A cold hydrazine suitable for liquid removal at the inlet of a vacuum pump

Abstract

The application provides cold hydrazine suitable for liquid removal at a vacuum pump inlet, comprising a cold hydrazine cylinder body, an air inlet at the top of the cold hydrazine cylinder body, a condensate discharge outlet at the bottom of the cold hydrazine cylinder body, and a gas outlet at the middle of the cold hydrazine cylinder body; a functional cylinder is arranged at the top of the inner side of the cold hydrazine cylinder body, the functional cylinder separates the inner cavity of the cold hydrazine cylinder body into an inner heat exchange cavity and an outer heat exchange cavity, a through hole for connecting the inner heat exchange cavity and the outer heat exchange cavity is arranged on the side wall of the functional cylinder, a collecting pipe extending to the bottom of the cold hydrazine cylinder body is arranged at the bottom of the functional cylinder, an inner heat exchange assembly is arranged in the inner heat exchange cavity, an outer heat exchange assembly is arranged in the outer heat exchange cavity, heat exchange spaces are sequentially formed between the inner side of the inner heat exchange assembly, the inner heat exchange assembly and the functional cylinder, the outer heat exchange assembly and the functional cylinder, and the outer heat exchange assembly and the cold hydrazine cylinder body, the air inlet extends to the heat exchange space on the inner side of the inner heat exchange assembly, and a sealing plate is arranged between the air inlet and the inner heat exchange assembly. The application prolongs the residence time of gas-phase materials in the cold hydrazine by forcedly prolonging the residence time of gas-phase materials in the cold hydrazine, and enhances the heat exchange effect.

Description

Technical Field

[0001] This invention belongs to the field of vacuum system technology, and in particular relates to a cold hydrazine suitable for liquid removal at the inlet of a vacuum pump. Background Technology

[0002] In vacuum systems, moisture and organic solvents in the vacuum container are volatile, typically generating large amounts of vapor. To improve the pumping performance and vacuum level of the vacuum pump, hydrazine is generally used to condense these volatile condensable gases, reducing their adverse effects on the vacuum system. Existing technology commonly uses hydrazine in fixed tubesheet heat exchangers. While this structure is simple, the gas flow rate is very high under the vacuum pump, regardless of whether it passes through the shell or tube side of the heat exchanger. A large heat exchange area is required to achieve ideal performance, resulting in high manufacturing costs. However, since the inlet pipe size is usually not very large, when using large-diameter hydrazine, the inlet gas phase distributor must be considered to prevent uneven heating of the heat exchanger tube bundle. Therefore, improving the heat exchange structure to achieve better heat exchange and enhance condensation efficiency is particularly important. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the deficiencies in the prior art and proposes a cold hydrazine suitable for liquid removal at the inlet of a vacuum pump.

[0004] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0005] A cold hydrazine suitable for dehydrating liquid at the inlet of a vacuum pump includes a cold hydrazine cylinder. The cold hydrazine cylinder has an air inlet at the top, a condensate outlet at the bottom, and a gas outlet in the middle. A functional cylinder is provided at the top of the inner side of the cold hydrazine cylinder, which divides the inner cavity of the cold hydrazine cylinder into an inner heat exchange chamber and an outer heat exchange chamber. The side wall of the functional cylinder has a through hole connecting the inner heat exchange chamber and the outer heat exchange chamber. A collection pipe extending to the bottom of the cold hydrazine cylinder is provided at the bottom of the functional cylinder. An inner heat exchange component is installed in the inner heat exchange chamber, and an outer heat exchange component is installed in the outer heat exchange chamber. Heat exchange spaces are sequentially formed between the inner side of the inner heat exchange component, between the inner heat exchange component and the functional cylinder, between the outer heat exchange component and the functional cylinder, and between the outer heat exchange component and the cold hydrazine cylinder. The air inlet extends to the heat exchange space inside the inner heat exchange component, and a sealing plate is provided between the air inlet and the inner heat exchange component.

