JP2010069477A - Fermentation apparatus for food residue - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fermentation apparatus for food residue where water vapor is efficiently exhausted and deterioration in gas permeability does not occur as well while evading the increase of energy cost and its complication and enlargement. <P>SOLUTION: In the fermentation apparatus, food residue and aerobic microorganisms are mixed in a treatment vessel 10 having air-tightness, and the food residue is fermented while performing aeration agitation. Agitation blades 21 in a plurality of upper and lower stages are radially elongated around a rotary shaft 20 erected at the inside of the vertical treatment vessel 10. An air feed blower 25 is communicated to the lower edge of the rotary shaft 20. The lower edge part of the rotary shaft 20 and the agitation blade 21a at the lowest stage are made hollow, and a plurality of vent holes are made at the lower face of the agitation blade 21a at the lowest stage. Exhaust is forcedly performed by an exhaust blower 15 via an exhaust port 12 at the upper face while feeding air from the lower face of the agitation blade 21a at the lowest stage. The aeration rate (m<SP>3</SP>/min) is controlled to ≥20%, preferably ≥50% to the volume (m<SP>3</SP>) of the treatment vessel 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a food residue fermentation treatment apparatus for fermenting food residues such as food waste and food production by-products while aeration and stirring in an airtight container using the action of aerobic microorganisms.

  Every year, food residues such as food waste and food production by-products are generated in large quantities from the food manufacturing industry, restaurant industry, and food distribution industry. For example, fishery products such as fishery products, meat, and vegetables produce garbage such as fish scraps, meat scraps and vegetable scraps. Surplus foods are discarded from the food distribution industry, and okara and sake lees are produced as food by-products from the tofu and liquor manufacturers. Conventionally, these food residues are often incinerated or landfilled. However, incineration requires equipment costs and there are also dioxin problems. Landfill has problems such as generation of odor and securing of location. Therefore, composting such as manure and compost, or feed for livestock has been increasing as a food recycling resource for reducing the environmental burden. In addition, for example, okara can be used as an ingredient for various dishes, but there are still problems with the texture and the consumption as an ingredient is very small, and most of it is used as industrial waste or general waste. It is currently being discarded.

  However, food residues have a high moisture content (water content), so they can easily be spoiled and poor in storage safety, and are heavy and bulky, resulting in poor transport efficiency and wide storage space. There are many challenges to do. For this reason, in recent years, food residues have been increased to feed or compost by utilizing the fermentation action of microorganisms. Examples of such a food residue fermentation treatment apparatus include Patent Documents 1 to 3. In these apparatuses, food residues and aerobic microorganisms are mixed in an airtight container, and food residues and the like are fermented by the action of aerobic microorganisms while aerated and stirred in the container.

  Specifically, Patent Document 1 is an okara fermentation processing apparatus, in which a rotating drum having airtightness is horizontally installed on a gantry. The agitating means for agitating the inside of the rotating drum includes a rotating shaft extending in the horizontal direction and an agitating blade rotating longitudinally around the rotating shaft in the horizontal direction. Heated air heated by a heating burner is sent from one side wall of the rotating drum and exhausted from the other side wall of the rotating drum through an exhaust pipe. The heated air is intermittently supplied based on a detection signal of a temperature sensor provided in the discharge unit.

  In the fermentation treatment apparatus of Patent Document 2, the inside of a treatment tank having airtightness is divided into a lower processing unit and an upper dehumidifying unit. In the processing unit, the rotation shaft is horizontally provided in the horizontal direction, and the stirring blade is vertically rotated in the rotation axis direction. Moreover, the heating means is provided in the process tank, and it has the structure which heated air spouts from the bottom wall of a process part. The dehumidifying section has a cooling means and a structure for collecting dew drops collected by the action of the cooling means.

  The fermentation treatment apparatus of Patent Document 3 is configured by separating the inside of a sealed container into a pre-fermentation layer containing an immature product and an aged layer containing no immature product. The odor generated in the pre-fermentation layer is sucked together with fresh air by a pump and vented into the deposition layer. Odor is digested by microorganisms by the fermenting action of the sedimentary layer, aeration is maintained at high temperature and humidity, and suction is performed from the upper space with a blower, and condensed water is captured in the exhaust pipe. And the vertical-type fermentation processing apparatus is described in FIGS. 5-7 as a modification (paragraphs 0021-0022). This apparatus has a hermetic laminated structure in which containers are stacked in four layers. The stirring means is of a vertical axis screw type, and the driving device is in each layer as a cart device that moves back and forth and right and left on a horizontal track. A partition wall is provided between each layer, and the food residue overflows each upper edge by stirring, and sequentially drops and moves to a lower container. A vent pipe is disposed on the bottom surface of the container, and is connected to an air supply port from an air pump. A blower discharge pipe is opened in the upper space. A heat insulating material and a heating body are provided on the outer periphery of each container. The heated body is kept at a high temperature and the evaporated water is not condensed but sucked with ventilation, cooled by the outside air, and condensed water is captured by the demister. Most of the odor is removed by dissolving in water. Ventilation with reduced humidity by outside air from the inlet pipe is blown from the plate into the container, permeated through the aging layer, finished and deodorized, the food residue dried with some fermentation heat, and exhausted from the chimney to a high place with a blower The In addition, a supply hopper and a crusher are attached to a supply lift connected to an input port provided on the upper surface of the vertical container, and the input is made into a small lump and then supplied to a high place container.

