CN203394741U - Reciprocating piston pump with improved inlet valve arrangement - Google Patents

Abstract

The utility model provides a reciprocating piston pump with improved inlet valve arrangement. A valve component can move between an open position and a closed position by virtue of liquid force, wherein the head of the valve component is separated from a valve base on the open position, and the head of the valve component is contacted with the valve base on the closed position. The valve component comprises a valve rod; the valve rod does not block liquid which flows through the inlet of the valve. When the valve is closed, the head, which is contacted with the valve base, of the valve component is in a spherical shape or a frustum shape. The valve component is made from polymer materials. The inlet valve does not adopt a bias component for bringing the valve component to the closed position.

Description

The reciprocating piston pump of arranging with improved suction valve

Technical field

The disclosure relates to a kind of reciprocating piston pump of arranging with improved suction valve.

Background technique

Reciprocating piston pump is for carrying fluid in various application.In order to improve pump performance, need reduce the obstruction in territory, fluid flow region (especially around pump inlet and outlet) and limit the caused pressure loss.When the fluid of pumping is liquid gas, this is particular importance, because if pressure drop is too large, so just may causes the vaporization of liquid gas and reduce pumping efficiency.When too many liquid gas is vaporized, pump can shut down.Reciprocating piston pump is just being applied in automobile application, for example, and for being delivered to internal-combustion engine as the fuel of LNG Liquefied natural gas (LNG).In make some systems that fuel supplies with of gaseous fuel, reciprocating pump must with at least about 3000psi and sometimes can reach 4000 or the pressure of 5000psi carry out transfer the fuel, for example when fuel, directly injected the situation of firing chamber.For direct injection firing chamber, the pressure of fuel must be raised to the level that the fuel that overcomes inner cylinder pressure and allow aequum was injected with the required time limit.For other application, if fuel is injected into the gas handling system of motor, so required fuel discharge pressure is relatively low, and for example, for most of motors, the fuel pressure between about 100psi and 300psi is enough.In the disclosure, the pump operating in this lower pressure range is referred to herein as " low pressure pump ".This class pump operates by the head pressure of 100psi to 300psi conventionally, and is designed to allow the MDP of 600psi.

In known reciprocating piston pump, in pump inlet, provide safety check automatically to open and to allow fluid to flow into pumping chamber (when pumping chamber's volume increases) during aspirating stroke, and close and prevent that fluid from passing through circumfluence (when pumping chamber's volume reduces) during the compression stroke of pump.Similarly, safety check is usually located in pump discharge, thereby opens during compression stroke, and the fluid of closing during aspirating stroke and preventing from having discharged by outlet is back in pumping chamber.

Be designed to describe in U.S. Patent number 7,607,898 that an embodiment for the reciprocating piston pump of automobile application owns together claimant.Because fluid pressure action is in breather check valve, the breather check valve of described pump is to close during compression stroke whole process almost.That is to say, the different fluid pressure that acts on breather check valve member causes it move to closed position and be maintained in its closed position, and is pressed against on valve seat.When pump piston is regained the pressure decreased in Shi， pumping chamber during aspirating stroke, so that it is lower than the supply pressure of the fluid in the gas-entered passageway of pump, and suction valve member is removed and in an open position aspirating stroke whole process almost from valve seat.

In order to reduce the possibility for delivery of the fluid vaporization in the reciprocating piston pump of liquid gas, thereby need to improve, reduce the anti-devaporation of pressure drop.

Model utility content

A kind of reciprocating piston pump that improved suction valve is arranged that has is disclosed.Described reciprocating piston pump comprises: pumping chamber, and described pumping chamber is defined by the following: cylinder body, the flange that is placed in the piston in described cylinder body and covers the end relative with described piston of described cylinder body; And suction valve, described suction valve comprises the valve member with head and valve rod.The head surface of described suction valve is to the surface that comprises valve seat, and described valve rod extends with the direction towards piston from the head.Described valve rod does not block and flows through import and enter the fluid in suction valve, and moves between the closed position that contacts with described valve seat with described valve member head of the open position that can be separated by with described valve seat at described valve member head by fluid force of described valve member.Described suction valve allows fluid to flow through import and prevent that fluid from flowing in the opposite direction on a direction.

In preferred embodiments, described reciprocating piston pump has preferably 100 to 300psi head pressure.Described pump can be designed to allow the MDP of 600psi.

In preferred embodiments, the head that described valve seat has cone-shaped and a described valve member has spherical form.

In other embodiments, the valve seat of described valve member and head all have frusto-conical shape separately.In these embodiments, the angle that the frusto-conical shape of the head of described valve member forms is preferably greater than the angle of the frusto-conical shape formation of described valve seat.