[0006] The air inlet at the top of the hydrazine cylinder extends into the heat exchange space inside the inner heat exchange assembly. A sealing plate isolates the air inlet area from the heat exchange assembly, ensuring that the liquid-containing gas enters the inner heat exchange chamber in a directional manner and first undergoes initial condensation in the heat exchange space inside the inner heat exchange assembly. The separation effect of the aforementioned functional cylinder forms a double heat exchange chamber structure. The gas that is not fully condensed enters the outer heat exchange chamber through the heat exchange space between the inner heat exchange assembly and the functional cylinder, and undergoes secondary condensation through the outer heat exchange assembly, thus extending the gas phase condensation path and significantly improving the condensation efficiency.

[0007] The collection tube at the bottom of the functional cylinder extends to the bottom of the hydrazine cylinder, allowing condensed liquid from both the inner and outer heat exchange chambers to be discharged centrally, preventing liquid accumulation from affecting heat exchange efficiency. The gas outlet is located in the middle of the hydrazine cylinder, allowing the condensed clean gas to exit from the middle layer, while the condensate sinks to the bottom due to gravity, achieving efficient gas-liquid separation. This invention provides a hydrazine system with a multi-stage heat exchange space partitioning design, combined with physical isolation between the gas flow path and the liquid collection path. This ensures sufficient condensation while preventing gas short-circuiting or liquid back-mixing, making it particularly suitable for the pretreatment of gases with high liquid content and effectively protecting downstream vacuum pump equipment.

[0008] Furthermore, the internal heat exchange assembly includes a coiled internal heat exchange tube, with internal heat exchange medium connecting pipes at both ends of the internal heat exchange tube, and the internal heat exchange medium connecting pipes having an internal heat exchange tube interface extending outward from the cold hydrazine cylinder.

[0009] Furthermore, the inner sleeve is fixed to the functional cylinder by an inner support.

[0010] Furthermore, the external heat exchange component includes an outer jacket, in which an external heat exchange tube is coiled. Both ends of the external heat exchange tube are respectively provided with external heat exchange medium pipes. The external heat exchange medium is connected to an external heat exchange tube interface that extends outward from the hydrazine cylinder. When the gas phase moves in the hydrazine cylinder, the temperature difference between the inner heat exchange chamber and the outer heat exchange chamber drives the formation of natural convection, which promotes the airflow to pass along a longer airflow path, increases the contact area between the gas phase and the heat exchange component, and effectively improves the condensation effect.

[0011] Furthermore, the outer jacket is fixed to the cold hydrazine cylinder by an external support.

[0012] Furthermore, a condensate collection pipe support is provided between the collection pipe and the inner wall of the cold hydrazine cylinder.

[0013] Furthermore, the lower part of the cold hydrazine cylinder is provided with support legs.

[0014] Furthermore, the side wall of the condensate cylinder is provided with a level gauge port. In application, a level gauge is installed at the level gauge port to measure the amount of condensate in the shell. The level gauge can also be interlocked with an external valve at the condensate outlet to realize automatic opening and closing control of the external valve.

[0015] Furthermore, a filtration structure is provided at the gas outlet, including a guide duct corresponding to the gas outlet, and a baffle installed inside the guide duct. The gas phase passes through the gas vent, and when the gas comes into contact with the baffle, the liquid phase in the gas is trapped by the baffle. Therefore, condensable liquid gas can be prevented from escaping from the gas outlet to the greatest extent possible.

[0016] Compared with existing technologies, the present invention has the following advantages:

[0017] This invention creates a functional cylinder within a cold hydrazine cylinder, with a set of heat exchange components installed both inside and outside the functional cylinder. This allows the gaseous phase entering the cold hydrazine cylinder to sequentially exchange heat with the corresponding heat exchange components in the heat exchange spaces between the inner heat exchange components, between the inner heat exchange components and the functional cylinder, between the outer heat exchange components and the functional cylinder, and between the outer heat exchange components and the cold hydrazine cylinder. This forces the gaseous material to prolong its residence time inside the cold hydrazine, enhancing the heat exchange effect. At the same time, it saves on the consumption of cooling medium, reducing equipment operating costs. Because condensable gases condense more fully, it reliably ensures the stability of the vacuum system. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 A schematic diagram of the structure created by this invention;

[0020] Figure 2 A schematic diagram of the present invention after removing the internal and external heating components;

[0021] Figure 3 A schematic diagram illustrating the internal and external heating components of this invention;

