 to draw the dehydrated sludge between the drum dryers 2 and 2 rotating inward. The sheet-shaped sludge adhered to the surfaces of the drum dryers 2 and 2 is gelatinized by heating rapidly while thinly extending to a thickness corresponding to the gap between the drum dryers 2 and 2. Drying is performed while the dryers 2 and 2 are rotating, and the dried solids are scraped off and transferred by scrapers 4 and 4 disposed above and outside the drum dryers 2 and 2. Conveyors 5,5 and continuously discharged outside through the discharge conveyer 6.

  On the other hand, exhaust gas containing evaporated vapor (vapor) evaporated from the dewatered sludge discharged from the housing 1 is released to the atmosphere by the fan 7.

  By the way, in the said sludge dryer, the unpleasant odor which generate | occur | produces from a dehydration sludge is contained in exhaust gas, It is necessary to discharge | release an exhaust gas to air | atmosphere after carrying out a deodorizing process.

  Therefore, conventionally, in order to deodorize the exhaust gas of the sludge dryer and release it to the atmosphere, the exhaust gas is heated with a burner or the like to burn odors, or the heating temperature is lowered to use a catalyst. A deodorizing device for deodorizing at the downstream side of the fan 7 is provided.

  However, since all of the conventional deodorizing devices need to heat the exhaust gas, a large amount of fuel is required to heat the exhaust gas, which increases the fuel cost and increases the running cost. It also has problems from the viewpoint of resource protection and global warming.

  In order to solve the above-described problems, an object of the present invention is to provide a deodorizing apparatus for a sludge dryer that is low in running cost and is friendly to the global environment.

  In order to achieve the above object, the present invention provides a deodorization apparatus for use in a sludge dryer for drying sludge, which introduces exhaust gas containing evaporating vapor generated from sludge dried by the sludge dryer. A wet scrubber that cools and dehumidifies by showering the exhaust gas with a refrigerant, and an exhaust gas that is cooled and dehumidified by the wet scrubber to remove condensed water from the evaporated vapor are introduced, and the odor contained in the exhaust gas is removed by microorganisms. In order to maintain the biological deodorization tower that biochemically deodorizes in the state and the activity of microorganisms in the biological deodorization tower in an enhanced state, the temperature of the exhaust gas introduced from the wet scrubber to the biological deodorization tower is set to the outside air temperature. And the wets so as to maintain the optimum temperature for the activity of microorganisms in the biological deodorization tower regardless of the temperature of the vapor generated in the sludge dryer. Is characterized in that a cooling means for cooling the coolant to be used for showering the exhaust gas with rubber.

According to the present invention, the exhaust gas containing the evaporated vapor evaporated from the dewatered sludge discharged from the sludge dryer is showered with a refrigerant with a wet scrubber, cooled and dehumidified, and then the microorganisms with a biological deodorization tower. Biological deodorization treatment can be performed, and the running cost can be reduced as compared with the conventional case, and the generation of CO _{2 that} causes global warming is eliminated and the global environment can be protected. Moreover, when the exhaust gas is showered with a refrigerant by a wet scrubber and cooled and dehumidified, the temperature of the exhaust gas introduced from the wet scrubber to the biological deodorization tower is reduced by using the refrigerant cooled by the cooling means. Regardless of the outside air temperature or the temperature of the evaporating vapor generated in the sludge dryer, it can be maintained at the optimum temperature for microbial activity in the biological deodorization tower. The deodorization is performed efficiently.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a flow sheet diagram showing an embodiment of a deodorizing apparatus for a sludge dryer according to the present invention applied to the sludge dryer shown in FIG. In FIG. 1, the same or corresponding parts as in FIG.

  In FIG. 1, 8 is a wet scrubber provided on the downstream side of the fan 7, which introduces exhaust gas containing evaporating vapor evaporating from dehydrated sludge dried by a sludge dryer, and uses the exhaust gas as a refrigerant, For example, it is cooled and dehumidified by showering with cooling water.

  9 is a biological deodorization tower provided on the downstream side of the wet scrubber 8 via the air / water separator 10, and is filled with a carrier (for example, activated carbon, etc.) carrying microorganisms therein. The odor components in exhaust gas are captured and decomposed by countless microorganisms that are deodorized.

  The steam separator 10 is provided to further remove the moisture, since the exhaust gas cooled and dehumidified by the wet scrubber 8 still contains moisture. The exhaust gas from which the condensed water by the evaporated steam is removed by the steam separator 10 is introduced into the biological deodorization tower 9, and the condensed water removed from the exhaust gas by the steam separator 10 is drained along with the cooling water as drainage. 11 is discharged.

