A desulfurization absorption tower slurry density online measurement device and method

Abstract

The invention discloses an online measurement device and method for the density of slurry in a desulfurization absorption tower, belonging to the technical field of waste gas treatment in thermal power generation, comprising an absorption tower body, both sides of the absorption tower body are connected with ventilation ducts, and the surface of the absorption tower is sequentially connected with drainage pipes from top to bottom. The invention uses a pressure-stabilizing pump to extract slurry from the inner cavity of the absorption tower body, and then adjusts a first balancing valve and a pressure-stabilizing pump to keep the pressure of the outflowing slurry consistent with the pressure of the slurry in the absorption tower body at a corresponding height, and at the same time, a crushing knife is used to crush sediments, so that the sediments are converted into fine particles again and dissolved in the slurry, thereby improving the accuracy of slurry density detection, and then a second balancing valve is used to balance the pressure of the slurry flowing out of the fixed box again, and then a measuring cylinder is arranged on the outer side of the absorption tower body, and then the slurry overflows upward from the bottom of the measuring cylinder, and a differential pressure transmitter is used to detect the density of the slurry in the measuring cylinder.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas treatment in thermal power generation, and in particular to an online measurement device and method for slurry density in a desulfurization absorption tower. Background Art

[0002] The method of generating electricity by using the energy contained in combustibles is collectively referred to as thermal power generation. According to the power generation method, thermal power generation is divided into coal-fired steam turbine power generation, oil-fired steam turbine power generation, gas-steam combined cycle power generation and internal combustion engine power generation. Thermal power still occupies most of the electricity market. Only when thermal power technology is continuously improved and developed can it meet the requirements of a harmonious society.

[0003] At present, the density measurement of slurry in the desulfurization absorption tower of thermal power plants mainly adopts the following two methods: the first method is to install a differential pressure transmitter on the absorption tower body to convert the slurry density; the second method is that the slurry enters the mass flow meter after sampling and is obtained through the Coriolis mass flow method. However, the use of differential pressure transmitters has the following disadvantages: because multiple agitators and slurry circulation pumps in the absorption tower need to run continuously, the slurry in the tower is always in a state of violent movement, which greatly disturbs the pressure measurement point. At the same time, the sediment blocks the transmitter, affecting the measurement accuracy and data stability. The Coriolis mass flow method has the following disadvantages: it is expensive, and the equipment itself has a life cycle. Due to the gradual wear and tear after use, it will cause zero drift and unstable measurement data. When the instrument fails, it needs professional personnel to detect and repair it, and the maintenance cost is high. Summary of the invention

[0004] The object of the present invention is to provide an online measurement device and method for the density of slurry in a desulfurization absorption tower. A measuring cylinder is arranged on the outside of the absorption tower body, and the slurry is then overflowed upward from the bottom of the measuring cylinder. A differential pressure transmitter is used to detect the density of the slurry in the measuring cylinder. At the same time, a first balancing valve, a second balancing valve and a pressure-stabilizing pump are used to stabilize the pressure of the drained slurry to prevent the slurry from shaking violently during detection, thereby improving the accuracy of detection and solving the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A desulfurization absorption tower slurry density online measurement device, comprising an absorption tower body, both sides of the absorption tower body are connected with ventilation ducts, the surface of the absorption tower body is sequentially connected with drainage pipes from top to bottom, one end of the drainage pipe away from the absorption tower body is connected with a guide pipe, one end of the guide pipe away from the drainage pipe is connected with a detection box, the drainage pipe passes through the inner cavity of the detection box and extends upward and is connected with a measuring cylinder, the top of the measuring cylinder is connected with a differential pressure transmitter, a pressure-stabilizing pump and a first balancing valve are respectively arranged on the drainage pipe, the middle part of the guide pipe is connected with a fixed box, the inner cavity of the fixed box is provided with a crushing assembly, and the top of the detection box is provided with a slurry reflux assembly;

