Apparatus and method for producing organic fertilizer

Abstract

The present invention addresses the problem of, for example: trapping nitrogen volatilizing in the atmosphere into a fertilizer; producing an organic fertilizer capable of avoiding problems associated with a long-term use of a chemical fertilizer, including deterioration of soil environment; and producing an organic fertilizer such that a contained organic component can be pulverized in a processing step and used as a feed for soil microorganisms, and that is also capable of achieving soil reclamation.　Provided are an apparatus and a method for producing an organic fertilizer, the apparatus comprising a decomposition processing unit having a two-layer structure of a first layer for steaming decomposition processing of an organic material and a second layer formed such that a heat medium oil can be circulated along the outside of the first layer. The first layer is provided with an agitation plate for agitating the organic material. The agitation plate has a rubbing part that rubs the organic material against an inner wall surface. The second layer includes, in a circulation flow path for the heat medium oil, a heater for heating and managing the temperature of the heat medium oil. The decomposition processing unit performs processing in which the heat medium oil circulating in the second layer is heated and the temperature of the heat medium oil is managed by the heater, and indirect heating is performed by rubbing the organic material against the inner wall surface of the first layer that has been heated to a higher temperature due to heat conduction from the heat medium oil, so that water contained in the organic material is vaporized.

Description

Organic fertilizer production equipment and production method

[0001] The present invention relates to an apparatus and method for producing organic fertilizer.

[0002] Conventionally, fermented chicken manure, produced by fermenting chicken manure, has been known as a type of compost (special fertilizer) used in agriculture. Livestock manure is commonly used as fertilizer because it contains phosphorus, potassium, and small amounts of nitrogen, which are essential for growing vegetables.

[0003] Fermentation of livestock manure is carried out by the activity of aerobic microorganisms, and during the fermentation process, the temperature of the livestock manure rises due to the heat of fermentation (approximately 80°C), which kills pathogenic bacteria such as Salmonella, E. coli, and Staphylococcus, as well as viruses, making it possible to use the manure as fertilizer that is safe for people and vegetables. The fermentation period is approximately 30 to 40 days.

[0004] Japanese Patent Application Laid-Open No. 2002-220294

[0005] Compost (special fertilizer) produced through fermentation emits greenhouse gases such as methane and nitrous oxide during the fermentation process, and during this process, approximately half of the nitrogen contained in the organic matter combines with oxygen in the air to become nitrous oxide, which is lost as a vapor in the atmosphere.As a result, fermented compost (special fertilizer) alone cannot provide the nitrogen necessary to increase the productivity of agricultural crops, so the necessary nitrogen and other components are usually supplemented with chemical fertilizers (fossil fuels, naphtha, etc.).

[0006] However, the long-term use of chemical fertilizers reduces the activity of microorganisms in the soil, worsening the soil's aggregate structure and root environment, and causing the accumulation of heavy metals, which worsens the soil environment. If vegetables are grown in such soil, the nutritional value of the vegetables harvested will gradually decrease year by year.

[0007] To address this issue, the Ministry of Agriculture, Forestry and Fisheries is promoting specially cultivated agricultural products (reduced chemical fertilizer and pesticide cultivation), but it is difficult to increase crop productivity without compensating for the reduced amount of chemical fertilizer.In addition, it is difficult worldwide to consistently procure organic fertilizers that contain a large amount of ingredients, which can be used as an alternative to chemical fertilizers, and to compensate for the lack of ingredients in conventional compost such as fermented chicken manure, the low concentration of fertilizer ingredients in the compost has to be compensated for by increasing the amount of compost added, which requires a great deal of effort and causes problems such as unpleasant odors.

[0008] The present invention aims to address these problems. Specifically, the objectives of the present invention are to confine within the fertilizer the nitrogen that would otherwise volatilize into the atmosphere during fermentation, to produce an organic fertilizer that can avoid problems such as soil pollution and deterioration that accompany the long-term use of chemical fertilizers, to produce an organic fertilizer that also regenerates the soil by crushing the organic matter contained in the fertilizer during the treatment process and using it as food for soil microorganisms, and to produce an organic fertilizer that can increase crop productivity while avoiding problems that arise from the use of large amounts of fertilizer.

[0009] In order to solve such problems, the organic fertilizer production apparatus according to the present invention has a decomposition treatment unit with a two-layer structure consisting of a first layer for steaming and decomposing organic matter, and a second layer formed along the outside of the first layer so that thermal oil can circulate, and the first layer is provided with an agitation plate that rotates around a rotating shaft column as an axis to agitate the organic matter, and the agitation plate has a rectangular plate shape and is formed at the tip of a column member extending from the rotating shaft column so as to be inclined in the direction of rotation of the rotating shaft column during treatment with respect to the extension direction, and has a rubbing portion that rubs the organic matter against the inner wall surface of the first layer in a region that is closest to the inner wall surface of the first layer as the rotation occurs, and a stirring edge is formed along the diagonal of the rectangle on the surface facing the inner wall surface, and the rubbing portion is formed in the region such that, of the four sides of the side surface, two sides that are always parallel to the horizontal direction are inclined so that one side facing the direction of rotation during the treatment is farther from the inner wall surface than the other side, the second layer has a heater in the circulation flow path of the thermal oil that heats and controls the temperature of the thermal oil, and the decomposition treatment portion heats and controls the temperature of the thermal oil circulating in the second layer with the heater, rubs the organic matter against the inner wall surface of the first layer which has become hot due to heat transfer from the thermal oil, and performs a process of evaporating the moisture contained in the organic matter.

