CN218624748U - Anti-air-bound centrifugal methanol unloading pump - Google Patents

Abstract

The utility model belongs to the technical field of liquid unloading, in particular to an air-bound resistant centrifugal methanol unloading pump, which comprises a pump body, wherein the inner space of the pump body is divided into a suction section, a front cavity, a volute, a discharge cavity, a separation cavity, a discharge section and a liquid storage cavity; a front impeller is arranged in the front cavity, and a main impeller is arranged in the volute chamber; the liquid medium containing gas enters the pump body from the suction pipe, sequentially flows through the suction section, the front cavity, the volute chamber and the discharge section, one part of the liquid medium is discharged from the discharge pipe, the other part of the liquid medium is diffused in the discharge cavity, at the moment, part of the gas escapes, the rest of the gas returns to the separation cavity and the liquid storage cavity along with the liquid medium which does not enter the discharge pipe, and the liquid medium enters the volute chamber from the liquid storage cavity through the backflow port to be subjected to next cycle gas escape. The utility model has the characteristics of high anti gas ties up ability, high-effect and area are little etc, guarantee that jar (groove) car interior medium does not have to remain, the uninstallation thoroughly completely.

Description

Anti-gas-bound centrifugal methanol unloading pump

Technical Field

The utility model belongs to the technical field of the liquid is unloaded, concretely relates to centrifugal methyl alcohol pump of unloading is tied up to anti gas for the strong volatility light hydrocarbon liquid of uninstallation.

Background

China is a large country for importing, producing and consuming petroleum products, particularly methanol products, and transportation and unloading are inevitable in the process of each stage. With the development of national economy, the transport and discharge capacity will be larger and larger. The unloading is to transfer oil and hydrocarbon products transported by train, ship or automobile to a storage tank, and the process is completed by pump products. The pump products for completing unloading are divided into displacement pumps: sliding vane pumps (vane pumps), gear pumps, oscillating rotor pumps; centrifugal pump: ordinary centrifugal pump, ordinary self priming pump, unload self priming pump. The centrifugal pump makes the conveyed medium obtain kinetic energy under the action of centrifugal force, thereby completing unloading.

In order to prevent the liquid from overflowing from the suction pipe of the pump after unloading, which causes unsafe hidden trouble, the standard provides that a crane pipe is arranged on the suction pipe of the unloading pump, namely a U-shaped pipe is designed on the suction pipe, and the suction pipe is filled with gas due to the existence of the U-shaped pipe, so that the gas enters the pump to form a gas-bound phenomenon. The centrifugal pump is not filled with the conveyed liquid before starting, or air seeps into the pump in the running process, because the density of gas is less than that of the liquid, the generated centrifugal force is small, the air cannot be thrown out, the fluid in the pump shell generates negative pressure along with the centrifugal motion of the motor, the negative pressure is not enough to suck the liquid into the pump shell, and the pump loses self-suction capability and cannot convey the liquid like being bound by the gas, which is called as the air-bound phenomenon of the centrifugal pump. With the increasing amount of unloaded low-density media, the problem that the media in the vehicle cannot be completely unloaded is more and more prominent.

Disclosure of Invention

To the problem that exists among the prior art, the utility model provides a centrifugal methyl alcohol pump of unloading is tied up to anti gas has high anti gas and ties up characteristics such as ability, high-effect and area are little, guarantees that jar (groove) car interior medium does not have to remain, the uninstallation thoroughly completely.

In order to achieve the above object, the utility model adopts the following technical scheme:

the utility model provides an anti-air-bound centrifugal methanol unloading pump, which comprises a pump body, wherein the inner space of the pump body is divided into a suction section, a front cavity, a volute, a discharge cavity, a separation cavity, a discharge section and a liquid storage cavity; the front cavity is internally provided with a front impeller, the volute is internally provided with a main impeller, the front impeller and the main impeller are fixed on a main transmission shaft, and the main transmission shaft penetrates out of the rear end of the pump body; the inlet of the suction section is fixedly connected with a suction pipe, the outlet of the discharge chamber is fixedly connected with a discharge pipe, and a liquid injection port is arranged in the discharge pipe; the liquid medium containing gas enters the pump body from the suction pipe, sequentially flows through the suction section, the front cavity, the volute chamber and the discharge section, one part of the liquid medium is discharged from the discharge pipe, the other part of the liquid medium is diffused in the discharge cavity, part of the gas escapes at the moment, the rest of the gas returns to the separation cavity and the liquid storage cavity along with the liquid medium which does not enter the discharge pipe, and the liquid medium enters the volute chamber from the liquid storage cavity through the return port to be subjected to next cycle gas removal.

