JP2013154316A - Fermentation treatment method of organic waste and apparatus that executes the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment method and an apparatus that can efficiently remove malodor in exhaust gas generated by garbage treatment in a garbage treatment apparatus by a fermentation treatment.SOLUTION: Exhaust gas G1 that has a malodorous component caused in a process that performs the fermentation treatment of garbage T in a fermentation chamber 1 is led to a deodorization and cooling tank 9, and the malodorous component in the exhaust gas G1 is subjected to adsorption removal by the ultrafine particle of circulating water jetted from a fine particle nozzle 18, and the jetting amount of the ultrafine particle is regulated so that the malodorous component is not evaporated by the re-temperature rise of the exhaust gas G1 by the latent heat discharge based on the coagulation of water vapor in the exhaust gas G1, and almost all of the malodorous component are removed by the deodorization and cooling tank 9. In the exhaust gas that goes out of the deodorization and cooling tank 9 as primary treatment gas G2, the water content is removed in a cooling and gas-liquid separation tank 13, and the remaining malodorous component is removed by a supplementary deodorizing device 14, then the exhaust gas is emitted to the atmosphere as a final treatment gas G3.

Description

  The present invention relates to a method for treating organic waste such as raw food and an apparatus for carrying out the method, and in particular, efficiently fermenting these organic waste by suppressing the generation of bad odor in garbage treatment. The present invention relates to a waste disposal method and apparatus.

  In recent years, a large amount of raw garbage has been generated in households, restaurants and the like, and disposal thereof has become a problem. Garbage contains a large amount of moisture, and it rots in a short period of time, especially when the temperature is high, such as in summer, and generates a foul odor. As for garbage disposal, disposal methods such as landfill are sanitary problems, and it is difficult to secure such a disposal site. In addition, considering the corruption, the processing of garbage can be carried out by placing individual garbage processing equipment closer to the place where the garbage is generated than the method of mass accumulation and mass processing in the plant. It is desirable to process in a short time. In other words, it is desirable to arrange relatively small-scale devices in multiple points, and to perform processing quickly by using these devices relatively close to the garbage generation source.

From such a viewpoint, various apparatuses for processing raw garbage have been proposed in addition to large-scale garbage processing plants. In this case, since garbage is an organic waste containing a large amount of moisture, incineration requires a large amount of thermal energy, and also requires treatment of exhaust gas accompanying incineration. It can be said that this is an uneconomical method for garbage disposal. For this reason, as shown in the following patent documents, there have been proposed a number of apparatuses and methods for biologically decomposing garbage.
JP-A-7-124538 JP-A-8-168742 JP 2001-340879 A JP 2007-001778 A

  This type of apparatus, including the inventions described in the above-mentioned patent documents, includes a fermentation chamber (usually having a stirring means), a means for processing a gas with odor generated in the fermentation chamber, and a means for supplying air to the fermentation chamber. In many cases, it has a means for deodorizing the malodorous gas generated in the fermentation chamber.

  Such a fermentation treatment apparatus also has advantages and disadvantages due to the difference in configuration. Here, even if it is simply called raw garbage, plant garbage such as vegetable scraps, animal garbage such as fish and meat, cooked leftover food, etc., size, moisture content, behavior during stirring, etc. are quite different It is. As a result, even if air is supplied to the fermentation chamber and the input garbage is agitated, the air does not spread uniformly over the entire garbage, and the passage of air is extremely small or no air is supplied at all. Will occur. In such a portion, the aerobic fermentation bacteria do not grow and anaerobic rot bacteria are generated. In an extreme case, there is a possibility that the whole garbage thrown into the processing apparatus is rotted.

  In fact, including the above points, it is difficult to completely eliminate malodorous components from the gas generated from the fermentation chamber. Therefore, when this type of device is used as an actual machine, Deodorizing treatment is absolutely necessary. That is, if the deodorizing process is not properly performed as an apparatus, it is impossible to employ a garbage disposal system in which relatively small-scale apparatuses as described above are arranged in multiple points.

As a method for deodorizing treatment, there are methods such as adsorption of malodorous components by activated carbon or the like, thermal decomposition of malodorous components, decomposition of malodorous components using microorganisms, and the like.
Of these, the malodorous component adsorption method using activated carbon or the like requires a large or multi-stage adsorption means because the amount of gas generated by fermentation decomposition is relatively large, and a large amount of water vapor generated during the fermentation process is the treatment target gas. Since it is contained, there exists a problem that the performance of adsorbents, such as activated carbon, will fall significantly in a short period.