[0010] In addition, the organic fertilizer production method according to the present invention uses an apparatus having a decomposition treatment section with a two-layer structure consisting of a first layer for steaming and decomposing organic matter and a second layer formed along the outside of the first layer so that thermal oil can circulate, and heats and controls the temperature of the thermal oil to a predetermined temperature, and agitates the organic matter in the first layer with a stirring plate in the shape of a square plate, which is formed at the tip of a column member extending from a rotating shaft column and is inclined with respect to the extension direction in the rotation direction of the rotating shaft column during treatment, and has a stirring edge formed along the diagonal line of the square that rotates around the rotating shaft column, and In a region that comes close to the inner wall surface of the first layer as the rotational movement occurs, the organic material is rubbed against the inner wall surface of the first layer by a rubbing portion that is formed on two of the four sides of the side that are always parallel to the horizontal direction, with one side on the rotation direction side during the treatment being farther from the inner wall surface than the other side, and water vapor generated by evaporation of water contained in the organic material is discharged from the first layer, and this process is continued until the organic material reaches a specific temperature.

[0011] With the organic fertilizer production device and production method having these characteristics, it is possible to produce organic fertilizer that can confine within the fertilizer nitrogen that would otherwise volatilize into the atmosphere during fermentation processing, avoid problems such as deterioration of the soil environment that accompanies the long-term use of chemical fertilizers, produce organic fertilizer that also regenerates the soil by crushing the organic matter contained in the fertilizer during the processing process and using it as food for soil microorganisms, and produce organic fertilizer that can increase crop productivity while avoiding problems that arise from the use of large amounts of fertilizer.

[0012] FIG. 4 is a configuration block diagram of an organic fertilizer production device according to an embodiment of the present invention. FIG. 5 is a front view of a decomposition treatment unit according to an embodiment of the present invention. FIG. 6 is a right side view of a decomposition treatment unit according to an embodiment of the present invention. FIG. 7 is a right side view of a decomposition treatment unit during steam decomposition treatment according to an embodiment of the present invention. FIG. 8 is a partial enlarged view of FIG. 4. FIG. 9 is an explanatory diagram showing the steam decomposition treatment process according to an embodiment of the present invention. FIG. 10 is a diagram comparing the components of an organic fertilizer (chicken manure) produced according to an embodiment of the present invention with conventional fermented chicken manure and dried chicken manure. FIG. 11 is a diagram comparing the components of an organic fertilizer (pig manure, cow manure) produced according to an embodiment of the present invention with conventional special fertilizers (pig manure, cow manure). FIG. 12 is a diagram showing chemical analysis values ​​of an organic fertilizer produced according to an embodiment of the present invention. FIG. 13 is a diagram showing the decomposition of organic matter in an organic fertilizer produced according to an embodiment of the present invention.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals denote parts having the same functions, and duplicated descriptions in the drawings will be omitted as appropriate.

[0014] The present invention provides an organic fertilizer production apparatus and method, which include a step of subjecting organic matter to steam decomposition treatment, thereby suppressing nitrogen loss due to fermentation and producing organic fertilizer with a higher nitrogen content than conventional compost (special fertilizer) from the same raw materials. Steam decomposition treatment refers to a process in which the material to be treated (organic matter) is rubbed against the high-temperature inner wall surface of a decomposition chamber, where the organic matter is thermally decomposed by indirect heating while evaporating the water contained in the organic matter, and the organic matter is then heated while being stirred until it reaches a specific temperature. Specific details will be described later.

[0015] (Configuration of the organic fertilizer production apparatus) Hereinafter, the configuration of the organic fertilizer production apparatus 1 will be described with reference to Fig. 1. The organic fertilizer production apparatus 1 includes a decomposition treatment section 10, a vent 30, a rotation drive section 40, a heater 50, and a cooling section 60.

[0016] The decomposition treatment unit 10 is formed from a first layer (hereinafter, decomposition layer) 11 and a second layer (hereinafter, oil layer) 12 formed along the outside of the decomposition layer 11. That is, the decomposition treatment unit 10 has a two-layer structure consisting of the decomposition layer 11 and the oil layer 12. Each layer is made of stainless steel, with the stainless steel outer layer of the decomposition layer 11 being approximately 10 millimeters thick, and the stainless steel outer layer of the oil layer 12 being approximately 4 millimeters thick. The decomposition layer 11 has a generally elliptical cylindrical shape with its side extending perpendicular to the axial direction of the cylinder (see FIG. 3 ), and the oil layer 12 has a circulation flow path along the outside of the decomposition layer 11 through which thermal oil can circulate. In this embodiment, edible oil that dissipates heat as little as possible is used as the thermal oil circulating through the oil layer 12. The edible oil used as the thermal oil should be energy-efficient and easy to store heat and control temperature. It is also preferable that the edible oil be capable of long-term use (e.g., continuous operation for approximately 200 to 350 days).