Further, the pump body includes pump casing and pump cover, the pump cover passes through the bolt and the nut is fixed at the rear end of pump casing, the pump body sealed pad has been placed between pump cover and the pump casing.

Furthermore, the center of the rear end of the pump cover is fixedly connected with a mechanical seal through a bolt and a nut; and a shaft sleeve fixed on the main transmission shaft is arranged at the central hole of the mechanical seal, and the main transmission shaft penetrates through the shaft sleeve of the mechanical seal and extends into the pump shell.

Furthermore, the rear end of the pump cover is fixedly connected with a suspension assembly, and the suspension assembly is used for supporting the main transmission shaft.

Furthermore, the rear end face of the main impeller leans against the front end face of a shaft sleeve of the mechanical seal, an impeller sealing gasket is arranged between the main impeller and the shaft sleeve of the mechanical seal, and the rear end face of the front impeller is attached to the front end face of the main impeller.

Furtherly, still press cap and impeller bolt including the impeller, the impeller is pressed the cap laminating and is being put at the preceding terminal surface of leading impeller, the sealing washer has been placed between impeller pressure cap and the leading impeller, the impeller bolt passes the impeller and presses the cap to fix the preceding terminal surface at final drive shaft.

The main impeller dynamic seal device further comprises a pump body port ring and a separating valve plate, wherein the pump body port ring is installed at the rear part of a front cavity of the pump shell, and the pump body port ring and the excircle of the front end part of the main impeller form a main impeller dynamic seal; the separating valve plate is fixed at the outlet of the volute chamber and the inlet of the discharge section.

The pump further comprises a front impeller sleeve, the front impeller sleeve is mounted at the front part of a front cavity of the pump shell, and the front impeller sleeve and the outer circle of the front impeller form a front impeller dynamic seal.

Further, the front impeller adopts an axial flow impeller; the number of blades at the outlet part of the main impeller is twice that of the blades at the inlet part; the number of the blades of the front impeller is the same as that of the blades of the inlet part of the main impeller.

Furthermore, the preposed impeller and the main impeller are made of duplex stainless steel or ultra-low carbon duplex stainless steel.

Compared with the prior art, the utility model has the advantages of it is following:

when the unloaded liquid medium contains gas, the liquid medium enters the pump body from the suction pipe and sequentially flows through the suction section, the front cavity, the volute and the discharge section, a part of the liquid medium is directly discharged from the discharge pipe, the other part of the liquid medium is diffused in the discharge cavity, part of the gas escapes at the moment, the rest of the gas returns to the separation cavity and the liquid storage cavity along with the liquid medium which does not enter the discharge pipe, and the liquid medium enters the volute from the liquid storage cavity through the backflow port to obtain kinetic energy to be subjected to next cycle gas separation; until the gas in the pipeline is completely discharged. The utility model discloses an air-tie phenomenon can be overcome to the pump of unloading, can not be because of gaseous piling up influence pump in the pump from the ability of inhaling and unable transport liquid, is convenient for like this unload the medium in the tank car totally, avoids because the uninstallation is unclean for the economic loss that the user caused, has avoided the non-empty car of tank car to return the fuel loss that causes and has increased, has avoided the surplus medium to volatilize in the tank car and has caused the pollution, harm passerby health to the road along the way. Moreover, the suction section, the front chamber, the volute chamber, the discharge chamber, the separation chamber, the discharge section and the liquid storage chamber are combined together, so that the size of the pump is reduced, and the installation floor area is reduced.

Drawings

FIG. 1 is a front longitudinal cross-sectional view of an anti-air-lock centrifugal methanol unloading pump according to an embodiment of the present invention;

FIG. 2 is a side longitudinal cross-sectional view of a gas-lock resistant centrifugal methanol dump pump of an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a front impeller according to an embodiment of the present invention;

fig. 4 is an elevation view of a main impeller of an embodiment of the present invention;

fig. 5 is a side view of a main impeller of an embodiment of the present invention.

