Pump head device of plunger type metering pump

Abstract

The utility model relates to the technical field of pumps with variable measuring quantities, in particular to a pump head device of a plunger type metering pump. The pump head device of the plunger type metering pump comprises a pump head body, a liquid inlet and a liquid outlet are formed in the pump head body, a sealing filler cavity is formed in the pump head body, one end of the pump head body is an open end, the other end of the pump head body is a blind opening end, a through hole used for replacing sealing filler is formed in the blind opening end, a pressing bush is installed in the through hole, and the pressing bush is connected with the pump head body. The pressing bush is provided with flow guide holes corresponding to the liquid inlet and the liquid outlet, and the pump head body is further provided with a blocking piece which is used for pressing the pressing bush and blocking the through hole. When the sealing filler of the plunger type metering pump is replaced, the plugging piece can be detached firstly, then the pressing bush is taken out, old sealing filler is taken out from the open end of the pump head body, new sealing filler is added into the through hole, and the pressing bush and the plugging piece are installed in sequence, so that the operation of replacing the sealing filler can be completed. Therefore, the problem that the pump head body is inconvenient to disassemble when the sealing filler is replaced is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of variable-measurement-volume pumps, in particular to a plunger-type metering pump head device. Background Art

[0002] During the development of oil fields, the produced fluid of oil wells will cause different degrees of corrosion, waxing and scaling of the rod pump in the wellbore of the oil wells due to the different components of crude oil, natural gas and formation water and the content of impurities in the components. This will lead to the breakage of the sucker rod of the oil well, corrosion and perforation of the oil pipe, poor sealing of the pump and damage of the supporting tools, affecting the normal production of the oil wells. In severe cases, it can directly cause the well to be shut down and production to stop, reducing the production rate and economic benefits of the oil wells. In order to enable the normal production of the oil wells, various corrosion inhibitors, wax inhibitors and other agents need to be added to the oil wells to achieve the purpose of slowing down the corrosion, waxing and scaling of the rod pump in the wellbore. At present, the injection of corrosion inhibitors, wax inhibitors and other agents into oil wells uses a small-volume plunger metering pump. Since the pump head part is an integrated type, its operating space is also very limited during daily maintenance and repair operations due to its small size.

[0003] The plunger of a plunger metering pump is generally sealed with a packing (packing). Since the packing (packing) and the plunger are both wearing parts, they will become worn and unusable after long-term use. At this time, it is necessary to stop the machine and replace the plunger or packing. When replacing the plunger or packing (packing), the pump head part needs to be removed from the metering pump, and after replacing the plunger or packing (packing), the pump head part needs to be installed back to its original position. Due to the narrow space of the pump head and the small operating space, the maintenance and repair process is time-consuming and labor-intensive, which affects the pump start-up rate.

[0004] A Chinese invention patent with authorization announcement number CN101852194B and authorization announcement date September 5, 2012 discloses a plunger-type metering pump head, including an outlet valve assembly, a pump head body, an inlet valve assembly and a plunger, a polytetrafluoroethylene gasket, a shaft seal and a packing compression cap are sequentially installed in the pump head body, the packing compression cap and the pump head body are threadedly matched, one end of the plunger passes through the packing compression cap, the shaft seal and the polytetrafluoroethylene gasket in sequence to form a closed cavity with the pump head body, and the other end of the plunger is connected to the crosshead of the hydraulic end of the metering pump.

[0005] The above plunger metering pump head changes the plunger material of the metering pump from stainless steel to silicon nitride ceramic material, changes the original pre-tightening seal to a gap seal, and changes the material from the original packing or nitrile rubber to silicon nitride ceramic material. At the same time, a polytetrafluoroethylene gasket is added, and the polytetrafluoroethylene gasket is pre-tightened and deformed by rotating the packing compression cap, so that the pump head body and the plunger form a closed space, which effectively solves the liquid leakage problem of the traditional metering pump and greatly improves the service life of the metering pump. However, when replacing the shaft seal (sealing packing), the pump head part still needs to be removed from the metering pump for replacement, which is inconvenient to disassemble, has a large workload, and is difficult to disassemble and assemble. Utility Model Content

[0006] The utility model aims to provide a plunger type metering pump head device to solve the problem in the prior art that the pump head body is inconvenient to disassemble when replacing the sealing filler.

