CN117185240A - Extraction gun and extraction system comprising same - Google Patents

Abstract

The application relates to an extraction gun and an extraction system comprising the extraction gun. The extraction gun comprises: a gun rod assembly (1); a valve seat (21) arranged at the lower end of the gun rod assembly (1), a bottom valve (22) matched with the valve seat, and a valve rod (23) connected to the bottom valve (22); and an actuator (3) disposed on the gun rod assembly, wherein an upper end of the valve stem is coupled to the actuator (3), the actuator (3) driving the base valve via the valve stem to transition between three positions relative to the valve seat: a sealing position; an extraction position in which the bottom valve (22) is located above the valve seat (21) and spaced apart from the valve seat (21); and a spray position wherein the base valve is positioned below the valve seat and spaced from the valve seat (21). The application integrates the sealing, extraction and spraying functions into a single-layer gun rod assembly, thereby greatly improving the integration level, extraction precision, extraction efficiency and cleaning effect of the extraction system.

Description

Extraction gun and extraction system comprising same

Technical Field

The application relates to an extraction system for pumping fluid materials in the production of fluid materials in the industries of chemical engineering, food and the like, in particular to an extraction gun used in the extraction system.

Background

Extraction systems for pumping fluid materials are commonly used in the production of fluid materials in the chemical, food and other industries. For example, in the blending production of lubricating oils in the petrochemical field, the addition of bulk additives in large quantities is required to formulate lubricating oils that are adapted to the lubrication requirements of different equipment or vehicles, and therefore additive extraction systems exist in the prior art. In these fluid material extraction systems, an extraction gun is often used, which is connected to an extraction pump to extract the fluid material from the vat under the drive of the extraction pump, after which the fluid material is conveyed, for example, via a pipeline to a mixing tank or the like.

The existing extraction gun is generally not provided with a bottom valve, so the lower end of the extraction gun has no sealing function. The extraction gun cannot realize timely closing and sealing of the extraction gun when the extraction quantity is extracted, so that the extraction precision is poor. Nor does it perform the function of cleaning a container, such as a tub, containing fluid material.

In the prior art, although some extraction guns of DDU extraction systems can realize sealing and cleaning spraying functions, the extraction gun needs to be made into a sandwich structure, namely, the wall of the extraction gun comprises an inner wall and an outer wall, a spraying channel is defined between the inner wall and the outer wall, spraying holes are formed in the outer wall, and an inner material channel for extracting fluid materials is defined by the inner wall. The cleaning liquid is conveyed via the spray channel and sprayed through the spray holes onto the wall of the tub being cleaned. Because the external diameter of the extraction gun is limited by the size of the barrel mouth, the internal diameter of the internal material channel is greatly reduced by the extraction gun with the interlayer, so that the material extraction efficiency is lower, the extraction effect is poor, and the high-viscosity material can not be extracted from the barrel in a short time, which is the biggest pain point of the additive extraction system and the technical problem which is difficult to overcome.

Disclosure of Invention

The present application is directed to solving at least one of the problems discussed above and/or other disadvantages of the prior art.

To this end, the present application provides an exemplary extractor gun comprising a gun stem assembly, a valve seat disposed at a lower end of the gun stem assembly, a base valve mated with the valve seat, a valve stem coupled to the base valve, and a driver disposed on the gun stem assembly; wherein an interior passage is defined within the gun rod assembly, an upper end of the valve stem is coupled to the driver and moves within the interior passage upon actuation of the driver, wherein the driver actuates the base valve via the valve stem to transition it relative to the valve seat between three positions: a sealing position in which the base valve engages and seals against the valve seat; an extraction position wherein the bottom valve is positioned above and spaced apart from the valve seat; and a spray position wherein the base valve is positioned below and spaced apart from the valve seat.