[0022] Figure 4 This is a schematic diagram of the filtrate structure in this invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Cold hydrazine cylinder; 2. Air inlet; 3. Condensate outlet; 4. Gas outlet; 5. Functional cylinder; 6. Inner heat exchange chamber; 7. Outer heat exchange chamber; 8. Through hole; 9. Collection pipe; 10. Inner heat exchange assembly; 11. Outer heat exchange assembly; 12. Heat exchange space; 13. Air vent; 14. Sealing plate; 15. Inner jacket; 16. Inner heat exchange tube; 17. Inner heat exchange medium connection pipe; 18. Inner heat exchange tube interface; 19. Inner support; 20. Outer jacket; 21. Outer heat exchange tube; 22. Outer heat exchange medium connection pipe; 23. Outer heat exchange tube interface; 24. Outer support; 25. Condensate collection pipe support; 26. Support leg; 27. Liquid level gauge port; 28. Filtration structure; 29. ​​Air guide duct; 30. Baffle. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] A type of cold hydrazine suitable for liquid removal at the inlet of a vacuum pump, such as Figures 1 to 4 As shown, the device includes a hydrazine cylinder 1, with an air inlet 2 at the top, a condensate outlet 3 at the bottom, and a gas outlet 4 in the middle. The air inlet is used for gaseous material intake, the gas outlet is used for non-condensable gas phase discharge, and the condensate outlet is used for collecting condensate. A functional cylinder 5 is located at the top of the inner side of the hydrazine cylinder, dividing the inner cavity into an inner heat exchange chamber 6 and an outer heat exchange chamber 7. The side wall of the functional cylinder has a through-hole 8 connecting the inner and outer heat exchange chambers. As the core dividing component within the hydrazine cylinder, the design of the through-hole on its side wall directly affects the airflow direction; therefore, the through-hole is generally designed near the top of the hydrazine cylinder.

[0030] A collection tube 9 extending to the bottom of the cold hydrazine cylinder is provided at the bottom of the functional cylinder. The collection tube can be manufactured separately, and then the upper end of the collection tube is welded and fixed to the bottom of the functional cylinder, as long as the collection tube is connected to the inner cavity of the functional cylinder. Preferably, the bottom of the functional cylinder has a surface that slopes towards the collection tube, so that the condensate in the functional cylinder flows into the collection tube and is then discharged to the lower part of the cold hydrazine cylinder.

[0031] An internal heat exchange component 10 is installed in the internal heat exchange chamber, and an external heat exchange component 11 is installed in the external heat exchange chamber. Heat exchange spaces 12 are formed sequentially between the inner side of the internal heat exchange component, between the internal heat exchange component and the functional cylinder, between the external heat exchange component and the functional cylinder, and between the external heat exchange component and the cold hydrazine cylinder. The lower part of the air inlet extends into the heat exchange space inside the internal heat exchange component, and a sealing plate 14 is provided between the air inlet and the internal heat exchange component.

[0032] The internal heat exchange assembly includes coiled internal heat exchange tubes 16, which are tightly fitted together to form a coil structure, thus ensuring a certain degree of sealing. Heat exchange spaces are formed on both the inner and outer sides of the coil structure. Internal heat exchange medium inlets 17 are located at both ends of the internal heat exchange tubes, and internal heat exchange medium inlets 18 extend outwards from the cooling hydrazine cylinder. The inner jacket is fixed to the functional cylinder by an inner support 19. In the design without an inner jacket, as long as the internal heat exchange tubes are tightly coiled into a coil structure, even if a small amount of medium enters the heat exchange space outside the internal heat exchange assembly directly through the gaps in the coiled internal heat exchange tubes from the heat exchange space inside the internal heat exchange assembly, it will not significantly affect the heat exchange effect and can meet the heat exchange requirements under normal operating conditions. In an optional embodiment, the internal heat exchange component may be designed with an inner jacket 15, in which the internal heat exchange tubes are coiled and arranged, thereby ensuring that heat exchange spaces are formed on both sides of the internal heat exchange component. The inner jacket improves the regularity and sealing of the coil structure, making it easier for the overall assembly, maintenance and replacement of the component, and adapting to the heat exchange requirements under different operating conditions.

