JP2002336826A - Horizontal helical vane stirring type methane fermentation tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methane fermentation tank in which fermentation of methane can be efficiently carried to. SOLUTION: The horizontal methane fermentation tank is equipped with a source material feeding port 12 in one longitudinal end of a fermentation tank 10 installed almost horizontally and with an exit 18 for generated gas and with an exit 14 for treated liquid in the other longitudinal end of the tank 10. A rotary shaft 22 which supports stirring vanes is penetrated in the longitudinal direction at an almost center of the fermentation tank 10, while the end part of the rotary shaft 22 is connected to a driving means. A large number of stirring rods 24 are attached almost radially at a specified interval to the rotary shaft 22 in such a manner that the stirring rods are disposed helically to the shaft 22 so as to form the helical vanes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methane fermentation tank capable of efficiently extracting methane gas from organic waste such as livestock waste, marine waste, and household waste such as garbage. .

[0002]

2. Description of the Related Art Conventionally known methods of stirring a methane fermentation tank include a circulating stirring using a pump or the like, a mechanical stirring using a draft tube or the like, a gas stirring using gas injection, and a stirring blade method. For example, JP-A-52-4
Japanese Patent No. 4072 discloses a configuration in which part of the methane gas generated in the methane fermentation tank is returned to the methane fermentation tank and used for gas stirring.

[0003] Japanese Patent Application Laid-Open No. Sho 54-164058 discloses a configuration in which a spiral stirring blade is provided on a rotating shaft installed in a vertical direction in a silo-type methane fermentation tank. Japanese Unexamined Patent Publication No. 55-75986 discloses a sub-mixing box provided with a stirrer having a stirrer mounted radially on a horizontal rotating shaft in a staggered arrangement, and a horizontal rotating shaft having both feeding and stirring functions. An apparatus comprising a main mixing box with a dispensing helix with attached spiral blades is disclosed. Japanese Patent Application Laid-Open No. 10-263512 discloses a three-dimensional multi-stage fermentation apparatus including two or more fermenters and an aging tank located below the fermenter. A configuration is disclosed in which a rotating shaft is vertically attached to an arm, and a horizontal stirring blade and a spiral stirring blade are provided on the rotation shaft.

[0004]

In the conventional method of stirring a methane fermentation tank, a method of circulating stirring using a pump or a blower uses a large amount of electricity, which increases running costs. In addition, in the case of stirring by gas injection or mechanical stirring by a draft tube, livestock waste having a high solids concentration could not be sufficiently stirred, and the fermentation rate was low. In addition, since the conventional stirring blade method has been developed with the main aim of eliminating the fermentation unevenness by sufficiently stirring the raw materials, it is necessary to homogenize the internal solution appropriately to extract methane gas and homogenize microorganisms. Methane fermentation treatment could not be performed efficiently. Further, in the conventional stirring by the spiral blade, feeding out of the raw material and accompanying return occurred, and methane fermentation did not proceed sufficiently in the tank.

[0005] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to use a stirring means by a spiral blade capable of appropriately homogenizing a liquid in a fermentation tank, and to use methane regardless of the raw material properties. It is an object of the present invention to provide a horizontal spiral blade stirred methane fermentation tank capable of efficiently performing fermentation, efficiently extracting methane gas from organic waste as a raw material, and obtaining a liquid fertilizer having a high fertilizing effect.

[0006]

In order to achieve the above object, a horizontal spiral blade stirring type methane fermentation tank of the present invention is provided with an object to be treated at one longitudinal end of a fermentation tank installed substantially horizontally. In a horizontal methane fermentation tank having an input means and an evolved gas extraction means and a processed material discharge means at the other end in the longitudinal direction of the fermentation tank, a rotation supporting a stirring blade at a substantially central part in the fermentation tank. The shaft is penetrated in the longitudinal direction, the end of the rotating shaft is connected to the driving means, and a stir bar is attached to the rotating shaft substantially radially, and a large number of stir bars are spirally arranged on the rotating shaft. The stirring rod is attached at a predetermined interval to form a spiral blade.

