CSTR (continuous stirred-tank reactor) anaerobic fermentation tank with variable volume

Abstract

The invention discloses a variable-volume CSTR anaerobic fermentation tank which comprises a fermentation tank body, the fermentation tank body is composed of a top cover and a tank body, the bottom of the tank body is connected with a tank foundation, and the interior of the tank body is divided into a jacking area at the bottom and a fermentation area at the top by a middle sealing layer; a plurality of jacking units controlled by a controller to stretch out and draw back are arranged at the bottom of the middle sealing layer, and the jacking units can drive the middle sealing layer to ascend and descend, so that the volume of the fermentation area is changed. The volume of a fermentation area in the fermentation tank body can be changed along with the fluctuation of the feeding amount through the lifting of the jacking unit, so that the hydraulic retention time in the tank tends to be stable, and the fermentation effect is ensured; and the submersible stirrer and the shell breaking stirrer are used for breaking shells, so that the fermentation reaction is not influenced, the fermentation effect and the biogas yield are improved under the condition of saving energy consumption, and the fermentation effect is further ensured.

Description

Technical Field

[0001] The invention relates to the technical field of anaerobic fermentation tanks, in particular to a CSTR anaerobic fermentation tank with variable volume. Background Art

[0002] As a major energy consumer, China's development and utilization of new energy is of great significance to the sustainable development of the national economy. Biogas is an ideal gas fuel. Anaerobic fermentation refers to the process in which waste raw materials are stabilized through the metabolic activities of microorganisms under anaerobic conditions, accompanied by the production of methane and CO2. The fully mixed anaerobic fermenter (CSTR) is the main form of anaerobic fermentation in current engineering practice and the main means of treating agricultural waste today. Anaerobic fermentation is carried out in an anaerobic fermenter, so the quality of the fermenter directly affects the fermentation efficiency.

[0003] like Figure 1 As shown, the CSTR anaerobic fermentation tank in the prior art mainly consists of a fermentation tank body 1, a tank foundation located at the bottom of the fermentation tank body 1, a feed port 4, a discharge port 5, a sludge discharge port 6, an air outlet 7 arranged on the fermentation tank body 1, and a submersible agitator 12 and a shell-breaking agitator 13 arranged inside the fermentation tank body 1. The volume of the fermentation tank body 1 is fixed and cannot be adjusted; during use, due to the uncertainty of the raw material feed amount, the residence time of the feed in the fermentation tank varies, the anaerobic fermentation effect is unstable, and the biogas production fluctuates greatly; some organic waste floats above the reaction liquid and is difficult to be decomposed for a long time, thereby causing the organic waste to gradually harden and form a crust above the reaction liquid, seriously affecting the fermentation; when the raw material feed amount is large and the solid content is high, the solid content of the anaerobic sludge is high, resulting in difficulty in sludge discharge from the fermentation tank; thus, it is difficult to ensure the fermentation effect.

[0004] Therefore, how to design a CSTR anaerobic fermentation tank with variable volume, which can adjust the volume of the tank as needed to ensure the fermentation effect, has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the present invention provides a CSTR anaerobic fermentation tank with variable volume, which can adjust the volume of the tank as needed to ensure the fermentation effect.

[0006] To achieve the above technical purpose, the present invention provides a CSTR anaerobic fermentation tank with variable volume, comprising a fermentation tank body, wherein the fermentation tank body is composed of a top cover and a tank body, the bottom of the tank body is connected to the tank foundation, and the interior of the tank body is divided into a lifting area at the bottom and a fermentation area at the top by an intermediate sealing layer;

[0007] A plurality of lifting units controlled by a controller to extend and retract are arranged at the bottom of the middle sealing layer, and the lifting units can drive the middle sealing layer to rise and fall, thereby changing the volume of the fermentation area;

[0008] The output end of the lifting unit is connected to the bottom of the middle sealing layer, and the fixed end is connected to the lifting system foundation;

[0009] The top side of the fermentation area is provided with a feed inlet, and the bottom side is provided with a discharge port and a mud discharge port; the top cover is provided with an air outlet, and one side of the jacking area is provided with a sewage discharge port;

[0010] A submersible agitator and a shell-breaking agitator are arranged in the fermentation area, and the shell-breaking agitator is located on the top of the submersible agitator.