  In addition, in the thermal decomposition method that thermally decomposes malodorous components, energy costs such as fuel costs are required in order to generate high temperatures. In particular, as described above, since the gas to be treated contains a large amount of water vapor, the amount of energy used is larger. . In other words, this deodorization method is uneconomical to be provided in each processing apparatus, and in some cases, it may be said that the method does not meet the cost, such as the necessity of reprocessing the pyrolyzed gas. Furthermore, biological deodorization originally requires a large-scale facility, and it is practically impossible to employ a relatively small-scale garbage disposal apparatus.

The present invention is configured in view of the above-described problems of the prior art.
That is, in the present invention, a means for spraying water fine particles is disposed in a space through which a gas (processing target gas) generated in a fermentation chamber that performs fermentation processing of garbage passes or a deodorizing space, and the water fine particles A garbage processing apparatus configured to adsorb a malodorous component of a gas to be treated and reduce the gas temperature below a temperature at which the gas to be treated again generates malodor even if the malodorous component remains. is there.

  It is possible to effectively treat malodor by spraying water fine particles on the gas containing malodorous components generated in the fermentation chamber, and the means for generating water fine particles can be made small and inexpensive. Therefore, the entire apparatus can be provided in a small size and at a low cost. Therefore, a system in which the processing apparatuses are arranged at multiple points near the garbage generation source as described above can be constructed.

  Since the gas to be treated is cooled by the fine particles of water, the bad odor will not volatilize again even if the bad odor component remains, but in fact the majority of the bad odor component is removed by spraying the fine particles, Even if another deodorizing means is arranged in the subsequent stage, it is sufficient to install a small adsorbent as an auxiliary.

  A deodorizing / cooling tank is connected to the fermentation chamber, and the gas generated in the fermentation chamber is configured to flow into the deodorizing / cooling tank. Install spraying means. The fine water particles are, for example, extremely fine particles having a particle size of 5 μm or less. Embodiments of the present invention will be specifically described below with reference to the drawings.

1 to 3 show an embodiment of the present invention.
First, mainly in FIG. 1, the code | symbol 1 shows the fermentation chamber, and the code | symbol 2 has shown the stirring apparatus arrange | positioned in this fermentation chamber 1. FIG. Two stirring devices 2 are arranged in parallel in the fermentation chamber 2 as indicated by reference numerals 2A and 2B in FIGS.

  Specifically, the configuration of the stirring device 2 is mainly shown by a device denoted by reference numeral 2A. Reference numeral 2a is a rotating shaft that is configured to be rotated by driving means such as an electric motor 3 (3A), and to the rotating shaft 2a. On the other hand, a plurality of stirring blades (hereinafter simply referred to as “blades”) 2b are attached radially about the rotation shaft 2a. Further, since these blades 2b are attached at a constant angle (pitch) with respect to the axis of the rotary shaft 2a, the garbage T is agitated by the rotation of the rotary shaft 2a and is constant along the axial direction of the rotary shaft 2a. Configured to move in the direction.

  The stirring device 2B also has the same structure as the stirring device 2A. That is, the blade 2b is attached to the rotating shaft 2a, and the rotating shaft 2 is configured to be rotationally driven by another electric motor 3B.

  In the above configuration, when the pitch of the blades 2b with respect to the rotating shaft 2a in each of the stirring devices 2A and 2B is the same, the electric motors 3A and 3B are reversely rotated as shown in FIG. The garbage T moves from the arrangement side of the electric motor 3A toward the rear wall of the fermentation chamber 1, and in the stirring device 2B, conversely, moves from the rear wall of the fermentation chamber 1 to the electric motor 3B side. Thus, as shown by the arrows in FIG. 2, the garbage T is configured to sequentially move in the fermentation chamber 1 while being stirred by the individual stirring devices 2A and 2B. If the pitches of the blades 2b in the stirring devices 2A and 2B are reversed, it is naturally possible to make the behavior of garbage similar to the above by rotating the electric motors 3A and 3B in the same direction.

  Next, reference numeral 4 denotes an air supply device arranged at the bottom of the fermentation chamber 1. 4a is a container (hereinafter referred to as "branching header") that constitutes a space portion into which air supplied from an air supply means such as a blower described later flows, and is configured in a box shape, a pipe shape, or the like. A number of air holes 4b are formed in the branch header 4a, and the air is uniformly discharged into the fermentation chamber 1.