[0007] The crushing assembly includes a motor installed on the top of the fixed box, the output shaft of the motor penetrates the inner cavity of the fixed box and is fixed with a rotating shaft, a crushing knife is fixed on the surface of the rotating shaft, and the outer edge of the crushing knife is in contact with the inner cavity of the fixed box;

[0008] A control valve is installed on the drainage pipe, and the control valve position, the first balancing valve and the pressure-stabilizing pump are arranged in sequence along the direction of slurry flow in the drainage pipe;

[0009] The drainage pipe is provided with a second balancing valve, and the second balancing valve is located between the fixing box and the detection box;

[0010] It also includes a pressure sensor, which is fixed on the surface of the absorption tower body. One side of the pressure sensor penetrates into the inner cavity of the absorption tower body. The pressure sensor is electrically connected to a pressure-stabilizing pump of a corresponding height.

[0011] Preferably, the reflux component includes a circulation pump, which is installed on the top of the detection box. The water inlet of the circulation pump is connected to a water inlet pipe, and the end of the water inlet pipe away from the circulation pump passes through the inner cavity of the detection box and extends downward. The water outlet of the circulation pump is connected to a water outlet pipe, and the other end of the water outlet pipe is connected to the top of the absorption tower.

[0012] Preferably, a transverse plate is fixed to the inner cavity of the detection box, the transverse plate is located below the differential pressure transmitter and fixed to the surface of the measuring tube, the water outlet of the differential pressure transmitter is connected to a fixed pipe, and the end of the fixed pipe away from the differential pressure transmitter passes through the transverse plate and extends downward.

[0013] Preferably, a ladder is provided on the surface of the absorption tower body, and the pressure-stabilizing pump is fixedly connected to the ladder via a support rod.

[0014] Preferably, the crushing knives are distributed on the surface of the rotating shaft from top to bottom in sequence, and the upper and lower crushing knives are arranged in a staggered manner.

[0015] Preferably, based on the above-described online measurement device for the density of slurry in a desulfurization absorption tower, the present invention further provides an online measurement method for the density of slurry in a desulfurization absorption tower, comprising the following steps:

[0016] S1. First, set the parameters of the pressure-stabilizing pump according to the value fed back by the pressure sensor, and then open the control valve accordingly, so that the slurry in the absorption tower body is transported outward from the drainage pipe. When passing through the balancing valve, the balancing valve regulates the pressure of the outflowing slurry, so that the slurry pressure at both ends of the balancing valve remains basically consistent. At the same time, the outflowing slurry is introduced into the drainage pipe through the pressure-stabilizing pump. At the same time, the pressure-stabilizing pump can also regulate the pressure on both sides. At the same time, the pressure sensor at the corresponding drainage pipe position keeps the pressure of the slurry flowing into the drainage pipe consistent;

[0017] S2. Then the slurry flows into the fixed box along the guide pipe, and then the motor is started. At the same time, the output shaft of the motor drives the rotating shaft to rotate, and then the rotating shaft drives the crushing knife to crush and stir the slurry, crushing the sediment in the slurry to avoid the slurry density being too high, which leads to the generation of precipitation. At the same time, the sediment hits the internal diaphragm when passing through the differential pressure transmitter, causing the diaphragm to be damaged, affecting the differential pressure transmitter's detection of the slurry density;

[0018] S3. After the slurry with sediment is broken, it continues to pass through the second balancing valve to stabilize the shaking slurry, and then the slurry flows into the measuring cylinder along the guide pipe. At the same time, the slurry flows upward along the bottom of the measuring cylinder to fill the measuring cylinder, and then flows through the differential pressure transmitter from the fixed pipe to the bottom of the horizontal plate in the detection box. At the same time, the differential pressure transmitter can detect the density of the stable slurry in the measuring tube;

