Wide-temperature-range reciprocating plunger pump

Abstract

The invention relates to a wide-temperature-range reciprocating plunger pump, and belongs to the technical field of plunger pumps. Materials (such as a plunger, a stuffing box, a pump body, a valve assembly and the like) which are small in thermal expansion coefficient, high in toughness in a low-temperature environment and high in corrosion resistance are selected as core components, a sealing structure and a sealing material between the plunger and the stuffing box are adjusted, it is guaranteed that dynamic sealing is reliable in a wide temperature range, and stable operation can be achieved in the wide temperature range from-55 DEG C to 300 DEG C; and heat dissipation and low-temperature preheating of the core moving part are achieved through a circulating heat dissipation loop composed of the power end, the heat exchanger and the circulating motor, and the heat stability is ensured. Therefore, the reciprocating plunger pump can stably operate in a wide temperature range of-55 DEG C to 300 DEG C.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of plunger pumps, and relates to a wide-temperature-range reciprocating plunger pump. BACKGROUND

[0002] As a kind of high-efficiency and reliable positive displacement pump, the reciprocating plunger pump plays an indispensable role in industrial production. It relies on the reciprocating movement of the plunger in the pump cylinder to make the volume of the working chamber periodically increase and decrease, thereby achieving accurate delivery of the liquid. This kind of pump has many outstanding advantages, such as good self-priming performance, which can self-priming the liquid into the pump without additional liquid introduction device; wide adaptability to medium, which can effectively transport low-viscosity or high-viscosity liquid, or liquid containing impurities; high output pressure, which can meet the requirements of some harsh pressure processes.

[0003] However, the common reciprocating plunger pumps on the market are mostly suitable for normal temperature conditions, and it is difficult for them to operate stably in the face of such a wide temperature range of-55℃ to 300℃. There are many complex reasons behind this.

[0004] From the aspect of materials, in low-temperature environment, the toughness of ordinary metal materials will be greatly reduced, becoming brittle and hard to break. When the reciprocating plunger pump works in such a low-temperature environment, the key components such as the plunger and the pump cylinder are prone to breakage when subjected to the huge stress generated by reciprocating motion. For example, some commonly used alloy steel materials may have impact toughness that is only a fraction of that at normal temperature or even lower when the temperature is below-55℃, and they cannot withstand the impact load during normal operation of the plunger pump. In high-temperature environment, the strength of the material will decrease significantly, and creep phenomenon will occur. Like rubber seals, they will quickly age, harden, and lose elasticity at high temperatures of 300℃, resulting in a sharp decline in sealing performance and liquid leakage problems, affecting the normal operation of the pump.

[0005] From the perspective of lubrication, low temperature will greatly increase the viscosity of lubricating oil and reduce its flowability. This results in that the lubricating oil between the plunger and the pump cylinder, bearings and other moving parts cannot reach the friction surface in time and fully, forming an effective lubricating oil film, thereby exacerbating the wear between the components and shortening the service life of the pump. On the contrary, high temperature will reduce the viscosity of lubricating oil, making it easy to volatilize and oxidize, which also cannot provide good lubrication and protection for the moving parts, causing the parts to wear out and even causing serious failures such as jamming.

[0006] In addition, in a wide temperature range, the physical properties of the medium in the pump, such as viscosity and density, will change greatly. These changes will directly affect the performance parameters of the pump, such as flow and pressure, making it difficult for the pump to operate stably under the set working conditions and unable to meet the requirements of the production process.

[0007] Therefore, in order to solve these deficiencies in the prior art, it is particularly urgent to develop a new reciprocating plunger pump that can adapt to a wide temperature range. SUMMARY

[0008] Therefore, the purpose of the present application is to provide a wide temperature range reciprocating plunger pump that can operate stably in a wide temperature range.

[0009] To achieve the above purpose, the present application provides the following technical solutions: A wide temperature range reciprocating plunger pump, comprising a chassis, and a power motor assembly, a power end, a heat exchanger, a hydraulic end, and a circulating motor assembly arranged on the chassis; the power motor assembly is connected with the power end and provides power for the power end; the hydraulic end is fixed to the side surface of the power end; the oil outlet of the power end is connected with the first oil port of the heat exchanger, the second oil port of the heat exchanger is connected to the oil suction port of the circulating motor assembly, the oil outlet of the circulating motor assembly is connected back to the oil inlet of the power end, and the power end, heat exchanger and circulating motor assembly together constitute a heat dissipation circuit; a packing gland assembly is integrated in the mounting cavity of the power end.

