JP4782595B2 - Method and apparatus for fermentation treatment of food waste - Google Patents

Description

  The present invention relates to a fermentation treatment method and apparatus for a multi-tank circulation type food waste, which is an organic waste such as cooking residue and food waste discharged from hotels, restaurants, supermarkets, shopping centers and the like.

  Various environmental problems arise from the current mass production, mass consumption, mass disposal lifestyle, limited resources, and waste of energy. For sustainable development in the future, the environment and economy are integrated. Transformation into a type economic and social system is desired. Furthermore, regarding food wastes that are obligated to be reduced by the Food Recycling Law, there is a growing social demand for the formation of a recycling-oriented economic and social system through recycling (composting), and the efficiency of food waste is improved. Development of fermentation treatment equipment is desired.

Conventionally, in the treatment of food waste, generally, waste is put into a processing machine using a rotary kiln or the like to be mud, and then transported to an incineration plant for incineration.
Conventionally, as a method of reducing or composting (composting) food waste by aerobic fermentation, a natural fermentation method that slowly takes time and a method of biofermenting by drying food waste Has been done. In the natural fermentation method, the weight becomes about 1/10 after about 90 days, and in the dry / bio method, the weight becomes about 1/3 after about 90 days.

  Conventionally, as a fermentation treatment device for organic waste such as garbage, a heater is provided, and a fermentation adjustment tank for adjusting the input organic waste to a predetermined temperature and moisture content condition, and a fermentation adjustment tank A natural fermenter for naturally fermenting the transferred organic waste, and a drying tank for drying and discharging the organic waste transferred from the natural fermenter in order, further equipped with a heater The thing of a structure is known (for example, refer patent document 1).

Moreover, as a garbage processing device, an upper space is provided in the processing chamber and a plurality of partition walls are interposed, and the processing chamber is divided into a charging tank, a plurality of fermentation tanks and a storage tank, and a stirring transfer blade is provided in each tank. The thing of the structure which has arrange | positioned the supply pipe of warm air to the said several fermenter while making the provided rotating shaft penetrate is known (for example, refer patent document 2).
JP-A-7-204616 (first page, FIG. 2) Japanese Patent Laid-Open No. 7-16558 (2nd page, FIG. 1)

  The conventional natural fermentation method is fermented by the proper moisture concentration and improved air permeability by using auxiliary materials, and is implemented in rural areas, but it takes a long time to complete the fermentation because of the natural environment. is there. In addition, a large volume is required for processing in a natural environment for a long period of time, and further, the size of the apparatus increases because sub-materials are used. In addition, there is a problem in on-site implementation such as the need to store auxiliary materials. In the conventional drying / biofermentation method, the weight loss rate is about 70%, which is not sufficient in terms of volume reduction. Moreover, in the method of said patent document 1, 2, when the quantity of the food waste to process increases / decreases, it cannot fully cope with and the processed material obtained is hard to handle easily as compost. .

  The problems to be solved are that the conventional method has a long fermentation period and cannot efficiently process a large amount of food waste, and the apparatus and volume increase, and the processed product is easy to handle as compost (compost). The point is that it is not shaped.

The present invention is intended to provide a fermentation processing method and apparatus that can reduce the processing energy required for food waste processing and the complexity of work, and can greatly reduce and efficiently process a large amount of food waste. It is. In other words, we developed a fermentation treatment device that can be installed on-site in urban areas that satisfies the optimal fermentation environment (moisture, aeration, temperature, and return compost), maximizing the fermentation in the optimal fermentation environment, shortening the fermentation period, It is intended to save volume.
For this reason, the present invention includes a food waste input device, a stirring tank, a plurality of fermenters, a final treatment tank, a transport device for connecting them, and an aeration device, and controls the temperature, moisture, and aeration amount in the fermenter. The main feature is that food waste is fermented to obtain dry pellets that can be easily handled as compost.

  The method for fermenting food waste according to the present invention comprises adding food waste to a stirring tank, adding back compost to adjust the moisture, stirring and mixing, and then transferring and granulating the stirring and mixture. Transfer to 1 fermenter and add water while heating by aeration and ferment, then transfer and granulate fermented product, transfer to next fermentor and add water while heating by aeration and ferment After repeating the process to be performed at least once (one or more times), the fermented product is transferred to the final treatment tank, dried into pellets, and part of it is circulated into the stirring tank as the return compost, and the rest is processed. It is characterized by being discharged as compost.