[0017] The decomposition layer 11 is provided with an elliptical cylinder whose axial direction is parallel to the horizontal direction, and whose side surfaces extend vertically. Furthermore, a rotation shaft column 23 penetrates the elliptical cylinder bottom surface of the decomposition layer 11 from outside the decomposition processing unit 10 in the axial direction. The rotation shaft column 23 has a cylindrical shape, and rotates about its axis by a rotation drive unit 40 provided outside the decomposition processing unit 10. The rotation shaft column 23 penetrates a portion vertically below the center of gravity of the elliptical bottom surface of the decomposition layer 11 (see FIGS. 2 and 3 ).

[0018] The rotating blades 20 extend from the side of the rotating shaft column 23 in a direction perpendicular to the side of the rotating shaft column 23 toward the side of the decomposition layer 11. The rotating blades 20 rotate integrally as the rotating shaft column 23 is rotated by the rotary drive unit 40. The rotating shaft column 23 and the rotating blades 20 rotate clockwise during steam decomposition treatment in the right side view of the decomposition layer 11 in FIG. 3 described below. In the embodiment, there are three rotating blades 20, but this is not limited to this, and the number of rotating blades 20 provided may be one or more depending on the scale of the device and the size of the rotating blades 20. Specific details of the rotating blades 20 will be described later.

[0019] The circulation flow path of the oil layer 12 is connected to a heater 50, and the thermal oil circulating through the circulation flow path is heated by the heater 50 before circulating. The heater 50 heats the thermal oil to a predetermined temperature and controls the temperature. In this embodiment, the thermal oil is heated to a target temperature of 200°C. A thermal oil temperature sensor 51 is provided upstream of the heater 50 in the oil layer 12, and the temperature of the thermal oil is measured and controlled on an ongoing basis. The thermal oil circulating along the outside of the decomposition layer 11, controlled at 200°C, heats the inner wall surface 11A of the decomposition layer 11 by heat transfer. In addition, although not shown, a heat insulating material may be provided to cover the outside of the oil layer 12, i.e., the outside of the decomposition treatment unit 10, in order to suppress heat dissipation from the decomposition treatment unit 10 due to external air and facilitate temperature control.

[0020] The decomposition treatment unit 10 is also provided with an input unit 13 for inputting the organic matter to be treated into the decomposition layer 11, and a discharge unit 14 for discharging the organic fertilizer after the steam decomposition treatment. The discharge unit 14 is provided with a pulverizer (not shown) for pulverizing the solidified organic fertilizer remaining in the organic fertilizer after the steam decomposition treatment into powder.

[0021] The ventilation opening 30 is provided with an outside air inlet 31 that draws outside air into the decomposition layer 11 and an inside air outlet 32 ​​that discharges the inside air in the decomposition layer 11 to the outside. Specifically, a compressor 310 is connected to the outside air inlet 31 to draw outside air into the decomposition layer 11, and sends compressed outside air into the decomposition layer 11 that has become hot during the steam decomposition treatment of organic matter. An exhaust fan 320 is provided to the inside air outlet 32 ​​to discharge the inside air in the decomposition layer 11, and mainly discharges water vapor generated by the steam decomposition treatment from the decomposition layer 11 to the outside. The outside air inlet 31 and the compressor 310, and the inside air outlet 32 ​​and the exhaust fan, are connected by, for example, a ventilation duct 300.

[0022] The vent hole 30 is also provided at a high position in the vertical direction of the decomposition treatment unit 10. As described above, the rotating shaft column 23 is provided to penetrate the bottom surface of the substantially elliptical decomposition layer 11, slightly vertically below the center of gravity, so that the rotating impellers 20, which rotate around the rotating shaft column 23, do not reach the inner wall surface 11A on the vertically upper side of the decomposition layer 11. In other words, the vent hole 30 is provided at a position such that the rotating impellers 20 do not pass nearby when they rotate. This prevents, for example, organic matter in the decomposition layer 11 from entering and blocking the vent hole 30 during steam decomposition treatment, thereby preventing the intake of outside air and the exhaust of inside air.

[0023] The provision of the ventilation opening 30 improves the efficiency of the steam decomposition treatment by allowing water vapor generated by the steam decomposition treatment to be discharged from the decomposition layer 11 and preventing water vapor from accumulating within the decomposition layer 11. Furthermore, by heating the organic matter at 200°C, components that cause malodors, such as hydrogen sulfide, are thermally decomposed, and the odor is discharged together with the water vapor from the internal air exhaust opening 32, so that almost no malodor remains in the organic matter after the steam decomposition treatment.

[0024] Furthermore, the temperature of the air taken in through the outside air intake 31 rises due to compression by the compressor 310, so it is unlikely to become a factor in disturbing the temperature control in the decomposition layer 11. If the temperature of the taken in air differs from the temperature in the decomposition layer 11 and there is concern that this may become a factor in disturbing the temperature control, a separate heater may be provided to take in heated air. Therefore, even when steam decomposition treatment is carried out in an area with low outside temperatures, the outside temperature will not have an effect.

