Plunger pump with gas collection prevention function and control method thereof

Abstract

The invention discloses a plunger pump with a gas collection prevention function and a control method of the plunger pump. The plunger pump comprises a feeding screw, a main pump body, a pressure detection device and a control system. The feeding screw is provided with a feeding screw discharge hole; the main body pump comprises a material cavity and a pumping assembly; the material cavity is provided with a material cavity feed port, and the material cavity feed port is connected with the feed screw discharge port; the pumping assembly is used for pumping materials in the material cavity; the pressure detection device is used for detecting the pressure change in the material cavity; the control system controls the pumping assembly to work according to the detection result of the pressure detection device, so that energy consumption is reduced, and pipeline gas collection is prevented. Compared with the method for solving the gas collection problem by arranging an exhaust valve or directly installing a level gage, the method disclosed by the invention has the advantages that the occurrence frequency of the gas collection problem is reduced fundamentally, and other parts, except the elastic film, of the detection device are prevented from being in direct contact with the sludge by adopting a film coating mode; and compared with the mode of directly installing the level gage in the material cavity, the accuracy and the reliability are higher.

Description

Technical Field

[0001] The invention relates to a plunger pump with an anti-gas collection function and a control method thereof, and is particularly suitable for a plunger pump that conveys sludge with a moisture content of more than 75% or similar high-concentration viscous materials. Background Art

[0002] During the process of the plunger pump pumping sludge, if there is a lack of material but the plunger pump is still running, air will be pumped into the pipeline. When the air gathers to a certain volume, because the gas is compressible and the plunger pump has an intermittent delay characteristic, it will eventually cause the energy transmitted by the subsequent sludge in a single pumping stroke of the plunger pump to be used for the compression of the gas in the pipeline. The pumping pressure value of the pipeline sludge at the rear end of the gas and the back pressure value of the pipeline sludge at the front end of the gas reach a balance, and the accumulated gas in the pipeline is compressed-rebounded-compressed repeatedly, resulting in pumping failure.

[0003] At present, to deal with the failure of gas collection in the pipeline of sludge plunger pump, exhaust valves are usually installed at the end and middle of the pipeline. However, the gas collection position is uncertain, and the exhaust effect is not good. There is also a way to prevent air from entering the plunger pump by setting a material storage hopper at the feeding end of the plunger pump feeding screw, and directly installing a level meter on the top or side wall of the storage hopper to detect the material level. However, due to the viscosity and corrosiveness of the sludge, the level meter is often distorted and fails; and the fundamental reason for gas collection is that the plunger pump fails to effectively ensure the continuity of the pumped material during pumping, so that too much air is input into the pipeline with the material when the plunger pump is empty, causing gas collection. Therefore, it is necessary to develop a device that can monitor the air content in the pumped material and control the gas content of the material during the sludge pumping process, thereby reducing the possibility of gas collection. Summary of the invention

[0004] In order to solve at least one problem existing in the above background technology, the present invention provides a plunger pump with anti-gas collection function and a control method thereof, which is suitable for a plunger pump that transports sludge with a moisture content of more than 75% or similar high-concentration viscous materials.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] In a first aspect, the present invention provides a plunger pump with an anti-gas collection function, comprising a feeding screw, a main pump body, a pressure detection device and a control system;

[0007] The feeding screw is provided with a feeding screw inlet and a feeding screw outlet;

[0008] The main pump comprises a material cavity and a pumping assembly; the material cavity is provided with a material cavity feed port, and the material cavity feed port is connected to a feeding screw discharge port; the pumping assembly is used to pump the material in the material cavity;

[0009] The pressure detection device is used to detect the pressure change in the material cavity;

[0010] The control system controls the operation of the pumping assembly according to the detection result of the pressure detection device, thereby reducing energy consumption and preventing gas accumulation in the pipeline.

[0011] Furthermore, when the pressure detection device detects that the material cavity is filled with material to a first threshold value, the pressure detection device detects and sends a signal, and the control system controls the pumping component to operate to pump the material out of the material cavity of the main pump body.