JP 2006-110440 A JP 2002-35724 A JP-A-7-148479

  As described above, since the moisture content of the food residue is high as it is, the treatment of moisture becomes a problem in the fermentation process. Therefore, even the fermentation treatment apparatuses described in Patent Documents 1 to 3 have the above mechanism corresponding to moisture. In general, organic substances such as food residues are heated during fermentation by the action of aerobic microorganisms, and a large amount of water vapor is generated in the container. Therefore, in Patent Document 1, water is exhausted by aeration from one side of the horizontal container to the other side, but the water and the like cannot be satisfactorily ventilated in the food residue to be agitated, resulting in poor fermentation and drying efficiency.

  On the other hand, in patent document 2, since it ventilates upward from the bottom wall of a horizontal container, it can ventilate through the food residue which is being stirred. However, it is not possible to completely discharge water vapor simply by venting the inside of the container, and some water vapor may condense on the inner surface of the container and accumulate on the lower surface of the container. As a result, the vent hole in the bottom wall of the container is blocked, resulting in poor air permeability. Therefore, in Patent Document 2, a dehumidifying part having a cooling means is formed on the upper part of the processing part so that dew drops can be collected. However, this increases the complexity and size of the device, so that there remain problems in terms of cost. Also in Patent Document 3, although it is ventilated from the bottom wall to the top surface of the vertical container, the water vapor is a complicated structure that is discharged through the complicated path, so that the apparatus is inevitably complicated and enlarged.

  In addition, in Patent Documents 1 to 3, moisture removal is performed mainly by heating means. This not only increases the energy cost, but also increases the amount of water vapor generated per unit time. Therefore, in Patent Document 2 and Patent Document 3, dew droplets are collected by the above complicated mechanism, but it is almost impossible to collect all of the water vapor generated in large quantities, and the water vapor is quickly processed in the processing space. No measures have been taken to discharge outside. In other words, although attention is paid to quickly evaporating moisture, no particular attention is paid to the ventilation amount for discharging a large amount of generated water vapor.

  Moreover, in patent document 3 which uses a vertical container, the processed material thrown up into a vertical container by lifting up an input hopper with a supply lift is made into a small lump beforehand with a crusher. However, if the processed material is charged all at once from the charging port provided on the upper surface of the vertical container, the processed material is densely deposited in the vertical container, so that ventilation in the processed material is hindered. It is done.

  Accordingly, as a result of earnest examination, the present inventors have sought to obtain a fermentation treatment apparatus that efficiently discharges steam while avoiding complication and enlargement of the apparatus along with an increase in energy cost, and that does not deteriorate air permeability. The present invention was completed by finding that the above-mentioned problem can be solved by using a mold vessel while improving the location of the vent hole and forcibly evacuating, and by using an appropriate ventilation amount and charging method. That is, the present invention solves the above-mentioned problem, and obtains a fermentation treatment apparatus that can efficiently discharge water vapor while avoiding complication and enlargement of the apparatus along with an increase in energy cost and that does not deteriorate air permeability. With the goal.

  The present invention provides a food residue fermentation treatment apparatus and fermentation, in which a food residue and an aerobic microorganism are mixed in an airtight container, and the food residue is fermented by the action of the aerobic microorganism while aerated and stirred in the container. It is a processing method. The container is a vertical container, and a plurality of upper and lower stirrer blades extend radially around a rotation shaft standing in the vertical container. An air supply means for supplying air into the vertical container is connected to the lower end of the rotating shaft, and the lowermost stirring blade of the lower and upper multistage stirring blades is hollow. A plurality of vent holes are formed in the lower surface of the lowermost stirring blade so as to penetrate inside and outside. On the other hand, an exhaust port for exhausting the gas in the vertical container is provided on the upper surface of the vertical container, and an exhaust means for forcibly exhausting the gas in the vertical container is provided in the exhaust port. Are connected. And while air is supplied from the lower surface of the lowermost stirring blade through the rotating shaft from the air supply means, the food residue is fermented while forcibly exhausted by the exhaust means from the exhaust port, To do.

At this time, the amount of aeration (m ³ / min) in the vertical container per unit time is 20% or more, preferably 50% or more with respect to the volume (m ³ ) of the vertical container. The output of the exhaust means is preferably greater than or equal to the output of the air supply means.