In this fermentation treatment method, the temperature, moisture, and aeration rate in each fermenter are controlled. In this case, the temperature in each fermenter is controlled to be 30 to 40 ° C. and the moisture is 40 to 60%.
Moreover, the gas generated from the fermenter is supplied to a fermentor that stores fermented products having different maturity levels, and the pH of the fermented product is adjusted. In addition, the amount of exhaust to each fermenter is controlled so as to exceed the amount of supplied air so that the inside of the vessel is always kept at a negative pressure.

  The food waste fermentation treatment apparatus of the present invention is connected to a stirring tank equipped with a food waste input device, a plurality of fermenters connected to the downstream side of the stirring tank, and each fermenter. An aeration line for performing warming aeration, moisture adjusting means connected to each fermenter, a final treatment tank connected to the downstream side of the most downstream fermenter, a bottom of the stirring tank, and each fermentation Fermentation object conveyance device that connects the upper part of the tank and the upper part of the final treatment tank, a granulator provided in the conveyance apparatus, a pelletizing device provided in the lower part of the final treatment tank, and the pelletization apparatus It is characterized in that it is provided with a return compost circulation means for connecting the outlet of the tank and the upper part of the stirring tank.

In this fermentation treatment apparatus, temperature control means for controlling the temperature in each fermenter, moisture adjusting means for controlling the moisture in each fermenter, aeration for controlling the amount of ventilation into each fermenter A quantity control means is provided.
Further, the apparatus includes a transport device that moves the fermentation objects stored in the connected fermenters to designated fermenters or final treatment tanks, and further includes destination calculation means for calculating the destination from the temperature of each tank. ing. In addition, the fermentation objects with different maturity levels are stored in the connected fermentation tanks, and the gas generated from each tank is supplied to the tanks storing the fermentation objects with different maturity levels to adjust the pH of the objects. A ventilation means is provided.

  Moreover, it has the conveyance means which stored the fermentation target object from which a maturity degree differs in the connected fermenter, respectively, throws a target object into the target object from which a maturity degree differs, and adjusts the pH of a target object. Further, a drying system is provided in which one exhaust gas line provided with a deodorizer is connected to one of the connected fermenters, and the object is dried by the exhaust heat of the exhaust gas in the exhaust gas line. Further, an exhaust gas line is connected to the first fermentor (the lowest fermentor) upstream from the final treatment tank.

  A condensate tank is connected to the most cooled part of the aeration line, and it is dripped from the top of the fermenter via a water spray pipe provided at the top of each fermenter to adjust the moisture of the fermentation object. In this way, the moisture adjusting means is configured. In addition, a single supply / exhaust mechanism is provided for the connected fermentation tanks, and a calculation means is provided to keep the connected tanks at a negative pressure at all times by controlling the flow rate so that the exhaust amount exceeds the supply air amount. It has been. In addition, a pelletizing device is provided in the final processing tank, a part of the final processed product dried and pelletized by this pelletizing device is mixed with the fermentation object as return compost, and the remaining product is discharged. Is provided. The apparatus of this invention has a structure which connects a stirring tank, a fermenter, and a final treatment tank in the horizontal direction, and respond | corresponds with the increase / decrease in the number of combinations of the fermenter to connect with the increase / decrease in the required processing capacity.

As described above, the apparatus of the present invention is a multi-tank circulation type fermentation apparatus, and the optimum fermentation conditions are as follows.
(1) Adjust moisture to 40-60%. In other words, it is moisture that can be processed into blocks by granulation while retaining moisture necessary for fermentation. If the water content is less than 40%, the bacteria are not activated, and if the water content exceeds 60%, the waste becomes muddy and difficult to treat.
(2) Aeration temperature: Adjust to 30-40 ° C. When the temperature in the tank is less than 30 ° C and the temperature in the tank exceeds 40 ° C, the fermentation is not sufficiently performed.
(3) Ventilation amount The optimum circulation rate is controlled by an inverter.
(4) Ventilation conditions Improve air permeability by making it into a block with a granulator.
(5) Addition of bacteria Circulate decomposing bacteria in the return compost.
(6) Processed product pH Neutralization is performed by aerating the gas generated in the fermenters with different maturity levels to each other so that the bacteria can be maintained at neutrality.
(7) Processed oil content Decompose in response to fermentation with high oil content (15%).
(8) A weight loss ratio of 90% or more is obtained.