[0025] The temperature inside the decomposition layer 11 during the steam decomposition treatment is measured by measuring the temperature of the air discharged from the internal air outlet 32 ​​using a temperature / humidity sensor 321 provided in the internal air outlet 32. In addition, by measuring the humidity of the air discharged from the internal air outlet 32, it is possible to determine whether evaporation of the moisture contained in the organic matter during the steam decomposition treatment is complete. For example, when the humidity of the air discharged from the internal air outlet 32 ​​becomes normal humidity during the steam decomposition treatment, it is determined that evaporation of the moisture contained in the organic matter is complete.

[0026] The rotation drive unit 40 is provided outside the decomposition treatment unit 10 inside the organic fertilizer production apparatus 1, and rotates the rotation shaft column 23 by a gear mechanism. Specifically, the rotation drive unit 40 may be, for example, a motor, a so-called geared motor with an integrated transmission, or a Cyclo reducer (registered trademark).

[0027] As described above, the heater 50 is connected to the oil layer 12 through which the thermal oil circulates, and heats and controls the temperature of the thermal oil. In the circulation flow path of the oil layer 12, a thermal oil temperature sensor 51 is provided upstream of the heater 50 to measure the temperature of the thermal oil, and in the event of overheating, the heater 50 is stopped, for example, by thermostat control, to control the temperature and prevent the organic matter from burning. Examples of the heater 50 include a thermal medium heater or a thermal medium boiler (electric, gas, hydrogen, etc.).

[0028] The cooling section 60 is composed of rotary valves 61A and 61B, a pressure blower 62, and a conveying duct 63. Specifically, the high-temperature organic fertilizer discharged from the discharge section 14 of the decomposition processing section 10 flows into the conveying duct 63 by the rotary valve 61A. The conveying duct 63 is connected to the pressure blower 62, and the organic fertilizer that flows into the conveying duct 63 is conveyed within the conveying duct 63 by the wind pressure of the pressure blower 62. The organic fertilizer conveyed within the conveying duct 63 is cooled by the wind from the pressure blower 62. The cooled organic fertilizer flows from the conveying duct 63 into the rotary valve 61B and is released from the rotary valve 61B into a flexible container bag. The method for cooling the organic fertilizer in the embodiment is just one example, and the specific cooling method is not limited thereto.

[0029] Although not shown in the figure, the organic fertilizer production device 1 is also equipped with a small outlet for checking the state of the organic matter being treated, and a sprinkler for extinguishing a fire in the decomposition treatment unit 10 in the event that the factory equipment is stopped due to a power outage or the like.

[0030] Next, the rotating impeller 20 will be described with reference to Figures 2 and 3. As shown in Figures 2 and 3, the rotating impeller 20 is composed of a pillar member 22 extending vertically from the side surface of a rotating shaft column 23, and an agitating plate 21 provided at the tip of the pillar member 22. Specifically, the rotating shaft column 23 and the pillar member 22 are not integrally molded, but the pillar member 22 extends and is fixed to the rotating shaft column 23 by a pillar fixing portion 22A. The agitating plate 21 also has an agitating edge 211 and a rubbing portion 212.

[0031] The stirring plate 21 has a rectangular plate shape, and is provided at the tip of the pillar member 22 with its surface inclined in the direction of rotation (clockwise in FIG. 3) of the rotating shaft pillar 23 during steam decomposition treatment with respect to the extension direction of the pillar member 22 (see FIG. 3). Furthermore, a stirring edge 211 is provided on the surface of the stirring plate 21 on the side to which the pillar member 22 is not connected so as to follow the diagonal of the rectangular surface, and the stirring edge 211 is formed perpendicular to the surface of the stirring plate 21. The stirring edge 211 shown in the figure is substantially triangular, but is not limited to this and may have a different shape, such as a square shape.

[0032] The rubbing portion 212 refers to the side of the agitation plate 21 that is located farthest from the rotation shaft column 23 (see FIG. 3). The side of the agitation plate 21 that is the rubbing portion 212 is not formed perpendicular to the surface of the agitation plate 21, but is formed so as to be parallel or approximately parallel to the inner wall surface 11A of the decomposition layer 11 in the area where the rubbing portion 212 (described later) rubs the organic matter against the inner wall surface 11A of the decomposition layer 11. In the case of an approximately parallel shape, it is desirable that of the four sides of the surface of the rubbing portion 212, two sides parallel to the horizontal direction are inclined so that the side facing the rotation direction during the steam decomposition treatment is farther from the inner wall surface 11A than the other side. By forming the rubbing portion 212 in this manner, it becomes easier to apply a force that rubs the organic matter against the inner wall surface 11A of the decomposition layer 11 during the steam decomposition treatment.

[0033] 2 and 3 are not limited to the positions, shapes, and sizes of the inlet 13, outlet 14, and vent 30 shown in the drawings. For example, the vent 30 may be located in a position other than those shown, or multiple vents may be provided, as long as the vent 30 is located in a position that makes it difficult for organic matter to enter the vent 30 due to the operation of the rotating blades 20.