  Furthermore, a drying process is possible following the fermentation process. In this case, the temperature detection means for detecting the temperature in the vertical container is provided, and the temperature inside the container starts to decrease after the temperature rising state due to the action of the aerobic microorganism is maintained for a certain time. When detected by the temperature detection means, the aeration amount may be used as it is, but it is preferable to further perform a drying process with an aeration amount larger than the aeration amount of the fermentation treatment.

  The vertical container is preferably a three-layer heat insulating container having a heat insulating layer between an inner layer and an outer layer. In addition, a charging hopper provided adjacent to the vertical container is connected to a charging port provided on the upper surface of the vertical container via the charging pipe, and supplied from the charging hopper. It is preferable that the food residue is conveyed by air in the charging pipe by a blowing means connected to the charging hopper.

  According to the present invention, the rotating shaft of the stirring means is a vertical container in which the vertical axis is erected in the vertical direction, and is vented upward from the vent hole formed in the lower surface of the lowermost stirring blade. The configuration is simple, and the size of the apparatus can be prevented from becoming larger than necessary. Even if water vapor condenses on the inner surface of the container and the dew droplets accumulate in the lower part of the container, there is a gap of a predetermined size between the bottom of the container and the lowermost stirring blade, so that the vent hole is closed and vented. Sex does not get worse. In addition, since the vent hole is provided in the stirring blade that rotates around the rotation axis, the air supply part always moves, and the entire container can be efficiently and uniformly ventilated, and the water vapor discharge efficiency is high. In addition, since the water vapor is forcibly exhausted by the exhaust means, it is possible to quickly exhaust the water vapor and reduce the occurrence of condensation.

If the air flow rate per unit time (m ³ / min) is 20% or more with respect to the volume (m ³ ) of the vertical container, water vapor can be exhausted accurately, and the occurrence of condensation can be reduced. If the air flow rate per unit time (m ³ / min) is 50% or more with respect to the volume (m ³ ) of the vertical container, water vapor can be exhausted quickly, and the occurrence of condensation can be greatly reduced. As described above, in the present invention, moisture is removed mainly by setting the air flow rate, so that a sufficient increase in the amount of energy cost due to heating is avoided while ensuring a sufficient air volume for forced and quick exhaust of water vapor. be able to. In addition, since water vapor | steam is generate | occur | produced by the temperature rise by the effect | action of an aerobic microorganism, a forced heating means is not necessarily required, but it does not deny using a heating means.

  If the output of the exhaust means is greater than or equal to the output of the air supply means, the amount of ventilation in the container is determined by the output of the exhaust means. Therefore, the air flow necessary for exhausting the water vapor can be set directly by the output of the exhaust means for forcibly exhausting the water vapor, and more efficiently than when the air flow is determined by the output of the air supply means. Steam can be exhausted.

  If the food residue is simply fermented with aerobic microorganisms while simply aerated, moisture cannot be removed sufficiently to the extent that there is no problem in distribution and storage. Therefore, the food residue can be quickly dried by further increasing the aeration after the fermentation by aerobic microorganisms has progressed to some extent. Moreover, if the container has a heat insulating property, it is possible to more accurately prevent dew condensation due to a difference in temperature between the inside and outside of the outside air, and it is advantageous for promoting the fermentation by maintaining the temperature rise by fermentation.

  If the food residue supplied from the input hopper is conveyed by air in the input pipe by the air blowing means, the food residue will not be input into the vertical container at once, and the food residue may be densely accumulated in the vertical container. Absent. That is, since the food residue is gently accumulated, air easily passes through the food residue, and deterioration of air permeability can be avoided.

It is a partially broken block diagram of a fermentation treatment apparatus. It is a top view of a charging hopper. It is a graph which shows a temperature rising process.

  Below, although the fermentation processing apparatus of the food residue of this invention is demonstrated, it is not limited to this, A various change is possible in the range which does not change the summary of this invention. In FIG. 1, the partially broken block diagram of a fermentation processing apparatus is shown. As shown in FIG. 1, the fermentation processing apparatus main body 1 includes a processing container (component) 10 that stores food residues therein, an agitation unit that agitates food residues charged into the processing container 10, and an agitation unit. It has the drive means 30 which rotationally drives, and the ventilation means which ventilates the inside of the processing container 10.