[0010] Optionally, the packing gland assembly comprises a packing gland body, and a plunger is arranged inside the packing gland body; an adjusting nut, a guide sleeve and packing are sequentially arranged between the packing gland body and the plunger; the adjusting nut is located at the end side of the packing gland body and is used to press the packing by screwing to adjust the pre-tightening force and make the packing more closely fit the plunger; an O-ring is arranged at the end of the packing gland body matched with the mounting cavity of the power end to realize static sealing.

[0011] Optionally, the hydraulic end comprises a pump body and a pressing strip arranged on the top of the pump body, and a valve assembly is further arranged in the pump body; the pressing strip is used to seal the valve assembly.

[0012] Optionally, the pressing strip is fixed on the top of the pump body by a short bolt and a nut.

[0013] Optionally, the pump body is fixed on the side surface of the power end by a long bolt and a nut matched with the long bolt.

[0014] Optionally, the pump body and the pressing strip are made of 316L stainless steel, and the valve assembly is made of 2Cr13 stainless steel.

[0015] Optionally, the plunger and the packing gland body are made of 2Cr13 stainless steel.

[0016] Optionally, the plunger surface is further provided with a tungsten carbide coating; and the packing is made of a material combined with Teflon and aramid.

[0017] Optionally, the power unit is connected to the heat exchanger via a hose, and the circulating motor assembly is connected to the power unit via a hose.

[0018] The beneficial effects of this invention are as follows: This invention achieves long-term stable operation of a reciprocating plunger pump within an extreme temperature range of -55℃ to 300℃ through material selection, sealing structure optimization, and circulating heat exchange design. Its technical advantages are mainly reflected in the following aspects: Firstly, regarding wide temperature range adaptability, core components (such as plungers, stuffing boxes, pump bodies, and valve assemblies) are made of materials with low coefficients of thermal expansion, high toughness at low temperatures, and strong corrosion resistance. For example, 2Cr13 is used for the plungers and stuffing boxes, and 316L is used for the pump body. This significantly reduces the risk of dimensional deformation caused by drastic temperature changes, thereby avoiding functional failures caused by high-temperature jamming or low-temperature loosening. Simultaneously, the packing and spacers are made of polytetrafluoroethylene (PTFE) and its composite materials, which combine high and low temperature resistance, self-lubrication, and creep resistance, ensuring the sealing system maintains elasticity and tightness across the entire temperature range and effectively preventing media leakage.

[0019] Secondly, this invention improves the sealing reliability and maintainability of the system through multi-stage sealing and an adjustable preload structure. The stuffing box incorporates a combination of guide sleeve, packing, and spacers, and the sealing pressure is dynamically adjusted via an adjusting nut. This compensates for changes in preload caused by thermal expansion and contraction of the material, and also extends the lifespan of the seals. An O-ring is used in the static sealing stage to further block leakage paths. This dynamic and static combined, adjustable sealing design allows the pump to maintain stable sealing performance even under long-term temperature cycling conditions.

[0020] In addition, the independently designed closed-loop cooling system (power end - heat exchanger - circulating motor assembly) realizes active thermal management, which can not only effectively dissipate heat during high-temperature operation, but also prevent lubricant failure and component overheating.

[0021] Through the above-mentioned design features, this invention enables the plunger pump to maintain high reliability, long lifespan, and low maintenance requirements even under extreme temperature conditions, making it applicable to multiple technical fields.

[0022] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Fig. 1is a top view of the reciprocating plunger pump; Fig. 2 is a front view of the reciprocating plunger pump; Fig. 3 is a side view of the reciprocating plunger pump; Fig. 4 is a sectional view of the packing box assembly; Fig. 5 is a side view of the packing box assembly; Fig. 6 is a sectional view of the fluid end.