[0007] In order to achieve the above-mentioned purpose, the plunger type metering pump head device of the utility model adopts the following technical scheme:

[0008] A plunger metering pump head device comprises a pump head body, wherein the pump head body is provided with an inlet and a discharge port, and a sealing filler cavity is provided on the pump head body. One end of the pump head body is an open end, and the other end is a blind end. The blind end is provided with a through hole for replacing the sealing filler, and a clamping bushing is installed in the through hole. The clamping bushing is provided with guide holes corresponding to the inlet and the discharge port, and a sealing member for clamping the clamping bushing and sealing the through hole is also provided on the pump head body.

[0009] Beneficial effects: The plunger metering pump head device of the utility model is an improved invention. Specifically, a through hole for replacing the sealing packing is opened at the blind end of the pump head body, a compression bushing is installed in the through hole, a guide hole corresponding to the inlet and outlet ports on the pump head body is provided on the compression bushing, and a plugging piece for compressing the compression bushing and plugging the through hole is provided at the blind end of the pump head body. When replacing the sealing packing of the plunger metering pump, the plugging piece can be removed first, and then the compression bushing is taken out, and then the old sealing packing is taken out from the open end of the pump head body, and then a new sealing packing is added from the through hole, and the compression bushing and the plugging piece are installed in sequence to complete the operation of replacing the sealing packing, thereby solving the problem of inconvenient disassembly of the pump head body when replacing the sealing packing.

[0010] Furthermore, an inner thread section is provided at the outer end of the through hole, and the blocking member is a thread plug that is threadably matched with the inner thread section.

[0011] Furthermore, an outwardly turned edge is arranged on the outer peripheral surface of the screw plug, and the outwardly turned edge is in contact with the edge of the through hole.

[0012] Furthermore, the diameter of the internal thread section is larger than the diameter of the adjacent portion of the through hole, thereby forming an outwardly facing step surface in the through hole, and a sealing gasket is pressed between the inner end of the thread plug and the step surface.

[0013] Furthermore, the compression bushing includes a guide section and a compression section, and the guide section and the compression section are separately arranged.

[0014] Furthermore, at least two guide sections are provided, so as to adapt to pump head bodies of different lengths by selecting guide sections of different lengths or numbers.

[0015] Furthermore, a sealing stuffing box pressure cap is threadedly connected to one end of the pump head body away from the blocking member, and a screwing tool matching structure is provided on the sealing stuffing box pressure cap.

[0016] Furthermore, the screwing tool matching structure is a blind hole provided on the outer peripheral surface of the sealing stuffing box pressure cap.

[0017] Furthermore, a sealing packing gland is provided between the sealing packing box pressure cap and the pump head body, and the sealing packing gland has an outer flange that cooperates with the pump head body for stopping.

[0018] Furthermore, the outer diameter of the inner end of the sealing packing gland is smaller than the diameter of the through hole and larger than the inner diameter of the adapted sealing packing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a specific embodiment of the pump head device of the plunger-type metering pump of the utility model;

[0020] Figure 2 The utility model is a schematic diagram of a sealing stuffing box pressure cap, a sealing stuffing gland and a sealing stuffing of a plunger type metering pump.

[0021] In the figure: 1. pump head body; 101. liquid inlet; 102. liquid discharge port; 103. open end; 104. blind end; 105. step surface; 2. sealing packing; 3. pressing bushing; 301. pressing section; 302. guide section; 21. guide hole; 5. blocking piece; 501. outward turning edge; 6. sealing packing gland; 601. outer flange; 7. sealing packing box cap; 701. blind hole; 8. sealing gasket. DETAILED DESCRIPTION

[0022] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0023] In the prior art, when replacing the sealing packing, the pump head part needs to be removed from the metering pump for replacement. Due to the narrow space of the pump head position and the small operable space, it is inconvenient to disassemble, the workload is large, and the disassembly and assembly are difficult, which affects the pump start-up rate. In view of the above problems, the utility model designs a plunger metering pump head device. The core concept of the utility model is to open a through hole at the blind end of the pump head body for replacing the sealing packing, and install a clamping bushing and a sealing piece in the through hole in sequence. When replacing the sealing packing of the plunger metering pump, there is no need to disassemble the entire pump head body. Only the sealing piece and the clamping bushing on the through hole at the blind end of the pump head body need to be removed to complete the operation of replacing the sealing packing.