[0011] Preferably, an upper limit plate is provided in the fermentation area, and a lower limit plate is provided in the lifting area, and the upper limit plate and the lower limit plate cooperate to control the lifting and lowering height of the middle sealing layer.

[0012] Preferably, the middle sealing layer is composed of three layers: two lower steel plates and a middle rubber sealing ring.

[0013] The lifting units are hydraulic telescopic devices, and each of the lifting units has an independent hydraulic system and control system.

[0014] The control system is a proportional valve.

[0015] Preferably, a manhole is provided on one side of the jacking area.

[0016] Beneficial effects of the present invention:

[0017] Due to the above structural design, the volume of the fermentation area in the fermentation tank body can be changed with the fluctuation of the feed amount through the lifting and lowering of the jacking unit, so that the hydraulic retention time in the tank tends to be stable and the fermentation effect is guaranteed; the use of a submersible agitator and a shell-breaking agitator to break the shell does not affect the fermentation reaction, and the fermentation effect and biogas production are improved while saving energy, thereby further ensuring the fermentation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the prior art;

[0019] Figure 2 It is a schematic diagram of the structure of the present invention when the lifting unit is in a high position;

[0020] Figure 3 It is a schematic diagram of the structure of the present invention when the lifting unit is in a low position;

[0021] Figure 4It is a schematic structural diagram of the lifting unit part in the present invention.

[0022] In the figure: 1 fermentation tank body, 2 tank foundation, 3 lifting system foundation, 4 feed port, 5 discharge port, 6 mud discharge port, 7 gas outlet, 8 sewage outlet, 9 upper limit plate, 10 lifting unit, 11 middle sealing layer, 12 submersible agitator, 13 shell breaking agitator, 14 lower limit plate. DETAILED DESCRIPTION

[0023] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0024] Example:

[0025] like Figure 2-Figure 4 As shown, the variable volume CSTR anaerobic fermenter includes a fermenter body 1, which is composed of a top cover and a tank body. The bottom of the tank body is connected to the tank foundation 2, and the interior of the tank body is divided into a bottom lifting area and a top fermentation area by an intermediate sealing layer 11.

[0026] A plurality of lifting units 10 controlled to extend and retract by a controller are arranged at the bottom of the middle sealing layer 11. The lifting units 10 can drive the middle sealing layer 11 to rise and fall, thereby changing the volume of the fermentation area.

[0027] The output end of the jacking unit 11 is connected to the bottom of the middle sealing layer 11 , and the fixed end is connected to the jacking system foundation 3 .

[0028] A feed port 4 is provided on the top side of the fermentation area, and a discharge port 5 and a mud discharge port 6 are provided on the bottom side, so that materials can enter and exit the fermentation tank body 1; an air outlet 7 is provided on the top cover for collecting biogas, and a sewage discharge port 8 is provided on one side of the jacking area for cleaning up debris in the jacking area without affecting the operation of the jacking unit 10.

[0029] A submersible agitator 12 and a shell-breaking agitator 13 are provided in the fermentation area. The shell-breaking agitator 13 is located at the top of the submersible agitator 12. The submersible agitator 12 is provided to achieve material stirring. The shell-breaking agitator 13 is provided at the top of the tank to eliminate the influence of material crusting, thereby improving the fermentation effect and biogas production while saving energy.

[0030] The main innovations of the present invention are:

[0031] The effective volume of the fermentation area in the fermentation tank body 1 is controlled by lifting the middle sealing layer 11 by the lifting unit 10, so as to achieve a constant hydraulic retention time and ensure the fermentation effect.

[0032] Specifically, when the solid content of the anaerobic sludge in the fermentation tank body 1 is high, making it difficult to discharge the sludge from the fermentation tank, the lifting unit 10 can continuously raise the water level in the tank to increase the head pressure in the tank, so that the anaerobic sludge can be quickly pressed out of the tank, thereby realizing the self-draining function of the fermentation tank body 1.

[0033] An upper limit plate 9 is provided in the fermentation area, and a lower limit plate 14 is provided in the jacking area. The upper limit plate 9 and the lower limit plate 14 cooperate to control the jacking and lowering height of the middle sealing layer 11 to ensure the safe net height in the jacking area and facilitate subsequent maintenance of the equipment.