[0024] Reference signs: 1 base frame, 2 power motor assembly, 3 power end, 4 heat exchanger, 5 fluid end, 6 circulating motor assembly, 10 plunger, 11 adjusting nut, 12 packing box body, 13 guide sleeve, 14 packing, 15 spacer ring, 16 O-ring, 21 pump body, 22 pressing strip, 23 nut, 24 short bolt, 25 valve assembly, 26 long bolt. DETAILED DESCRIPTION

[0025] The present application is described in greater detail by the following specific examples, and other advantages and effects of the present application that can be easily understood by those skilled in the art from this disclosure. The present application can also be implemented or applied in other different specific embodiments, and various modifications or changes can be made to the details in this specification based on different views and applications without departing from the spirit of the present application. It should be noted that the drawings provided in the following examples only schematically illustrate the basic concept of the present application, and the following examples and features in the examples can be combined with each other without conflict.

[0026] Wherein, the drawings are only used for exemplary illustration, and the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation on the present application; in order to better illustrate the embodiments of the present application, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual product size; it is understandable to those skilled in the art that some known structures and their descriptions in the drawings may be omitted.

[0027] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] Please refer to Figs. 1-6 , a wide temperature range reciprocating piston pump, comprising a chassis 1, the chassis 1 is the support structure of the whole device, the chassis 1 is provided with power motor assembly 2, power end 3, heat exchanger 4, hydraulic end 5, circulating motor assembly 6. Power motor assembly 2 and power end 3 are connected and provide power for power end 3; hydraulic end 5 is fixed on the side of power end 3; the oil outlet of power end 3 is connected with the first oil port of heat exchanger 4 through the hose, the second oil port of heat exchanger 4 is connected to the oil suction port of circulating motor assembly 6, the oil outlet of circulating motor assembly 6 is connected back to the oil inlet of power end 3 through the hose, power end 3, heat exchanger 4 and circulating motor assembly 6 constitute a cooling circuit together; the installation cavity of power end 3 is integrated with packing box assembly.

[0029] The cooling circuit composed of power end 3, heat exchanger 4 and circulating motor assembly 6 takes circulating motor assembly 6 as the power source to drive the continuous flow of heat conducting oil in the closed pipeline. When working, the oil first flows out from the outlet oil port of power end 3, carrying the heat accumulated in the internal of power end 3 due to reciprocating motion, friction and medium transmission; then the hot oil enters the heat exchanger 4, and carries out convective heat exchange with the external cooling air or cooling medium in the heat exchanger 4, realizing the effective emission of heat to the outside world; the cooled oil is retransported back to the inlet oil port of power end 3 through the pressurization of circulating motor assembly, so as to complete a cycle. The cooling circulation circuit prevents the overheating of power end 3 and maintains the stable performance of lubricating oil through continuous circulation and cooling in the high temperature stage; in the low temperature stage, the circulating oil can gradually absorb the cold of the internal of power end 3, and through the heat exchanger 4, the external heat source can be introduced or the heat generated by the motor itself can be utilized when necessary, so as to slowly improve the system temperature, improve the low temperature starting condition, avoid cold brittleness and lubrication failure. Thus, a continuous and stable thermal environment guarantee can be provided for the core moving parts of piston 10 pump in a wide temperature range.

[0030] Among them, the packing box assembly includes a packing box body 12, which is the main structure, and a piston 10 is installed inside the packing box body 12. The packing box body 12 and the piston 10 are sequentially provided with an adjusting nut 11, a guide sleeve 13 and a packing 14. The guide sleeve 13 plays a guiding role to guide the movement of the piston 10; the packing 14 plays a sealing role to prevent leakage of the medium; the spacer ring 15 is located between the packings 14 to enhance the support and sealing effect. The adjusting nut 11 is located at the end side of the packing box body 12, and the packing 14 is pressed by screwing to adjust the pre-tightening force, so that it can better fit the piston 10; the end of the packing box body 12 matched with the installation cavity of the power end 3 is provided with an O-ring 16 to realize static sealing.

[0031] The hydraulic end 5 comprises a pump body 21 and a pressing strip 22 arranged on the top of the pump body 21, and the pressing strip 22 is fixed and locked on the top of the pump body 21 by short bolts 24 and nuts 23. The pump body 21 is fixed and locked on the side of the power end 3 by long bolts 26 and nuts 23.

[0032] The pump body 21 is further provided with a valve assembly 25. When the volume in the working chamber increases to form a low pressure, the inlet valve of the valve assembly 25 is pushed open by the external liquid to enter the pump body 21, and the outlet valve of the valve assembly 25 is closed due to the pressure of the liquid in the pipe. When the liquid is extruded to increase the pressure, the outlet valve is pushed open to press into the outlet pipeline, and the inlet valve is closed. The valve assembly 25 is sealed by the pressing strip 22.