In this example, an internal passageway is provided in the gun stem assembly that allows the valve stem to move therein, and an actuator is provided to actuate the valve stem to shift the base valve between three positions relative to the valve seat so that the extractor gun seals, extracts and sprays in three conditions. The spray can be realized without an interlayer, so that the inner diameter of an inner channel of the gun rod is maximized, the extraction efficiency of an extraction system is greatly improved, the production time is shortened, the maximized inner channel can meet the suction requirement of high-viscosity materials, the applicable material range is wider, and the extraction efficiency of the high-viscosity materials is integrally improved; further, the spraying function of the extraction gun can clean the sticky liquid attached to a container such as a barrel, so that the residual waste of materials in the barrel is reduced to the minimum, the waste of expensive materials and the pollution to the environment are reduced, the cost of washing the barrel by a user and the risk of cross contamination between materials are reduced, and the waste of a cleaning procedure and cleaning liquid is reduced; the sealing function enables the bottom valve to be closed in time, and the requirement of extraction precision is met. And the sealing, extraction and spraying functions are integrated in a single-layer gun rod assembly, so that the integration level, the automation degree, the extraction precision, the extraction efficiency and the cleaning effect of the extraction system are greatly improved.

According to one example of the application, a driver includes a first piston disposed within a housing of the driver and a first piston rod connected to the first piston, wherein the first piston rod is coupled to a valve stem, the first piston is actuatable downward to drive a base valve to a spray position, and is actuatable upward to drive the base valve to an extraction position.

In this example, the valve rod is connected with the piston rod to drive the bottom valve to reach the lower part of the valve seat so as to realize spraying, and the spraying and extraction functions are realized by a simple structure.

According to one example of the application, the driver further comprises a second piston arranged in the housing above the first piston and a second piston rod connected to the second piston, wherein an upper end of the first piston rod and a lower end of the second piston rod are capable of abutting and separating, wherein the second piston is capable of being actuated downwards to drive the foot valve to the sealing position via the second piston rod abutting the first piston rod.

In this example, by further providing the second piston and driving the bottom valve by the cooperation of the second piston rod and the first piston rod to achieve sealing, the integration of the shower function, the extraction function, and the sealing function is achieved at the same time with a simple structure.

According to one example of the application, the driver further comprises a first block-shaped body fixed in the housing of the driver between the first piston and the second piston and limiting the first piston and the second piston, wherein the first block-shaped body has a first central hole formed therein for the second piston rod to sealingly slide therein; the driver further comprises a second block-shaped body fixed in the housing of the driver at the lower side of the first piston, wherein a second central hole in which the first piston rod sealingly slides is formed in the second block-shaped body.

In the structure of this example, the piston function is realized in a simple structure by providing the first block-shaped body and the second block-shaped body to limit the positions of the first piston and the second piston.

According to one example of the application, a first port is formed in the housing, the first port being in fluid communication with a first piston chamber located between the first piston and the first block, a second port is in fluid communication with a second piston chamber located between the first piston and the second block, and a third port is in fluid communication with a third piston chamber above the second piston.

According to one example of the present application, the extraction gun further includes a solenoid valve for controlling the flow of fluid into and out of the first port, the second port, and the third port.

According to one example of the application, the solenoid valve comprises a two-position five-way double electrically controlled solenoid valve, wherein when the two-position five-way double electrically controlled solenoid valve is located at the position A communicated with the third port, the second piston is driven downwards until abutting against the first block-shaped body, and the second piston rod abuts against the first piston rod to drive the bottom valve to a sealing position; and when the two-position five-way double-electric control electromagnetic valve is positioned at the position B communicated with the first port, the first piston is driven downwards until the first piston abuts against the second block-shaped body, the first piston rod is separated from the second piston rod, and the bottom valve is driven to reach the spraying position.

According to an example of the application, the solenoid valve further comprises a two-position three-way single-electric-control solenoid valve, and when the two-position three-way single-electric-control solenoid valve is located at a position communicated with the second port, the first piston is driven upwards until the first piston abuts against the first block body, and at the moment, the first piston rod drives the bottom valve to reach the extraction position.

According to one example of the application, the driver further comprises a first return spring disposed between the first piston and the second block.

According to an example of the application, the driver further comprises a third block fixed in the housing of the driver above the second piston and a second return spring arranged between the third block and the second piston.

