CN201873676U - Discharging device of discharging system of digestion tank used in straw methane engineering - Google Patents

Abstract

A discharge device for the discharge system of the digestion tank of the straw biogas project. The material is discharged by a spiral tube. The entrance of the spiral tube goes deep into the middle and lower part of the digestion tank. The outlet is higher than the liquid level in the digestion tank, and the material liquid in the digestion tank is discharged through the rotation of the spiral tube. The digestion tank of the utility model will not cause large fluctuations in the liquid level of the waste water in the digestion tank, and will not cause the pressure of the air chamber in the digestion tank, no matter when feeding or discharging or at the same time. Large changes, even some misoperations, will not damage the digestion tank, ensuring the safety of the digestion tank.

Description

The discharge device of the discharge system of the digestion tank of the straw biogas project

technical field

The utility model relates to a discharge device for a straw biogas engineering digestion tank.

Background technique

In the countryside, due to the large amount of straw, the straw is chopped and added to the anaerobic digestion tank. Under hot and humid conditions, biogas will be generated. Biogas is biomass energy and belongs to renewable energy. Because the straw particles are larger and lighter, it is difficult to discharge the material. If the discharge system is not perfect, it will be very unfavorable to the entire biogas production. Therefore, when straw is used as raw material for biogas production, it is very necessary to improve the discharge device.

At present, there are three main ways to discharge the straw digestion tank:

(1) Upper feeding and upper discharging methods: In the straw digestion tank, feed at one end of the upper part and discharge at the other end of the upper part, and discharge while feeding. The advantage of this way of feeding and discharging materials is that the water pressure in the digestion tank is stable, and the disadvantage is that there is a short circuit phenomenon, and the short circuit phenomenon is serious.

(2) Upper feeding and lower discharging methods: In the straw digestion tank, feeding at one end of the upper part and discharging at the other end of the lower part, the feeding and discharging are not carried out at the same time. Under normal circumstances, the material is discharged first and then fed. The advantage of this way of feeding and discharging materials is that there is no short circuit phenomenon. The disadvantage is that the water pressure and air pressure in the digestion tank are unstable, and it is difficult to control the biogas control system.

(3) Upper feed and spiral tube discharge methods: the use of rotating spiral discharge pipes can solve the shortcomings of the existing two discharge methods. Of course, it also has disadvantages, and it needs power.

At present, the straw biogas project is in its infancy. Most of the processes and treatment methods basically follow the traditional biogas treatment process. However, due to the characteristics of straw wastewater, the traditional process must be improved. At present, according to the characteristics of straw wastewater, a consensus has been reached on the upper feeding, but it has not been determined whether the wastewater is discharged from the top or the bottom, because each has its own advantages and disadvantages. At present, most of them adopt the bottom discharge method. This method will not cause a short circuit, but it will cause the liquid level in the digestion tank to fluctuate up and down, causing the pressure in the gas chamber to fluctuate, which will have a great impact on the safety of the tank. During the operation and operation, the staff should always The pressure change in the digester is monitored, so the training requirements for the staff are very strict, and the degree of automation of the digester is high.

Utility model content

The purpose of this utility model is to provide a new discharge device for a new straw biogas digestion tank. This device makes a spiral tube according to the characteristics of straw wastewater. There is a certain inclination angle and a certain speed. Under this specific condition, no matter whether the digestion tank is feeding or discharging or feeding at the same time, it will not cause the waste water level of the digestion tank to be large. Fluctuating up and down, it will not cause large changes in the pressure of the air chamber in the digestion tank, and even some misoperations will not damage the digestion tank, ensuring the safety of the digestion tank.

The utility model adopts the following technical scheme: a new discharge device for the discharge system of the digestion tank of the straw biogas project, which uses a spiral tube to discharge the material. The corner protrudes upwards out of the digestion tank, the outlet of the spiral tube is higher than the liquid level in the digestion tank, and the material liquid in the digestion tank is discharged through the rotation of the spiral tube.

The inclination angle of the spiral pipe is 40-50 degrees, the outlet of the spiral pipe is more than 10 cm above the liquid level of the waste water in the digestion tank, and operates at a speed of 90 rpm. So as to achieve a stable discharge effect.