[0034] The middle sealing layer 11 is composed of three layers of two lower steel plates and a middle rubber sealing ring, which isolates the lifting area from the fermentation area to ensure the water tightness inside the fermentation tank body 1, and can rise and fall together with the start-up of the lifting unit 10.

[0035] The lifting unit 10 is a hydraulic telescopic device, and each lifting unit 10 has an independent hydraulic system and control system, wherein the control system is a proportional valve. Each lifting unit 10 can act alone, or the proportional valve of each lifting unit 10 can be controlled to achieve synchronous lifting.

[0036] In some embodiments, a manhole is provided on one side of the jacking area, which can be used as an inspection passage.

[0037] In other embodiments, the roof is a hard roof or a membrane roof structure.

[0038] The working principle and use process of the present invention:

[0039] The user first obtains the daily feed volume through the process front-end flow meter, calculates the change in the tank volume by calculating the change in the daily feed volume, and starts to control the jacking unit 10. Each jacking unit 10 is equipped with an independent hydraulic system and electrical control system. Each jacking unit 10 can be single-acting or linked (switchable interlocking), and the lifting movement speed can be adjusted steplessly.

[0040] The lifting of the jacking unit 10 is synchronously controlled, and the alarm prompt function and the function of resuming operation after adjustment can be set to ensure operational safety; the displacement value of the jacking unit 10 is transmitted to the PLC; the jacking displacement value is calculated by the PLC, and the proportional valve of each jacking unit 10 is controlled to achieve jacking synchronization. When the synchronization error exceeds the set range, the alarm stops, and the operator switches the control mode to the single-action mode and fine-tunes it to the horizontal state before lifting the workpiece synchronously.

[0041] The submersible agitators 12 in the fermentation tank body 1 can be arranged in multiple layers in the tank, and the installation method is a capsule-style installation, which is convenient for the maintenance and replacement of the agitators. When the jacking starts, the submersible agitators 12 in the lower layer are closed and exit the tank through the capsule without affecting the jacking progress. At the same time, the submersible agitators 12 in the upper layer are turned on to continue stirring; when the top shell breaking position is reached, the shell breaking agitator 13 is started to break the crusted part. When shell breaking is not needed, the jacking system lowers the liquid level and returns to the normal operating level, thereby improving the fermentation effect while saving energy.

[0042] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A CSTR anaerobic fermentation tank with variable volume, comprising a fermentation tank body, characterized in that: The fermentation tank body is composed of a top cover and a tank body, the bottom of the tank body is connected to the tank base, and the interior of the tank body is divided into a lifting area at the bottom and a fermentation area at the top by an intermediate sealing layer; A plurality of lifting units are arranged at the bottom of the middle sealing layer, and the lifting units can drive the middle sealing layer to rise and fall, thereby changing the volume of the fermentation area; The output end of the lifting unit is connected to the bottom of the middle sealing layer, and the fixed end is connected to the lifting system foundation; The top side of the fermentation area is provided with a feed inlet, and the bottom side is provided with a discharge port and a mud discharge port; the top cover is provided with an air outlet, and one side of the jacking area is provided with a sewage discharge port; A submersible agitator and a shell-breaking agitator are arranged in the fermentation area, and the shell-breaking agitator is located on the top of the submersible agitator.

2. The variable volume CSTR anaerobic fermentation tank according to claim 1, characterized in that: An upper limit plate is arranged in the fermentation area, and a lower limit plate is arranged in the lifting area. The upper limit plate and the lower limit plate cooperate to control the lifting and lowering height of the middle sealing layer.

3. The variable volume CSTR anaerobic fermentation tank according to claim 1 or 2, characterized in that: The middle sealing layer is composed of three layers: two lower steel plates and a middle rubber sealing ring.

4. The variable volume CSTR anaerobic fermentation tank according to claim 3, characterized in that: The lifting units are hydraulic telescopic devices, and each of the lifting units has an independent hydraulic system and control system.

5. The variable volume CSTR anaerobic fermentation tank according to claim 4, characterized in that: The control system is a proportional valve.

6. The variable volume CSTR anaerobic fermentation tank according to claim 5, characterized in that: A manhole is arranged on one side of the jacking area.

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