[0034] (Steam decomposition treatment) Next, the steam decomposition treatment will be described with reference to Figures 4 and 5. The steam decomposition treatment is a treatment in which organic matter is rubbed against the inner wall surface 11A while being stirred in the decomposition layer 11, thereby thermally decomposing the organic matter by indirect heating and evaporating the moisture contained in the organic matter. The moisture content of the organic matter introduced into the decomposition layer 11 is approximately 40% to 60%. In Figures 4 and 5, the organic matter is indicated by diagonal lines sloping downward to the right.

[0035] During the steam decomposition treatment, thermal oil maintained at 200°C circulates through the oil layer 12 outside the decomposition bed 11, so that the inner wall surface 11A of the decomposition bed 11 is heated to approximately 200°C due to heat transfer, and the organic matter is rubbed against the inner wall surface 11A at approximately 200°C by the rubbing portion 212 of the rotating blades 20 to thermally decompose the organic matter, and the contained moisture is evaporated while being agitated by the agitating edge 211. Specifically, as shown in Figure 4, organic matter that accumulates vertically below the decomposition bed 11 is scooped up by the agitating edge 211 of the rotating blades 20 and agitated within the decomposition bed 11, and as the rotating blades 20 rotate, the rubbing portion 212 rubs the organic matter against the inner wall surface 11A of the decomposition bed 11 in a region close to the inner wall surface 11A of the decomposition bed 11.

[0036] The rubbing of the organic matter against the inner wall surface 11A by the rubbing portion 212 is performed in the region vertically below the dashed-dotted line C shown in the figure, for example, while the rubbing portion 212 passes between points A and B. As described above, the rotary shaft column 23 from which the rotating blades 20 extend is provided to penetrate slightly vertically below the center of gravity of the bottom surface of the substantially elliptical decomposition layer 11, so that the rotating blades 20 do not reach the inner wall surface 11A on the vertically upper side of the decomposition layer 11, and therefore, almost no rubbing occurs vertically above the dashed-dotted line C.

[0037] 5 , the rubbing portion 212 moves as indicated by the arrow T due to the rotation of the rotary blade 20, and at point A, the rubbing portion 212 starts rubbing the organic matter against the inner wall surface 11A of the decomposition layer 11. Between points A and B, the rubbing portion 212 is desirably formed so as to be parallel or approximately parallel to the inner wall surface 11A of the decomposition layer 11; for example, the rubbing portion 212 shown in the figure is formed approximately parallel to the inner wall surface 11A of the decomposition layer 11.

[0038] As the rubbing portion 212 moves, organic matter located on the arrow T between points A and B in the decomposition layer 11 penetrates between the rubbing portion 212 and the inner wall surface 11A of the decomposition layer 11, and is rubbed against the inner wall surface 11A of the decomposition layer 11 by the rubbing portion 212 in the direction indicated by arrow P.

[0039] Furthermore, since the agitating edge 211 is formed along the diagonal of the rectangular surface of the agitating plate 21, the organic matter is agitated in the left-right direction by the agitating edge 211 near the vertically lower part of the decomposition layer 11 where the organic matter accumulates.

[0040] Furthermore, the thicknesses of the stainless steel in the decomposition layer and oil layer described above are set to 10 mm for the outer layer of the decomposition layer and 4 mm for the outer layer of the oil layer, so that they can withstand the internal pressure caused by the rubbing portion 212 rubbing the organic matter against the inner wall surface 11A of the decomposition layer 11 during the steam decomposition treatment. For example, if there is a risk that the internal pressure of the decomposition layer 11 during the steam decomposition treatment will increase due to factors such as increasing the area of ​​the rubbing portion 212 by making the stirring plate 21 thicker or changing the angle at which the rubbing portion 212 is formed to increase the rubbing force, the stainless steel layer is formed to a thickness that can withstand the generated internal pressure.

[0041] The steam generated by the steam decomposition treatment is appropriately discharged from the inside air outlet 32, and outside air is taken in from the outside air inlet 31, thereby preventing the steam from remaining in the decomposition layer 11 and efficiently increasing the temperature to carry out the steam decomposition treatment. The steam decomposition treatment continues until the temperature of the organic matter reaches approximately 150°C to 160°C.

[0042] (Treatment Process) Next, the process of producing organic fertilizer using the organic fertilizer production apparatus 1 will be described with reference to Figure 6. First, the heater 50 heats the thermal oil circulating in the oil layer 12 until it reaches 200°C (step S01). The temperature of the thermal oil is detected by a thermal oil temperature sensor 51 provided upstream of the heater 50 in the oil layer 12 and is managed by adjusting the output of the heater 50. In the event of overheating, the heater 50 is stopped, for example, by thermostat control, to prevent the organic matter from burning. Once the temperature of the thermal oil reaches 200°C, the organic matter is introduced into the decomposition layer 11 (step S02). The moisture content of the organic matter introduced into the decomposition layer 11 is 40% to 60%.

