JPH0243519Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to a storage tank for storing gas, and is particularly suitable for storing the gas generated by performing small- to medium-scale methane fermentation using agricultural, livestock, and fishery waste in cold regions. It provides a gas holder.

Traditionally, agricultural and livestock waste has been used as fertilizer, but in recent years, with the aim of effectively utilizing energy, research has been conducted on small and medium-sized scales to use microorganisms to perform methane fermentation and gasify the waste.

However, methane fermentation is carried out at a high temperature of 35 to 40 degrees Celsius, and the resulting gas is stored for a period of time and taken out when needed to serve as fuel, so there is no problem in warm regions, but in cold regions, the gas produced by fermentation is A large amount of moisture may freeze and close the piping, or if a floating roof type gas holder is used to store gas, the seal water used for the water seal will freeze and the floating roof will lose its ability to rise and fall. Since antifreeze must be used in this method, there are inconveniences such as the equipment being expensive. Therefore, the inventors carried out research to create a gas holder that could allow methane fermentation to occur in cold regions as well as in warm regions, and store the generated gas without any trouble. When storing gas in a floating roof type gas holder, an outer tank and an inner tank are installed inside and outside the floating roof of the gas holder, and seal water is placed between the inner tank and the outer tank, and the side wall of the floating roof is placed inside the tank. This problem was solved by inserting the inner tank and sealing it with water, and providing a hot water storage tank inside the inner tank to prevent the seal water from freezing and warming the stored gas to prevent the water from freezing.

An example of this invention will be explained with reference to the attached drawings.
Reference numeral 1 denotes an outer tank, and a layer of glass wool or other heat insulating material 5 is provided on the outside of the inner wall 2, bottom surface 3, and ceiling 4 to improve the heat insulation effect, and an air vent pipe 6 is provided at the top of the ceiling 4 to connect the inside and outside of the outer tank 1. The air is communicated with each other. In addition, the inner tank 7 is fixed concentrically on the surface of the bottom 3 and sealed, and seal water 8 is placed between the side wall 2 of the outer tank 1 and the inner tank 7, and a cylindrical floating tube is placed in the seal water 8. A side wall 10 of the roof 9 is inserted, and rolling rollers 11, 11 are provided between the side wall 10 and the inner wall 2 to enable the floating roof 9 to move up and down. Furthermore, a sealed hot water storage tank 12 is fixed concentrically inside the inner tank 7 and on the bottom surface 3. Inside the floating roof 9, a gas inflow pipe 13 and a gas outflow pipe 14 are provided, each penetrating the inner tank 7 and standing upright.
Further, at the bottom of the hot water storage tank 12, there is a hot water circulation pipe 17,
17', and 18, 18', and an air vent pipe 19 is provided at the upper part. Furthermore, an air vent pipe 16 is provided in the inner tank 7.

An example of the operation of the device of this invention will be described with reference to FIG. 2. Human and animal excrement, fermentable agricultural waste, etc. are placed in a methane fermentation tank 20, brought to an anaerobic state, and heated to 35 to 37° C. for fermentation. Gas mainly composed of methane generated in the fermenter 20 flows into a gas reservoir 21 between the floating roof 9 and the inner tank 7 through a gas pipe 13 provided at the top, and pushes up the floating roof 9. The gas in the gas reservoir 21 is taken out through the gas outlet pipe 14, and most of it is supplied to the gas boiler 22 to heat the water in the boiler 22. The heated hot water goes through hot water circulation piping 1
7 is discharged and pumped into the hot water storage tank 12 by the pump 23.
flow inside. The hot water whose temperature has decreased in the hot water storage tank 12 is returned to the boiler 22 via the hot water circulation pipe 17', where it is heated again and circulated.
The water temperature in the hot water storage tank 12 is heated so that it is always maintained at 60 to 90°C. This hot water is further drawn out through a pump 25 through a circulation pipe 18 that connects the hot water storage tank 12 and a heater 24 provided in the fermenter 20, and the temperature is controlled by a static mixer installed in the middle of the pipe 18. The fermenter 20 is mixed with cold water in the vessel 26, heated so that the temperature inside the fermenter 20 is maintained at 35-37°C, and the cooled water is returned to the hot water storage tank 12 via the circulation pipe 18'.
In addition, the hot water drawn out through the circulation pipe 18 is transferred to the branch pipe 2.
It is taken out at step 7 and used for heating, cleaning, etc. of livestock barns, etc. Incidentally, since the hot water is drawn outside for use, the amount of water decreases, but for this reason, a pipe 28 is connected to the circulation pipe 17', and cold water or return water from the heating system is replenished to compensate for the decrease.

On the other hand, by providing a hot water storage tank 12 in the inner tank 7 and storing hot water with a large specific heat as a heat source,
Since the amount of heat retained per unit volume of the entire gas holder is increased, there is little temperature drop even if the outside air is rapidly cooled, and furthermore, since the hot water storage tank 12 is in contact with the heated air in the inner tank 7, less heat radiation is required. Moreover, since the seal water 8 is in contact with the side wall 10 of the heated inner tank 7, it does not freeze even in the outside temperature below the freezing point, and the vertical movement of the floating roof is smooth. Since the gas is also heated, water will not freeze and clog the pipes. Since the device of the present invention does not have a separate hot water tank, it requires less site space, improves workability, and helps improve thermal economy.

As mentioned above, the device of this invention has a simple structure and brings many benefits, and is extremely useful especially in cold regions when used as a gas holder for methane fermentation of waste from small and medium-scale agriculture and livestock processing and fishery processing. .

[Brief explanation of the drawing]

FIG. 1 shows a side sectional view of the gas holder of this invention, and FIG. 2 is an explanatory view showing an example of use of the gas holder of this invention. 1...Outer tank, 7...Inner tank, 9...Floating roof, 12
...Hot water storage tank, 13...Gas inflow piping, 14...
...Gas outflow piping, 20...Methane fermentation tank, 22
...Gas boiler.

Claims (1)

[Scope of utility model registration request] In a floating roof type gas holder that stores gas generated from methane fermentation, an inner tank and an outer tank are installed inside and outside the floating roof, a water seal is placed between the inner and outer tanks, and a hot water storage tank is installed inside the inner tank. A gas holder for methane fermentation, characterized in that the gas holder has a four-tank structure, and hot water circulation piping is arranged between the hot water storage tank and the gas boiler, and between the hot water storage tank and the fermentation tank internal heater.