JP6834095B2 - Methane fermenter - Google Patents

Description

The present invention relates to a methane fermenter.

Livestock manure put into the methane fermentation tank contains sand, and sand may accumulate at the bottom of the tank due to long-term operation. When sand is accumulated, the effective processing volume of the tank is reduced by that amount, and the extraction port of the digestive juice may be filled with sand. Therefore, it is necessary to discharge the sand regularly. In the conventional sand discharge method, the amount of sand is checked regularly, and when the amount reaches a predetermined amount, the digestive juice of livestock manure in the tank is emptied, and then a person enters the tank and a vacuum hose is used. The accumulated sand was discharged to the outside by using the above.

However, with this discharge method, a series of steps of "drainage of digestive juice in the tank-> ventilation in the tank-> discharge of sand" takes days, and even after the discharge of sand is completed, "drainage of digestive juice into the tank" It takes a considerable number of days for the process of "returning → resetting the fermentation operation in consideration of the doubling time of fermenting bacteria".

To solve this problem, Patent Document 1 describes a technique in which a stirrer installed inside a methane fermentation tank is rotated in the reverse direction to collect sediments in the center of the bottom of the tank, and a pump discharges the sediments to the outside of the tank. ing.

Japanese Unexamined Patent Publication No. 2014-161813

In the technique of Patent Document 1, the sediment is moved and sucked by the convection of the digestive juice in the methane fermentation tank. However, in order to generate convection of digestive juice in the tank, there is a problem that the shape of the methane fermenter and the layout of the stirrer are limited. Further, depending on the fluidity of the digestive juice, a predetermined convection effect may not be obtained.

The present invention has been created to solve such a problem, and an object of the present invention is to provide a methane fermenter capable of efficiently discharging sand without being restricted by the shape of the methane fermenter and the layout of the stirrer. And.

In order to solve the above problems, the present invention is provided with a fermenter main body, a suction tube having a plurality of suction holes for sucking sand accumulated on the bottom of the fermenter main body, and an outside of the fermenter main body. It is provided with a suction pump that is operated by pressure water to generate a negative pressure in the suction pipe, and an umbrella-shaped screen plate that is provided above the suction holes at intervals to reduce clogging of the suction holes. A plurality of the suction pipes are arranged, and each suction pipe is assembled into one via an on-off valve, and the on-off valve is sequentially switched and opened to communicate with the suction pump to suck the accumulated sand. To do.

According to the present invention, by providing a suction tube having a plurality of suction holes formed, the accumulated sand can be efficiently sucked regardless of the shape of the fermenter main body and the layout of the stirrer. By providing a suction pump that operates by pressure water to generate a negative pressure in the suction pipe, mechanical blockage in the pump due to sand or impurities is less likely to occur.

According to the present invention, by sequentially switching and opening the on-off valves, the number of suction pipes can be increased without increasing the output of the suction pump, and a wide range of accumulated sand can be removed. In addition, the suction force of each suction pipe can be made the same, and uneven suction of accumulated sand can be prevented.

Further, the present invention is characterized by comprising a solid-liquid separator that separates the sand sucked by the suction pipe and the pressure water.

According to the present invention, since the sand and the pressure water are separated, the sand can be easily treated, the pressure water can be reused, and the pressure water can be circulated.

According to the present invention, sand can be efficiently discharged without being restricted by the shape of the methane fermenter and the layout of the stirrer.

It is a block diagram of the methane fermenter which concerns on this invention. It is a top view which shows the suction tube. It is a top view which shows the suction tube which concerns on the modification.

As shown in FIG. 1, organic waste W such as livestock manure is charged from the original tank 21 into the fermenter main body 2 of the methane fermentation tank 1. The fermenter body 2 has, for example, a cylindrical shape. In the fermenter main body 2, the organic waste W is methane-fermented by anaerobic methane-fermenting bacteria, and the digestion gas is appropriately used as gas energy in a boiler, a generator, or the like. The digestive juice is transferred from a drawing port (not shown) to a downstream processing step. The sand contained in the livestock manure is deposited on the bottom of the methane fermenter 1. In the methane fermentation tank 1, an impeller type stirrer 5 for stirring the organic waste W is arranged in a state where the rotation axis is tilted.

The methane fermenter 1 is provided outside the fermenter body 2, a suction tube 3 having a plurality of suction holes 6 for sucking sand S deposited on the bottom of the fermenter body 2, and a suction tube 3 formed on the outside of the fermenter body 2. It includes a suction pump 4 that operates with pressure water to generate a negative pressure in the suction pipe 3.