[0043] Once the organic matter has been added, the steam decomposition process begins (Step S03). The added organic matter is agitated by the rotating blades 20 within the decomposition tank 11, rubbing against the inner wall surface 11A and increasing in temperature, resulting in thermal decomposition and evaporation of the contained moisture. First, pathogenic bacteria such as Salmonella, E. coli, Staphylococcus, and harmful seeds are killed between the temperature at which the organic matter was added and 80°C (Step S04). The temperature then continues to rise, and when the temperature of the organic matter reaches approximately 100°C to 110°C, the temperature rise temporarily stops. If the organic matter contains moisture, the temperature will not rise above 100°C to 110°C.

[0044] The steaming and decomposition treatment at 100°C to 110°C completely evaporates the moisture contained in the organic matter (step S05). Once the moisture contained in the organic matter has completely evaporated, the temperature of the organic matter begins to rise again. The water vapor generated by the steaming and decomposition treatment is discharged together with the odor from the internal air outlet 32 ​​to the outside of the organic fertilizer production apparatus 1. Once the moisture has completely evaporated, the foul odor of the organic matter is almost completely eliminated, and the organic matter becomes almost odorless.

[0045] When the temperature starts to rise from 110°C, the organic matter crushing process is then carried out (step S06). Between 110°C and 160°C, the organic matter that has lost its moisture is further rubbed against the inner wall surface 11A of the decomposition layer 11 by the rubbing unit 212, and the organic matter contained therein, such as cellulose, is crushed into a fine powder. The organic matter crushing process is carried out until the temperature of the organic matter reaches approximately 150-160°C.

[0046] When the temperature of the organic matter reaches 150-160°C, the organic matter crushing process is terminated (step S07). The temperature of the organic matter is determined by taking out a small amount from the small outlet when the temperature and humidity sensor detects normal humidity. When the organic matter crushing process is completed, the steaming and decomposition process is terminated (step S08). The organic fertilizer is discharged from the discharge section 14 of the decomposition processing section 10 (step S09). When discharged, any organic fertilizer that was not completely pulverized during the steaming and decomposition process is pulverized by a pulverizer provided in the discharge section 14.

[0047] The organic fertilizer discharged from the discharge section 14 flows from the rotary valve 61A into the transport duct 63, and while the organic fertilizer is being transported, it is subjected to a forced cooling process using cold air from the pressure blower 62 (step S10). The organic fertilizer that has flowed into the transport duct 63 is transported by the wind pressure of the pressure blower 62. The temperature of the air from the pressure blower is about 40°C, and the organic fertilizer being transported through the transport duct 63 is cooled to about 60°C by the wind from the pressure blower 62. The organic fertilizer cooled to 60°C flows from the transport duct 63 into the rotary valve 61B, and is discharged from the rotary valve 61B into the flexible container bag 70 (step S11).

[0048] The processing time from step S01 to step S11 varies depending on the moisture content of the organic matter (40% to 60%), but can be completed in approximately 5 to 8 hours. The moisture content of the organic matter varies depending on the amount of moisture ingested by livestock, for example, depending on the season (temperature).

[0049] The organic fertilizer produced under such temperature control through a process that includes steam decomposition treatment contains more nitrogen than the nitrogen content contained in conventional compost (special fertilizer).

[0050] (Comparison of Components) Using Figure 7, the components of the treated organic fertilizer of this embodiment and a conventional fertilizer are compared. The raw material of the illustrated fertilizers is all chicken manure. The component contents of the products shown in Figure 7 are the values ​​of the component contents listed on the products actually sold, and the component contents of the test results are the values ​​of the component contents listed on the test result certificate submitted by the contractor after a commissioned test. The measurement items are the three items of total nitrogen, total phosphate, and total potassium, in accordance with the items listed on the products. Furthermore, the method for measuring the components in the commissioned tests was the Fertilizer Analysis Method (the method of the National Institute for Agro-Environmental Sciences, Ministry of Agriculture, Forestry and Fisheries).

[0051] Here, fermented chicken manure and dried chicken manure are used for comparison. Fermented chicken manure is chicken manure that has been fermented and then dried. Dried chicken manure is chicken manure that has been dried directly with hot air.

[0052] First, a comparison was made between fermented chicken manure and the treated chicken manure of this embodiment. The total amount of nitrogen contained in the first fermented chicken manure product was 3.5% of the total components, the total amount of nitrogen contained in the second product was 2.5% of the total components, and the total amount of nitrogen contained in the third product was 2.3% of the total components. The average total amount of nitrogen for these three products was 2.77% of the total components. In contrast, for the treated chicken manure of this embodiment, the total amount of nitrogen contained in the treated chicken manure in the first test results was 5.23% of the total components, the total amount of nitrogen contained in the treated chicken manure in the second test results was 4.8% of the total components, and the total amount of nitrogen contained in the treated chicken manure in the third test results was 6.05% of the total components. The average total amount of nitrogen for these three test results was 5.36% of the total components. This resulted in the treated chicken manure of this embodiment having an average total nitrogen content that was 2.59% higher than that of commercially available conventional fermented chicken manure.