According to one example of the present application, the driver further comprises an adjusting nut assembly provided at an upper end of the housing of the driver, wherein the adjusting nut assembly is coupled to the second piston rod for adjusting the position of the foot valve. This allows the bottom valve to be adjusted to a proper position relative to the valve seat even in the presence of manufacturing or assembly errors.

According to another aspect of the present application, there is provided an extraction system comprising the extraction gun of each of the examples described above.

The extraction gun and extraction system according to examples of the application have at least one of the following benefits: the sealing, extracting and spraying functions are integrated in a single-layer gun rod assembly, so that the integration level, the precision and the efficiency of the extracting gun are greatly improved; the size of the internal channel of the gun rod assembly is maximized, so that the extraction speed and the extraction efficiency are greatly improved, and the extraction time is shortened; the suction requirement of high-viscosity materials is met, and the applicable material range is wider; the cleaning of the viscous liquid which is remained in the barrel and clings to the wall can be realized, the residual waste of materials in the barrel is reduced to the greatest extent, the residual quantity is controlled to the lowest, the waste of expensive materials and the pollution to the environment are reduced, the cost of washing the barrel by a user and the risk of cross contamination between materials are reduced, and the waste of cleaning procedures and cleaning liquid is reduced; the whole extraction system is simple to operate, high in automation degree and capable of improving the working efficiency and the productivity; the cross contamination is avoided, and the quality reliability of the product is ensured; the leakage is avoided, the material loss is reduced, the site is clean, and the potential safety hazard is avoided.

Drawings

The above and other features and advantages of the present application will become apparent from the following detailed description provided with reference to the accompanying drawings. It is to be understood that the following drawings are merely schematic and are not necessarily drawn to scale, and are not to be construed as limiting the application, in which:

FIGS. 1a, 1b and 1c show schematic cross-sectional views of an extraction gun in a sealing position, an extraction position and a spraying position, respectively, according to an exemplary embodiment of the application; and

fig. 2a, 2b and 2c schematically show the valve seat and the base valve in the sealing position, the extraction position and the spraying position, respectively.

Detailed Description

Embodiments of the present application are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding and enabling description of the application to one skilled in the art. It will be apparent, however, to one skilled in the art that the present application may be practiced without some of these specific details. Furthermore, it should be understood that the application is not limited to specific described embodiments. Rather, any combination of the features and elements described below is contemplated to implement the application, whether or not they relate to different exemplary embodiments. Thus, the following aspects, features, embodiments and advantages are merely illustrative and should not be considered elements or limitations of the claims except where explicitly set out in a claim.

It should be noted that, the positional relationship indicated by the terms of upper, lower, etc. mentioned in the present application are positional relationships based on those shown in the drawings, which are merely for convenience in describing the embodiments of the present application and simplifying the description, and are not indicative or implying that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present application. Moreover, these orientations or positional relationships are merely relative concepts in three-dimensional space, and can be changed according to different positions and different use states of the extractor gun. These and other directional terms should not be construed as limiting terms.

It should be noted that, in the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "connected" and "connected" should be interpreted broadly, and may be, for example, a fixed connection, such as welding, etc., or a detachable connection, such as a screw connection, a clamping connection, etc.; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific circumstances. It should also be noted that "coupled" herein refers to various ways of connecting different components together to allow them to be coupled together, including ways in which two components are indirectly connected together through other intermediate components, as well as ways in which two components are directly connected together.

Furthermore, terms such as "first," "second," and the like, are used herein to describe elements of the present application, and are merely used to distinguish between the elements and are not intended to limit the nature, sequence, order, or number of such elements.

