JPS6341877B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a composting method for composting biological materials such as animals, plants, biological bacteria, sludge, kitchen waste, etc., and uses for the composting method. This relates to composting equipment.

(Prior Art) Generally, composting of biological materials is carried out by putting the material to be composted into a vertical or horizontal fermentation tank equipped with a stirrer, and by aeration and stirring. In this case, in order to promote the composting reaction, a method is used in which the temperature of the composting reaction is raised to around 60° C. or higher, and the water content is evaporated during aeration and discharged to the outside of the fermenter. However, in this method, when the material to be composted, such as kitchen waste, has a high moisture content, aeration itself becomes difficult and the fermentation rate decreases, resulting in a decrease in the composting temperature and the rate of evaporation of moisture. In addition, it is difficult to reduce the moisture content of finished compost to less than 40%, which results in products that emit odors and cause insect damage during storage, and the equipment inevitably becomes larger and more expensive. . Furthermore, there is a drawback that the required stirring power by the built-in stirrer becomes large. Furthermore, although the composting temperature is controlled by adjusting the aeration rate, there is a problem in that the degree of freedom in this adjustment is small and operation is cumbersome.

Another method is to load the material to be composted into a model rotary kiln and compost it through aeration and rotational agitation using the rotary kiln method. The disadvantage is that it is difficult.

Furthermore, the material to be composted is loaded into a horizontal composting device with a built-in agitator, and the water vapor that evaporates from the material to be composted is removed when composting is performed by aeration and stirring.
There is also a method of condensing water in a cooler installed in the upper space of the composting equipment, collecting the condensed water in a water collection pan, and discharging it outside the composting equipment, but although it is good at removing water, the required stirring power is The disadvantage is that it becomes large.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned difficulties and disadvantages. The purpose of the present invention is to provide a composting method that can smoothly and sufficiently remove waste materials, and a composting device used in the composting method.

(Means for Solving the Problems) The present invention adopts a rotary kiln method in order to reduce the required stirring power, the aeration amount is limited to the amount necessary to maintain fermentation, and the water vapor evaporated from the composted material is The cylindrical body of the rotary kiln is made of a hydrophobic material that has a large number of pores that allow only gases such as air and water vapor to pass through, in order to perform the separation smoothly. This is what was done. That is, in the composting method of the present invention, compost is placed inside a rotary kiln made of a hydrophobic material that is installed inside a cover casing and has a large number of pores on the side surface that allow only gases such as air and water vapor to pass through. In a reaction process in which a compound is loaded and the composted material is composted by aeration of an oxygen-containing gas and agitation accompanying the rotation of the rotary kiln, water vapor evaporated from the composted material is passed through the pores and composted by the rotation of the rotary kiln. It surrounds the kiln completely or partially and is maintained at a temperature below the composting reaction temperature to the extent that it does not inhibit the composting reaction, and is further transferred to a condensing means disposed between the cover casing and the rotating kiln. Condensed,
The present invention is characterized in that the condensed water is discharged outside the cover casing. Further, the composting device of the present invention is provided with a ventilation port and a compostable material input hopper at one end, and an exhaust port, a compost discharge port, and a condensed water discharge port at the other end. Inside the horizontal cover casing,
The inner surface of a cylinder made of hydrophobic material has numerous pores that allow only gases such as air and water vapor to pass through.
The cylinder is equipped with a transfer baffle plate, and one end of the cylinder is provided with an inlet communicating with the ventilation port and an input means communicating with the compostable material input hopper, and the other end is provided with the compost discharge port. A rotary kiln is provided with a discharge means leading to the rotary kiln, and a condensing means is provided between the cover casing and the rotary kiln, completely or partially surrounding the rotary kiln. .