[0053] Next, dried chicken manure and the treated chicken manure of this embodiment are compared. Unlike fermented chicken manure, dried chicken manure has not been fermented, and therefore, nitrogen components are not lost through volatilization compared to fermented chicken manure. Therefore, it is characterized by containing more nitrogen components than fermented chicken manure. The total amount of nitrogen contained in the first dried chicken manure product was 4.3% of the total components, the total amount of nitrogen contained in the second dried chicken manure product was 4.5% of the total components, and the total amount of nitrogen contained in the third dried chicken manure product was 4.3% of the total components. The average total nitrogen content of these three products was 4.37% of the total components. In contrast, the average total nitrogen content of the treated chicken manure of this embodiment was 5.36% of the total components, resulting in an average total nitrogen content of the treated chicken manure of this embodiment that was 0.99% higher than that of conventional commercially available dried chicken manure.

[0054] The above test results show that the treated chicken manure produced in this embodiment contains more nitrogen than conventional compost (special fertilizer). In particular, compared to dried chicken manure, which is made by drying organic matter to evaporate the moisture contained in the organic matter, the treated chicken manure in this embodiment contains about 0.99% more nitrogen. This shows that simply drying alone is not enough to maintain a high nitrogen content in organic fertilizer, and that this is an effect unique to the treatment process of this embodiment, which includes a steam decomposition treatment process.

[0055] In the above explanation, chicken manure has been used as the organic material for the steam decomposition treatment, but the organic material is not limited to this. Figure 8 shows the components contained in fermented pig manure and fermented cow manure that are actually sold, and in pig manure and cow manure produced by the steam decomposition treatment of this embodiment.

[0056] The ingredients contained in the sold products are the values ​​of the ingredient content listed on the product actually sold, and the ingredient content of the test results are the values ​​of the ingredient content listed on the test result certificate submitted by the contractor after the commissioned test. The measurement items are the three items of total nitrogen, total phosphate, and total potassium, in accordance with the items listed on the product. In addition, the measurement methods for the ingredients contained in the commissioned test were the DeValta alloy sulfuric acid method for total nitrogen, the vanadomolyptic acid method for total phosphate, and the atomic and optical method for total potassium for both the treated swine manure and the treated cow manure.

[0057] First, a comparison will be made between fermented swine manure and the swine manure treated in this embodiment. The total amount of nitrogen contained in the fermented swine manure is 3.4% of the total components. In contrast, the total amount of nitrogen contained in the swine manure treated in this embodiment is 4.3% of the total components, meaning that the total amount of nitrogen in the swine manure treated in this embodiment is 0.9% higher than that of conventional fermented swine manure that is commercially available.

[0058] Next, a comparison will be made between fermented cow manure and the cow manure treated in this embodiment. The total amount of nitrogen contained in the fermented cow manure is 0.63% of the total components. In contrast, the total amount of nitrogen contained in the cow manure treated in this embodiment is 1.4% of the total components. As a result, the total amount of nitrogen in the cow manure treated in this embodiment is 0.77% higher than that of conventional fermented cow manure that is commercially available.

[0059] From the above results, by performing thermal decomposition by steam decomposition treatment in this embodiment instead of decomposing organic matter by fermentation treatment, it is possible to prevent nitrogen components from volatilizing into the atmosphere, and by not performing fermentation treatment, it is possible to reduce the amount of greenhouse gases generated, and it is possible to produce organic fertilizer that contains more nitrogen components than conventional compost (special fertilizer).

[0060] (Comparison of decomposition ability of organic matter) Next, test results of decomposition ability of organic matter in organic fertilizers produced by the process including the steam decomposition treatment in this embodiment are shown with reference to Figures 9 and 10. The test results shown in Figures 9 and 10 are analytical values ​​described in the test result certificate submitted by the contractor after the commissioned test.

[0061] The six test materials were steam-decomposed cow manure, cow manure + food residue, pig manure, pig manure + food residue, chicken manure, and chicken manure + food residue. For the materials with added food residue, the food residue was added so that it accounted for less than 10% of the total. The purpose of testing materials with added food residue was to conduct tests under the same conditions as most livestock manures that have traditionally been fermented, where food residue is added so that it accounts for less than 10% of the total.

[0062] The survey items were moisture, total nitrogen, total carbon, ADF (acid detergent fiber), lignin, crude ash, and silica, as per standard methods. Regarding the decomposition of organic matter, readily decomposable organic matter was defined as carbon, and persistent organic matter as ADF (acid detergent fiber). For several organic materials, including livestock manure compost, a high positive correlation (r2 = 0.921) was observed between the ADF content and the amount of organic matter remaining in the soil for three months (persistent organic matter), with the regression equation passing through the origin. Furthermore, since the amount of carbon in the ADF and the amount of carbon remaining for three months were roughly consistent, ADF is considered to be persistent organic matter itself.

[0063] (Chemical analysis values) In Figure 9, units other than moisture are mg per 1 g of dry matter. As shown in Figure 9, the component values ​​of "cow manure" and "cow manure + food" were roughly similar to those of general cow manure compost, except for a slightly lower crude ash content. In addition, the silica content was high, indicating the possibility of use as a silicate fertilizer. Compared to the component values ​​of general pig manure compost, "pig manure" and "pig manure + food" had higher total nitrogen, carbon, ADF, and lignin, and lower crude ash. This indicates that they are rich in organic matter. Furthermore, no significant differences were observed between "pig manure" and "pig manure + food." The component values ​​of "chicken manure" and "chicken manure + food" were roughly similar to those of general chicken manure compost, except for a higher carbon content and lower crude ash content.

