RU2540326C1 - Biogas plant - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: biogas plant includes vertical sealed cylindrical tank (1) equipped with dome (3) and bottom (4), which have a shape of a flattened cone. Bottom (4) is installed with its smaller base downwards, and with dome (3), vice versa, upwards. The external part of the tank and bottom (4) is wound with heating strip (5) connected to temperature control (6). Inside tank (1) there is a mixing device representing two-bladed agitators (8) installed perpendicular on horizontal shaft (7). Shaft (7) is offset downwards from the centre of tank (1). Blades (9) of agitator (8) have a meshed structure of a trapezoid shape, which converges towards the axis of shaft (7). Span of blades (9) located in the centre of the shaft is larger than that of the adjacent blades.

EFFECT: enlarging the range of plants for processing of organic wastes of agricultural production; obtaining a disinfected biological fertiliser without any smell, which can be used as a fertiliser without any additional operations.

2 dwg

Description

The present invention relates to agriculture, is intended for anaerobic digestion of organic agricultural waste and can be used for the production of biogas, organic fertilizers and feed additives.

Known household digester (RU 2491233, C02F 11/04, 08/27/2013), consisting of a cylindrical body with thermal insulation, which is divided by perforated partitions into 4 sections - fermentation chambers. The device has loading and unloading nozzles, a hydraulic shutter for biogas removal and is enclosed in a hard casing.

The disadvantage of this device is the design complexity due to divisions into sections, which is not necessary for small digesters, due to the fact that this does not affect the biogas production process. The device does not have a mixing mechanism, which could increase the production of biogas and reduce the duration of fermentation.

Known bioreactor (RU 2427123, C02F 3/28, C02F 11/04, AC 3/02, publ. 08/27/2011), consisting of a housing, which is a steel metal tubular tank, divided by partition walls into several sections. Inside the working part of the housing connected to the gas tank, a mixer with blades is horizontally mounted, offset from the center of the tank.

The disadvantage of this bioreactor is the design complexity, insufficiently high degree of mixing efficiency of the fermented mass, which does not affect the increase in biogas yield.

The closest in technical essence to the claimed invention is a bioreactor (see RU 124261 U1, C05F 3/00, publ. 01.20.2013), consisting of a vertical cylindrical sealed tank with a conical bottom and a spherical dome mounted on supports. The bottom of the tank is covered with heating tape. The tank is equipped with loading and unloading nozzles, a nozzle for biogas removal.

The disadvantage of this bioreactor is the lack of a mixing device, which does not ensure the completeness of fermentation of the substrate and slows down the rate of biogas output due to the formation of a crust in the upper part of the tank.

The technical result of the invention is to increase productivity and increase biogas yield.

The above technical result is achieved by the fact that in a biogas plant comprising a sealed vertical cylindrical tank mounted on supports, loading and unloading pipes, a pipe for biogas removal, the tank is equipped with a bottom in the form of a truncated cone covered with a heating tape, according to the invention, the tank is wrapped with a heating tape and equipped with a dome having the shape of a truncated cone, facing upward with a smaller base; a mixing device is installed inside the tank; two-bladed mixers, the blades of which have a trapezoidal mesh design, tapering to the axis of the shaft, while the span of the blades located in the center of the shaft is larger than the span of the adjacent blades.

Distinctive features of the claimed device are the presence of a new structural element, namely, paddle mixers of a mesh design, as well as the winding of the tank with heating tape.

Additional winding of the tank with heating tape allows you to accelerate the fermentation processes in the tank, thereby increasing the productivity of the installation.

The presence of a mixing device in the installation with a mesh form of the blades allows to achieve a uniform distribution of groups of anaerobic bacteria in the tank, which accelerates their access to the unfermented substrate. The execution of the blades of the central mixer with a larger scale than that of adjacent adjacent blades, as well as the implementation of their trapezoidal shape, expanding outward (or tapering to the axis of the shaft), as if repeating the shape of the conical bottom and when the mixers rotate create the necessary turbulent vortices around the blades, prevent loss precipitation on the bottom and walls of the tank, thereby ensuring a uniform temperature distribution throughout the volume of the tank, which accelerates the fermentation processes and increases the biogas yield. The mesh form of the design allows you to save the optimal amount of bacteria collected in groups, necessary for intensive fermentation, without breaking the bacteria into single atoms, for which the substrate needs to be fermented into small groups to begin intensive processing of the substrate. This provides a high speed and degree of decomposition of the substrate, which increases the biogas yield and thereby increases the productivity of the installation.