[0012] Furthermore, when gas continuously enters the material chamber and the pressure detection device detects that the material in the material chamber drops to a second threshold value, the pressure detection device detects and sends a signal, and the control system controls the pumping component to stop working or slow down the pumping speed, waiting for the material to continue to fill the material chamber, and restarts until the material chamber is filled with material to the first threshold value.

[0013] Furthermore, an opening is provided on the side of the feeding screw discharge port and is connected to the opening of the pressure detection device.

[0014] Furthermore, the pressure detection device includes a shell, a detection head, a connecting rod, a No. 1 proximity switch, a No. 2 proximity switch and an elastic coating; the outer edge of the elastic coating is installed between the side opening of the feeding screw discharge port and the shell; the inner surface of the elastic coating is connected to the detection head; the connecting rod is installed in the detection head; the No. 1 proximity switch and the No. 2 proximity switch are installed in the shell to detect the position of the connecting rod; the installation position of the No. 1 proximity switch and the No. 2 proximity switch in the shell is adjustable; when the No. 2 proximity switch sends a signal, the control system controls the main pump body to pump; when the No. 1 proximity switch sends a signal, the control system controls the main pump body to stop pumping or slow down the pumping speed.

[0015] Furthermore, the shell includes a fixing frame, a connecting rod support frame and a proximity switch mounting frame; a flange at one end of the fixing frame is connected and fixed to a side opening flange of a feeding screw outlet; both sides of the connecting rod support frame are respectively connected to the proximity switch mounting frame and the fixing frame by flanges and bolts; a waist-shaped hole is processed on one side of the proximity switch mounting frame to install the No. 1 proximity switch and the No. 2 proximity switch.

[0016] Furthermore, there is a sealing plate at each of the left and right ends of the connecting rod support frame, a through hole is processed at the center of the sealing plate, and a linear bearing is fixed in the through hole by bolts.

[0017] Furthermore, the connecting rod is a T-shaped connecting rod, one end of which is a round rod with a thread at the end of the round rod, and the other end is a round plate; the T-shaped connecting rod passes through a linear bearing in a connecting rod support frame, with the threaded end facing the fixed frame and the round plate end facing the proximity switch mounting frame.

[0018] Furthermore, the detection head is a circular plate, and a threaded hole is processed at the center of the circular plate so as to be fixed to the T-shaped connecting rod through a threaded connection.

[0019] In a second aspect, the present invention provides a control method for the plunger pump with an anti-gas collection function as described above, the method comprising:

[0020] When the feeding screw starts to work, the material is fed into the feeding screw from the feeding port, discharged from the feeding screw discharge port, and then enters the material cavity of the main pump body; when the material cavity of the main pump body is filled with material, the elastic coating of the pressure detection device is squeezed and deformed, pushing the internal detection head to move away from the material cavity, driving the connecting rod to move in the same direction until the No. 2 proximity switch detects the round plate end of the T-shaped connecting rod and sends a signal; when the plunger pump control system receives this signal, it controls the main pump body pumping assembly to start working, and pumps the material out of the main pump body material cavity.

[0021] When gas continuously enters the material cavity of the main pump body, the material filling rate in the material cavity of the main pump body gradually decreases. When the force exerted by the material on the elastic coating is less than the force exerted by the elastic coating to restore its deformation, the detection head moves toward the material cavity under the pulling force of the elastic coating, driving the T-shaped connecting rod to move in the same direction until the No. 2 proximity switch stops sending a signal, and the No. 1 proximity switch detects the round plate end of the T-shaped connecting rod and sends a signal; when the control system receives this signal, it controls the pumping assembly of the main pump body to stop working or slow down the pumping speed, waiting for the material to continue to fill the material cavity of the main pump body, and restarts after the cavity is filled with material.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides a plunger pump with an anti-gas collection function and a control method thereof. A pressure detection device is arranged at the side wall of the feeding screw outlet, and two proximity switches are installed at different positions at the same level on the side wall of the device bracket. When the material cavity of the main pump body is completely filled with materials and the materials are squeezed to reach the elastic coating on the side of the device, the end of the slide rod is pushed to move toward the proximity switch until the proximity switch sends a signal. When the No. 2 proximity switch sends a signal, the plunger pump control system controls the main pump body to start pumping; when the No. 1 proximity switch sends a signal, the plunger pump control system controls the main pump body to stop pumping or slow down the pumping speed, so as to ensure the continuity of the material supply in the main pump body cavity, and prevent the main pump body from pumping too much air into the conveying pipeline due to insufficient materials, causing pipeline gas collection and thus causing pumping failure.