The spiral pipe, and the position, angle, rotational speed, filter, and circulation pump of the entrance and exit of the spiral pipe are very important.

1. The position of the entrance and exit of the spiral tube: a. The entrance: the position must be at the bottom of the digestion tank. After soaking in water, the straw will gradually sink into the bottom of the digestion tank with the spiral. As time goes on, the straw at the bottom of the tank will become more and more The more, without stirring, three levels are formed in the digestion tank, the upper part is the straw that has not been soaked for a long time, the middle part is the clear night, and the lower part is the straw that has been soaked for a long time. b. Outlet: The location must be 30 cm higher than the liquid level of the waste water in the digestion tank. The reason for determining this 30 cm is that the gas in the digestion tank has 30 cm of air pressure. The higher the speed of the spiral tube, the higher the lifting height.

2. Determination of the inclination angle of the spiral pipe: After testing, the spiral discharge pipe can obtain a good result of the discharge volume at a certain speed and an inclination angle of 40-50 degrees.

3. Determination of the speed of the spiral pipe: install the discharge pipe at 45 degrees, and choose a different relationship between the speed and the lift. When the rotating speed is 90 rev/min, its head is 10 centimeters.

4. Determination of the diameter of the spiral pipe: the specification stipulates that the discharge pipe should be 2 sizes larger than the feed pipe. It is found through experiments that the larger the pipe diameter, the greater the power consumption of the motor, and the smaller the pipe diameter, the smaller the power consumption of the motor . Therefore, the diameter of the spiral tube is set at DN150.

5. The filter is used to separate the decomposed straw and biogas slurry entering the spiral tube.

6. The circulating water pump has a certain negative pressure at the inlet of the spiral pipe, so that the decomposed straw is sucked into the spiral pipe.

The beneficial effects of the utility model are:

1. At a certain speed of the spiral tube, the maximum discharge angle is 43 degrees, which is the best.

2. When the speed is 90 rpm, the effective power of the motor is the highest.

Description of drawings

Fig. 1 is the installation diagram of the spiral pipe of the biogas digestion tank of the present invention.

Motor-1 Reducer-2 Exit-3 Agitator-4 Agitator-5 Spiral Tube-6 Inlet-7 Maximum Water Level-8 Undecomposed Straw Area-9 Biogas Slurry-10 Decomposed Straw Area-11 Sand Settlement Area-12 Circulation Water pump-13 Filter-14 Valve-15 Valve-16 Effective water level-H Spiral pipe lift-h Distance between tank wall and outlet-L

Detailed ways

The utility model will be described in further detail below through specific embodiments, so as to help understand the content of the utility model.

As shown in Figure 1, it is a schematic diagram of a discharge spiral tube installed on the reactor of the present utility model. It includes an enamel assembled tank for fermentation and gas production and a discharge spiral tube. The discharge spiral tube is installed on the body of the enamel assembled tank at an oblique direction at a certain angle. The inlet 7 is located at the bottom of the decomposed straw area 11. The discharge spiral Pipe 6 protrudes upwards from the tank wall obliquely. Because the air pressure in the digestion tank is slightly higher, its outlet 3 should be higher than the highest water level 8 in the tank to prevent siphon phenomenon. The role of the agitator 4 is to stir the undecomposed straw area 9 to fully mix the straw with the biogas slurry. The function of the agitator 5 is to stir the straw in the decomposed straw area 11 when the spiral tube is working, so that the decomposed straw is sucked away by the spiral tube. The propeller blades in the spiral tube 6 are low-speed blades, therefore, the motor 1 should pass through the reducer 2 to be connected to the spiral tube 6 .

During operation, there are 3 situations, the first one is discharging first, then feeding. The second kind of feeding and discharging is carried out at the same time. During the 3rd kind of feed, spiral pipe 6 does not start.