  The processing container 10 is a vertically long cylindrical heat insulating container, and an inlet 11 for feeding food residue and an exhaust port 12 for exhausting water vapor are provided on the top wall of the processing container 10. The processing container 10 corresponds to a vertical container of the present invention. An input hopper 40 adjacent to the processing vessel 10 is connected to the input port 11 via an input pipe 41. An exhaust blower 15 is connected to the exhaust port 12 via an exhaust pipe 14. The exhaust port 12, the exhaust pipe 14, and the exhaust blower 15 constitute a ventilation means. Driving means 30 is disposed below the processing container 10, and an outlet 16 for taking out food residues after processing is provided on the bottom wall of the processing container 10. The outlet 16 is also provided with a lid (not shown) that can be hermetically sealed. The lid can be opened and closed manually or mechanically. Moreover, it may be connected so that rotation is possible via a hinge, and it is good also as a slide opening-and-closing type. Reference numeral 35 denotes a temperature sensor as temperature detecting means for detecting the temperature inside the processing container 10.

  As shown in the enlarged view of the main part of FIG. 1, the processing container 10 has a three-layer structure having a heat insulating layer 10c between a metallic outer layer 10a and a metallic inner layer 10b. The heat insulating layer 10c is not particularly limited as long as it can exhibit heat insulating properties, and can be a glass wool layer, a rock wool layer, a foamed resin layer, a vacuum layer, or the like. You may combine these suitably. In this embodiment, the outer layer 10a and the inner layer 10b are made of steel, and the heat insulating layer 10c is a glass wool layer. More specifically, the outer layer 10a is SS400 and the inner layer 10b is SUS304. In addition, since the temperature change of the inner layer 10b is greater than that of the outer layer 10a, the thickness Tb of the inner layer 10b is preferably thicker than the thickness Ta of the outer layer 10a. For example, the thickness Tb of the inner layer 10b is greater than the thickness Ta of the outer layer 10a. It is preferable to make it 2 times or more. Further, in order to ensure a good heat insulating effect, the thickness Tc of the heat insulating layer 10c is preferably the largest compared to the thickness Ta of the outer layer 10a or the thickness Tb of the inner layer 10b. For example, the thickness Tc of the heat insulating layer 10c is It is preferable to set it to 3 times or more with respect to the thickness Ta. In this example, the outer layer 10a was 2 mm, the inner layer 10b was 4.5 mm, and the heat insulating layer 10c was 65 mm.

  The stirring means includes a rotating shaft 20 erected so as to be rotatable at a central portion in the processing container 10, and a plurality of stirring blades 21 extending radially around the rotating shaft 20. The rotary shaft 20 extends vertically from the drive means through the bottom wall of the processing vessel 10 to the top wall, and the stirring blades 21 are provided in a plurality of stages in the vertical direction from the lower portion to the upper portion of the rotary shaft 20. The form of the stirring blade 21 may be a blade shape or a rod shape. From the viewpoint of stirring efficiency, a screw type having blade-shaped stirring blades is preferable. Alternatively, a spiral drill type (so-called auger type) may be used. The rotating shaft 20 includes an upper solid portion 20a and a hollow portion 20b connected to the lower portion of the solid portion 20a. Of the plurality of upper and lower stirring blades 21, only the lowermost stirring blade 21 a is hollow and communicates with the internal space of the hollow portion 20 b of the rotating shaft 20. In addition, a plurality of vent holes (not shown) are formed in the lower surface of the lowermost stirring blade 21a so as to penetrate inside and outside. The other stirring blades 21 are solid. The lowermost stirring blade 21 a is provided at a position above the bottom wall of the processing vessel 10 by a predetermined amount, so that a predetermined amount of gap is provided between the lowermost stirring blade 21 a and the bottom wall of the processing vessel 10. There is.

  In addition to the exhaust port 12, the exhaust pipe 14, and the exhaust blower 15, the ventilation means for venting the processing container 10 includes an air supply blower 25 and an air supply pipe 26 having one end connected to the air supply blower 25. Become. The other end of the air supply pipe 26 is connected to the lower end of the hollow portion 20 b, that is, the lower end of the rotary shaft 20. As the driving means 30, a hydraulic motor unit, a general electric motor unit, or the like can be used. The output of the drive means 30 is transmitted to the rotary shaft 20 via a gear portion 31 meshed with the lower portion of the rotary shaft 20.

  As shown in FIG. 1 and FIG. 2, the charging hopper 40 includes a rotating body 42 that pivots at the center thereof, a plurality of stirring rods 43 connected to the rotating body 42, and an inside of the charging hopper 40. And a screw feeder 44 for extruding food residues. In this embodiment, two stirring rods 43 are connected to the rotating body 42, and the stirring rods 43 slide on the bottom surface of the charging hopper 40. Thereby, the food residue stored in the charging hopper 40 is accurately supplied to the screw feeder 44. The screw feeders 44 are juxtaposed in two locations, and food residues are configured to drop downward at the tip of each screw feeder 44. Below the tip of each screw feeder 44, the input pipe 41 is connected and a blower blower 45 as a blower is connected. As a result, the food residue dropped from the tip of each screw feeder 44 is blown off by the air from each blower blower 45 and is air-conveyed through the input pipe 41, and is sequentially input from the input port 11 into the processing container 10. Is done. The input pipes 41 extending from the screw feeders 44 may be joined together in the middle, or two input ports 11 may be provided. Reference numeral 46 denotes a drive mechanism for the rotating body 42.