[0024] Compared with setting an exhaust valve or directly installing a level meter to solve the gas collection problem, the present invention reduces the frequency of the gas collection problem from the root cause. By adopting a coating method, other components of the detection device except the elastic coating are prevented from direct contact with the sludge (the detection head and T-shaped connecting rod behind the elastic coating will not directly contact the sludge due to the existence of the elastic coating side, so their operation process will not be subject to unnecessary resistance due to the existence of the sludge). Compared with the method of directly installing the level meter in the material chamber, the present invention has higher accuracy and reliability and extends the service life of the detection element.

[0025] The core mechanism device provided by the present invention can automatically control the start and stop or the running speed of the plunger pump according to the filling situation of the material in the material cavity of the main pump body; wherein, the design of the waist-shaped hole on the side of the proximity switch mounting frame allows the distance between the two proximity switches to be freely adjusted, and then the interval time of starting and stopping the plunger pump can be controlled according to actual needs, thereby improving the energy utilization rate of the plunger pump equipment, thereby achieving the purpose of energy saving and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a plunger pump with an anti-gas collection function provided in an embodiment of the present invention;

[0027] Figure 2 It is a structural schematic diagram of a pressure detection mechanism;

[0028] Figure 3 for Figure 2 A-axis partial enlarged view;

[0029] In the figure: 1-feeding screw; 1.1-feeding screw inlet; 1.2-screw body; 1.3-feeding screw outlet; 2-pressure detection device; 2.1-fixed frame; 2.2-connecting rod support frame; 2.3-proximity switch mounting frame; 2.4-waist-shaped hole; 2.4.1-No. 1 proximity switch; 2.4.2-No. 2 proximity switch; 2.5-T-shaped connecting rod; 2.6-linear bearing; 2.7-detection head; 2.8-elastic coating; 3-main pump body; 3.1-material chamber; 3.2-pumping system; 3.3-frame; 3.4-material chamber inlet. DETAILED DESCRIPTION

[0030] Example:

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a signal connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, which can be said to be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "head", "tail", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0032] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0033] In order to solve the problem of gas collection failure in the existing sludge plunger pump pipeline, refer to Figure 1 As shown, this embodiment provides a plunger pump with an anti-gas collection function, which mainly includes a feeding screw 1, a main pump body 3, a pressure detection device 2 and a control system (not shown).

[0034] The feeding screw 1 is used to convey and buffer materials to the main pump body 3, and is provided with a feeding screw inlet 1.1, a screw body 1.2 and a feeding screw outlet 1.3.

[0035] The main pump body 3 is used for conveying materials, and mainly comprises a material chamber 3.1, a pumping assembly 3.2 and a frame 3.3; a material chamber feed port 3.4 is also arranged above the material chamber 3.1, and the material chamber feed port 3.4 is connected to the lower part of the feeding screw outlet 1.3, and the feeding screw 1 can convey the material from the feeding screw feed port 1.1 through the screw body 1.2 to the feeding screw outlet 1.3, and then enter the material chamber 3.1 through the material chamber feed port 3.4 of the main pump body 3, and the material is conveyed through the pipeline by the pumping assembly 3.2.