  Reference numeral 5 is a blower that supplies air A to the branch header, 6 is a heating chamber that raises the temperature of the air discharged from the blower 5 to a constant temperature, and 7 is a heater that heats the air that has flowed into the heating chamber 6. By doing so, the air is heated so that the temperature in the fermentation chamber 1 becomes a predetermined temperature.

  Reference numeral 9 denotes a deodorization / cooling tank, which is connected to the fermentation chamber 1 through an exhaust passage 8. Reference numeral 10 is a circulating water tank, 11 is a circulating water pump, 12 is a compressor, 13 is a cooling / gas-liquid separation tank, 19 is an exhaust blower for exhausting the processing gas in the cooling / gas-liquid separation tank 13, and 14 is an auxiliary deodorizing device. , 15 is a control unit for controlling these devices.

Next, the method and the apparatus for carrying out the method will be described more specifically with reference to FIG. 4 and FIG.
First, garbage T is thrown into the fermentation chamber 1 (S1 in FIG. 4). As shown in the figure, the input amount is such that the blades 2b of the stirring devices 2A and 2B are hidden. As a result, a space 1a having a volume substantially equal to the input volume of the garbage T, for example, is formed on the upper part of the garbage T in the fermentation chamber 1, and this space 1a is steam generated during fermentation of the garbage T as described later. It is also used as a buffer space for adjusting the partial pressure of the. Subsequently, a fermenting bacterium (actually a fermenting bacterium charge having a fermenting bacterium) is input to the garbage T (S2).

  When a predetermined amount of garbage T is charged, the two agitators 2A and 2B are operated to agitate the garbage T 2 and simultaneously move in the fermentation chamber 1 as indicated by the arrows in FIG. 2 (S3). At this time, the air A supplied from the nozzle 4b of the air supply device 4 located at the bottom of the garbage T is made to contact the garbage T evenly (S4). In addition, the rotation speed of each stirring apparatus 2A, 2B is about 2 rpm.

  In order to effectively promote the fermentation of the garbage T, the temperature of the garbage T needs to be about 70 ° C. to 80 ° C. However, since the fermentation is immature immediately after the input of the garbage T, this temperature The temperature of the air A supplied to the fermentation chamber 1 by operating the heater 7 is raised to, for example, about 50 ° C. and supplied to the fermentation chamber 1 to increase the temperature of the garbage T. Promote fermentation (S5 / S6). Note that since the air discharged from the blower 5 is compressed, the temperature of the air A has increased in advance due to this compression (about 30 ° C. at 13 kpa), and the electrical energy for heating the heater 7 is reduced accordingly. The Further, in the case of normal operation where fermentation is stable, it is basically unnecessary to use the heater 7.

  When the ambient temperature of the raw garbage T reaches the temperature at which fermentation continues efficiently due to the promotion of fermentation, the heater 7 is turned off (S7), and normal temperature air A is supplied (S8). When the controller 15 is used, the ambient temperature of the garbage T is detected by the temperature sensor S2, and the above control is automatically performed by turning on and off the power switch SW of the heater 7 based on the detection result. it can. The following description is based on the assumption that the control unit 15 automatically performs control.

  As the fermentation progresses, the water contained in the garbage T evaporates and becomes a gas, so that its volume increases about 1000 times. For this reason, the pressure in the fermentation chamber 1 rises. However, since the increase in pressure suppresses the generation of steam and consequently suppresses fermentation, the pressure in the fermentation chamber 1 should be kept below a certain value. Is desirable. As described above, the space 1a having a large volume is formed in the upper portion of the fermentation chamber 1 for the purpose of using the space 1a as a buffer space for increasing pressure.

  The control unit 15 detects the pressure (atmospheric pressure) of the space 1a with the pressure sensor S1 (A10), and compares the degree of opening of the damper 16 in the exhaust passage 8 with comparison with the processing state of the deodorizing / cooling tank 9 at the rear stage of the fermentation chamber 1. It adjusts and it controls so that the pressure in the fermentation chamber 1 may become below a fixed value (S11 / S12). In this case, since the space 1a has a buffer function as described above even if the opening of the damper 16 cannot be temporarily opened to the set value due to the treatment state of the deodorizing / cooling tank 9, the fermentation chamber 1 has the buffer function as described above. The situation in which the pressure inside increases rapidly can be avoided.

