JPS6038093A - Methane fermentation tank - Google Patents

Abstract

PURPOSE:To enhance methane fermentation capacity by attaching a spacer to an atachment and detachment flange provided to an insert port in a freely detachable manner while attaching a heating and stirring unit having a support frame, a heater and a stirrer to said spacer. CONSTITUTION:A fermentation stock solution receives sufficient stirring and heating by a heating and stirring unit 25 to be accelerated in methane fermentation due to methane producing bacteria present in the fermentation solution 35 in a tank 20 and gradually moves from the side of a charging pipe port 42 to the side of a discharge pipe port 44 while methane gas is discharged to the space above the fermentation solution 35. The methane gas discharged to the space above the fermentation solution 35 is sent to a gas purifying and storing apparatus through a gas discharge pipe port 39. The fermentation solution 35 in the methane fermentation tank is pumped up by a pump 29 to be scattered to the inside and outside of a warm water coil 31 from an emitting pipe port 34 and heated while passes the inside or outside of the warm water coil 31 and again fallen to a suction port 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a methane fermentor that forms part of a methane fermentation system.

Recently, methane fermentation using agricultural and livestock waste has been attracting attention as part of local energy creation and prevention of environmental pollution, and practical application of methane fermentation systems of various sizes is on the horizon. Development efforts are continuing towards this goal. At the current technological level, gin, 000
Large-scale methane fermentation systems are similar to sludge digestion systems at sewage treatment plants, and system equipment costs increase. Therefore, there are very few customers who can install such a methane fermentation system.

On the other hand, in the case of small and medium-sized enterprises with 500 to 5,000 animals,
There are many customers who can install medium-scale or small-scale methane fermentation systems. However, for these customers, the amount of funds that can be invested in system equipment costs is relatively small, and it may be difficult to
Since the 1lIII rating and construction costs of the methane fermentation tank itself generally account for a very large proportion of the total cost of the methane fermentation system, the cost performance of the methane fermentation tank holds the key to whether or not the methane fermentation system can be introduced.

FIG. 1 shows an entire example of the above-mentioned medium-sized and small-scale methane fermentation system, and a cylindrical vertical methane fermentation tank is used in this methane fermentation system.

An overview of the methane fermentation system will be explained below.

The soy sauce 3 discharged from the pigpen 1 into the waste reservoir 2 is pumped into a cylindrical vertical methane fermentation tank 5 by a waste pump 4. This methane fermentation tank 5 is equipped with a stirring pump that sucks in at the bottom and discharges at the top. A coil 7 is provided.

The stirring pump No. 6 is driven by an electric motor, and electric wiring 8 runs through the methane fermentation tank 5.

Digested methane gas generated in the methane fermentation tank 5 passes through a dehydrator 9 and a desulfurizer 10 to a water-controlled gas holder 11.
is supplied to A part of the methane gas held in the gas holder 11 is used as fuel for the boiler 12, and hot water produced by the boiler 12 is sent to the internal hot water coil 7 for heating.

The above-mentioned cylindrical vertical methane fermentation tank 5 has the following drawbacks.

1) From a cost perspective, a cylindrical tank made of double-fiber-reinforced plastic plates with intermediate insulation is used, but as the internal volume of this cylindrical tank increases, the fermentation efficiency due to transportation and heating increases. In order to prevent the building from deteriorating, the madder height is increased, making it more likely to collapse during an earthquake or typhoon. For example, in a methane fermentation system that can accommodate 500 pigs, the internal volume of the methane fermentation tank is 20 go (tank outside dimension: φ
2280rxx5921H) is the limit, and if the height is lowered and the outer diameter is increased, transportation becomes difficult.

2) As the height increases, the water pressure of the fermentation liquid in the methane fermentation '4vkS becomes too strong, making it difficult to withstand water pressure at the bottom of the methane fermentation 1v5.

3) When the height increases, the lift of the waste pump 4 and the stirring pump 6 increases, and the energy consumption of these pumps 4 and 6 increases in comparison to their scale.

4) As the height increases, lightning rods and other #rw countermeasures will be required.

5) Maintenance of the internal heating coil 7 and stirring pump 6 is difficult.

6) Decreases the fermentation efficiency of the internal hot water coil for heating.
In other words, in order to prevent a decrease in fermentation efficiency, the hot water coils have a concentric multilayer structure in order to uniformly heat the tank in the horizontal direction.

FIG. 2 shows a typical example of a cylindrical horizontal methane fermentor. This methane fermentation tank 15 has three stirring pumps 16 of the same type as the stirring pump 6, spaced apart from each other in the lateral direction. These stirring pumps 16 are inseparable from the tank 15a of the methane fermentation tank 15.

Further, an internal hot water coil 17 for heating is provided extending in the lateral direction of the tank 15 a from the side of the tank 15 a to the lower part of the tank 15 a. This heating internal hot water coil 1
7 is also inseparable from the tank 15a.