[0036] The pressure detection device 1 is used to detect the pressure change in the material chamber 3.1. The control system controls the operation of the pumping component according to the detection result of the pressure detection device 2, thereby achieving the purpose of reducing energy consumption and preventing gas collection in the pipeline.

[0037] When the pressure detection device 2 detects that the material chamber 3.1 is filled with material to a first threshold value (full), the pressure detection device 2 detects and sends a signal, and the control system controls the pumping component 3.2 to pump the material out of the material chamber 3.1 of the main pump body; when the pressure detection device detects that the material filling rate in the material chamber gradually decreases and drops to a second threshold value, the pressure detection device 2 detects and sends a signal, and the control system controls the pumping component 3.2 to stop working or slow down the pumping speed, waiting for the material to continue to fill the material chamber, until the material chamber is filled with material to the first threshold and then restarts, and the cycle is repeated, thereby achieving the purpose of reducing energy consumption and preventing gas collection in the pipeline.

[0038] In a specific embodiment, an opening is provided on the side of the feeding screw outlet 1.3 and is connected to the opening of the pressure detection device 2. Figure 2 As shown, the pressure detection device 2 includes a shell, a detection head 2.7, a T-shaped connecting rod 2.5, a proximity switch No. 1 2.4.1, a proximity switch No. 2 2.4.2 and an elastic coating 2.8. Among them, the shell includes a fixing frame 2.1, a connecting rod support frame 2.2 and a proximity switch mounting frame 2.3; the flange at one end of the fixing frame 2.1 is connected and fixed to the side opening of the feeding screw 1 discharge port 1.3 through a flange and bolts; the two sides of the connecting rod support frame 2.2 are respectively connected to the proximity switch mounting frame 2.3 and the fixing frame 2.1 through flanges and bolts; a plurality of waist-shaped holes 2.4 are processed on one side of the proximity switch mounting frame 2.3. Specifically, the outer edge of the elastic coating 2.8 is located between the side opening flange of the feeding screw discharge port 1.3 and the shell flange of the pressure detection device 2, and the elastic coating is clamped and fixed by two flanges through fasteners; the inner surface of the elastic coating 2.8 is bonded to the detection head 2.7. The elastic coating has the characteristics of stretchability, elasticity and corrosion resistance, and can make the detection head 2.7 achieve a self-resetting effect through the elasticity of the elastic coating itself. In addition, the elastic coating also has the function of isolating the sludge from direct contact with other parts of the detection device except the elastic coating.

[0039] Specifically, there is a sealing plate at each end of the connecting rod support frame 2.2. The sealing plate is made of carbon steel. A through hole is processed in the center of the sealing plate and two sets of linear bearings 2.6 are fixed by bolts. The linear bearings 2.6 can greatly reduce the friction during the operation of the T-shaped connecting rod 2.5, making it easier to reset it.

[0040] Specifically, the detection head 2.7 is fixed to the T-shaped connecting rod 2.5 by threaded connection. The detection head 2.7 is a circular plate with a threaded hole in the center of the circular plate; the threaded hole is a blind hole; one end of the T-shaped connecting rod 2.5 is a circular rod with threads at the end of the circular rod, and the other end is a circular plate; the T-shaped connecting rod 2.5 passes through the linear bearing 2.6 in the connecting rod support frame 2.2, with the threaded end facing the fixing frame 2.1 and the circular plate end facing the proximity switch mounting frame 2.3.

[0041] Specifically, the first proximity switch 2.4.1 and the second proximity switch 2.4.2 are respectively located at different positions in the same waist-shaped hole 2.4 of the proximity switch mounting frame 2.3, and are used to detect the position of the round plate of the T-shaped connecting rod 2.5. The positions of the first proximity switch 2.4.1 and the second proximity switch 2.4.2 can be adjusted according to actual operating conditions to adapt to different pressure conditions generated when sludge exists in the material chamber.