[0019] S4. Turn on the circulation pump to reintroduce the slurry flowing into the detection box into the inner cavity of the absorption tower body through the circulation pump.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention draws slurry out of the inner cavity of the absorption tower body by a pressure-stabilizing pump, and then adjusts the first balancing valve and the pressure-stabilizing pump to keep the outflowing slurry consistent with the slurry pressure in the absorption tower body at the corresponding height position, and at the same time, a crushing knife is used to crush the sediment to convert the sediment into fine particles that are dissolved in the slurry again, thereby improving the accuracy of slurry density detection, and then a second balancing valve is used to balance the pressure of the slurry flowing out of the fixed box again, and then a measuring cylinder is set on the outside of the absorption tower body, and then the slurry overflows from the bottom of the measuring cylinder, and a differential pressure transmitter is used to detect the density of the slurry in the measuring cylinder, and at the same time, the first balancing valve, the second balancing valve and the pressure-stabilizing pump are used to stabilize the pressure of the drained slurry to prevent the slurry from shaking violently during detection, thereby improving the accuracy of detection.

[0022] The present invention detects the pressure of slurry at different heights inside the absorption tower body by means of a pressure sensor, and then uses a differential pressure transmitter to regulate the pressure of the drained slurry, so that the pressure is not inconvenient and the calculated density is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the three-dimensional structure of the drainage tube of the present invention;

[0025] Figure 3 It is a three-dimensional structural schematic diagram of the fixing box and the detection box of the present invention;

[0026] Figure 4 It is a schematic diagram of the side cross-sectional three-dimensional structure of the detection box of the present invention;

[0027] Figure 5 It is a schematic diagram of the cross-sectional three-dimensional structure of the fixing box of the present invention.

[0028] Numbers in the figure: 1. Absorption tower body; 2. Drainage pipe; 3. Guide pipe; 4. Detection box; 5. Measuring cylinder; 6. Pressure difference transmitter; 7. Pressure-stabilizing pump; 8. First balancing valve; 9. Fixed box; 10. Crushing assembly; 101. Motor; 102. Rotating shaft; 103. Crushing knife; 11. Reflux assembly; 111. Circulation pump; 112. Water inlet pipe; 113. Water outlet pipe; 12. Control valve; 13. Horizontal plate; 14. Fixed pipe; 15. Second balancing valve; 16. Pressure sensor; 17. Ladder. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides Figures 1 to 5The device for measuring the density of slurry in a desulfurization absorption tower shown in the figure comprises an absorption tower body 1, both sides of the absorption tower body 1 are connected with ventilation ducts, the surface of the absorption tower body 1 is connected with drainage pipes 2 in sequence from top to bottom, the end of the drainage pipe 2 away from the absorption tower body 1 is connected with a drainage pipe 3, the end of the drainage pipe 3 away from the drainage pipe 2 is connected with a detection box 4, the drainage pipe 2 passes through the inner cavity of the detection box 4 and extends upward and is connected with a measuring cylinder 5, the top of the measuring cylinder 5 is connected with a differential pressure transmitter 6, a pressure-stabilizing pump 7 and a first balancing valve 8 are respectively arranged on the drainage pipe 2, the middle part of the drainage pipe 3 is connected with a fixed box 9, the inner cavity of the fixed box 9 is provided with a crushing assembly 10, and the top of the detection box 4 is provided with a slurry reflux assembly 11;

[0031] The crushing assembly 10 includes a motor 101 installed on the top of the fixed box 9. The output shaft of the motor 101 penetrates the inner cavity of the fixed box 9 and is fixed with a rotating shaft 102. A crushing knife 103 is fixed on the surface of the rotating shaft 102. The outer edge of the crushing knife 103 fits with the inner cavity of the fixed box 9. The motor 101 drives the rotating shaft 102 to rotate, and then the rotating shaft 102 drives the crushing knife 103 to rotate, so as to crush the sediment flowing into the fixed box 9 and then dissolve it in the solution slurry to prevent the sediment from damaging the internal diaphragm when flowing through the differential pressure transmitter 6.