[0064] (Decomposition of organic matter) In the graph shown in Figure 10, the vertical axis is the ADF content (refractory organic matter) and the horizontal axis is the amount of carbon decomposition over 14 days (easily decomposable organic matter). Furthermore, "+ food" indicates that food residue was added. As shown in Figure 10, "cow manure" contained little easily decomposable organic matter and much less decomposable organic matter. This is a similar trend to other cow manure composts. "Cow manure + food" contained more easily decomposable organic matter than "cow manure", but the amount of less decomposable organic matter was about the same. "Chicken manure" contained more easily decomposable organic matter than "cow manure", but the amount of less decomposable organic matter was about the same. "Pig manure + food", "chicken manure", and "chicken manure + food" contained more easily decomposable organic matter than the other test materials. Furthermore, "chicken manure" and "chicken manure + food" contained less less recalcitrant organic matter.

[0065] Thus, although differences were observed within the test materials, when compared with the entire plot of other livestock manure composts, they were within the range of the corresponding livestock manure composts, and it is thought that there are no significant differences between easily decomposable and difficult to decompose organic matter.

[0066] These results show that the decomposition of organic matter by steam decomposition treatment, i.e., the properties of organic fertilizer, are comparable to those of general livestock manure compost. This indicates that there is little risk of damage from easily decomposable organic matter and that steam decomposition treatment has the same soil improvement effect as livestock manure. In other words, steam decomposition treatment is almost as effective at decomposing organic matter as fermentation treatment.

[0067] The embodiments of the present invention have been described above in detail with reference to the drawings, but the specific configuration is not limited to the described embodiments, and the present invention also includes design changes and the like within the scope of the gist of the present invention.

[0068] 1: organic fertilizer production device, 10: decomposition treatment section, 11: decomposition layer, 11A: inner wall surface, 12: oil layer, 13: input section, 14: discharge section, 20: rotating blade, 21: agitation plate, 211: agitation edge, 212: rubbing section, 22: pillar member, 22A: pillar fixing section, 23: rotating shaft pillar, 30: ventilation port, 31: outside air intake port, 32: inside air exhaust port, 300: ventilation duct, 310: pressure pump, 320: exhaust fan, 321: temperature and humidity sensor, 40: rotation drive section, 50: heater, 51: thermal oil temperature sensor, 60: cooling section, 61A, 61B: rotary valve, 63: conveying duct, 70: flexible container bag

Claims

1. A decomposition treatment device having a two-layer structure consisting of a first layer for steaming and decomposing organic matter, and a second layer formed along the outside of the first layer to allow heat transfer oil to circulate, wherein the first layer is provided with an agitation plate that rotates around a rotating shaft column as an axis to agitate the organic matter, the agitation plate being a rectangular plate shape, and formed at the tip of a column member extending from the rotating shaft column, with an inclination in the direction of rotation of the rotating shaft column during treatment with respect to the extension direction, and having a rubbing part that rubs the organic matter against the inner wall surface of the first layer in a region that comes close to the inner wall surface of the first layer as it rotates, which is the side farthest from the plate-shaped rotating shaft column, and a stirring edge is formed along the diagonal of the rectangle on a surface facing the inner wall surface that is provided on the rotation direction side of the rubbing part, and the rubbing part is formed such that, of the four sides of the side surface, two sides that are always parallel to the horizontal direction in the region are inclined so that one side in the direction of rotation during treatment is farther from the inner wall surface than the other side, The second layer has a heater in a circulation flow path of the thermal oil for heating and controlling the temperature of the thermal oil, and the decomposition treatment unit heats and controls the temperature of the thermal oil circulating in the second layer with the heater, rubs the organic matter against the inner wall surface of the first layer which has become hot due to heat transfer from the thermal oil, and performs indirect heating to evaporate the moisture contained in the organic matter.

2. Using an apparatus having a two-layer decomposition treatment section consisting of a first layer for steaming and decomposing organic matter, and a second layer formed along the outside of the first layer to allow heat transfer oil to circulate, the heat transfer oil is heated to a predetermined temperature and the temperature is controlled, the organic matter is stirred in the first layer with a stirring plate having a rectangular plate shape, which is formed at the tip of a column member extending from a rotating shaft column and is inclined with respect to the extension direction in the direction of rotation of the rotating shaft column during treatment, and a stirring edge is formed along the diagonal of the rectangle that rotates around the rotating shaft column, and the organic matter is rubbed against the inner wall surface in the area close to the inner wall surface of the first layer by a rubbing part formed on the side furthest from the plate-shaped rotating shaft column and in a region that comes close to the inner wall surface of the first layer as a result of the rotational motion, on two of the four sides of the side that are always parallel to the horizontal direction, such that one side on the rotation direction side during treatment is farther from the inner wall surface than the other side, The method for producing an organic fertilizer further comprises the steps of: discharging water vapor generated by evaporation of water contained in the organic matter from the first layer; and continuing the step until the organic matter reaches a specific temperature.

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