[0042] Accordingly, this embodiment also provides a control method based on Figure 1 The plunger pump with anti-gas collection function shown in the figure comprises:

[0043] When the feeding screw 1 starts to work, the material is fed from the feeding port 1.1 of the feeding screw 1, discharged from the discharge port 1.3, and then enters the material cavity 3.1 of the main pump body 3; when the material cavity 3.1 of the main pump body 3 is filled with material, the elastic coating 2.8 of the pressure detection device 2 is squeezed and deformed, pushing the internal detection head 2.7 to move away from the material cavity 3.1, driving the T-shaped connecting rod 2.5 to move in the same direction, until the No. 2 proximity switch 2.4.2 detects the round plate end of the T-shaped connecting rod 2.5 and sends a signal; when the plunger pump control system receives this signal, it controls the pumping system 3.2 of the main pump body 3 to start working, and pumps the material out of the material cavity 3.1 of the main pump body 3;

[0044] When gas continuously enters the material cavity 3.1 of the main pump body 3, the material filling rate in the material cavity 3.1 of the main pump body 3 gradually decreases, and when the force exerted by the material on the elastic coating 2.8 is less than the force of the elastic coating 2.8 to restore its deformation, the detection head 2.7 moves toward the material cavity 3.1 by the pulling force of the elastic coating 2.8, driving the T-shaped connecting rod 2.5 to move in the same direction until the No. 2 proximity switch 2.4.2 stops sending a signal, and the No. 1 proximity switch 2.4.1 detects the round plate end of the T-shaped connecting rod 2.5 and sends a signal; when the plunger pump control system receives this signal, it controls the pumping system 3.2 of the main pump body 3 to stop working or slow down the pumping speed, waiting for the material to continue to fill the material cavity 3.1 of the main pump body 3, until the material cavity 3.1 is filled with material and then restarted, and the cycle is repeated, thereby achieving the purpose of reducing energy consumption and preventing gas collection in the pipeline.

[0045] In summary, the present invention sets a pressure detection device at the side wall of the feeding screw outlet, and installs two proximity switches at different positions at the same level on the side wall of the device bracket. When the material cavity of the main pump body is completely filled with materials and the materials are squeezed to the elastic film on the side of the device, the end of the slide rod is pushed to move toward the proximity switch until the proximity switch sends a signal. When the No. 2 proximity switch sends a signal, the plunger pump control system controls the main pump body to start pumping; when the No. 1 proximity switch sends a signal, the plunger pump control system controls the main pump body to stop pumping or slow down the pumping speed, so as to ensure the continuity of the material supply in the main pump body cavity, and prevent the main pump body from pumping too much air into the conveying pipeline due to insufficient materials, causing air collection in the pipeline and thus causing pumping failure.

[0046] Compared with setting an exhaust valve or directly installing a level meter to solve the gas collection problem, the present invention reduces the frequency of the gas collection problem from the root cause. By adopting a coating method, other parts of the detection device except the elastic coating are prevented from direct contact with the sludge. Compared with the method of directly installing the level meter in the material chamber, the present invention has higher accuracy and reliability, and extends the service life of the detection element.

[0047] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A plunger pump with anti-gas collection function, characterized in that: It includes feeding screw, main pump body, pressure detection device and control system; The feeding screw is provided with a feeding screw inlet and a feeding screw outlet; The main pump comprises a material cavity and a pumping assembly; the material cavity is provided with a material cavity feed port, and the material cavity feed port is connected to a feeding screw discharge port; the pumping assembly is used to pump the material in the material cavity; The pressure detection device is used to monitor the pressure changes in the material cavity in real time; The control system controls the operation of the pumping assembly according to the monitoring result of the pressure detection device to reduce energy consumption and prevent gas accumulation in the pipeline.

2. The plunger pump with anti-gas collection function according to claim 1, characterized in that: When the pressure detection device detects that the material cavity is filled with material to a first threshold value, the pressure detection device detects and sends a signal, and the control system controls the pumping component to operate and pump the material out of the material cavity of the main pump body.