[0033] Further, the pump body 21 and the pressing strip 22 are made of 316L stainless steel, which has excellent corrosion resistance and mechanical properties. The plunger 10, the stuffing box 12 and the valve assembly 25 are made of 2Cr13 stainless steel, which has good high and low temperature performance, high hardness, good corrosion resistance, small thermal expansion coefficient and strong toughness in low temperature environment. The surface of the plunger 10 is further provided with a tungsten carbide coating to increase the wear resistance; the spacer ring 15 is made of polytetrafluoroethylene material.

[0034] The wide temperature range reciprocating plunger pump selects materials with small thermal expansion coefficient, strong toughness in low temperature environment and strong corrosion resistance as the main core components (such as the plunger 10, the stuffing 14 box, the pump body 21 and the valve assembly 25), to meet the operation requirements in a wide temperature range; the sealing structure and sealing material between the plunger 10 and the stuffing 14 box are also adjusted. Through the dynamic sealing of the adjusting nut 11 and the static sealing of the O-ring 16, the pump can still maintain stable sealing performance and wear resistance in long-term temperature cycle conditions, so that the whole device can stably operate in a wide temperature range of-55℃ to 300℃.

[0035] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, which should be covered in the scope of the claims of the present application.

Claims

1. A wide-temperature-range reciprocating plunger pump, characterized in that: The device includes a base frame (1), and a power motor assembly (2), a power end (3), a heat exchanger (4), a hydraulic end (5), and a circulating motor assembly (6) mounted on the base frame (1). The power motor assembly (2) is connected to the power end (3) and provides power to the power end (3). The hydraulic end (5) is fixed to the side of the power end (3). The oil outlet of the power end (3) is connected to the first oil port of the heat exchanger (4), the second oil port of the heat exchanger (4) is connected to the oil inlet of the circulating motor assembly (6), and the oil outlet of the circulating motor assembly (6) is connected back to the oil inlet of the power end (3). The power end (3), the heat exchanger (4), and the circulating motor assembly (6) together form a heat dissipation circuit. A stuffing box assembly is integrated into the mounting cavity of the power end (3).

2. The wide temperature range reciprocating plunger pump according to claim 1, characterized in that: The stuffing box assembly includes a stuffing box body (12), inside which a plunger (10) is provided; between the stuffing box body (12) and the plunger (10), an adjusting nut (11), a guide sleeve (13) and a packing (14) are sequentially fitted; wherein the adjusting nut (11) is located on the end side of the stuffing box body (12), and the packing (14) is tightened by screwing to adjust its preload so that it fits the plunger (10) better; one end of the stuffing box body (12) that mates with the mounting cavity of the power end (3) is provided with an O-ring (16) to achieve static sealing.

3. The wide temperature range reciprocating plunger pump according to claim 1, characterized in that: The hydraulic end (5) includes a pump body (21) and a pressure strip (22) disposed on the top of the pump body (21). A valve assembly (25) is also provided inside the pump body (21). The pressure strip (22) is used to seal the valve assembly (25).

4. The wide temperature range reciprocating plunger pump according to claim 3, characterized in that: The pressure bar (22) is fixed to the top of the pump body (21) by short bolts (24) and nuts (23).

5. The wide temperature range reciprocating plunger pump according to claim 3, characterized in that: The pump body (21) is fixed to the side of the power end (3) by a through bolt (26) and a nut (23) that matches the bolt (26).

6. The wide temperature range reciprocating plunger pump according to claim 3, characterized in that: The pump body (21) and pressure bar (22) are made of 316L stainless steel, and the valve assembly (25) is made of 2Cr13 stainless steel.

7. The wide temperature range reciprocating plunger pump according to claim 2, characterized in that: The plunger (10) and stuffing box (12) are made of 2Cr13 stainless steel.

8. The wide temperature range reciprocating plunger pump according to claim 2, characterized in that: The plunger (10) is also coated with tungsten carbide; the filler (14) is made of a combination of Teflon and aramid.

9. The wide temperature range reciprocating plunger pump according to claim 1, characterized in that: The power end (3) is connected to the heat exchanger (4) via a hose, and the circulating motor assembly (6) is connected to the power end (3) via a hose.

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