The result of the first kind of discharging first and feeding later is that there are more biogas residues discharged. The main reason is that there is a gap between the spiral blade of the spiral tube 6 and the pipe wall. When the spiral tube 6 is started, the spiral blade will decompose the straw area 11 Larger particles are continuously pushed up through the spiral movement, while the biogas slurry flows back from the gap between the spiral blade and the pipe wall. During the operation of the digestion tank, there are often situations where biogas residue is needed but not biogas slurry. At this time, the operation mode of discharging first and then feeding can be adopted. There is an agitator 5 in the decomposed straw area 11 , and when the helical tube 6 is opened, the agitator 5 must be opened at the same time to facilitate the working efficiency of the helical tube 6 .

The result of the second kind of feeding and discharging being carried out at the same time is that the biogas residue and biogas slurry are also discharged at the same time. What is the concentration of the decomposed straw area 11 at the bottom in the digestion tank, so what is the concentration of the discharge. The helical movement of the helical tube 6 just plays the role of stirring and preventing blockage in the helical tube. When the helical tube 6 is opened, the agitator 5 must be opened simultaneously to facilitate the working efficiency of the helical tube 6 .

The spiral movement of the spiral discharge pipe does not start when feeding in the third type, and the result is that there is more biogas slurry discharged. Since the spiral movement stops, when the liquid level in the digestion tank is higher than the maximum water level when feeding, the spiral pipe is at When the spiral movement stops, the material can also be discharged, but at this time, the role of the propeller blade in the spiral tube is to prevent the biogas residue from being discharged, and only the biogas slurry can be discharged through the spiral tube. The agitator 5 is opened simultaneously to facilitate the work efficiency of the helical tube 6 .

More than 3 kinds of feeding and discharging situations, all will open circulating water pump 13, and its effect is to improve the working efficiency of spiral pipe 6. Valve 15 is a normally open valve, and valve 16 is a normally closed valve. When maintenance or blockage, valve 16 can be opened.

In the straw biogas digestion tank, the straw is relatively light, and part of the decomposed straw still floats above the liquid in the digestion tank. There is a stirrer 4 to stir continuously, so it is not suitable for agglomeration. However, because there is no stirrer in the discharge pipe, the output There should be agglomeration in the material tube, and the agglomeration blocks the pipeline. With the agitation and upward thrust of the spiral tube 6 on the material liquid, the problem of blockage is solved. In order to solve the clogging problem and save electricity, the spiral pipe 6 should be a straight pipe without turning. At the same time, the discharge pipe must be discharged on the side wall of the fermenter to discharge the feed liquid. Therefore, the spiral pipe 6 should have a certain angle. . It can be seen from Figure 1 that the smaller the angle between the spiral tube and the bottom of the pool, the longer the tube length and the greater the cost. When the angle is larger and the tube is shorter, the cost will be smaller, and the discharge liquid tends to flow horizontally, but when the angle between the spiral tube 6 and the bottom of the pool is too small, the spiral tube will be lengthened, which will increase the resistance along the pipeline. It will increase the power of the motor. Therefore, the appropriate angle between the spiral pipe 6 and the bottom of the pool is very important. An optimal angle will make the spiral tube of the digestion tank get an optimal discharge effect. As shown in Figure 1, the included angle is 40-50 degrees.

In the north, the outer part of the spiral tube of the straw digestion tank should be insulated to prevent the exit of the spiral tube from being blocked by freezing and affecting the discharge. For example, in the south, the exit of the spiral tube may not be insulated.

The height of the outlet 3 of the spiral tube 6 is higher than the maximum water level 8 of the digestion tank. When the spiral tube 6 is misoperated, there will be no positive and negative pressure fluctuations. Safe for straw digesters. The motor 1 at the spiral pipe 6 top has rainproof facility.

Claims (3)

1. A discharge device for the discharge system of the digestion tank of the straw biogas project, which is characterized in that: the material is discharged by a spiral tube, the entrance of the spiral tube goes deep into the middle and lower part of the digestion tank, and the spiral tube extends upward at a certain oblique angle to digest Outside the tank, the outlet of the spiral tube is higher than the liquid level in the digestion tank. 2. The discharging device of the straw biogas project digestion tank discharging system according to claim 1, characterized in that: the inclination angle of the spiral pipe is 40-50 degrees. 3. The discharge device of the straw biogas project digestion tank discharge system according to claim 1 or 2, characterized in that: the spiral tube is a spiral tube that rotates at 90 rpm. the

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