  A supply pump 12 is provided between the wet scrubber 8 and the water storage tank 13, and supplies the cooling water used for exhaust gas showering from the water storage tank 13 by the wet scrubber 8.

  The water storage tank 13 is divided into a raw water tank 16 for storing raw water supplied from the water supply tank 15 by the submersible pump 14 and a cooling water tank 17 for storing cooling water obtained by cooling the raw water in the raw water tank 16. In addition, the raw water is sent from the raw water tank 16 toward the cooling water tank 17 by the circulation pump 18.

  Reference numeral 19 denotes a cooling tower which is a cooling means provided in the middle of sending the raw water of the raw water tank 16 of the water storage tank 13 to the cooling water tank 17 by the circulation pump 18, and the raw water tank 16 of the water storage tank 13 by the circulation pump 18. The raw water is introduced from the air and cooled by bringing the raw water into contact with the outside air taken in by a blower. The raw water cooled by the cooling tower 19 is sent to the cooling water tank 17 as cooling water and stored.

  The cooling tower 19 can adjust the cooling temperature of the cooling water according to the outside air temperature, the temperature of the evaporated steam generated by the sludge dryer, and the temperature of the exhaust gas after being showered with the cooling water by the wet scrubber 8. Can be maintained at a constant temperature regardless of the outside air temperature or the temperature of the evaporated vapor generated in the sludge dryer, and thereby the temperature of the exhaust gas introduced into the biological deodorization tower 9 can be used for the activity of microorganisms in the biological deodorization tower 9. It can be maintained at the optimum temperature.

  Next, the effect | action by the deodorizing apparatus of the sludge dryer which concerns on this invention comprised as mentioned above is demonstrated.

  The raw water is supplied from the water supply tank 15 to the raw water tank 16 of the water storage tank 13 by the submersible pump 14 and stored, and the raw water (for example, temperature: around 40 ° C.) from the raw water tank 16 of the water storage tank 13 by the circulation pump 18. ) Is sent to the cooling water tank 17 and is cooled by the cooling tower 19 in the middle thereof and stored in the cooling water tank 17 as cooling water (for example, temperature: around 30 ° C.).

  At the same time, the cooling water is supplied from the cooling water tank 17 of the water storage tank 13 to the wet scrubber 8 by the supply pump 12, and the cooling water is sprinkled in the wet scrubber 8, and the inside of the wet scrubber 8 is cooled by the cooling action of the cooling water. Place in the environment.

  In this state, high-temperature (for example, temperature: 60 ° C. to 100 ° C.) exhaust gas containing evaporated vapor evaporated from the dewatered sludge discharged from the housing 1 is introduced into the wet scrubber 8 by the fan 7. The exhaust gas introduced into the wet scrubber 8 is showered with cooling water in the wet scrubber 8 so as to be cooled to a low temperature (for example, 40 ° C. or less) and at the same time, most of the evaporated vapor is cooled. Condensed in water, the water content is greatly reduced. The exhaust gas that has been showered by the wet scrubber 8 and from which the condensed water from the evaporated vapor has been removed is separated into air and water by the steam separator 10 and then introduced into the biological deodorization tower 9. The malodorous component is captured and decomposed at, and deodorized, and then released to the atmosphere with the malodor removed. On the other hand, the cooling water that has been cooled and dehumidified by showering the exhaust gas in the wet scrubber 8 is discharged into the drain groove 11 as drainage together with the condensed water by the evaporated steam.

In the sludge dryer deodorization apparatus according to the present invention, the wet scrubber 8 and the biological deodorization tower 19 are attached to the sludge dryer, and the exhaust gas contains the evaporated vapor evaporated from the dewatered sludge discharged from the housing 1 of the sludge dryer. Since the gas was showered with cooling water with the wet scrubber 8 and cooled and dehumidified, the biological deodorization tower 19 biologically deodorized with microorganisms and released into the atmosphere. Can be reduced, and the generation of CO _{2 that} causes global warming is eliminated, thereby protecting the global environment.