  Examples of the food residue as the object to be treated include garbage and food by-products generated from the food manufacturing industry, the restaurant industry, the food distribution industry, and organic sludge generated in food factories. Examples of food waste include fish scraps, meat scraps, vegetable scraps and the like left over from the food service industry, as well as fishery products, meat, and vegetables. Examples of food production by-products include brewing by-products such as sake lees, shochu, beer lees, miso, and fruit juice residue, as well as remaining okara after squeezing soy milk during tofu production.

  The aerobic microorganism that is introduced into the processing container 10 together with the food residue for fermentation of the food residue is preferably an aerobic microorganism that can be activated (proliferated) at 30 to 90 ° C. This is because the drying of the food residue is promoted by utilizing the temperature rise accompanying the fermentation. Therefore, it is preferable to activate at least 50 ° C. in order to lead the food residue to a high temperature range of about 50 to 90 ° C. Examples of such aerobic microorganisms include genus Geobatisul and Bacillus. Specifically, Geobacillus as a bacterium of the genus Geobacillus. Geobacillusthermodenitrificans, Geobacillus. Steobaothermophilus (Geobacillusstearothermophilus), Geobacillus. Coastophilus (Geobacillus kaustophilus), Geobacillus. Geobacillus subterranens, Geobacillus. Thermobavorans, Geobacillus. Examples include Cardobasilus caldoxylosilyticas. Moreover, as a bacterium of the genus Bacillus, Bacillus sp. TAT105 (Bacillus sp. TAT105), Bacillus sp. And TAT112 (Bacillus sp. TAT112). Among them, Geobacillus. Thermodenitificans and Geobacillus. Cardiochio lyticus is preferred. These aerobic microorganisms may be used alone or in combination of two or more. In addition, when using an anaerobic microorganism, since ventilation | gas_flowing by air cannot be performed, for example, it is necessary to ventilate using an inert gas etc., it is not preferable in terms of cost.

  The food residue contains fibrous polysaccharides such as cellulose and hemicellulose. The fibrous polysaccharide is difficult to be decomposed by fermentation by the action of aerobic microorganisms and has a poor texture. Therefore, particularly when fermented food residues are used as feed, it is preferable to mix polysaccharide-degrading enzymes together with aerobic microorganisms. Addition of a polysaccharide-degrading enzyme to food residues is also advantageous in that low-molecular sugars such as glucose, which are nutrient sources for aerobic microorganisms, are produced. Polysaccharide-degrading enzymes include an exo type that decomposes a polysaccharide polymer from its end and an end type that decomposes a polysaccharide polymer from its middle, and either can be used. The activation temperature of the polysaccharide-degrading enzyme is preferably about 10 to 90 ° C, more preferably about 30 to 80 ° C. In order to promote fermentation, a sugar source such as glucose or a fermentation aid such as bran may be added.

  Next, a food residue fermentation process performed by the fermentation processing apparatus 1 will be described. First, food residues such as food waste and food production by-products generated from a food production factory are introduced into the input hopper 40, and aerobic microorganisms and polysaccharide-degrading enzymes are mixed as appropriate. If a certain amount of the fermented material after the previous treatment is left in the processing container 10, it is not necessary to mix the aerobic microorganisms to the charging hopper 40. As shown in FIG. 1, food residues and the like that have dropped from the tip of the screw feeder 44 are air-conveyed through the input pipe 41 by the blower blower 45 and are sequentially input into the processing container 10 from the input port 11. At this time, naturally, the outlet 16 is also sealed. The food residue may be conveyed from a stock yard by a belt conveyor, or directly from a food manufacturing factory or the like. When a predetermined amount of food residue or the like can be introduced, the blower blower 45 is stopped, and then the food residue is fermented while the air supply blower 25 and the exhaust blower 15 are driven to ventilate the processing container 10. Specifically, the air supplied from the air supply blower 25 to the lower end of the rotary shaft 20 through the air supply pipe 26 passes through the hollow portion 20b below the rotary shaft 20 and the lowermost stirring blade 21a in this order. The air is blown out from a plurality of vent holes formed in the lower surface of the lowermost stirring blade 21a. The air blown out from the lower surface of the lowermost stirring blade 21a flows upward through the food residue and, together with water vapor and odor generated from the food residue, is exhausted from the exhaust port 12 through the exhaust pipe 14 by the exhaust blower 15. It is forced to exhaust. In addition, since the air supplied from the air supply blower 25 is blown out from the stirring blade 21a rotating around the rotation shaft 20, it can be uniformly vented throughout the processing vessel 10.