  In addition, as a basic design of the equipment structure, a plurality of fermenters that satisfy the fermentation conditions are connected to circulate the processed material between the tanks. As an example of a deodorization system, a platinum catalyst type deodorization apparatus is used which controls the supply / exhaust amount so that the inside of the fermenter has a negative pressure. In addition, the treated product is made into dry pellets having a diameter of 5 to 10 mm that can be applied to a compost spraying device to improve handling.

Since this invention is comprised as mentioned above, there exist the following effects.
(1) As shown in FIG. 3, in the conventional natural fermentation method, the weight loss rate is about 90% in about 90 days, and in the conventional dry / biofermentation method, the weight loss rate is about 70% in about 90 days. However, in the fermentation apparatus of the present invention, the weight loss rate can be reduced to about 90% in about 30 days.
(2) By performing the high-speed fermentation treatment, the apparatus can be reduced in volume (compact) and reduced in cost, and can be installed in a current machine room such as a hotel.
(3) By increasing or decreasing the fermenter, it is possible to easily cope with the increase or decrease in capacity.
(4) Since the treated product is a dry pellet, it can be easily sprayed by a compost spraying device, and the handling becomes extremely easy.

  Food waste input device, stirring tank, multiple fermenters, final treatment tank and conveying device connecting them, with the objective of reducing the volume efficiently in a short period of time and obtaining an easy-to-handle processed material (compost) This was achieved by providing a venting device, controlling the temperature, moisture, and aeration rate in the fermenter to ferment food waste and providing a pelletizing device at the bottom of the final processing bath.

Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications.
FIG. 1 shows a schematic configuration of a food waste fermentation treatment apparatus according to a first embodiment of the present invention, and FIG. 2 shows a process of the apparatus in FIG. In the apparatus of this example, the turning-over process required for fermentation (the process of raising the object that was below) is performed by transferring the processed product from the tank in the apparatus to the tank. In addition, each tank is unitized, and the number of tanks is changed according to the processing capacity, so that the basic structure corresponding to the required capacity is obtained without changing the basic structure. Furthermore, the inside of each tank is controlled to an optimum environment (aeration temperature, moisture, aeration amount) for fermentation, and a mechanism for performing high-speed fermentation.

  As shown in FIG. 1, the fermentation treatment apparatus of this example includes a stirring tank 10 provided with a food waste charging device 16 and a plurality of fermentation tanks connected to the downstream side of the stirring tank 10 (this example). Then, as an example, the 1st fermenter 11, the 2nd fermenter 12, the 3rd fermenter 13, the nth fermenter 14), the aeration means 40 connected to each fermenter for performing warming aeration, and each fermentation The moisture adjusting means 46 connected to the tank, the final treatment tank 15 connected to the downstream side of the most downstream fermenter 14, the bottom of the stirring tank 10, and the fermenters 11, 12, 13, 14 A fermentation object transport device 18 that connects the upper part and the upper part of the final treatment tank 15; a granulator 20 provided in the transport apparatus 18; a pelletizing device 22 provided in the lower part of the final treatment tank 15; Back pile connecting the outlet of the pelletizing device 22 and the upper part of the stirring tank 10 And a circulating means 24.

  26 is a processed product (compost) extraction line (processed material transport mechanism), 28 is an exhaust gas line, 30 is a deodorizer provided in the exhaust gas line, 32 is an air heater (heat exchanger), 34 is an exhaust gas fan, 36 is an intake fan, 38 is a circulation fan, 40 is a ventilation means, 42 is a condensed water tank, 44 is a water spray pipe, 46 is a moisture adjusting means, 48 is a condenser plate, 50 is an oximeter, 52 is a controller, and 54 is A bypass line, 56 is a bypass valve, 58 and 60 are vent holes, and 62 is an intake pipe.