3. The plunger pump with anti-gas collection function according to claim 1, characterized in that: When gas continuously enters the material cavity and the pressure detection device detects that the material in the material cavity drops to the second threshold value, the pressure detection device detects and sends a signal, and the control system controls the pumping component to stop working or slow down the pumping speed, waiting for the material to continue to fill the material cavity, and restarts until the material cavity is filled with material to the first threshold value.

4. The plunger pump with anti-gas collection function according to claim 1, characterized in that: An opening is arranged on the side of the feeding screw discharge port and is connected to the opening of the pressure detection device.

5. The plunger pump with anti-gas collection function according to any one of claims 1 to 4, characterized in that: The pressure detection device comprises a housing, a detection head, a connecting rod, a No. 1 proximity switch, a No. 2 proximity switch and an elastic coating; the outer edge of the elastic coating is installed between the side opening of the feeding screw outlet and the housing; the inner surface of the elastic coating is connected to the detection head; The connecting rod is installed in the detection head; The first proximity switch and the second proximity switch are installed in the housing to detect the position of the connecting rod; The installation positions of the No. 1 proximity switch and the No. 2 proximity switch in the housing are adjustable; when the No. 2 proximity switch sends a signal, the control system controls the main pump body to pump; when the No. 1 proximity switch sends a signal, the control system controls the main pump body to stop pumping or slow down the pumping speed.

6. The plunger pump with anti-gas collection function according to claim 5, characterized in that: The shell includes a fixing frame, a connecting rod support frame and a proximity switch mounting frame; a flange at one end of the fixing frame is connected and fixed to a side opening flange of a feeding screw outlet; both sides of the connecting rod support frame are respectively connected to the proximity switch mounting frame and the fixing frame through flanges and bolts; a waist-shaped hole is processed on one side of the proximity switch mounting frame to install the No. 1 proximity switch and the No. 2 proximity switch.

7. The plunger pump with anti-gas collection function according to claim 6, characterized in that: The left and right ends of the connecting rod support frame are each provided with a sealing plate, a through hole is processed in the center of the sealing plate, and a linear bearing is fixed in the through hole by bolts.

8. The plunger pump with anti-gas collection function according to claim 5, characterized in that: The connecting rod is a T-shaped connecting rod, one end of which is a round rod with a threaded end, and the other end is a round plate; the T-shaped connecting rod passes through a linear bearing in a connecting rod support frame, with the threaded end facing the fixed frame and the round plate end facing the proximity switch mounting frame.

9. The plunger pump with anti-gas collection function according to claim 8, characterized in that: The detection head is a circular plate, and a threaded hole is processed at the center of the circular plate so as to be fixed with the T-shaped connecting rod through threaded connection.

10. A control method for the plunger pump with anti-gas collection function according to claim 5, characterized in that: The method comprises: When the feeding screw starts to work, the material is fed into the feeding screw from the feeding port, discharged from the feeding screw discharge port, and then enters the material cavity of the main pump body; when the material cavity of the main pump body is filled with material, the elastic coating of the pressure detection device is squeezed and deformed, pushing the internal detection head to move away from the material cavity, driving the connecting rod to move in the same direction until the No. 2 proximity switch detects the round plate end of the T-shaped connecting rod and sends a signal; when the plunger pump control system receives this signal, it controls the main pump body pumping assembly to start working, and pumps the material out of the main pump body material cavity. When gas continuously enters the material cavity of the main pump body, the material filling rate in the material cavity of the main pump body gradually decreases. When the force exerted by the material on the elastic coating is less than the force exerted by the elastic coating to restore its deformation, the detection head moves toward the material cavity under the pulling force of the elastic coating, driving the T-shaped connecting rod to move in the same direction until the No. 2 proximity switch stops sending a signal, and the No. 1 proximity switch detects the round plate end of the T-shaped connecting rod and sends a signal; when the control system receives this signal, it controls the pumping assembly of the main pump body to stop working or slow down the pumping speed, waiting for the material to continue to fill the material cavity of the main pump body, and restarts after the material cavity is filled with material.

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