Referring to fig. 1a, 1b and 1c, an extraction gun according to an exemplary embodiment of the application is shown. The extractor gun comprises a gun bar assembly 1 at the lower side in fig. 1a, 1b and 1c, the gun bar assembly 1 being hollow, defining an internal passage 11 inside. The gun bar assembly 1, as shown in fig. 1a, 1b and 1c, includes a connection 12 that is connected to an extraction pump (not shown) to pump fluid material (e.g., additives) from a container (e.g., a barrel) through an internal passage 11 or to pump fluid (e.g., a cleaning agent) into the container through the internal passage 11. The extraction gun also comprises a valve seat 21 arranged at the lower end of the gun rod assembly 1, a bottom valve 22 matched with the valve seat and a valve rod 23 connected with the bottom valve 22; the extractor gun further comprises an actuator 3 arranged at the upper end of the gun rod assembly 1, wherein the upper end of the valve rod 23 is coupled to the actuator 3 and is capable of being reciprocally moved up and down in the interior channel 11 under the drive of the actuator 3, wherein the actuator 3 via the valve rod 23 drives the bottom valve 22 to switch it relative to the valve seat 21 between the sealing position, the extracting position and the spraying position shown in fig. 2a, 2b and 2 c. In the sealing position shown in fig. 1a, 2a, the bottom valve 22 engages and seals against the valve seat 21, thus preventing fluid material from returning from the extractor gun to the container, or from entering the extractor gun from the container. In the extraction position shown in fig. 1b, 2b, the foot valve 22 is positioned above the valve seat 21 and spaced from the valve seat 21, and fluid material is pumped from the container into the extraction gun via the gap between the foot valve 22 and the valve seat 21 by the extraction pump in communication with the extraction gun. In the spray position as shown in fig. 1c, 2c, the bottom valve 22 is located below the valve seat 21 and spaced from the valve seat 21. Fluid, such as cleaning agent, is injected into the vessel from the internal passage 11 of the extractor gun via the gap between the bottom valve 22 and the valve seat 21 to effect spray cleaning of the inner wall of the vessel.

As shown in fig. 1a, 1b and 1c, the driver 3 comprises a first piston 31 arranged in a housing 30 of the driver 3 and a first piston rod 39 connected to the first piston 31, wherein the first piston rod 39 is coupled to the valve stem 23, for example by means of a coupling. The driver 3 further includes a second piston 32 provided in the housing 30 at an upper side of the first piston 31, and a second piston rod 321 connected to the second piston 32, wherein a lower end of the second piston rod 321 is capable of abutting and separating from an upper end of the first piston rod 39. The driver further comprises a first block 34, a second block 35 and a third block 33 fixed to the housing 30 of the driver. The first block 34 is located between the first piston 31 and the second piston 32, and is capable of limiting the first piston 31 and the second piston 32, wherein a first center hole in which the second piston rod 321 sealingly slides is formed in the first block 34. A second block 35 is fixed to the housing 30 of the driver at the lower side of the first piston 31, the second block 35 having a second central hole formed therein for the first piston rod 39 to sealingly slide therein. The third block 33 is fixed to the housing 30 of the driver at the upper side of the second piston 32, and has a third center hole formed therein for the connecting rod 331 to sealingly slide therein. A three-stage extractor gun driver is formed by three blocks 33, 34 and 35. And, the connecting rod 331 is connected at a lower end to the second piston 32 and at an upper end to the adjusting nut assembly 5. The adjusting nut assembly 5 is coupled to the second piston rod 321 so that the position of the base valve 22 can be adjusted by the adjusting nut assembly 5, which enables the position of the base valve 22 corresponding to the valve seat 21 to be adjusted even in the case where there is a manufacturing or assembling error.

As shown in fig. 1a, 1b and 1c, the actuator further comprises a first return spring 37 arranged between the first piston 31 and the second block 35 and a second return spring 36 arranged between the third block 33 and the second piston 32. Formed on the housing 30 are a first port P1, a second port P2, and a third port P3, the first port P1 being in fluid communication with a first piston chamber 311 between the first piston 31 and the first block 34, the second port P2 being in fluid communication with a second piston chamber 312 between the first piston 31 and the second block 35, and the third port P3 being in fluid communication with a third piston chamber 322 between an upper side of the second piston 32 and the third block 33.