[0032] A control valve 12 is installed on the drainage pipe 2. The control valve 12, the first balancing valve 8 and the pressure-stabilizing pump 7 are arranged in sequence along the direction of the slurry flowing in the drainage pipe 2. The control valve 12 controls the on-off of the drainage pipe 2, which is convenient for protecting the device.

[0033] A second balancing valve 15 is provided on the drainage pipe 2, and the second balancing valve 15 is located between the fixed box 9 and the detection box 4. The second balancing valve 15 is used to rebalance the slurry flowing out of the fixed box 9 to prevent the slurry from surging under the drive of the crushing knife 103.

[0034] It also includes a pressure sensor 16, which is fixed to the surface of the absorption tower body 1. One side of the pressure sensor 16 penetrates into the inner cavity of the absorption tower body 1. The pressure sensor 16 is electrically connected to the pressure-stabilizing pump 7 at a corresponding height. The pressure inside the absorption tower body 1 can be detected by the pressure sensor 16. At the same time, the value of the pressure-stabilizing pump 7 can be adjusted according to the detected pressure value to ensure that the pressure of the slurry flowing out is consistent with the pressure of the slurry inside the absorption tower body 1.

[0035] The slurry is extracted from the inner cavity of the absorption tower body 1 by the pressure-stabilizing pump 7, and then the first balancing valve 8 and the pressure-stabilizing pump 7 are adjusted to keep the outflowing slurry consistent with the slurry pressure in the absorption tower body 1 at the corresponding height position. At the same time, the crushing knife 103 is used to crush the sediment to convert the sediment into fine particles that are dissolved in the slurry to improve the accuracy of the slurry density detection. Then, the second balancing valve 15 is used to balance the pressure of the slurry flowing out of the fixed box 9 again. Subsequently, a measuring cylinder 5 is set on the outside of the absorption tower body 1, and then the slurry overflows from the bottom of the measuring cylinder 5 upward. The density of the slurry in the measuring cylinder 5 is detected by the differential pressure transmitter 6. At the same time, the first balancing valve 8, the second balancing valve 15 and the pressure-stabilizing pump 7 are used to stabilize the pressure of the drained slurry to prevent the slurry from shaking violently during detection, thereby improving the detection accuracy.

[0036] The reflux assembly 11 includes a circulation pump 111, which is installed on the top of the detection box 4. The water inlet of the circulation pump 111 is connected to a water inlet pipe 112. One end of the water inlet pipe 112 away from the circulation pump 111 passes through the inner cavity of the detection box 4 and extends downward. The water outlet of the circulation pump 111 is connected to a water outlet pipe 113. The other end of the water outlet pipe 113 is connected to the top of the absorption tower. The slurry overflowing from the top of the measuring cylinder 5 is reintroduced into the interior of the absorption tower body 1 through the circulation pump 111, while ensuring the sealing of the overall equipment.

[0037] A transverse plate 13 is fixed to the inner cavity of the detection box 4. The transverse plate 13 is located below the differential pressure transmitter 6 and fixed on the surface of the measuring tube 5. The water outlet of the differential pressure transmitter 6 is connected to a fixed pipe 14. The end of the fixed pipe 14 away from the differential pressure transmitter 6 passes through the transverse plate 13 and extends downward. The detection box 4 can be divided into upper and lower layers by the transverse plate 13. The upper layer can observe the conditions of the differential pressure transmitter 6 and the measuring tube 5 through the box door, and the lower layer can collect the overflowed slurry.

[0038] A ladder 17 is provided on the surface of the absorption tower body 1, and the pressure-stabilizing pump 7 is fixedly connected to the ladder 17 through a support rod. The ladder 17 facilitates maintenance personnel to repair the equipment. At the same time, the pressure-stabilizing pump 7 can be fixedly supported to prevent the drainage pipe 2 and the guide pipe 3 from being overloaded.