The reference numbers in the figures denote:

1. the centrifugal pump comprises a suction section, a front chamber, a volute chamber, a discharge chamber, a separation chamber, a discharge section, a liquid storage chamber, a pump body, a pump cover, a pump body sealing gasket, a mechanical seal, a suspension assembly, a pump sealing gasket, an impeller pressing cap, an impeller bolt, a sealing ring, a pump body opening ring, a separation impeller sleeve, a separation valve plate, a transmission key and a backflow opening, wherein the suction section comprises a suction section, the discharge section comprises a discharge section, a liquid storage chamber 7, a front impeller 8, a main impeller 9, a main transmission shaft 10, a suction pipe 11, a discharge pipe 12, a liquid injection opening 13, a pump body 14, a pump cover 15, a pump body sealing gasket 16, a mechanical seal, a suspension assembly 18, a suspension assembly 19, an impeller sealing gasket, an impeller pressing cap 20, an impeller bolt, a sealing ring 22, a pump body opening ring 23, a pump body opening ring 24, a front impeller sleeve, a separation valve plate 25, a transmission key and a backflow opening.

Detailed Description

In order to make the technical solutions in the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments.

As shown in fig. 1 and 2, the anti-air-lock centrifugal methanol unloading pump of the present embodiment includes a pump body, an inner space of which is divided into a suction section 1, a front chamber 2, a volute 3, a discharge chamber 4, a separation chamber 5, a discharge section 6 and a liquid storage chamber 7; the front cavity 2 is internally provided with a front impeller 8, the volute 3 is internally provided with a main impeller 9, the front impeller 8 and the main impeller 9 are fixed on a main transmission shaft 10 through a transmission key 26, the main transmission shaft 10 penetrates out from the rear end of the pump body, and the main transmission shaft 10 drives the front impeller 8 and the main impeller 9 to rotate so as to realize the work of the pump and finish unloading. The pump body includes pump casing 14 and pump cover 15, and pump cover 15 passes through the bolt and the nut is fixed at pump casing 14's rear end portion, and the coincidence of the horizontal central line of the two places pump body sealed pad 16 between pump cover 15 and pump casing 14. The suction pipe 11 is fixed on a flange at the inlet of the suction section 1 at the front part of the pump body through bolts, and the inlet of the suction section 1 is positioned at the horizontal position of the front end part of the pump shell 14 and is higher than the horizontal central line of the pump shell 14. The discharge pipe 12 is bolted to an outlet flange of the discharge chamber 4 at a central position on top of the pump housing 14. The discharge pipe 12 is provided with an injection port 13 for injecting a liquid medium into the pump body. The liquid medium containing gas enters the pump body from the suction pipe 11 and flows through the suction section 1, the front cavity 2, the volute 3 and the discharge section 6 in sequence, one part of the liquid medium is discharged from the discharge pipe 12, the other part of the liquid medium is diffused in the discharge cavity 4, part of gas escapes at the moment, the rest of gas returns to the separation cavity 5 and the liquid storage cavity 7 along with the liquid medium which does not enter the discharge pipe 12, and the liquid medium enters the volute 3 from the liquid storage cavity 7 through the return opening 27 to be subjected to next circulation gas removal.

The center of the rear end of the pump cover 15 is fixedly connected with a mechanical seal 17 through bolts and nuts; the central hole of the mechanical seal 17 is provided with a shaft sleeve fixed on the main transmission shaft 10, and the main transmission shaft 10 penetrates through the shaft sleeve of the mechanical seal 17 and extends into the pump housing 14. The rear end of the pump cover 15 is fixedly connected with a suspension assembly 18, and the suspension assembly 18 is used for supporting the main transmission shaft 10. The back end face of the main impeller 9 leans against the front end face of the shaft sleeve of the mechanical seal 17, an impeller sealing gasket 19 is arranged between the main impeller 9 and the shaft sleeve of the mechanical seal 17, and the back end face of the front impeller 8 is tightly attached to the front end face of the main impeller 9. An impeller pressing cap 20 is attached to the front end face of the front impeller 8, a sealing ring 22 is arranged between the impeller pressing cap 20 and the front impeller 8, and an impeller bolt 21 penetrates through the impeller pressing cap 20 and is fixed to the front end face of the main transmission shaft 10.