In this case, the tip of the stirring rod can be made substantially T-shaped. In addition, a support rod having a bifurcated stirring rod may be provided, one end of the support rod may be fixed to the stirring rod, and the other end of the support rod may be fixed to the rotating shaft. Further, the processed material discharging means may be configured to include a substantially inverted U-shaped pipe for discharging the processed material by overflow. In addition, at least the fermenter wall surface on the side of the material to be treated is provided with a jacket structure through which a heating medium (hot water or the like) can flow, so that the inside of the fermenter is heated to a temperature suitable for methane fermentation. preferable.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications. . 1 to 4 show a horizontal spiral blade stirring type methane fermentation tank according to a first embodiment of the present invention. A raw material input port 12 is provided at an upper portion of one end portion of the substantially cylindrical and horizontally long fermenter 10, and a processing liquid outlet 14 is provided at the other end portion. The treatment liquid discharge pipe 16 is constituted by a substantially inverted U-shaped pipe as shown in FIG. 1 so that, for example, the digestion liquid in which the methane fermentation has sufficiently proceeded in the fermenter 10 is discharged from the treatment liquid outlet 14 by overflow. And also
Fermenter 1 so that the outlet side of fermenter 10 is slightly higher
0 body is slightly inclined. In addition, fermenter 10
A generated gas outlet 18 is provided at the upper end of the other end of the
The methane gas generated in the fermenter 10 is supplied to the generated gas outlet 18.
Taken out of Reference numeral 20 denotes a relief port at an abnormally high pressure of the generated gas.

As an example, a stirring rod 24 having a substantially T-shaped tip is radially attached to a rotating shaft 22 provided at a substantially central portion in the fermenter 10.
A number of stirring rods 2 are arranged at predetermined intervals so as to be spirally arranged.
4 is attached. Further, as shown in FIG. 3, for example, the stirring rod 24 is forked by a support rod 26 and is fixed to the rotating shaft 22 at two places. In the drawings, a part of a spirally arranged stirring rod is illustrated in a simplified manner. Further, in this example, as shown in FIG. 4, the rotary shaft 22 is provided on the upstream side and the downstream side, and a drive source such as a motor is installed at each end. Of course, it is also possible to adopt a configuration in which it is performed. 28 is a gear control device.

The wall surface of the fermenter 10 is made of a heat insulating material. As shown in FIG. 1, a heating medium such as hot water can flow through the upstream side wall of the raw material inlet 12 side. A heat exchanger 30 having a jacket structure is provided, and the temperature inside the fermenter 10 is adjusted to a temperature suitable for methane fermentation (for example, 35 to 5
(Approximately 0 ° C.). The entire wall surface of the fermenter or an appropriate portion of the wall surface may have a jacket structure.

In the fermenter 10, materials to be treated (for example, livestock waste such as livestock manure,
Living waste such as garbage and marine waste) are digested (fermented) under anaerobic conditions through a short-term (eg, about 12 to 24 hours) acid fermentation period, and as fermentation proceeds, methane, etc. Gas is generated. The residence time in the fermenter 10 is, for example, about 20 to 30 days. At this time, since the liquid is sufficiently stirred by the stirring rods 24 arranged in a spiral shape, the liquid content can be appropriately homogenized, so that methane gas extraction, microorganism homogenization, etc. are efficiently performed, and As a result, methane fermentation proceeds efficiently. In addition, generation of scum can be effectively prevented. In this case, the stirring speed is, for example, about 1 rpm, and the stirring is performed intermittently about once every 10 minutes.

The stirring means using the spiral blades of the present invention, that is, a plurality of stirring rods 24 arranged in a spiral, can sufficiently stir even livestock waste having a high solid matter concentration, and furthermore, the methane fermentation proceeds. Since only stirring can be performed without affecting the required residence time in the tank, methane gas can be efficiently extracted from the raw material, and a liquid fertilizer having a high fertilizing effect can be manufactured. Methane gas generated by methane fermentation is taken out from the generated gas outlet 18 and used as fuel, and electricity and heat are recovered.
The processing liquid (digestion liquid) after methane fermentation is supplied to the processing liquid outlet 1
4 and used for liquid fertilizers and the like or their production.