When the sand S is unevenly deposited on the bottom of the fermenter main body 2 by being agitated by the impeller of the stirrer 5, the suction pipe 3 may be arranged only in the vicinity of the depositing place instead of the entire bottom. As an example, as shown in FIG. 2, the suction pipe 3 includes a base pipe 3A extending in the radial direction of the fermenter main body 2 at the bottom of the fermenter main body 2 and branch pipes 3B and 3C branching to the left and right from the base pipe 3A. It is configured with and. The base end side of the base pipe 3A communicates with the suction pump 4 via an on-off valve 32. A plurality of sets of branch pipes 3B and 3C are arranged, for example, at intervals in the extending direction of the base pipe 3A, depending on the size and shape of the methane fermentation tank 1. A plurality of suction holes 6 are formed in the base pipe 3A, the branch pipes 3B, and 3C at appropriate intervals.

The suction hole 6 may be formed downward, upward, or laterally. When the suction hole 6 is formed so as to face upward, it is possible that the sand is likely to be clogged. In this case, by appropriately installing an umbrella-shaped screen plate 9 or the like above the suction hole 6 at intervals, it is possible to prevent sand lumps or the like from being directly sucked into the suction hole 6. Clogs can be reduced.

A modified example of the suction tube is shown in FIG. The suction pipe 31 includes a plurality of base pipes 31A that communicate with each other inside and outside the fermenter main body 2. A plurality of suction holes 6 are formed in each base tube 31A at appropriate intervals. Each base pipe 31A is assembled into one outside the fermenter main body 1 via an on-off valve 32, and then communicates with the suction pump 4. The opening and closing of the on-off valve 32 may be automatic control or manual operation. As a method of opening and closing the on-off valve 32, it is desirable to sequentially switch and open the on-off valve 32 in order to increase the negative pressure in each base pipe 31A.

The suction pump 4 is composed of, for example, a jet pump. The suction pump 4 is operated by the pressure water supplied from the drive water pump 7 to generate a negative pressure in the suction pipe 3. As the driving water used in the driving water pump 7, groundwater or digestive juice obtained in the methane fermentation tank 1 can be used. The sand sucked by the suction pipe 3 is separated into sand and water by the solid-liquid separator 8 together with the pressure water. A pressure water tank (not shown) may be provided to store the water separated by the solid-liquid separator 8 and reuse it as pressure water. Pressure water can be circulated and used by this pressure water tank.

By periodically performing such a series of sand removal operations by timer control or the like, the amount of sand S in the fermenter main body 2 can be suppressed and the decrease in the effective processing volume of the fermenter main body 2 can be prevented. Of course, the sand removal operation may be performed at an arbitrary time depending on the input status of the organic waste W. Further, a detection sensor (not shown) for detecting sand may be provided inside the fermenter main body 2, and the sand removal operation may be performed based on the detection signal of the detection sensor.

According to the methane fermentation tank 1 of the present invention, by providing the suction pipe 3 in which a plurality of suction holes 6 are formed, sand S can be efficiently sucked regardless of the shape of the fermenter main body 2 and the layout of the stirrer 5. Since the shape of the fermenter main body 2 and the layout of the stirrer 5 are not restricted, the present invention can be easily applied to the existing methane fermenter. Further, by providing the suction pump (jet pump) 4 which is operated by the pressure water to generate a negative pressure in the suction pipe 3 as the suction pump, mechanical blockage in the pump due to sand or impurities is less likely to occur.

Further, as shown in FIG. 3, a plurality of base pipes 31A are arranged as the suction pipes 3, and each base pipe 31A is assembled into one via an on-off valve 32 and communicated with the suction pump 4. By sequentially switching and opening the on-off valve 32, the number of the base pipes 31A can be increased without increasing the output of the suction pump 4, and a wide range of accumulated sand can be removed. In addition, the suction force of each base pipe 31A can be made the same, and uneven suction of accumulated sand can be prevented.

The preferred embodiment of the present invention has been described above. The present invention can be implemented without limiting the shape of the fermenter main body 2 and the layout of the stirrer 5 to those shown in the figure. Further, the stirrer 5 does not necessarily have to be set. Further, if a plurality of suction holes 6 are formed, the suction pipe 3 can be implemented without being limited to the one shown in the figure.

1 Methane fermenter 2 Fermenter body 3, 31 Suction pipe 4 Suction pump 5 Stirrer 6 Suction hole 8 Solid-liquid separator

Claims (2)

A fermenter main body, a suction pipe having a plurality of suction holes for sucking sand accumulated on the bottom of the fermenter main body, and a suction pipe provided outside the fermenter main body and operated by pressure water to negatively affect the suction pipe. A suction pump for generating pressure and an umbrella-shaped screen plate provided above the suction holes at intervals to reduce clogging of the suction holes are provided.
A plurality of the suction pipes are arranged, and each suction pipe is assembled into one via an on-off valve, and the on-off valve is sequentially switched and opened to communicate with the suction pump to suck the accumulated sand. Methan fermenter. The methane fermenter according to claim 1, further comprising a solid-liquid separator that separates the sand sucked by the suction pipe and the pressure water.

Images