The extractor gun further comprises solenoid valves to control the flow of working fluid (e.g. pressurized air) into and out of the first port P1, the second port P2 and the third port P3, thereby effecting control over the position of the valve stem 23 and the base valve 22. Those skilled in the art understand that the solenoid valve used in the present application may be a gas circuit solenoid valve or a liquid circuit solenoid valve, and the type and number of solenoid valves used are not limited to the two-position five-way double-electric control solenoid valve 6 and the two-position three-way single-electric control solenoid valve 7 shown in fig. 1a, 1b and 1c, as long as control over each port and working fluid can be achieved. Illustratively, in fig. 1a and 1c it is shown that the extractor gun comprises a two-position five-way double electronically controlled solenoid valve 6, wherein when the two-position five-way double electronically controlled solenoid valve 6 is in position a in communication with the third port P3, gaseous medium enters the upper side of the second piston 32 through the third port P3, the second piston 32 is driven downwards until it abuts against the first block 34, the second piston rod 321 abuts against the first piston rod 39 driving the valve stem 23 and the bottom valve 22 into a sealing position; and when the two-position five-way double-electric control electromagnetic valve is positioned at the position B communicated with the first port P1, the first piston 31 is driven downwards until the first piston 31 abuts against the second block-shaped body 35, in the process, the first piston 31 drives the first piston rod 39 to be separated from the second piston rod 321, and the first piston rod 39 drives the bottom valve 22 to reach the spraying position. The extraction gun further comprises a two-position three-way single-electric-control electromagnetic valve 7, when the two-position three-way single-electric-control electromagnetic valve is positioned at a position communicated with the second port P2, the first piston 31 is driven upwards until the first piston abuts against the first block 34, and at the moment, the first piston rod 39 drives the bottom valve 22 to move upwards to reach an extraction position.

The operation of the extractor gun of the present application will now be described with reference to figures 1a, 1b and 1c and 2a-2 c.

The end of the extractor gun, in the example of figures 1a, 1b and 1c, is the lower end of the gun stem assembly 1, including the valve seat 21 and bottom valve 22, submerged below the level of the fluid material to be pumped in the vessel. When the extraction gun needs to perform extraction operation, the two-position three-way single-electric control electromagnetic valve 7 is actuated to a position communicated with the second port P2, gas enters the second piston cavity 312 between the first piston 31 and the second block body 35 through the second port P2, the first piston 31 is driven upwards until abutting against the first block body 34, the first return spring 37 is stretched, and at the moment, the first piston rod 39 drives the valve rod 23 and the bottom valve 22 to move upwards through the connecting shaft 41 to reach the extraction position shown in fig. 1b and 2 b. In this position, the bottom valve 22 is located above the valve seat 21 and spaced apart from the valve seat 21, and fluid material is drawn from the container into the internal passage 11 of the extractor gun via the gap between the bottom valve 22 and the valve seat 21 by the action of the extractor pump in communication with the extractor gun at the connection 12 and is sucked out via this internal passage.

The gun rod component of the extraction gun with the exemplary structure of the application does not cause the diameter of an internal material channel to be too small due to the arrangement of an interlayer, namely a double-layer wall as in the prior art, maximizes the size of the internal channel due to the use of a single-layer structure, can maximally realize the extraction of materials, maximizes the flow, greatly improves the extraction speed and the extraction efficiency, and shortens the extraction time. And the larger internal channel size enables the extraction gun to have high extraction capacity, meets the suction requirement of high-viscosity materials, has wider applicable material range and integrally improves the extraction efficiency of the high-viscosity materials.

After the amount of fluid material suction meets the requirements, the extractor gun is brought into a sealing position. The two-position three-way single-control solenoid valve 7 is actuated to the exhaust position and the two-position five-way double-control solenoid valve 7 is actuated to the a position in communication with the third port P3, gas passing through the third port P3 into the third piston chamber 322 between the second piston 32 and the third block 33, the second piston 32 being driven downwards until it abuts the first block 34, in the process the second piston rod 321 being driven against the first piston rod 39, the first piston rod 39 driving the valve rod 23 and the base valve 22 downwards through the coupling shaft 41 to the sealing position as shown in fig. 1a, 2 a. In this position, the bottom valve 22 engages and seals against the valve seat 21, thereby preventing fluid material from returning from the extractor gun to the container, or from the container into the extractor gun. The extraction gun can be closed in time after the extraction gun is extracted to the required amount, and fluid materials are prevented from flowing between the extraction gun and the container, so that the accuracy of the extraction amount is ensured, and metering errors are avoided.