[0024] Based on the above invention concept, Figure 1 As shown, a plunger metering pump head device of the utility model comprises a pump head body 1, a liquid inlet 101 and a liquid discharge port 102 are provided on the pump head body 1, a sealing stuffing cavity is provided on the pump head body 1, one end of the pump head body 1 is an open end 103, and the other end is a blind end 104, the blind end 104 is provided with a through hole for replacing the sealing stuffing 2, a clamping bushing 3 is installed in the through hole, the clamping bushing 3 is provided with a guide hole 401 corresponding to the liquid inlet 101 and the liquid discharge port 102, and a sealing member 5 for clamping the clamping bushing 3 and sealing the through hole is also provided on the pump head body 1.

[0025] Among the above components, Figure 1In the illustrated embodiment, the pump head body 1 is a cylinder, one end of which is an open end 103, and the other end is a blind end 104, and a sealing packing 2 is installed in the pump head body 1. The pump head body 1 is provided with a liquid inlet 101 and a liquid discharge port 102, which are respectively connected to the inlet valve assembly and the outlet valve assembly. The liquid inlet 101 is the entrance for the liquid to enter the pump head. When the plunger retreats, the volume in the pump head body 1 increases, forming a negative pressure, so that the liquid is sucked into the pump head body 1 through the liquid inlet 101. The liquid discharge port 102 is the outlet for the liquid to be discharged from the pump head body 1. When the plunger moves forward, the volume in the pump head body 1 decreases, so that the liquid is discharged through the liquid discharge port 102 under the action of pressure. The blind end 104 is provided with a through hole 105, the diameter of the through hole 105 is larger than the diameter of the sealing packing 2, and the sealing packing 2 in the pump head body 1 can be replaced through the through hole 105. A clamping bushing 3 is installed in turn in the through hole 105, and the shape of the clamping bushing 3 is a hollow cylinder. In order to smoothly install the clamping bushing 3 into the pump head body 1, the outer diameter of the clamping bushing 3 is set to be smaller than the inner diameter of the pump head body 1. The clamping bushing 3 includes a clamping section 301 and a guide section 302. Considering the convenience of maintenance and replacement, the guide section and the clamping section are separated. The clamping section 301 is used to compress the sealing packing 2 to prevent liquid leakage under high pressure, reduce the wear between the plunger rod and the pump head body 1, and improve the life and operation efficiency of the plunger metering pump. The guide section 302 is provided with guide holes 21 corresponding to the liquid inlet 101 and the liquid outlet 102, which can guide the flow direction of the fluid in the pump head body 1, help stabilize the pressure distribution of the fluid in the pump head body 1, and improve the stability of the plunger metering pump. There are at least two guide sections 302. Specifically, guide sections 302 of different lengths or numbers can be selected according to pump head bodies 1 of different lengths. In some other embodiments, the clamping section 301 and the guide section 302 of the clamping bushing 3 can also be arranged integrally.

[0026] In such Figure 1 In the embodiment shown, a plugging member 5 is installed at the through hole of the pump head body 1. The plugging member 5 is a threaded plug, which can compress the bushing 3 and plug the through hole to prevent foreign matter from entering the pump head body 1, and is convenient for disassembly, cleaning and maintenance of the components in the pump head body 1. The outer end of the through hole is provided with an internal thread section. The threaded plug 5 is in the shape of a cylinder. One end of the threaded plug is a threaded hole, which is threadedly connected with the internal thread section, and the other end is a hexagon, which is convenient for installation and removal. An outer circumferential surface of the threaded plug is provided with an outer flank 501, which fits the flank 501 with the edge of the through hole to achieve a better sealing effect. In some other embodiments, the plugging member 5 can also be a flange cover, etc. The diameter of the internal thread section is larger than the diameter of the adjacent part of the through hole, and an outward step surface 105 is formed in the through hole, which can facilitate the installation of the threaded plug. A sealing gasket 8 is pressed between the inner end of the threaded plug and the step surface 105, which can prevent the leakage of liquid in the pump head body 1 and improve the sealing of the pump head body 1. In some other implementations, a sealing ring, etc. can also be used.