[0013]

As described above, the present invention has the following effects. (1) Methane fermentation can be carried out efficiently regardless of the raw material properties by using the stirring means with spiral blades that can achieve appropriate homogenization of the liquid in the fermentation tank. While taking out methane gas well,
It is possible to produce a liquid fertilizer having a high fertilizing effect. (2) Since methane gas can be efficiently extracted, the obtained electricity and heat are abundant, and these energies can be effectively used for equipment in the system. For example,
It is possible to heat the raw material receiving tank and the like with the waste heat recovered from the methane gas. (3) Equipment costs and operating costs can be reduced, and maintenance is easy.

[Brief description of the drawings]

FIG. 1 is a partially cutaway cross-sectional configuration explanatory view showing a horizontal spiral blade stirring type methane fermentation tank according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of the left side surface of the methane fermentation tank shown in FIG.

FIG. 3 is an explanatory diagram showing a schematic configuration of a cross section taken along line AA of the methane fermentation tank shown in FIG.

FIG. 4 is a partially schematic sectional plan view of the methane fermentation tank shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fermentation tank 12 Raw material input port 14 Processing liquid outlet 16 Processing liquid discharge pipe 18 Generated gas outlet 20 Escape port 22 Rotating shaft 24 Stirring rod 26 Support rod 28 Gear control device 30 Heat exchanger

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C02F 11/04 B09B 3/00 ZABC C05F 17/02 D (72) Inventor Masaki Tsuzawa 1-1-1, Higashikawasakicho, Chuo-ku, Kobe-shi No. 3 Kawasaki Heavy Industries, Ltd. Kobe headquarters F-term (reference) 4D004 AA03 AA04 BA03 BA04 CA18 CA22 CB04 CB28 CB31 CC07 4D059 AA01 AA07 AA08 BA12 BA44 BA48 BA56 BJ02 BJ03 CB06 CC01 4G037 AA03 A01 BA03A01 CA03 CA05 CA12 CA17 DA30 DB10 EA03 EA10 4H061 CC32 CC55 FF01 GG12 GG14 GG16 GG18 GG43 GG50 GG68 GG69

Claims (5)

[Claims] 1. A fermenter installed in a substantially horizontal direction, having one end in the longitudinal direction of the fermenter having a treatment object input means, and the other end of the fermenter in the longitudinal direction having a generated gas extracting means and a treated substance discharge means. In a horizontal methane fermentation tank having a, a rotating shaft supporting a stirring blade in a substantially central part in the fermentation tank is penetrated in the longitudinal direction,
The end of the rotating shaft is connected to the driving means, and the stirring rod is attached to the rotating shaft in a substantially radial manner, and a large number of stirring rods are attached at predetermined intervals so that the stirring rod is spirally arranged on the rotating shaft. A horizontal spiral blade stirring type methane fermentation tank characterized by forming spiral blades. 2. The horizontal spiral blade stirring type methane fermentation tank according to claim 1, wherein the tip of the stirring rod is substantially T-shaped. 3. A support rod having a bifurcated stirring bar is provided.
The horizontal spiral blade stirring methane fermentation tank according to claim 1 or 2, wherein one end of the support rod is fixed to a stirring rod, and the other end of the support rod is fixed to a rotating shaft. 4. A horizontal spiral blade stirring methane fermentation tank according to claim 1, wherein the treated material discharging means comprises a substantially inverted U-shaped pipe for discharging the treated material by overflow. 5. A fermenter having at least a wall surface on the side of the material to be treated which has a jacket structure through which a heating medium can flow, so that the inside of the fermenter can be heated to a temperature suitable for methane fermentation. The horizontal spiral blade stirring type methane fermentation tank according to any one of claims 1 to 4.