In preferred embodiments, described valve member is made by polymer material.This polymer material can be the polymer based on fluorocarbon, for example polychlorotrifluoroethylene.

Preferably, described valve import is dimensioned to avoid the essence pressure drop of the import of described suction valve and the fluid stream between outlet.

The main body of described suction valve comprises guide groove, and described guide groove for guiding the valve rod of described valve member when described valve member moves between open position and closed position.

Reciprocating piston pump disclosed herein further comprise allow fluid in one direction between import with export between mobile discharge safety check, described discharge safety check is poppet valve, and it comprises main body and the valve member that can move between open position and closed position.Described discharge safety check further comprises resilient member, and described resilient member makes described valve member be biased to closed position.In described closed position, the head of described valve member contact valve seat.The head of described valve member preferably has spherical form.In some embodiments, described valve member comprises the head with frusto-conical shape.

The valve member of described discharge safety check is made by polymer material, and the polymer based on fluorocarbon for example, as polychlorotrifluoroethylene.

Reciprocating piston pump disclosed herein for example can be handled, in the fluid that approaches pumping at the temperature of its boiling point, LNG Liquefied natural gas.

Accompanying drawing explanation

Accompanying drawing shows certain preferred embodiment of the present utility model, but described embodiment should not be considered as limiting by any way spirit or scope of the present utility model.

Fig. 1 shows according to the perspective view of the reciprocating piston pump that comprises suction valve of the utility model embodiment.

Fig. 2 is the viewgraph of cross-section of the reciprocating piston pump shown in Fig. 1.

Fig. 3 is the viewgraph of cross-section that comprises suction valve disclosed herein and the end of the reciprocating piston pump of discharge safety check.

Fig. 4 shows the viewgraph of cross-section of the suction valve of the valve member that comprises the head with spherical form.

Fig. 5 shows the viewgraph of cross-section of another embodiment of the suction valve of the valve member comprise the head with frusto-conical shape.

Embodiment

Pump assembly 100 shown in Fig. 1 to Fig. 3 comprises the reciprocating pump that is connected to drive unit by axle.An embodiment of the application of this pump assembly be for delivery of using in internal-combustion engine as the liquid gas (as LNG) of fuel consumption.Because LNG stores at low temperatures, so the reciprocating pump of showing is positioned at, be called as cold junction 110 position herein, and the drive unit that is positioned at end opposite is called as warm end 112 in this article.Although disclosed pump is to describe with respect to this specifically should being used for, it should be understood that, identical improvement can be used in other pump that the fluid of pumping at the temperature that approaches its boiling point operates and adopt, and the pressure drop in pumping unit is used can cause fluid vaporization time.

Fig. 1 and Fig. 2 show perspective view and the viewgraph of cross-section of pump assembly 100, described pump assembly comprises the warm end drive unit 116 at 112 places, the suction tude 118 at cold junction 110 places, cold junction 110 is connected to extension tubing 114 and the discharge tube 120 of warm end 112, and described discharge tube receives the fluid from the outlet of pumping chamber.Drive unit 116 can be thereby that the U.S. Patent Application No. 7,739 that for example claimant owns together, described in 941 by using hydraulic fluid pressure to produce the hydraulic driving machine that to-and-fro motion causes that driven plunger 127 moves in drive unit.Driven plunger 127 is connected to pump piston 124 by axle 122.Pump piston 124 moves back and forth and forms dynamic fluid seals with the inwall that defines the pumping cylinder 126 of pumping chamber 128 in pumping cylinder 126.Cold junction 110 is preferably dipped in the fluid being stored in reservoir vessel or storage tank (not shown).During aspirating stroke, when pump piston 124 moves in direction 130, fluid flows out and flows to throughway valve suction port 119 from fluid supply via suction tude 118 in direction 123.The member of cold junction 110 is shown in more detail with the sectional view amplifying in Fig. 3.The withdrawal of pump piston in direction 130 causes that the hydrodynamic pressure in pumping chamber 128 reduces, and this allows the hydrodynamic pressure in valve suction port 119 that suction valve member 144 is mentioned from valve seat 146.In a preferred embodiment, as shown in Figure 3, suction valve member 144 only drives by fluid force, and without any mechanical bias, is different from the expulsion valve member 164 of mechanically being setovered by spring 166, and this will describe below in more detail.For suction valve 140, the advantage of this not biasing means is that to open the resistance that suction valve 140 overcomes less, and this has reduced pressure drop.In addition, be different from known breather check valve, valve member 144 comprises from valve suction port 119 to the valve rod 156 extending at a distance.For high-pressure service pump, need to make to take a breath volume (swept volume) thus maximize and reduce the amount of dead space and improve pump efficiency because can obtain high pressure by reducing not swept volume.Yet for low pressure pump, this problem of less consideration, because larger dead space is acceptable, still realizes required head pressure simultaneously.The advantage of locating in this way the valve rod 156 extending towards pumping chamber 128 is: in valve suction port 119, do not occupy any space, so valve rod 156 do not cause any restriction in whole flow region, and this causes lower pressure drop.During compression stroke, when pump piston 124 moves in direction 132, pressure fluid is discharged via discharging safety check 160Cong pumping chamber 128, through pump discharge 121 and further through discharge tube 120.