[0027] In such Figure 1 and Figure 2 In the illustrated embodiment, the open end 103 of the pump head body 1 away from the plugging member 5 is threadedly connected with a sealing stuffing box pressure cap 7, which is in the shape of a hollow cylinder, and its diameter is larger than the diameter of the sealing stuffing 2. The sealing stuffing box pressure cap 7 can protect the sealing stuffing 2 from the erosion of impurities, moisture and pollutants in the external environment, which helps to extend the service life of the sealing stuffing 2 and maintain its sealing performance, and can adjust the tightness of the sealing stuffing 2. Considering the convenient installation and removal of the sealing stuffing box pressure cap 7, a screwing tool matching structure is provided on the sealing stuffing box pressure cap 7, and the screwing tool matching structure is a blind hole 701 provided on the outer peripheral surface of the sealing stuffing box pressure cap, and the blind hole 701 can be used with a screwing tool to install and remove the sealing stuffing box pressure cap 7. A sealing packing gland 6 is provided between the sealing packing box pressure cap 7 and the pump head body 1. The outer diameter of the inner end thereof is smaller than the diameter of the through hole and larger than the inner diameter of the sealing packing 2. The sealing packing gland 6 is used to compress the sealing packing 2. Appropriate pressure can be applied to press the sealing packing 2 tightly against the sealing surface to prevent fluid and gas from leaking from the sealing surface. The sealing packing gland 6 is in the shape of a hollow cylinder. The sealing packing gland 2 is provided with an outer flange 601, which can cooperate with the open end 103 of the pump head 1 to improve the sealing ability of the pump head body 1.

[0028] When replacing the sealing packing 2 of the plunger metering pump, first close the inlet and outlet valves of the metering pump and release the pressure and vent it, then remove the sealing piece 5 in the through hole on the blind end 104 of the metering pump head body 1, take out the sealing gasket 8, the guide section 302 and the pressing section 301 of the compression bushing 3, and then remove the sealing packing box pressure cap 7 and the sealing packing gland 6 at the open end 103 of the metering pump head, take out the old sealing packing 2, add the new sealing packing 2 from the through hole on the blind end 104 of the metering pump head body 1, install the pressing section 301 and the guide section 302 of the compression bushing 3, the sealing gasket 8 and the sealing piece 5 in turn, and then install the sealing packing gland 6 and the sealing packing box pressure cap 7 from the open end 103 of the metering pump head, and adjust the tightness of the sealing packing box pressure cap 7 through the blind hole 701 on the sealing packing box, and the operation of replacing the sealing packing 2 can be completed.

Claims

1. A plunger type metering pump head device, comprising a pump head body, the pump head body is provided with a liquid inlet and a liquid discharge port, the pump head body is provided with a sealing packing cavity, one end of the pump head body is an open end, and the other end is a blind end, characterized in that: The blind end is provided with a through hole for replacing the sealing filler, a compression bushing is installed in the through hole, the compression bushing is provided with guide holes corresponding to the inlet and outlet ports, and a sealing member for compressing the compression bushing and sealing the through hole is also provided on the pump head body.

2. The plunger type metering pump head device according to claim 1, characterized in that: An inner thread section is arranged at the outer end of the through hole, and the plugging member is a thread plug which is threadably matched with the inner thread section.

3. The plunger type metering pump head device according to claim 2, characterized in that: An outwardly turned edge is arranged on the outer peripheral surface of the thread plug, and the outwardly turned edge is in contact with the edge of the through hole.

4. The plunger type metering pump head device according to claim 2, characterized in that: The diameter of the internal thread section is larger than the diameter of the adjacent portion of the through hole, thereby forming an outwardly facing step surface in the through hole, and a sealing gasket is pressed between the inner end of the thread plug and the step surface.

5. The plunger type metering pump head device according to any one of claims 1 to 4, characterized in that: The compression bushing comprises a guide section and a compression section, and the guide section and the compression section are separately arranged.

6. The plunger type metering pump head device according to claim 5, characterized in that: At least two guide sections are provided, so as to adapt to pump head bodies of different lengths by selecting guide sections of different lengths or numbers.

7. The plunger type metering pump head device according to claim 1, characterized in that: A sealing stuffing box pressure cap is threadedly connected to one end of the pump head body away from the blocking member, and a screwing tool matching structure is arranged on the sealing stuffing box pressure cap.

8. The plunger type metering pump head device according to claim 7, characterized in that: The screwing tool matching structure is a blind hole arranged on the outer peripheral surface of the sealing stuffing box pressure cap.

9. The plunger type metering pump head device according to claim 7, characterized in that: A sealing packing gland is provided between the sealing packing box pressure cap and the pump head body, and the sealing packing gland has an outer flange that cooperates with the pump head body for blocking.

10. The plunger type metering pump head device according to claim 9, characterized in that: The outer diameter of the inner end of the sealing packing gland is smaller than the diameter of the through hole and larger than the inner diameter of the adapted sealing packing.

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