The cylindrical horizontal methane fermentation tank 15 described above has the following major drawbacks.

7) The stirring pump t6 and the internal heating coil 17 are:
Since it is inseparable from the tank 15a, maintenance and inspection are difficult, and if maintenance and inspection are to be performed, the inside of the tank 15a must be emptied.

8) In order for the methane fermentation tank 15 to be able to be transported by a regular truck and to have a small internal volume, the outer diameter should be less than 2.8 m in diameter and less than -11" + 10 m in length, but the total length of the fermentation tank 15 is It is difficult to uniformly heat and stir the mixture over the entire range.

The purpose of the present invention is to eliminate the drawbacks of conventional cylindrical vertical and horizontal methane fermenters, enhance the heating and stirring effects, and improve the methane fermentation performance. The purpose of the present invention is to provide a methane fermentation tank that is easy to use.

To achieve this object, the present invention provides a cylindrical horizontal methane fermentation tank, in which at least one insertion port is provided at the top of the tank, and this insertion port is provided with a release flange, while a A heating/stirring unit that is equipped with a warming device and a stirrer and has a spacer on the top of the support frame is inserted into the tank through the insertion port, and the spacer is removably attached to the tax increase flange. shall be.

Hereinafter, preferred embodiments of the present invention will be described in detail based on FIGS. 3 to 5. The horizontal cylindrical methane fermentation tank 20 has a base surface 22 with a plurality of legs 21.
Fixed. The entire wall of the tank 20 has an inner wall and an outer wall made of fiber-reinforced plastic, and has a structure in which a heat insulating material made of polyurethane is filled between these walls.

The outer diameter and overall length of the tank 20 are appropriately selected depending on the scale of the methane fermentation system.

However, in consideration of transportation by a low-floor large truck rather than a special transport claw such as a large trailer, an outer diameter of 2.8 m or less is preferable.

It is easy to expand the unit L2 scale with a maximum internal volume of 50 go.

A plurality of insertion ports 23 are provided at the top of the tank 20 at regular intervals in the longitudinal direction of the tank 20, projecting slightly upward. Each insertion port 23 has a square cross section and has a rectangular attachment/detachment flange 24 at its upper end.

A heating/stirring unit 25 is inserted into the tank 20 from each insertion port 2:3. This heating/stirring unit 25 mainly consists of a support frame consisting of a plurality of vertically extending rods 26 and a bottom plate 27 fixed to the lower ends of these rods 26, and this support frame 28. installed at the center of the shaft of
A submersible stirring pump 29 as an agitator, a discharge pipe 30 extending upwardly within the support frame 28 from the stirring pump 20,
An internal hot water coil 31 that spirally surrounds the stirring pump 29 and the discharge pipe 30 and extends upward while being inscribed in the shell 26, and a rectangular spacer 32 that is placed on the ejection flange 24 of the insertion port 23. It consists of

An Ifj stirring pump 29 is provided on the bottom plate 27 of the support frame 28, and a stirring pump 29 is provided at the lower end of the stirring pump 29.
Fermentation liquid circulation inlet 3 communicating with discharge pipe 30 via 9
3 are arranged.

At the upper end of the discharge pipe 30, as shown in FIGS. 4 and 5, discharge pipe ports 34 are provided which cross in a cross shape and are open at each of four ends. Further, this discharge pipe port 34 opens above the liquid level of the fermented liquid 35,
Furthermore, in order to improve circulation efficiency, a terminal box 36 for cable connection, a hot water inlet 37 and a hot water outlet 38 are provided on two opposing sides, respectively, inside the internal hot water coil 31 for heating as a heater. and a gas discharge pipe port 39 on each of the other two opposing faces. These gas discharge ports 39 are connected to a gas purification and storage device that constitutes the other part of the methane fermentation system. Terminal box 3 for couple connection above
An electric cable 40 extends from the stirring pump 6 to a motor (not shown) in the stirring pump 29. The hot water inlet port 37 and the hot water outlet port 38 are provided with a square top lid 41 placed on the top surface of the spacer 32 on the internal hot water coil 31 for heating. The upper lid 41 has a valve 41a installed in the center.
Air release W411) which also serves as fermentation gas inspection is in tank 20.
It is arranged so that the inside and the atmosphere side are connected.

The above-mentioned heating/stirring unit 25 may be provided in one unit or in number a depending on the internal volume of the tank 20 and the required heating/stirring capacity.

On the - side of the tank 20 (left side in Fig. 4),
A fermentation stock solution input pipe port 42 is provided at the top, and a drain 43 is provided at the bottom.

On the other side of the tank 20 (the right side in FIG. 4),
A fermentation waste liquid discharge pipe port 44 and a liquid level gauge 45 are provided at the top, and a drain 43 is provided at the bottom.