Flange 142 defines an end of pumping chamber 128 and is provided for holding suction valve 140 and the main body of discharge safety check 160.Flange 142 further comprises fluid passage, so fluid can flow in pumping chamber 128 and from pumping chamber 128 to discharging safety check 160 by suction valve 140.Flange 142 further comprises the guide surface 154 with the surface engagement of valve rod 156, thus when suction valve member 144 opening and valve seat position between guide the movement of described suction valve member while moving.

Suction valve and expulsion valve can adopt other layout and not depart from the category of claimed equipment.For example, suction valve and expulsion valve can have the independently Fluid Sealing main body that is fixed in flange 142 separately or they can be accommodated in the same enclosure of separating with flange 142.

Consult now some CONSTRUCTED SPECIFICATION of suction valve 140, as shown in Figure 3, the valve member 144 of showing is in its fixed position, is positioned on valve seat 146, thereby prevents that fluid from flowing to the passage 150 being communicated with pumping chamber 128 fluids from valve suction port 119.Valve member 144 comprises head 152, and it is described valve member contacts with valve seat 146 and towards the part of valve import 119.

Fig. 4 and Fig. 5 are the amplification views of two embodiments of valve member, by reference to numeral 144 and 144A indication.These views are shown respectively contribute to form the head 152 of excellent sealing and the feature of 152A in the situation that be there is no mechanical bias.Because the extra sealing load that does not have mechanical device (as spring) to provide, so just the different fluid pressure of valve member 144 and any side of 144A activates it.While using the valve of previously known, between valve member and valve seat, form larger area of contact.As shown in Figure 4 and Figure 5, the position limitation that valve member contacts with valve seat in Fig. 4 by shown in A-B and in Fig. 5 by the linear circumference point of contact shown in C-D.Importantly, these point of contact with define valve import 119 edge and be separated by with wider diameter.This is because more may there is manufacturing deficiency in this edge, and if this edge is used as the valve seat contacting with valve element, this can cause poor sealing so.

The embodiment of showing in Fig. 4, when suction valve 140 cuts out, valve head 152 towards and the valve member side that contacts with valve seat 146 on there is spherical form.Valve seat 146 is surperficial parts of taper.

In the embodiment of showing at Fig. 5, valve member 144A is not spherical form, but there is the head 152A of frusto-conical shape, as the surperficial shape that forms valve seat, exception be that angle [alpha] that the frusto-conical shape of head 152A forms is preferably greater than and forms the angle beta that the surface of valve seat 146 forms.The angle difference of these shapes produces linear circumference point of contact haply between head 152A and valve seat 146.

Pump assembly 100 further comprises discharges safety check 160, in the amplification view of Fig. 3, clearly shows.Discharging safety check 160 allows fluid only in one direction from valve air inlet 162 flow valves outlet ports 121.Discharging safety check 160 is poppet valves, and described poppet valve comprises the valve member 164 that can move between open position and fixed position.Valve member 164 has with the valve member 144 of suction valve 140 similarly constructs.It can comprise the head with spherical or frusto-conical shape on the valve member side contacting with valve seat when valve cuts out.Valve seat has frusto-conical shape, and have in the embodiment of frusto-conical shape at valve head, the angle that the frusto-conical shape of valve head forms is preferably greater than the angle that valve seat forms, so that contacting between valve member and valve seat is linear haply, as described in about suction valve.Yet what discharge safety check 160 was different from suction valve 140 is that it is mechanical bias in closed position.This is because during compression stroke, while producing pressure in pumping chamber 128, it contributes to keep discharging safety check 160 and closes until reach predetermined threshold pressure, and the pressure drop being caused by this extra resistance seldom can cause fluid vaporization, even to being also like this in the situation of the low pressure pump defining in the disclosure.Another of this design permission is characterised in that the size of valve import 162 can be less than the size of the suction port 119 being associated with suction valve 140 for discharging safety check 160.The valve of two same sizes is different from using, and expulsion valve is arranged to reduced size and contributes to for larger suction valve provides more space, is that two valves have reduced and the spatial constraints of using flange 142 and main body to be associated.