Figure 1 shows the appearance of the biogas plant, figure 2 - section aa in figure 1.

The biogas plant contains a vertical sealed cylindrical tank 1 mounted on supports 2 and equipped with a dome 3 and a bottom 4 having the shape of a truncated cone. The bottom 4 is set smaller base down, and the dome 3, on the contrary, up. The outer part of the tank 1 and the bottom 4 is wrapped with heating tape 5 connected to the temperature controller 6. Inside the tank 1 there is a mixing device, which is a two-blade mixer 8. mounted perpendicular to the horizontal shaft 7. The shaft 7 is shifted down from the center of the tank 1. The blades 9 of the mixer 8 have mesh structure of a trapezoidal shape, tapering to the axis of the shaft 7. The span of the blades 9 located in the center of the shaft 7 is larger than the span of the adjacent blades.

On the dome 3 of the tank 1, a loading pipe 10, a pressure sensor 11, a pipe 12 for biogas removal are installed. In the lower part of the conical bottom 4 is located the discharge pipe 13.

Biogas plant works as follows.

To create an anaerobic environment, water is poured into the tank through the loading pipe 10 until it is completely filled. Next, the source material in the form of organic animal waste (liquefied fresh manure (litter) with a moisture content of 92-93%) is poured into the tank 1 and filled to a level 2/3 of the height of the tank 1. At the same time, manure flows by gravity into the tank 1, and water is drained through the discharge pipe 13. After filling the tank 1, all valves of the installation are tightly closed, include a heating tape 5, regulated by thermostat 6, which maintains the temperature within 33-36 ° C. The substrate is fermented in the installation 6 days before the formation of biogas. The resulting biogas accumulates in the vacuum space formed under the dome 3 and part of the tank 1, and exits through the pipe 12. During the processing of manure and the formation of biogas in an anaerobic medium, periodic mixing of the substrate is necessary to ensure uniform supply of methane-forming bacteria with nutrients, to prevent sedimentary material and crust in the top layer of the installation, which prevents the exit of biogas. The blades 9 of the mixing device provide the most complete mixing of the substrate, their mesh design destroys large groups of bacteria and the resulting crust in the upper part of the substrate. The central mixer with a large sweep of the blades prevents precipitation on the bottom 4 and together with the side mixers provide intensive mixing of the substrate, accelerating the fermentation processes in the tank 1. After the 6th day, the processed waste is discharged in the amount of 18-20 liters through the discharge pipe 13 and at the same time load the tank with new raw materials. Then the unloading of the processed waste is carried out periodically every 2 days during the loading of the tank 1 with new raw materials.

The pressure in the dome of the tank 1 is monitored using a sensor 11.

The gas obtained from a biogas plant can be used for domestic needs, and the processed substrate is a biological fertilizer. It is devoid of a specific smell, completely disinfected and can be used as fertilizer without additional operations. Also, this substrate after certain technical operations can be used as a feed additive for farm animals.

Claims (1)

Biogas plant, including a sealed vertical cylindrical tank mounted on supports, loading and unloading nozzles, a nozzle for biogas removal, the tank is equipped with a bottom in the form of a truncated cone, covered with heating tape, characterized in that the tank is wrapped with heating tape and equipped with a dome having the shape of a truncated of the cone facing upwards, a mixing device is installed inside the tank, which is mounted perpendicularly to the horizontal shaft, offset from the center of the tank downward, two-blade mixers, the blades of which have a mesh design of a trapezoidal shape, tapering to the axis of the shaft, while the span of the blades located in the center of the shaft is larger than the span of the adjacent blades.

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