  As the fermentation progresses, the garbage T and the fermenting bacterium carrier become dry powder, and a part thereof is scattered in the exhaust passage 8 as dust together with the exhaust gas G1 (S14). Since this dust may adhere to the inner surface of the exhaust passage 8 and eventually close the exhaust passage 8, a cleaning nozzle 17 is provided for the purpose of preventing the adhesion of dust. Dust is removed by washing (S15), and the drainage from which the dust has been removed is configured to flow into the deodorization / cooling tank 9 through the exhaust passage 8. . The water droplets ejected from the cleaning nozzle 17 may be a normal nozzle that ejects water droplets having a relatively large particle diameter for dust removal, but a nozzle that ejects water droplets of fine particles, which will be described later, may also be used. Is possible.

  Gas (exhaust gas) G1 generated by fermentation contains not only a large amount of water vapor but also malodorous components such as low boiling point ammonia. The amount of heat generated by fermentation of raw garbage is about 5000 kcal / kg on average, and this amount of heat is mainly discharged outside the fermentation chamber 1 together with the exhaust gas G1 as latent heat of water vapor.

  Here, it is known that water adsorption is an effective deodorization method for removing malodorous components in the gas. However, when water is sprayed on the exhaust gas without special consideration, condensation of water vapor in the exhaust gas is performed. As a result, there is a problem that the latent heat is released, and as a result, the temperature of water such as spray water rises, and ammonia or the like, which is the low-boiling malodorous substance, is evaporated again to produce a bad odor.

  In other words, when the exhaust gas G1 is deodorized, it is necessary to simultaneously perform deodorization and cooling of the exhaust gas containing water vapor (directly cooling water sprayed on the exhaust gas). Reference numeral 18 denotes a fine particle nozzle provided in the deodorizing / cooling tank 9 to achieve this object.

  The water particles ejected from the fine particle nozzle 18 are nozzles for ejecting fine particles having a small diameter of 5 μm or less (hereinafter referred to as “ultra fine particles”). By making water into ultrafine particles, the surface area of water is increased, and the adsorption efficiency of malodorous components in the exhaust gas G1 can be increased. Further, the adsorption of malodorous components and the cooling of the exhaust gas G1 can be performed at the same time by balancing the heat absorption due to evaporation of ultrafine water and the heat generation due to the release of latent heat due to condensation of water vapor in the exhaust gas G1. .

  Specifically, if the temperature of the exhaust gas G1 is 30 ° C. or higher, malodorous components are evaporated and malodorous odors are generated, so that the atomization air supplied from the compressor 12 and the ultrafine particles supplied from the circulation tank 10 are used. The supply amount of the circulating water is appropriately adjusted so as to adjust the temperature of the exhaust gas G1 to be equal to or lower than the above temperature (S16). Incidentally, the circulating water is cooled to a predetermined temperature in the cooling / gas-liquid separation tank 13. These controls are automatically controlled by the controller 15 based on the temperature information of the temperature sensor S3 disposed in the deodorizing / cooling tank 9.

  By jetting ultrafine water while adjusting the temperature of the exhaust gas G1, most of the malodorous component in the exhaust gas is removed and flows into the cooling / gas-liquid separation tank 13 as the primary processing gas G2, The primary processing gas G2 that has been gas-liquid separated in the gas-liquid separation tank 13 is freed of malodorous components remaining in the auxiliary deodorizing device 14 and released to the atmosphere as the final processing gas G3 (S17 / S18). In addition, since most of the deodorizing components are removed using ultrafine particles in the deodorizing / cooling tank 9 as described above, the primary processing gas G2 may be directly opened to the atmosphere after gas-liquid separation in many cases. Therefore, the auxiliary deodorizing device 14 is for auxiliary use only, and a small capacity is sufficient. For example, in the case of activated carbon, it is sufficient to arrange a small number of small-sized activated carbon mats.

  On the other hand, the water sprayed from the cleaning nozzle 17 and the fine particle nozzle 18 and accumulated at the bottom of the deodorizing / cooling tank 9 flows into the circulation tank 10, and the water separated from the primary treatment gas G 2 in the cooling / gas-liquid separation tank 13 is It flows directly into the circulation tank 10 and is supplied to the washing nozzle 17 and the fine particle nozzle 18 to be used as circulating water. Unnecessary water is discharged from the circulation tank 10 and then subjected to purification treatment and discharged outside the system. On the other hand, the circulating water used in the system is not shown, but it is recycled in the system as circulating water after appropriate treatments such as precipitation, removal of solids by filtration, etc., and introduction of a neutralizing agent. The

  In parallel with the exhaust gas treatment described above, fermentation of the garbage T proceeds in the fermentation chamber 1 and finally becomes a dry residue. When the fermentation process is completed in this way, the residue is discharged from the fermentation chamber 1 and is subjected to the next process.