Valve member is made by polymer material, for example the polymer based on fluorocarbon, more specifically polychlorotrifluoroethylene.

Discharging safety check 160 works as follows.Valve is conventionally biased member and is biased in its closed position, and described biasing member is preferably the spring 166 that impels valve member 164 to push its fixed position to or the mechanical part of other resilient member form.When pump piston 124 moves the fluid pressurizeing in pumping chamber 128 in direction 132, the fluid of pressurization flow to the import 162 of discharging safety check 160 by passage 150, thereby wherein fluid pressure action is mentioned valve member 164Cong Qi fixed position at the head of valve member 164.At open position, discharge safety check 160 and allow fluid flow to outlet 121 and flowing to discharge tube 120 from described outlet from import 162.

For the claimed feature of disclosed pump assembly is described better, in the drawings, some details relevant with the well known elements that forms described pump are simplified.The real work of pump is arranged and is comprised more structure details.

In preferred embodiments, theme suction valve and discharge safety check valve member are separately made by polymer material, and for example the polymer based on fluorocarbon, is more clearly polychlorotrifluoroethylene.Material property due to polychlorotrifluoroethylene, it is preferred material, and described material property comprises the compatible low thermal coefficient of expansion of the metal parts that connects with its institute's face, it and the compatibility of gas component, its low vapor permeates speed and its sealed nature of coordinating with metal seat valve material.In addition, polychlorotrifluoroethylene is stable at low temperatures material and for other material of cryogenic applications, is therefore preferred relatively.

Although shown and described concrete member of the present utility model, embodiment and application, it should be understood that, the utility model is not limited to described concrete member, embodiment and application, because not departing from the scope of the present disclosure, especially according to the aforementioned instruction in the situation that, those skilled in the art can modify.

Claims (16)

1. a reciprocating piston pump, is characterized in that, it comprises:

Pumping chamber, it is defined by the following: cylinder body, the flange that is placed in the piston in described cylinder body and covers the end relative with described piston of described cylinder body; And

Suction valve, it comprises the valve member with head and valve rod, wherein said head surface extends with the direction towards described piston from described head to the surface and the described valve rod that comprise valve seat, described whereby valve rod does not block and flows through import and enter the fluid in described suction valve, between the closed position that the open position that described valve member can be separated by with described valve seat at described head by fluid force contacts with described valve seat with described head, moves.

2. reciprocating piston pump according to claim 1, is characterized in that, it is the low pressure pump with the head pressure that can reach 600psi.

3. reciprocating piston pump according to claim 1, is characterized in that, the described head that described valve seat has cone-shaped and wherein said valve member has spherical form.

4. reciprocating piston pump according to claim 1, is characterized in that, the described head that described valve seat has cone-shaped and wherein said valve member has cone-shaped.

5. reciprocating piston pump according to claim 4, is characterized in that, the angle that the described cone-shaped of the described head of described valve member forms is greater than the angle of the cone-shaped formation of described valve seat.

6. reciprocating piston pump according to claim 1, is characterized in that, described valve member is made by polymer material.

7. reciprocating piston pump according to claim 6, is characterized in that, described polymer material is the polymer based on fluorocarbon.

8. reciprocating piston pump according to claim 7, is characterized in that, described polymer material is polychlorotrifluoroethylene.

9. reciprocating piston pump according to claim 1, is characterized in that, described import is set up size to avoid the described import of described suction valve and the essence pressure drop of the fluid between outlet.

10. reciprocating piston pump according to claim 1, is characterized in that, the main body of described suction valve comprises guide groove, and described guide groove for guiding the described valve rod of described valve member when described valve member moves between described open position and described closed position.

11. reciprocating piston pumps according to claim 1, it is characterized in that, it further comprises discharge safety check, described discharge safety check allows fluid between import and outlet, to flow in one direction, wherein said discharge safety check is poppet valve, and it comprises main body and the valve member that can move between open position and closed position.

12. reciprocating piston pumps according to claim 11, is characterized in that, described discharge safety check further comprises resilient member, and described resilient member makes the described valve member of described discharge safety check be biased to described closed position.

13. reciprocating piston pumps according to claim 11, it is characterized in that, the described valve member of described discharge safety check comprises the head with spherical form, and described head contacts with the valve seat of described discharge safety check when described valve member is in described closed position.

14. reciprocating piston pumps according to claim 11, is characterized in that, described valve member comprises the head with frusto-conical shape, and described head contacts with the valve seat of described discharge safety check when described valve member is in described closed position.

15. reciprocating piston pumps according to claim 11, is characterized in that, the described valve member of described discharge safety check is made by polymer.

16. according to the reciprocating piston pump described in any one in claim 1 to 15, it is characterized in that, described fluid is LNG Liquefied natural gas.

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