  In the fermenting apparatus configured in this way, as shown in FIG. 2, the food waste (garbage etc.) is put into the agitation tank 10 and a part of the return compost from the pelletizing apparatus 22 is added to adjust the moisture. Then, the agitation / mixture is transferred and granulated, transferred to the first fermenter 11 and added with moisture while being heated by aeration, and then fermented product is transferred and granulated. After repeating the process of transferring to the next fermenter (second fermenter 12) and adding water while heating by aeration and fermenting in the third fermenter 13 and the nth fermenter 14, The fermented product is transferred to the final treatment tank 15, dried and pelletized by the pelletizing device 22, a part is circulated to the stirring tank 10 as the return compost, and the rest is discharged as a processed product.

  By recirculating a part of the dried pellet of the pelletizing apparatus 22 to the stirring tank 10 as return compost, the water content of the input can be adjusted and fermented bacteria can be added. Moreover, the acidic gas and water vapor | steam which generate | occur | produce from the acidic target object at the early stage of fermentation hit the condensation plate 48 of a downstream fermenter, and are sprinkled as acidified condensed water.

  The first fermentation tank, that is, the nth fermentation tank 14 is exhausted upstream from the final treatment tank 15, and a deodorizer 30 is provided in the middle of the exhaust gas line 28. The exhaust air of the exhaust gas at the outlet of the deodorizer 30 is recovered by the air heater 32 and heated, and the supplied air is supplied to the bottom of the final treatment tank 15 to dry the object in the final treatment tank 15. The tank is ventilated from the suction port (vent 60) at the top through the vent pipe of the vent means 40. In addition, the oxygen concentration in the fermenter 14 adjacent to the final treatment tank 15 is measured with an oximeter 50, and the supply / exhaust amount is calculated so that the inside of the tank becomes a negative pressure while controlling the oxygen concentration to a reference range. An air supply / exhaust mechanism having a control mechanism is configured. That is, the oximeter 50 is connected to the fans 34 and 36 via the controller 52.

  A tank 42 for storing condensed water naturally condensed is disposed at the lower part of the ventilation pipe of the ventilation means 40 connected to the final treatment tank 15, and the condensed water in the tank 42 is used for watering the upstream fermenter, and surplus The minute is discharged as waste water. Further, the aeration temperature and the aeration amount of the fan 38 are calculated from the temperature in each fermenter. That is, a thermometer 64 is connected to each fermenter, and these thermometers 64 are connected to the circulation fan 38 via the controller 66.

  A cutting device 68 such as a screw conveyor is provided at the bottom of the agitation tank 10 and each fermenter, and is conveyed to the granulator 20 by a conveying device 18 such as a belt conveyor and a screw conveyor common to each tank. In this granulator 20, the processed product whose shape has collapsed due to the pressure of the cutting device 68 in the fermenter is granulated and processed into a block shape of 5 to 20 mm to ensure the promotion of aeration in the fermenter. In addition, the processed product whose properties have been stabilized by the fermentation treatment in the final treatment tank 15 is processed into dry pellets that are easy to handle with the pelletizing device 22, a part is sent to the agitation tank 10, and the remaining part is taken out as pellet compost.

The exhaust gas line 28 and the intake pipe 62 are connected by a bypass line 54 provided with a bypass valve 56. When the intake air temperature is lower than the set temperature, the bypass valve 56 is opened so that high-temperature exhaust gas is mixed into the intake air. It is configured. In FIG. 1, valves other than the damper and the bypass valve 56 are omitted.
Although this embodiment demonstrated the case where a fermenter was 4 or more n groups as an example, it is possible to make a fermenter into 2 units, 3 units, 4 units or more by the processing amount of food waste. .

1 is a systematic schematic configuration diagram of a food waste fermentation treatment apparatus according to a first embodiment of the present invention. It is process explanatory drawing which shows the flow of a process in the apparatus shown in FIG. It is a graph which shows the relationship between the processing days and the processed material weight in the conventional fermentation processing system and the fermentation processing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stirring tank 11 1st fermenter 12 2nd fermenter 13 3rd fermenter 14 nth fermenter 15 Final processing tank 16 Input device 18 Fermentation object conveyance apparatus 20 Granulator 22 Pelletizer 24 Return compost circulation means 26 Processed (compost) extraction line (processed material transport mechanism)
28 Exhaust gas line 30 Deodorizer 32 Air heater (heat exchanger)
34 Exhaust gas fan 36 Intake fan 38 Circulation fan 40 Ventilation means 42 Condensed water tank 44 Water spray pipe 46 Moisture adjustment means 48 Condensation plate 50 Oxygen meter 52 Controller 54 Bypass line 56 Bypass valve 58, 60 Ventilation port 62 Intake pipe 64 Thermometer 66 Controller 68 Cutting device