When it is desired to clean a container, such as an additive cartridge, the extractor gun is brought into a spraying position. At this time, the two-position five-way double-electric control electromagnetic valve 7 is actuated to the position B communicated with the first port P1, gas enters the first piston cavity 311 between the first piston 31 and the first block 34 through the first port P1, the first piston 31 is driven to move downwards until abutting against the cylindrical part 351 on the second block 35, the first piston rod 39 is driven by the first piston 31 to move downwards, and the valve rod 23 and the bottom valve 22 are driven by the connecting shaft 41 to move downwards to reach the spraying position shown in fig. 1c and 2 c. The second piston 32 moves upward by the second return spring 36, and the lower end of the second piston rod 321 is separated from the upper end of the first piston rod 39 and is no longer abutted against each other. In this spray position, the bottom valve 22 is located below the valve seat 21 and spaced from the valve seat 21. Fluid, such as cleaning agent, is driven by the pump to be sprayed into the container from the internal channel 11 of the extraction gun through the gap between the bottom valve 22 and the valve seat 21, so as to realize spray cleaning of the inner wall of the container. Through the exemplary structure of the application, the cleaning of the residual adhesive viscous material in the barrel is realized, the residual waste of the material in the barrel is reduced to the greatest extent, the residual quantity is controlled to the lowest, the waste of expensive materials and the pollution to the environment are reduced, the cost of washing the barrel by a user and the risk of cross contamination between the materials are reduced, and the waste of the cleaning procedure and the cleaning liquid is reduced.

Therefore, in the application, the driver is arranged, so that the extraction gun can realize the sealing of materials (the bottom valve is closed in time to realize the extraction precision), the extraction (the extraction of materials in the barrel is realized through the internal channel with the largest drift diameter) and the spraying (the barrel washing function) under three states. The three functions are integrated in the single-layer gun rod assembly, so that the precision and the efficiency of the extraction system are greatly improved, the production time is shortened, the suction requirement of high-viscosity materials can be met, the applicable material range is wider, and the extraction efficiency of the high-viscosity materials is also integrally improved.

The application also provides an extraction system using the extraction gun, which is simple to operate, does not need manpower, can improve the working efficiency and the productivity, and realizes automatic operation; and the container can be cleaned, cross contamination is avoided, the quality reliability of the product is ensured, the extraction precision is improved, leakage is avoided, the material loss is reduced, and the site is clean and has no potential safety hazard.

It should be noted that while a preferred arrangement is shown in the figures, i.e. the driver 3 is provided at the upper end of the gun rod assembly 1, one skilled in the art will appreciate that other arrangements may be employed, such as a manner in which the first piston rod 39 of the driver 3 is arranged parallel to the valve stem 23 in the gun rod assembly 1 and coupled by a coupling member to effect actuation.

It should be noted that the above-described embodiments should be regarded as illustrative only, and the present application is not limited to these embodiments. Many changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the application, by considering the contents of this specification. The true scope of the application is defined by the following claims and their equivalents.

Claims (12)

1. An extraction lance, wherein the extraction lance comprises:

a gun rod assembly (1), an internal channel (11) being defined within the gun rod assembly (1);

a valve seat (21) arranged at the lower end of the gun rod assembly (1), a bottom valve (22) matched with the valve seat and a valve rod (23) connected to the bottom valve (22); and

-an actuator (3), the upper end of the valve stem (23) being coupled to the actuator (3) and being movable in the internal passage (11) under the actuation of the actuator (3), wherein the actuator (3) actuates the foot valve (22) via the valve stem (23) to switch between three positions relative to the valve seat (21):

-a sealing position in which the bottom valve (22) is in abutment with and seals against the valve seat (21);

-an extraction position in which the bottom valve (22) is located above the valve seat (21) and spaced apart from the valve seat (21); and

a spraying position in which the base valve (22) is located below the valve seat (21) and spaced apart from the valve seat (21).