A pump body opening ring 23 is arranged at the rear part of the front cavity 2 of the pump shell 14, the pump body opening ring 23 and the excircle of the front end part of the main impeller 9 form a main impeller dynamic seal, so that internal leakage is reduced, liquid is reduced to return to the main impeller 9, and the efficiency of the pump is improved. The front part of the front cavity 2 of the pump shell 14 is provided with a front impeller sleeve 24, the front impeller sleeve 24 and the outer circle of the front impeller 8 form a front impeller dynamic seal, so that internal leakage is reduced, gas diffusion and overflow are inhibited, a conveyed medium can smoothly enter an inlet of the main impeller 9, kinetic energy provided by the main impeller 9 is obtained again, and unloading is finished.

The separating valve plate 25 is fixed at the outlet of the volute 3 and the inlet of the discharge section 6, and has the function of preventing the liquid medium from circulating in the volute 3 along the outer circumference of the main impeller 9, so that the medium enters the discharge section 6, and the phenomenon that the volute 3 is blocked by the expansion of gas in the volute 3 is avoided.

Preferably, as shown in fig. 3, the front impeller 8 adopts an axial-flow impeller with high blade density, large wrap angle, low inlet flow angle and small outlet angle, so that the medium obtains kinetic energy before entering the main impeller 9, the main impeller 9 is prevented from cavitation erosion, and meanwhile, the overflow of gas when entering the main impeller 9 is inhibited, and the channel of the main impeller 9 is blocked, so that the medium cannot be sucked; the pump lift can also be increased. As shown in fig. 4 and 5, the main impeller 9 is a special-shaped impeller with a large blade wrap angle, in which the number of blades at the inlet portion is small and the number of blades at the outlet portion is large, and the number of blades at the outlet portion of the main impeller 9 is twice the number of blades at the inlet portion; the few inlet part blades are used for increasing the inlet area and improving the effective cavitation allowance of the pump, and the increased outlet part blades are used for inhibiting the diffusion of a medium, reducing the overflow of gas, reducing the diffusion loss and improving the efficiency of the pump. In order to improve the cavitation erosion resistance of the pump, the number of blades of the front impeller 8 is designed to be the same as that of the inlet part of the main impeller 9, and the axial distance L1=38mm between the outlet side of the blades of the front impeller 8 and the inlet side of the blades of the main impeller 9.

Preferably, the material of the front impeller 8 and the main impeller 9 is a known metal material with excellent cavitation erosion resistance: the duplex stainless steel or the ultra-low carbon duplex stainless steel improves the cavitation erosion resistance of the impeller, reduces the damage of the cavitation erosion to the impeller and prolongs the service life of the pump.

The working principle is as follows:

in the initial stage of unloading for the first time, liquid with the same component as the unloaded medium needs to be filled through the liquid filling port 13, and the filled medium fills the suction section 1, the front cavity 2, the volute 3, the liquid storage cavity 7, the separation cavity 5 and the discharge section 6 of the pump shell 14 through the return port 27; when the main transmission shaft 10 is driven by the power mechanism to rotate, a medium in the pump shell 14 is driven by the front impeller 8 and the main impeller 9 to be discharged to the discharge pipe 12, vacuum is formed in the pump shell 14, the medium of a connecting pipeline between the suction pipe 11 of the pump and the discharge port at the bottom of the tank car and the gas in the pipeline enter the front cavity 2, the volute 3 and the discharge section 6 together, due to the existence of the gas, the medium only partially enters the discharge pipe 12, the other part diffuses in the discharge cavity 4, at this time, part of the gas escapes, the rest of the gas returns to the separation cavity 5 and the liquid storage cavity 7 along with the medium which does not enter the discharge pipe 12, and the medium enters the volute 3 from the liquid storage cavity 7 through the return port 27 to obtain kinetic energy to perform next cycle gas extraction; the escaping gas collects in the outlet chamber 4, and the medium discharged by the discharge section 6 is carried into the discharge pipe 12 and conveyed to the storage tank. And (3) until the gas in the pipeline is completely discharged, the pump enters a normal unloading program, the gas enters the pump body along with the medium in the later stage of unloading, and the steps are repeated to complete the whole unloading, so that the medium in the tank car is completely sucked.