  By the way, the raw water from the water supply tank 15 is supplied to the wet scrubber 8 without being cooled by the cooling tower 19, and the wet scrubber 8 includes a high temperature (for example, temperature: 60 ° C. to 100 ° C.) including the evaporated vapor evaporated from the dewatered sludge. Even if the exhaust gas is showered with raw water (eg, temperature: 40 ° C. or higher) and cooled and dehumidified, the exhaust gas is cooled and dehumidified by the shower ring, and the exhaust gas is discharged from the wet scrubber 8. When the temperature of the exhaust gas is 40 ° C. or higher and the temperature of the exhaust gas is 40 ° C. or higher, the microorganisms involved in capturing and decomposing the malodorous components of the exhaust gas in the biological deodorization tower 9 do not work well, and the deodorizing effect is reduced. End up.

  However, in the deodorizer of the sludge dryer according to the present invention, the raw water from the water supply tank 15 is cooled by the cooling tower 19 and supplied to the wet scrubber 8 as cooling water, and the evaporated steam evaporated from the dewatered sludge by the wet scrubber 8. The exhaust gas is exhausted from the wet scrubber 8 because the exhaust gas can be cooled and dehumidified by showering it with cooling water (for example, temperature: 30 ° C. or lower). The temperature of the exhaust gas is 40 ° C. or less at which microorganisms are actively activated in the biological deodorization tower 9, whereby the activity of microorganisms in the biological deodorization tower 9 is activated and the deodorizing effect can be improved.

  In addition, since the cooling temperature of the cooling water is adjusted in the cooling tower 19 according to the outside air temperature or the temperature of the evaporated steam generated in the sludge dryer, the temperature is not affected by the outside air temperature or the temperature of the evaporated steam generated in the sludge dryer. The temperature of the exhaust gas introduced into the biological deodorization tower 9 is maintained at 40 ° C. or less, which is the optimum temperature for the activity of microorganisms in the biological deodorization tower 9, thereby increasing the activity of microorganisms in the biological deodorization tower 9. Maintain and allow efficient deodorization over a long period of time.

  As mentioned above, although one Embodiment of the deodorizing apparatus of the sludge dryer which concerns on this invention was described, the deodorizing apparatus of the sludge dryer which concerns on this invention is not limited to this embodiment.

  For example, in the embodiment shown in FIG. 1, raw water is cooled by the cooling tower 19, but the cooling means of the present invention is not limited to the cooling tower 19, and the raw water is cooled by a cooling means other than the cooling tower 19. It is also possible to cool.

  In the embodiment shown in FIG. 1, the cooling water showered with the exhaust gas by the wet scrubber 8 is discharged into the drain groove 11 as drainage together with the condensed water by the evaporated vapor of the exhaust gas. The present invention is not limited to the one-way type, and a circulation system in which the cooling water showered with the exhaust gas by the wet scrubber 8 is returned to the water supply tank 15 as the raw water together with the condensed water by the evaporated vapor of the exhaust gas is adopted. It is also possible.

  Furthermore, in the embodiment shown in FIG. 1, the case where the present invention is applied to a double drum type sludge dryer having two drum dryers 2 and 2 in the housing 1 is described. However, the present invention is a double drum type sludge. The present invention is not limited to application to a dryer, and can be applied to a sludge dryer other than a double drum type sludge dryer.

It is a flow sheet figure showing one embodiment of the deodorization device of the sludge dryer concerning the present invention. It is a flow sheet figure which shows the sludge dryer which does not use a deodorizing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Drum dryer 3 Dehydrated sludge supply mechanism 4 Scraper 5 Transfer conveyor 6 Discharge conveyor 7 Fan 8 Wet scrubber 9 Biodeodorization tower 10 Air-water separator 11 Drain groove 12 Supply pump 13 Water storage tank 14 Submersible pump 15 Water supply tank 16 Raw water tank 17 Cooling water tank 18 Circulation pump 19 Cooling tower

Claims (1)

A deodorizing device used in a sludge dryer for drying sludge,
A wet scrubber that introduces exhaust gas containing evaporated vapor generated from the sludge dried by the sludge dryer, showers the exhaust gas with a refrigerant, and cools and dehumidifies;
A biological deodorization tower that introduces exhaust gas that has been cooled and dehumidified by the wet scrubber and removed condensed water from the evaporated vapor, and biochemically deodorizes odors contained in the exhaust gas;
In order to maintain the activity of microorganisms in the biological deodorization tower in an enhanced state, the temperature of the exhaust gas introduced from the wet scrubber to the biological deodorization tower is set to the outside air temperature or the temperature of the evaporated vapor generated in the sludge dryer. Irrespective of the sludge dryer, comprising a cooling means for cooling the refrigerant used for exhaust gas showering by the wet scrubber so as to maintain an optimum temperature for the activity of microorganisms in the biological deodorization tower. Deodorizing device.

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