  The food residue mixed with aerobic microorganisms is fermented by the action of the aerobic microorganisms, and the temperature is raised to about 40 to 70 ° C. If a polysaccharide-degrading enzyme is also mixed at the same time, the low-molecular-weight saccharide produced by the decomposition of the polysaccharide-degrading enzyme serves as a nutrient source for aerobic microorganisms and promotes fermentation. The temperature rising state is continued while fermenting due to the action of aerobic microorganisms in combination with the heat insulating property of the processing container 10 (see FIG. 3). In addition, it is preferable to heat the air supplied suitably so that the temperature rise by fermentation may not be cooled. At this time, the moisture content of the food residue is at least 30% or more, usually 50% or more, and 70% or more immediately after being transported from a food manufacturing factory or the like. Therefore, a large amount of water vapor is generated from the food residue by raising the temperature by the action of aerobic microorganisms. At the same time, by keeping the temperature elevated for a certain period of time, oxidation of unsaturated fatty acids such as linoleic acid contained in the food residue is promoted, and an oxidized odor of fat is generated.

Therefore, in order to avoid as much as possible that water vapor is condensed on the inner surface of the processing container 10 and dew droplets are accumulated in the lower part of the processing container 10, the air flow rate in the processing container 10 is generally set so that the water vapor is quickly discharged. It is higher than the ventilation rate. Although it varies depending on the processing conditions, the structure of the processing apparatus, the processing target, and the like, generally, the amount of aeration during the fermentation process is such that airflow is generated (for example, about 2 to 4 m ³ / min, 5 to 5 for the volume). 15%) is sufficient. On the other hand, in the present invention, the air flow rate per unit time (m ³ / min) is increased to at least 20% or more, preferably 50% or more, with respect to the volume (m ³ ) of the vertical container. Thereby, a large amount of water vapor generated from the food residue is quickly exhausted out of the processing container 10. The upper limit of the aeration amount is not particularly limited as long as the food residue is not blown up vigorously. This is because if the food residue is blown up vigorously, some of the food residue and aerobic microorganisms may be sucked up from the exhaust port 12 or fermentation due to the action of the aerobic microorganisms may be inhibited. Further, if the aeration amount is too high, the inside of the processing container is air-cooled, and there is a possibility that the temperature will not be increased to a preferable fermentation condition (temperature). Preferably, the air flow rate per unit time (m ³ / min) is set to about 200% or less with respect to the volume (m ³ ) of the vertical container. The outputs of the air supply blower 25 and the exhaust blower 15 may be basically the same, but if they are different, it is preferable that the output of the exhaust blower 15 be equal to or higher than the output of the air supply blower 25. In particular, it is preferable to set the output of the exhaust blower 15 to be higher than the output of the air supply blower 25 and set the air flow rate in the processing container by the output of the exhaust blower 15. If the air flow rate is set according to the output of the exhaust blower 15, the output of the air supply blower 25 may be relatively low, which is advantageous in reducing the energy cost.

  As described above, a large amount of water vapor generated is forcedly and rapidly exhausted out of the processing container 10, so that the amount of water vapor condensing on the inner surface of the processing container 10 is combined with the heat insulation of the processing container 10. Processing efficiency can be improved as much as possible. However, no matter how much the air flow is increased, it is impossible to completely prevent condensation. However, in the present embodiment, the vent hole from the air supply blower 25 is provided on the lower surface of the lowermost stirring blade 21a above the bottom wall of the processing container 10 by a predetermined amount, so that some dew droplets are generated in the processing container 10. Even if it accumulates in the lower part of the substrate, it is possible to reliably avoid deterioration of the air permeability and maintain good treatment efficiency. In addition, the evaporation of water mainly uses the temperature rise caused by the action of aerobic microorganisms, and the air flow rate is only increased in order to quickly exhaust the water vapor, so that a significant increase in energy cost can be avoided. Moreover, it has a simple structure while being able to handle dew drops.

  When fermentation by the action of aerobic microorganisms proceeds to some extent and is almost decomposed, the temperature in the processing vessel 10 gradually decreases (see FIG. 3). Therefore, when a temperature drop in the processing container 10 is detected by the temperature sensor 35, the process proceeds to a drying process. Since the drying treatment process mainly removes moisture from the food residue, it is preferable to increase the aeration rate over the fermentation treatment process. Specifically, it is preferable to perform the drying treatment with an aeration amount that is twice or more the aeration amount in the fermentation treatment step. This is because if the aeration amount in the drying treatment step is less than twice the aeration amount in the fermentation treatment step, the difference from the aeration amount in the fermentation treatment step is small, and rapid and efficient drying becomes difficult. The upper limit of the aeration amount in the drying treatment step may be about 5 times or less the aeration amount in the fermentation treatment step. In FIG. 3, “weak air flow” and “strong air flow” are relative strengths comparing the air flow rate in the fermentation process and the air flow rate in the drying process, and are not based on the general air flow rate. Absent. In the drying process, drying is preferably performed until the moisture content in the food residue is less than 30%, and more preferably, the moisture content is less than 20%. When the water content after the treatment is 30% or more, the rot easily proceeds, and the safety and storage stability deteriorate. Moreover, since the weight is large, the transportation efficiency is also deteriorated.