2. Extraction gun according to claim 1, characterized in that the driver (3) comprises a first piston (31) arranged within a housing (30) of the driver (3) and a first piston rod (39) connected to the first piston (31), the first piston rod (39) being coupled to the valve stem (23); wherein the first piston (31) can be actuated downwards to bring the bottom valve (22) to the spraying position, and the first piston (31) can be actuated upwards to bring the bottom valve (22) to the extraction position.

3. Extraction gun according to claim 2, characterized in that the driver (3) further comprises a second piston (32) arranged in the housing (30) above the first piston (31) and a second piston rod (321) connected to the second piston (32), the upper end of the first piston rod (39) and the lower end of the second piston rod (321) being able to abut and separate, wherein the second piston (32) is able to be actuated downwards to drive the foot valve (22) via the second piston rod (321) against the first piston rod (39) to the sealing position.

4. A extractor gun according to claim 3, wherein the drive further comprises:

a first block (34) fixed to the housing (30) of the driver between the first piston (31) and the second piston (32) and limiting the first piston (31) and the second piston (32), wherein a first center hole in which the second piston rod (321) sealingly slides is formed in the first block (34); and

a second block (35) fixed to the housing (30) of the driver at the lower side of the first piston (31), wherein a second center hole in which the first piston rod (39) is sealingly slid is formed in the second block (35).

5. Extraction gun according to claim 4, wherein the housing (30) is formed with a first port (P1), a second port (P2) and a third port (P3) for the ingress and egress of a working fluid, the first port (P1) being in fluid communication with a first piston chamber (311) located between the first piston (31) and the first block (34), the second port (P2) being in fluid communication with a second piston chamber (312) located between the first piston (31) and the second block (35), and the third port (P3) being in fluid communication with a third piston chamber (322) located on the upper side of the second piston (32).

6. Extraction gun according to claim 5, characterized in that it further comprises solenoid valves for controlling the passage of working fluid into and out of said first port (P1), second port (P2) and third port (P3).

7. Extraction gun according to claim 6, characterized in that the solenoid valve comprises a two-position five-way double electronically controlled solenoid valve, wherein when the two-position five-way double electronically controlled solenoid valve is in position a in communication with the third port (P3), the second piston (32) is driven downwards until it abuts against the first block (34), the second piston rod (321) abutting against the first piston rod (39) driving the bottom valve to the sealing position; and is also provided with

When the two-position five-way double-electric control electromagnetic valve is positioned at a position B communicated with the first port (P1), the first piston (31) is driven downwards until the first piston abuts against the second block body (35), the first piston rod (39) is separated from the second piston rod (321), and the bottom valve (22) is driven to reach the spraying position.

8. Extraction gun according to claim 7, characterized in that the solenoid valve further comprises a two-position three-way single-control solenoid valve, the first piston (31) being driven upwards until it abuts the first block (34) when the first piston rod (39) brings the bottom valve (22) to the extraction position, when the two-position three-way single-control solenoid valve is in a position in communication with the second port (P2).

9. Extraction gun according to one of claims 4 to 8, characterized in that the drive further comprises a first return spring (37) arranged between the first piston (31) and the second block (35).

10. Extraction gun according to claim 9, characterized in that the drive further comprises a third block (33) fixed to the housing (30) of the drive on the upper side of the second piston (32) and a second return spring (36) arranged between the third block (33) and the second piston (32).

11. Extraction gun according to one of claims 3 to 8, characterized in that the driver further comprises an adjustment nut assembly (5) arranged at the upper end of the housing (30) of the driver, wherein the adjustment nut assembly (5) is coupled to the second piston rod (321) for adjusting the position of the foot valve (22).

12. An extraction system, characterized in that it comprises an extraction lance according to any one of claims 1-11.