[0039] The crushing knives 103 are distributed on the surface of the rotating shaft 102 from top to bottom in sequence, and the upper and lower crushing knives 103 are arranged in a staggered manner. By setting the positions of the crushing knives 103, the crushing effect is improved, and the particle size of the crushed sediment is made uniform.

[0040] Based on the above-described online measurement device for slurry density in a desulfurization absorption tower, the present invention further provides an online measurement method for slurry density in a desulfurization absorption tower, comprising the following steps:

[0041] S1. First, set the parameters of the pressure-stabilizing pump 7 according to the value fed back by the pressure sensor 16, and then open the control valve 12 accordingly, so that the slurry in the absorption tower body 1 is transported outward from the drainage pipe 2. When passing through the balancing valve, the balancing valve regulates the pressure of the outflowing slurry, so that the slurry pressure at both ends of the balancing valve remains basically consistent. At the same time, the outflowing slurry is introduced into the drainage pipe 3 through the pressure-stabilizing pump 7. At the same time, the pressure-stabilizing pump 7 can also regulate the pressure on both sides. At the same time, the pressure sensor 16 corresponding to the position of the drainage pipe 2 keeps the pressure of the slurry flowing into the drainage pipe 3 consistent;

[0042] S2, then the slurry flows along the guide pipe 3 into the fixed box 9, and then the motor 101 is started, and at the same time, the output shaft of the motor 101 drives the rotating shaft 102 to rotate, and then the rotating shaft 102 drives the crushing knife 103 to crush and stir the slurry, and crush the sediment in the slurry to avoid the slurry density being too high, resulting in the generation of precipitation. At the same time, the sediment hits the internal diaphragm when passing through the differential pressure transmitter 6, causing the diaphragm to be damaged, affecting the differential pressure transmitter 6 to detect the slurry density;

[0043] S3, after the slurry with sediment is broken, it continues to pass through the second balancing valve 15 to stabilize the shaking slurry, and then the slurry flows into the measuring tube 5 along the guide tube 3, and at the same time, the slurry flows upward along the bottom of the measuring tube 5 to fill the measuring tube 5, and then flows through the differential pressure transmitter 6 from the fixed tube 14 to the bottom of the horizontal plate 13 in the detection box 4, and at the same time, the differential pressure transmitter 6 can detect the density of the stable slurry in the measuring tube;

[0044] S4, turning on the circulation pump 111, and reintroducing the slurry flowing into the detection box 4 into the inner cavity of the absorption tower body 1 through the circulation pump 111.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A desulfurization absorption tower slurry density online measurement device, comprising an absorption tower body (1), characterized in that: Both sides of the absorption tower body (1) are connected to ventilation ducts. The surface of the absorption tower body (1) is connected to drainage pipes (2) in sequence from top to bottom. The end of the drainage pipe (2) away from the absorption tower body (1) is connected to a guide pipe (3). The end of the guide pipe (3) away from the drainage pipe (2) is connected to a detection box (4). The drainage pipe (2) passes through the inner cavity of the detection box (4), extends upward and is connected to a measuring cylinder (5). The top of the measuring cylinder (5) is connected to a differential pressure transmitter (6). A pressure-stabilizing pump (7) and a first balancing valve (8) are respectively provided on the drainage pipe (2). The middle of the guide pipe (3) is connected to a fixed box (9). The inner cavity of the fixed box (9) is provided with a crushing assembly (10). The top of the detection box (4) is provided with a slurry reflux assembly (11). The pulverizing assembly (10) comprises a motor (101) mounted on the top of the fixed box (9); the output shaft of the motor (101) penetrates the inner cavity of the fixed box (9) and is fixed with a rotating shaft (102); a pulverizing knife (103) is fixed on the surface of the rotating shaft (102); and the outer edge of the pulverizing knife (103) is in contact with the inner cavity of the fixed box (9); A control valve (12) is installed on the drainage pipe (2), and the control valve (12), the first balancing valve (8) and the pressure-stabilizing pump (7) are arranged in sequence along the direction in which the slurry flows in the drainage pipe (2); The drainage tube (2) is provided with a second balancing valve (15), and the second balancing valve (15) is located between the fixing box (9) and the detection box (4); It also includes a pressure sensor (16), the pressure sensor (16) being fixed to the surface of the absorption tower body (1), one side of the pressure sensor (16) penetrating into the inner cavity of the absorption tower body (1), and the pressure sensor (16) being electrically connected to a pressure-stabilizing pump (7) of a corresponding height.