  When the fermentation process and the drying process are completed, the outlet 16 on the lower surface of the processing container 10 is opened, and the fermentation residue inside is taken out. The fermentation residue can be reused in agriculture and horticulture as feed for feeding livestock such as cattle, pigs, horses, and sheep and poultry such as chickens, and as compost such as manure and compost.

(Evaluation test)
An evaluation test was conducted on the relationship between the air flow rate and the treatment efficiency. About 3 tons of raw tofu (okara) having a water content of about 75% was put into a treatment container having a volume of 20 m ³ . In addition, about 10 m ^{3 of} fermented material previously fermented and dried as a fungus bed was put in the processing container. And it processed, carrying out ventilation | gas_flowing stirring in each condition shown in Table 1, and evaluated the water content in the fermented material in the state in a process process, and 24 hours after. The results are also shown in Table 1.

  From the results in Table 1, even under condition 1 where the air flow rate was set to be relatively high (23% with respect to volume), forced evacuation was not performed, so water easily stayed in the processing vessel, the temperature rise was high, but the moisture content Was hardly reduced, and the amount of condensed water was very large. As a result, the air permeability was also deteriorated, resulting in oxygen shortage and anaerobic fermentation. On the other hand, in the condition 2, the air flow rate is substantially the same as the condition 1 (23.5% with respect to the volume), but since the air is exhausted together with the air supply, the moisture can be exhausted quickly and accurately. Therefore, the moisture content in the fermented product was well reduced, and the generation of condensed water was relatively small. Further, since the temperature elevation was slightly lower than that in Condition 1, it was confirmed that good air permeability was ensured, and aerobic fermentation was surely performed. On the other hand, even if the ventilation rate is increased to 54.5% of the volume as in condition 3, the moisture content in the fermented product is higher than in condition 2 and the amount of condensed water generated is not exhausted unless exhausted. There were many. Therefore, the air permeability was slightly inferior, resulting in a somewhat anaerobic fermentation. From these results, it was found that the food residue can be treated accurately if the amount of aeration in the processing container is about 20% of the volume, assuming that the air is exhausted together with the air supply.

  Further, from the result of Condition 4, when the air flow rate in the processing container was 54.5% with respect to the volume while exhausting, the water content was less than 50%. Therefore, it was found that the air flow rate in the processing container is preferably 50% or more with respect to the volume.

  Further, from the result of Condition 5, it can be seen that if the air flow rate in the processing container is increased (135% with respect to the volume), the processing can be performed more quickly and the generation of condensed water is also reduced. However, since the air flow rate is high, the temperature rising temperature in the processing apparatus was about 55 ° C. Therefore, in order to raise the temperature to the temperature at which the aerobic microorganisms are activated (about 50 ° C.), it was found that about 200% is the limit even if the aeration amount in the processing container is higher than the volume. In condition 5, the air supply amount was the same as in condition 4 and only the exhaust amount was increased, but still good results were obtained. Accordingly, it was found that the air flow rate is preferably set by adjusting the exhaust amount rather than the air supply amount. Therefore, it is preferable that the output of the exhaust blower be equal to or higher than the output of the air supply blower.

(Modification)
In the above embodiment, the vent holes are provided only in the lowermost stirring blade. However, the vent holes are provided in a plurality of stirring blades (for example, the first and second stirring blades from the bottom) in the lower half region of the processing vessel. It is also preferable to provide a structure in which air is blown out. Alternatively, the rotary shaft may be hollow over the upper and lower ends, and an air supply blower may be connected not only to the lower end but also to the upper end to supply air from both the upper and lower ends of the rotary shaft. Although the processing container is a heat insulating container having a three-layer structure, it is also preferable to make the thickness Ta of the outer layer 10a thicker than the thickness Tb of the inner layer 10b. As the temperature detection means, a thermometer can be used in addition to the temperature sensor. In this case, the temperature in the processing apparatus is confirmed visually. The screw feeder of the charging hopper is not limited to two, and may be one or three or more. Moreover, although the subject of air permeability remains, it is not necessary to air convey a food residue with a ventilation blower.