Unless defined otherwise, technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The use of the terms "a" or "an" and "the" and similar referents in the description and the claims of the application do not necessarily denote a limitation of quantity. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Finally, it is to be noted that: the above description is only the preferred embodiment of the present invention, which is only used to illustrate the technical solution of the present invention, and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. An anti-air-bound centrifugal methanol unloading pump is characterized by comprising a pump body, wherein the inner space of the pump body is divided into a suction section, a front cavity, a volute, a discharge cavity, a separation cavity, a discharge section and a liquid storage cavity; a front impeller is arranged in the front cavity, a main impeller is arranged in the volute, the front impeller and the main impeller are fixed on a main transmission shaft, and the main transmission shaft penetrates out of the rear end of the pump body; the inlet of the suction section is fixedly connected with a suction pipe, the outlet of the discharge chamber is fixedly connected with a discharge pipe, and a liquid injection port is arranged in the discharge pipe; the liquid medium containing gas enters the pump body from the suction pipe, sequentially flows through the suction section, the front cavity, the volute chamber and the discharge section, one part of the liquid medium is discharged from the discharge pipe, the other part of the liquid medium is diffused in the discharge cavity, at the moment, part of the gas escapes, the rest of the gas returns to the separation cavity and the liquid storage cavity along with the liquid medium which does not enter the discharge pipe, and the liquid medium enters the volute chamber from the liquid storage cavity through the backflow port to be subjected to next cycle gas escape.

2. The air-lock resistant centrifugal methanol unloading pump of claim 1, wherein the pump body comprises a pump housing and a pump cover, the pump cover is fixed at the rear end part of the pump housing by bolts and nuts, and a pump body sealing gasket is placed between the pump cover and the pump housing.

3. The air-lock resistant centrifugal methanol unloading pump of claim 2, wherein the center of the rear end of the pump cover is fixedly connected with a mechanical seal through a bolt and a nut; and a shaft sleeve fixed on a main transmission shaft is arranged at the central hole of the mechanical seal, and the main transmission shaft penetrates through the shaft sleeve of the mechanical seal and extends into the pump shell.

4. The air-lock resistant centrifugal methanol unloading pump of claim 2, wherein the rear end of the pump cover is fixedly connected with a suspension assembly, and the suspension assembly is used for supporting the main transmission shaft.

5. The air-bound resistant centrifugal methanol dump pump of claim 3 wherein the back end face of the main impeller is against the front end face of the mechanical seal shaft housing, an impeller seal is placed between the main impeller and the mechanical seal shaft housing, and the back end face of the front impeller is in close proximity to the front end face of the main impeller.

6. The air-bound resistant centrifugal methanol dump pump of claim 1, further comprising an impeller pressure cap and an impeller bolt, wherein the impeller pressure cap is attached to the front end face of the front impeller, a seal ring is placed between the impeller pressure cap and the front impeller, and the impeller bolt penetrates through the impeller pressure cap and is fixed to the front end face of the main transmission shaft.

7. The air-lock resistant centrifugal methanol unloading pump of claim 2, further comprising a pump body port ring and a separation valve plate, wherein the pump body port ring is installed at the rear part of the front cavity of the pump housing, and the pump body port ring and the excircle of the front end part of the main impeller form a dynamic seal of the main impeller; the separating valve plate is fixed at the outlet of the volute chamber and the inlet of the discharge section.

8. The air-lock resistant centrifugal methanol dump pump of claim 2, further comprising a forward impeller sleeve mounted in front of the forward chamber of the pump housing, the forward impeller sleeve forming a forward impeller dynamic seal with an outer circumference of the forward impeller.

9. The air-lock resistant centrifugal methanol dump pump of claim 1 wherein the forward impeller is an axial flow impeller; the number of blades at the outlet part of the main impeller is twice that of the blades at the inlet part; the number of the blades of the front impeller is the same as that of the blades of the inlet part of the main impeller.

10. The air-lock resistant centrifugal methanol dump pump of claim 9, wherein the pre-impeller and the main impeller are made of duplex stainless steel or ultra-low carbon duplex stainless steel.

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