Hereinafter, the operation of the methane fermentation tank of the present invention described above will be explained. The fermentation stock solution is supplied to the tank 20 through the fermentation stock solution inlet port 42 by a suction pump 4 as shown in FIG.
The fermentation liquid is put into the tank and fermented during the retention period depending on the characteristics of the fermentation stock liquid, and is discharged as fermentation waste liquid at the fermentation waste liquid discharge pipe port 4.
Overflow from 4. That is, if the entire methane fermentation tank is viewed statically, fermentation waste liquid is discharged according to the amount of the raw U solution every day, and the liquid level in the tank 20 is regulated to a constant level.

The fermentation stock solution is sufficiently stirred and heated by the heating/stirring unit 25 to promote methane fermentation by the methane bacteria present in the fermentation solution 35 in the fermentation tank 20, and the methane fermentation is carried out in the upper space of the fermentation solution 35. While releasing methane gas, it gradually flows from the fermentation i-liquid input pipe port 42 side to the fermentation waste liquid discharge pipe port 44 side.

The methane gas released into the upper space of the fermentation liquid 35 is sent to the gas purification and storage device via the gas release pipe port 39.

In the above methane fermentation tank, the water intake port 3 for circulating fermentation liquid is
3 is pumped up by the stirring pump 29, and is sprayed inside and outside the heating internal hot water coil 31 from the discharge pipe port 34. The sprayed fermentation liquid is heated while passing inside or outside of the heating internal hot water coil 3, and descends again toward the fermentation liquid circulation suction port 33. In this way, stirring and heating are efficiently repeated.

Since the heating/stirring unit 25 is only detachably supported by the attaching/detachable flange 24 at the spacer 32, it can be easily removed from the tank 2o, and while being removed, The upper cover 41 is attached to the attachment/detachment flange 24, thereby not damaging the anaerobic environment inside the tank 20.

As described above, the present invention provides an insertion port with a removable flange at the top of a cylindrical horizontal tank, and a heater and a stirrer are disposed within a support frame, and a spacer is provided at the top of the support frame. The heating/stirring unit is inserted into the tank through the insertion port, and the spacer is removably attached to the detachable flange, so it is possible to easily adjust the temperature of the fermentation liquid and the climate of cold or warm regions. The number of heating/stirring units can be freely selected depending on various conditions such as conditions.

Furthermore, since the heating/stirring unit can be installed and removed at will, maintenance and inspection of the methane fermentation tank is easy.

[Brief explanation of drawings]

FIG. 2 is a schematic longitudinal sectional view of a horizontal cylindrical methane fermentation tank according to the prior art, and FIG. 3 is a methane fermentation system according to the present invention. A partially omitted plan view of the fermenter, FIG. 4 is a cross-sectional view taken along the line IV-ff in FIG. 3, and FIG. 5 is a cross-sectional view taken along the line ■-V in FIG. 4. 20. Tank, 23... Insertion port, 24... Detachable flange, 25... Heating/stirring unit, 28...
Support frame, 29... Stirrer, 31... Warmer, 32.
··Spacer. 27 jj Procedural Amendment (Import) 1981 9 II 61+ 1988 Patent Request No. 1470B5 2, Name of Invention: Methane Fermentation Tank 3, Relationship with the person making the amendment case Applicant (810) Meiden Co., Ltd. Association 4, Agent Address: 104 East 3;, Tochuo 1 Meimei) l'l' 1 Insult No. 29 Tsubakiji Building Specification "Detailed Description of the Invention" section and Figure 8 of the drawings, Figures 4 and 5. Jzu, : ,B, ,B;＼, 6. Contents of the amendment (1) In the specification, delete the phrase "air discharge for all purposes" on page 12, line 4. (2) Ibid., page 12, line 6, after “Iteru.”
This fermentation gas test tube 41b is for sampling the gas in the tank 20 during 1 when methane fermentation is normally performed in the tank 20. ” to join. (3) Ibid., p. 13, line 12, “In response to...
” followed by “in an anaerobic environment”. (4) Add ``in a sealed state'' after ``... detachable flange 241CJ'' in the second line of page 15 of the same document. (5) Correct the figures in Figures 3, 4, and 6 as shown in the attached sheet.

Claims (1)

[Claims] In a cylindrical horizontal methane fermentation tank, at least one insertion port (23) is provided at the top of the tank (a), a detachable flange (24) is provided in the insertion port (23), and a detachable flange (24) is provided at the top of the tank (a). ), a spacer is removably attached to the spacer, and a support frame (28) and a heater (3) are attached to the spacer.
1) and a heating/stirring unit (
25) A methane fermentation tank characterized in that '/J≦ is installed, and the heating/1/aging unit (25) is inserted into the tank (20) from the insertion port (23).