Claims (13)

While putting food waste into the agitation tank, adding back compost to adjust the moisture and stirring and mixing, then transferring and granulating the agitation and mixture, transferring to the first fermentor and heating by aeration The process of adding water and fermenting, then transferring and granulating the fermented product, transferring it to the next fermentor and heating it with aeration while heating it was repeated one or more times. After that, the fermented product is transferred to the final treatment tank, dried into pellets, a part is circulated to the stirring tank as the return compost, the rest is discharged as a processed product, and the gas generated from each fermenter A method for fermenting food waste, characterized in that the fermenter stores different fermented products and adjusts the pH of the fermented products . Fermentation processing method according to claim 1 food waste, wherein the temperature in each fermenter 30 to 40 ° C., and controls so moisture is 40% to 60%. The method for fermenting food waste according to claim 1 or 2 , wherein the amount of exhaust to each fermenter is controlled so as to exceed the amount of supply air, and the inside of the vessel is always kept at a negative pressure.   An agitation tank equipped with a food waste input device, a plurality of fermenters connected to the downstream side of the agitation tank, aeration means connected to each of the fermentation tanks for warming aeration, and Moisture adjusting means for controlling the water in each fermentor connected to the fermenter, a final treatment tank connected to the downstream side of the most downstream fermenter, the bottom of the stirring tank, and each fermenter Of the fermentation object transport device that connects the upper part of the final treatment tank and the upper part of the final treatment tank, a granulator provided in the transport apparatus, a pelletizing device provided in the lower part of the final treatment tank, and The return compost circulation means connecting the outlet and the upper part of the agitation tank, and the fermentation objects having different maturity levels are stored in the connected fermentation tanks, and the gas generated from each tank is converted to the fermentation objects having different maturity levels. To adjust the pH of the object Fermentation treatment apparatus of the food waste and the ventilation means comprising the. The apparatus for fermenting food waste according to claim 4 , further comprising temperature control means for controlling the temperature in each fermenter and aeration amount control means for controlling the aeration amount into each fermenter. Claims provided with a transport device for moving the fermentation objects stored in the connected fermenters to designated fermenters or final treatment tanks, and further comprising destination calculation means for calculating the destination from the temperature of each tank. Item 6. A food waste fermentation treatment apparatus according to Item 4 or 5 . Linked fermenter maturity degree different fermentation object was stored respectively, the object of the claims 4 to which a transport means which is adapted to put into different objects of maturity degree adjusting the pH of the object The fermentation treatment apparatus for food waste according to any one of 6 . The exhaust gas line of one system with a deodorizer in one of concatenated fermentors connected, exhaust gas line of an object in the waste heat of the exhaust gas with a drying means which is adapted to dry the claims 4-7 The food waste fermentation treatment apparatus according to any one of the above. The apparatus for fermenting food waste according to claim 8 , wherein an exhaust gas line is connected to the first fermentor upstream from the final treatment tank. A condensate tank is connected to the most cooled part of the aeration line, and it is allowed to drip from the top of the fermenter via the water spray pipe provided at the top of each fermenter to adjust the water content of the fermentation object. The food waste fermentation treatment apparatus according to any one of claims 4 to 9 , which constitutes moisture adjustment means. A system comprising a supply / exhaust mechanism of one system for the connected fermenter, and a calculation means for controlling the flow rate of the exhaust gas to exceed the supply air amount so that the connected tank is always kept at a negative pressure. Item 11. A food waste fermentation treatment apparatus according to any one of Items 4 to 10 . The final processing tank is equipped with a pelletizing device, equipped with a processed product transport mechanism that mixes a part of the final processed product dried and pelletized with this pelletizing device with the fermentation object as a return compost and discharges the rest. The fermentation treatment apparatus for food waste according to any one of claims 4 to 11 . Stirred tank fermenter, the final treatment bath is connected in the horizontal direction, the increase or decrease of the required processing capacity, according to any one of comprising a corresponding structure according to claim 4 to 12 in the number of combinations of increase and decrease of the fermenter to be connected Food waste fermentation treatment equipment.