(Function) When a material to be composted is composted by the composting method and apparatus of the present invention, water vapor evaporated from the material to be composted by the composting reaction is placed between the high-temperature composted material and the low-temperature condensing means. Due to the generated partial pressure gradient, water vapor is quickly transferred to the condensing means through a large number of pores on the entire circumference of the rotary kiln.
On the other hand, since the material to be composted is loaded in the rotary kiln and does not touch the condensing means, the water vapor is smoothly condensed, and the condensed water enters the rotary kiln made of hydrophobic material and wets the material to be composted. At the same time, only a part of the water vapor is discharged outside the cover casing along with the exhaust gas, and the composted material that has completed the composting reaction becomes compost and is discharged as compost from the cover casing. It is discharged from the exit.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In the diagram showing the composting apparatus used in the composting method of the present invention, 10 is a horizontal cover casing, and the cover casing 10 has a ventilation hole 18 and a bearing hole 11 at both ends of the horizontal cylinder.
An end plate 13 having an exhaust port 19 and a bearing hole 1
A compostable material input hopper 15 is provided at one end of the cover casing main body, which is provided with an end plate 14 having an end plate 14 having a casing 2, and faces into a hollow rotating shaft 22 (described later) supported by a bearing hole 11 through the ventilation hole 18. At the same time, a compost outlet 16 and a condensed water outlet 17 are provided at the lower part of the other end. 20
is a rotary kiln installed inside a horizontal cover casing 10, and the rotary kiln 20 has a large number of pores 2 that allow only gases such as air and water vapor to pass through.
1, Teflon, polyethylene, having...
An end plate 24 having a hollow rotating shaft 22 supported in the bearing hole 11 at both ends of a cylindrical body made of a hydrophobic material such as polypropylene, and an end plate 25 having a rotating shaft 23 supported in the bearing hole 12. A stirring/transfer baffle plate 26,... is provided on the inner surface of the cylindrical body.
..., and further, at one end of the cylindrical body, a charging means communicating with the compostable material charging hopper 15,
For example, an input spiral 27 is provided, and the other end is provided with a discharge means, such as a discharge port 28, which communicates with the compost discharge port 16. The hollow hole of the hollow rotary shaft 22 serves as an inlet 40 for introducing air into the rotary kiln 20 from the vent 18. The exhaust port 19 and the inside of the rotary kiln 20 communicate with each other through pores 21, . Reference numeral 31 denotes a heat insulating material applied to the outside of the cover casing 10, and the heat insulating material 31 and the cover casing 10 form a condensing means 30 that completely surrounds the rotary kiln 20. Although not shown, instead of providing a heat insulating material 31 on the outside of the cover casing 10 to form a condensing means,
A cooler may be disposed in a space between the cover casing 10 and the rotary kiln 20 so as to partially surround the rotary kiln to serve as a condensing means. In addition,
Instead of supporting the rotary kiln 20 horizontally as shown, the rotary kiln 20 may be supported at an angle so that the discharge port 28 side is slightly lower. In addition, rotary kiln 20
The cylindrical body may be replaced with the structure shown in the drawings, and the inside and outside of the reinforcing perforated cylindrical body may be covered with cloth made of a hydrophobic material. Furthermore, a ventilation port 18, an exhaust port 19, an inlet port 40
etc. may be formed in portions other than those shown.

Next, in order to perform composting using the above-mentioned composting apparatus, the material to be composted 100 is loaded into the rotary kiln 20 using the material to be composted input hopper 15 and the input spiral 27, and then suctioned from the exhaust port 19. The rotary kiln 20 is gradually rotated at a speed of, for example, once every 4 minutes, while an oxygen-containing gas, such as air, is vented to the composted material 100 through the vent 18 and the inlet 40 by evacuation. Then, the material to be composted 100 is stirred by the stirring/transfer baffle plate 26, . Therefore, the temperature of the composted material is 60℃.
The temperature reaches ~70℃, and the moisture contained in the composted material evaporates. Since the cylindrical body of the rotary kiln 20 is made of a hydrophobic material having a large number of pores 21 that allow only gas such as air or water vapor to pass through, the material to be composted 100 is The material to be composted 100 does not adhere to the rotary kiln 20 and block the pores 21, . By maintaining the temperature at a temperature slightly lower than the composting reaction temperature, for example, 45°C, to the extent that the composting reaction is not inhibited, a water vapor partial pressure gradient is created between the rotary kiln 20 and the condensing means 30. The water vapor evaporated from the composted material 100 passes through a large number of pores 21, . The condensed water is transferred to the inner surface of the casing 10 and condensed by the condensing means 30 to become condensed water at a temperature of 45° C., and the condensed water does not enter the cylindrical body of the rotary kiln made of hydrophobic material, but instead flows through the condensed water outlet. 1
7 and is discharged to the outside of the cover casing 10, and only a part of the water vapor evaporated from the composted material is discharged outside the cover casing 10 along with the exhaust, and the composted material that has completed the composting reaction becomes compost. The compost is then discharged from the compost discharge port 16 of the cover casing 10 by the stirring/transfer baffle plates 26, .