DESCRIPTION OF SYMBOLS 1 Fermentation processing apparatus 10 Processing container 10a Outer layer 10b Inner layer 10c Heat insulation layer 11 Inlet 12 Exhaust port 13 Cover 14 Exhaust pipe 15 Exhaust blower 16 Outlet 20 Rotating shaft 20a Solid part 20b Hollow part 21 Stirring blade 21a Bottom stirrer blade 25 Air supply blower 26 Air supply pipe 30 Driving means 31 Gear mechanism 35 Temperature sensor 40 Input hopper 41 Input pipe 43 Stirring rod 44 Screw feeder 45 Blower

Claims (13)

A food residue fermentation treatment apparatus, wherein food residues and aerobic microorganisms are mixed in an airtight container, and the food residues are fermented by the action of aerobic microorganisms while aerated and stirred in the container,
The container is a vertical container, and a plurality of upper and lower stirrer blades extend radially around a rotation shaft standing in the vertical container,
An air supply means for supplying air into the vertical container is connected to the lower end of the rotating shaft, and the lowermost stirring blade of the lower and upper multistage stirring blades is hollow. , A plurality of vent holes are formed in the lower surface of the lowermost stirring blade so as to penetrate inside and outside,
An exhaust port for exhausting the gas in the vertical container is provided on the upper surface of the vertical container,
Exhaust means for forcibly exhausting the gas in the vertical container is connected to the exhaust port,
In addition to supplying air from the lower surface of the lowermost stirring blade through the rotating shaft from the air supply means, the food residue is fermented while being forcibly exhausted by the exhaust means from the exhaust port. , Food residue fermentation treatment equipment. The food residue according to claim 1, wherein the ventilation rate (m ³ / min) in the vertical container per unit time is set to 20% or more with respect to the volume (m ³ ) of the vertical container. Fermentation processing equipment. The food residue according to claim 1, wherein the air flow rate (m ³ / min) in the vertical container per unit time is set to 50% or more with respect to the volume (m ³ ) of the vertical container. Fermentation processing equipment.   The food residue fermentation treatment apparatus according to any one of claims 1 to 3, wherein an output of the exhaust means is greater than or equal to an output of the air supply means. A drying treatment is possible following the fermentation treatment,
Having temperature detecting means for detecting the temperature in the vertical container;
After the temperature rising state due to the action of the aerobic microorganisms is maintained for a certain period of time, when the temperature detecting means detects that the temperature in the container has started to decrease, the aeration rate is larger than the aeration rate of the fermentation treatment. The food residue fermentation treatment apparatus according to claim 1, further drying.   The said vertical container is a fermentation treatment apparatus of the food residue in any one of Claims 1 thru | or 5 which is a heat insulation container of the three-layer structure which has a heat insulation layer between an inner layer and an outer layer. The upper surface of the vertical container is provided with an inlet for introducing food residue,
A charging hopper adjacent to the vertical container is connected to the charging port via a charging pipe,
A blowing means is connected to the charging hopper,
The food residue fermentation treatment apparatus according to any one of claims 1 to 6, wherein the food residue supplied from the charging hopper is pneumatically conveyed through the charging tube by the blowing means. A food residue fermentation treatment method in which a food residue and aerobic microorganisms are mixed in an airtight container, and the food residue is fermented by the action of aerobic microorganisms while aerated and stirred in the container,
A plurality of upper and lower stirrer blades extend radially around a rotation shaft standing in the container, and an air supply means for supplying air into the container is connected to a lower end of the rotation shaft, so that the rotation The lowermost stirrer blade of the lower end of the shaft and the upper and lower stirrer blades is hollow, and a plurality of vent holes are formed in the lower surface of the lowermost stirrer blade so as to penetrate inside and outside. The upper surface of the container is provided with an exhaust port for exhausting the gas in the container, and the exhaust port is connected to an exhaust means for forcibly exhausting the gas in the container. Using the container,
In addition to supplying air from the lower surface of the lowermost stirring blade through the rotating shaft from the air supply means, the food residue is fermented while being forcibly exhausted by the exhaust means from the exhaust port. , Fermentation processing method of food residue. The food residue according to claim 8, which is fermented by setting the aeration amount (m ³ / min) in the vertical container per unit time to 20% or more with respect to the volume (m ³ ) of the vertical container. Fermentation processing method. The food residue according to claim 8, wherein fermentation is performed with an air flow rate (m ³ / min) in the vertical container per unit time being 50% or more with respect to the volume (m ³ ) of the vertical container. Fermentation processing method.   The method for fermenting food residues according to any one of claims 8 to 10, wherein the output of the exhaust means is greater than or equal to the output of the air supply means. Providing a temperature detecting means for detecting the temperature in the vertical container;
After the temperature rising state due to the action of the aerobic microorganisms is maintained for a certain period of time, when the temperature detecting means detects that the temperature in the container has started to decrease, the aeration rate is larger than the aeration rate of the fermentation treatment. The method for fermentation treatment of a food residue according to claim 8, further drying. An input hopper provided adjacent to the vertical container is connected to an input port for supplying a food residue provided on the upper surface of the vertical container via an input pipe,
The food residue fermentation treatment method according to any one of claims 8 to 12, wherein the food residue supplied from the input hopper is air-conveyed in the input tube by a blowing unit connected to the input hopper.

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