  As mentioned above, in order to process garbage in a place close to the garbage generation source by arranging a plurality of the present invention in a specific area, it is assumed that the processing device is configured in a small size. It is possible to configure it as a large apparatus.

It is a systematic diagram which shows the whole structure of the garbage processing apparatus which concerns on this invention. It is a top view of the stirring apparatus provided in the fermentation chamber 1 in FIG. It is sectional drawing by the AA line of FIG. It is a flowchart which shows the state which implements the method which concerns on this invention. FIG. 5 is a flowchart showing a continuation of the flowchart shown in FIG. 4.

DESCRIPTION OF SYMBOLS 1 Fermentation chamber 1a (fermentation chamber) upper space 2, 2A, 2B Stirrer 2a (stirring device) rotating shaft 2b (stirring device) Stirring blade 3, 3A, 3B (for stirring device driving) Electric motor 4 Air supply Device 4a (Air supply device) Branch header 4a (Air supply device) Air hole 5 Blower 6 (Supply air) heating chamber 7 Heater 8 Exhaust passage 9 Deodorizing / cooling tank 10 Circulating water tank 11 Circulating water pump 12 (Fine particles) Compressor for nozzle 13 Cooling / gas-liquid separation tank 14 Auxiliary deodorization device 15 Control device 16 Damper 17 Cleaning nozzle 18 Fine particle nozzle 19 Exhaust blower A Air G1 Exhaust gas G2 Primary processing gas G3 Final processing gas S1 Temperature sensor S2 Pressure sensor S3 Temperature Sensor SW Heater switch T Garbage

Claims (8)

A method of fermenting organic waste such as raw garbage put into a fermentation chamber with a fermenting bacterium, wherein the gas generated in the fermentation process in the fermentation chamber is exhausted out of the fermentation chamber as exhaust gas, The ultrafine particles of water are sprayed on the discharge route, and by adjusting the spray amount of the ultrafine particles of water, the adsorption of malodorous components in the exhaust gas and the temperature adjustment of the exhaust gas are performed. A method for fermentation treatment of organic waste. A device that ferments organic waste such as garbage that has been put into the fermentation chamber with fermenting bacteria, and adjusts the spray amount of ultrafine water particles to the route that discharges the exhaust gas generated in the fermentation chamber to the outside. Organic waste that is configured to adsorb odorous components in the exhaust gas and adjust the temperature of the exhaust gas by arranging spraying means possible and adjusting the spray amount of the ultrafine water particles Fermentation processing equipment. The fermentation chamber is connected to the deodorization / cooling tank via the exhaust passage, and the exhaust gas generated in the fermentation chamber is configured to flow into the deodorization / cooling tank. Fine particles that inject ultrafine water into the deodorization / cooling tank 3. A nozzle is provided, and ultrafine water sprayed on the exhaust gas and water condensed with water vapor in the exhaust gas are configured to accumulate as circulating water at the bottom of the deodorizing / cooling tank. The organic waste fermentation treatment apparatus described. A cooling / gas / liquid separation tank is provided downstream of the deodorization / cooling tank, and an auxiliary deodorization device is provided downstream of the cooling / gas / liquid separation tank, so that the exhaust gas deodorized by the deodorization / cooling tank is primary. 4. The process gas according to claim 3, wherein the process gas flows into the cooling / gas-liquid separation tank and is removed to the atmosphere as the final process gas after removing the malodorous components remaining in the auxiliary deodorizing apparatus after removing water. Fermentation processing equipment for organic waste. 5. An organic waste fermentation according to claim 3 or 4, wherein a washing nozzle is provided in an exhaust passage connecting the fermentation chamber and the deodorizing / cooling tank so as to wash away dust scattered from the fermentation chamber. Processing equipment. The fermentation chamber is provided with a pair of stirrers each having a rotating shaft, a stirring blade provided on the rotating shaft, and a drive means for rotating the rotating shaft, and the organic waste is stirred by the operation of the pair of stirrers. The organic waste according to any one of claims 2 to 5, wherein the organic waste is configured to move in a certain direction in the fermentation chamber along the axial direction of the rotation shaft of each stirring device. Waste fermentation treatment equipment. The fermenting treatment of organic waste according to any one of claims 2 to 6, wherein an air supply device for supplying air to the organic waste being stirred is arranged at the bottom of the fermentation chamber. apparatus. 8. The organic waste fermentation treatment apparatus according to claim 7, wherein means for heating the air is disposed in a path for supplying air to the air supply apparatus.

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