2. The online measurement device for slurry density of a desulfurization absorption tower according to claim 1, characterized in that: The reflux assembly (11) comprises a circulation pump (111), the circulation pump (111) being installed on the top of the detection box (4), the water inlet of the circulation pump (111) being connected to a water inlet pipe (112), one end of the water inlet pipe (112) away from the circulation pump (111) passing through the inner cavity of the detection box (4) and extending downward, the water outlet of the circulation pump (111) being connected to a water outlet pipe (113), the other end of the water outlet pipe (113) being connected to the top of the absorption tower.

3. The online measurement device for slurry density of a desulfurization absorption tower according to claim 1 is characterized in that: A transverse plate (13) is fixed to the inner cavity of the detection box (4), the transverse plate (13) is located below the differential pressure transmitter (6) and is fixed to the surface of the measuring tube (5), the water outlet of the differential pressure transmitter (6) is connected to a fixed pipe (14), and one end of the fixed pipe (14) away from the differential pressure transmitter (6) passes through the transverse plate (13) and extends downward.

4. The online measurement device for slurry density of a desulfurization absorption tower according to claim 1, characterized in that: A ladder (17) is provided on the surface of the absorption tower body (1), and the pressure-stabilizing pump (7) is fixedly connected to the ladder (17) via a support rod.

5. The online measurement device for slurry density of a desulfurization absorption tower according to claim 2 is characterized in that: The crushing knives (103) are distributed on the surface of the rotating shaft (102) in sequence from top to bottom, and the upper and lower crushing knives (103) are arranged in a staggered manner.

6. A method for online measurement of slurry density in a desulfurization absorption tower, based on an online measurement device for slurry density in a desulfurization absorption tower according to any one of claims 1 to 5, characterized in that: The steps include: S1. First, set the parameters of the pressure-stabilizing pump according to the value fed back by the pressure sensor, and then open the control valve accordingly, so that the slurry in the absorption tower body is transported outward from the drainage pipe. When passing through the balancing valve, the balancing valve regulates the pressure of the outflowing slurry, so that the slurry pressure at both ends of the balancing valve remains basically consistent. At the same time, the outflowing slurry is introduced into the drainage pipe through the pressure-stabilizing pump. At the same time, the pressure-stabilizing pump can also regulate the pressure on both sides. At the same time, the pressure sensor at the corresponding drainage pipe position keeps the pressure of the slurry flowing into the drainage pipe consistent; S2. Then the slurry flows into the fixed box along the guide pipe, and then the motor is started. At the same time, the output shaft of the motor drives the rotating shaft to rotate, and then the rotating shaft drives the crushing knife to crush and stir the slurry, crushing the sediment in the slurry to avoid the slurry density being too high, which leads to the generation of precipitation. At the same time, the sediment hits the internal diaphragm when passing through the differential pressure transmitter, causing the diaphragm to be damaged, affecting the differential pressure transmitter's detection of the slurry density; S3. After the slurry with sediment is broken, it continues to pass through the second balancing valve to stabilize the shaking slurry, and then the slurry flows into the measuring cylinder along the guide pipe. At the same time, the slurry flows upward along the bottom of the measuring cylinder to fill the measuring cylinder, and then flows through the differential pressure transmitter from the fixed pipe to the bottom of the horizontal plate in the detection box. At the same time, the differential pressure transmitter can detect the density of the stable slurry in the measuring tube; S4. Turn on the circulation pump to reintroduce the slurry flowing into the detection box into the inner cavity of the absorption tower body through the circulation pump.

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