As described above, most of the water vapor that evaporates from the material to be composted 100 due to fermentation heat etc. in the process of the composting reaction is condensed in the cover casing 10 by the condensing means 30, and on the other hand,
Since the amount of ventilation is limited to the amount necessary for fermentation, the amount of heat that is discarded as steam outside the cover casing 10 is small, so the amount of heat required for removing moisture from the composted material can be reduced.

Furthermore, in order to promote the composting reaction, fermented compost may be mixed with the material to be composted and the mixture may be loaded into the rotary kiln.

Next, the inner volume of the rotary kiln in the illustrated composting apparatus is set to 7 m ³ , and the rotary kiln has a water content of 67%.
Composting was carried out for 7 days by loading 230 kg of crushed kitchen waste, keeping the inner temperature of the cover casing at 45°C, and limiting the amount of ventilation to the amount necessary to maintain fermentation. It reached around 63℃,
The evaporated water vapor condensed very smoothly and became 80 kg of condensed water, while the water vapor removed during exhaust was 45 kg, yielding 90 kg of compost with a moisture content of 30%, which was stable. and could be stored. Furthermore, strict regulation of the aeration rate was not required during the composting process. The experimental result was obtained.

(Effects of the Invention) Since the present invention uses a rotary kiln, the stirring power is small, and fermentation heat is effectively used to condense water vapor that evaporates from the material to be composted on the inside or inside of the cover casing. By converting the water into condensed water and preventing it from flowing back into the composted material using a hydrophobic material with a large number of pores, the amount of heat required to remove water from the composted material can be reduced and composting can be achieved sufficiently. It becomes possible. In addition, since the water vapor evaporated from the composted material is condensed by the condensing means that completely or partially surrounds the rotary kiln made of hydrophobic material having many pores, the condensation is carried out smoothly and Since condensed water does not enter the rotary kiln and is discharged outside the cover casing, and only a portion of the evaporated water vapor is discharged outside the cover casing along with the exhaust, a large amount of moisture can be effectively removed from the composted material. Therefore, it becomes possible to remove it.

[Brief explanation of drawings]

The drawings show an embodiment of the composting apparatus used in the composting method of the present invention, in which Fig. 1 is a longitudinal sectional front view with a part cut away, and Fig. 2 is a longitudinal sectional view taken along the line - in Fig. 1. FIG. 10: Cover casing, 11, 12: Bearing hole, 13, 14: End plate, 15: Composted material input hopper, 16: Compost discharge port, 17: Condensed water discharge port, 18: Ventilation port, 19: Exhaust port, 20: Rotating kiln, 21: Pore, 22: Hollow rotating shaft, 23: Rotating shaft, 24, 25: End plate, 26: Stirring/transfer baffle plate, 27: Input spiral, 28: Discharge port, 30: Condensation Means, 31: Heat insulating material, 40: Inlet, 100:
Compostable material.

Claims (1)

[Claims] 1. A rotary kiln made of a hydrophobic material that is installed inside a cover casing and has a large number of pores on the side surface that allow only gases such as air and water vapor to pass through, and the material to be composted is loaded into the rotary kiln. In the reaction process in which the composted material is composted by aeration of oxygen-containing gas and agitation accompanying the rotation of the rotary kiln, water vapor evaporated from the composted material is passed through the pores to the entire surface of the rotary kiln. completely or partially surrounded and maintained at a temperature lower than the composting reaction temperature to the extent that the composting reaction is not inhibited, and further transferred to a condensing means disposed between the cover casing and the rotary kiln for condensation; A composting method characterized by discharging condensed water outside the cover casing. 2 A horizontal cover casing is provided with a ventilation port and a compostable material input hopper at one end, and an exhaust port, a compost discharge port, and a condensed water discharge port at the other end. A cylinder made of a hydrophobic material having a large number of pores that allows only gases such as water vapor to permeate is equipped with a baffle plate for stirring and transfer on the inner surface, and one end of the cylinder is equipped with an inlet that leads to the ventilation hole. A rotary kiln is installed, the rotary kiln having a mouth and an input means communicating with the compostable material input hopper, and a discharge means communicating with the compost discharge port at the other end, and between the cover casing and the rotary kiln. A composting device characterized in that it is provided with condensing means that completely or partially surrounds a rotary kiln. 3. The composting apparatus according to claim 2, wherein the condensing means is provided with a heat insulating material on the outside of the cover casing. 4. The composting apparatus according to claim 2, wherein the condensing means includes a cooler provided in a space between the cover casing and the rotary kiln.