[0033] The external heat exchange assembly includes an outer jacket 20, within which an external heat exchange tube 21 is coiled. Both ends of the external heat exchange tube are respectively provided with external heat exchange medium inlets 22, and the external heat exchange medium is connected to an external heat exchange tube interface 23 extending outward from the hydrazine cylinder. When the gas phase moves within the hydrazine cylinder, the temperature difference between the inner and outer heat exchange chambers drives natural convection, promoting the airflow along a longer path, increasing the contact area between the gas phase and the heat exchange assembly, and effectively improving the condensation effect.

[0034] The outer jacket is fixed to the cold hydrazine cylinder by an outer support 24. A condensate collection pipe support 25 is provided between the collection pipe and the inner wall of the cold hydrazine cylinder to ensure that the collection pipe is stable and does not shake inside the equipment. The inner support ensures that the inner heat exchange tube does not shake inside the equipment, and the outer support ensures that the outer heat exchange tube does not shake inside the equipment. As an example, the aforementioned inner support, outer support, and condensate collection pipe support are all made of angle steel.

[0035] The lower part of the condensate cylinder is equipped with support legs 26, which can effectively support the condensate cylinder. The structural design of the support legs must take into account avoiding interference with the structures on the condensate cylinder. For example, the support legs must avoid the condensate discharge port. The side wall of the condensate cylinder is equipped with a level gauge port 27. In application, a level gauge is installed in the level gauge port to measure the amount of condensate in the shell. The level gauge can also be interlocked with an external valve at the condensate discharge port to realize automatic opening and closing control of the external valve.

[0036] For example, two liquid level gauges, one upper and one lower, are installed at the bottom of the condensate cylinder. The valve is connected to the PLC control system. When the lower liquid level gauge detects that the condensate level is lower than the lower limit setting, it sends a signal to the PLC control system. The PLC control system then issues a command to close the valve, preventing the discharge of liquid phase through the condensate outlet. Conversely, when the upper liquid level gauge detects that the condensate level is higher than the upper limit setting, it sends a signal to the PLC control system. The PLC control system then issues a command to open the valve, allowing the liquid phase to be discharged through the condensate outlet. This achieves automated control of condensate discharge.

[0037] A filtration structure 28 is provided at the gas outlet, including a guide duct 29 corresponding to the gas outlet. The gas phase passes through the guide duct before exiting the gas outlet. The guide duct can be a cylindrical structure inclined or perpendicular to the axis of the hydrazine cylinder. The material must be corrosion-resistant. Typically, the guide duct is welded or fixed to the inner wall of the hydrazine cylinder via connectors, and the guide duct and the inner wall of the hydrazine cylinder are sealed. To further improve the condensation effect, a baffle 30 can be installed inside the guide duct to intercept the condensed liquid phase carried in the gas. As a structural feature, several air passage holes 13 can be provided on the baffle plate. The gas phase passes through the air passage holes, and when the gas comes into contact with the baffle plate, the liquid phase in the gas is intercepted by the baffle plate. Therefore, the discharge of condensable liquid gas from the gas outlet can be minimized.

[0038] As another structural form, the baffles can be multi-layered annular or spiral baffles, with the spacing between the baffles gradually decreasing along the airflow direction to form a stepped airflow path. During the process of the gas phase being discharged into the gas outlet through the guide duct, it flows spirally or linearly downwards along the inner wall of the duct, extending the gas residence time to promote condensation. Therefore, during the gas phase discharge process, the extended airflow path through the guide duct, combined with the baffles disturbing the airflow, significantly improves condensation efficiency.

[0039] Working principle: The gas phase enters the inner heat exchange component through the inlet. The sealing plate on the upper side of the first heat exchange component seals the heat exchange space inside the inner heat exchange component. After entering the heat exchange space inside the inner heat exchange component, the gas phase moves downwards, successively passing through the heat exchange spaces between the inner heat exchange component and the functional cylinder, between the outer heat exchange component and the functional cylinder, and between the outer heat exchange component and the condensate cylinder. During its passage through each heat exchange space, the gas phase exchanges heat with the cooling medium inside the heat exchange tubes. The condensate falls and is collected, while the gas phase is discharged through the condensate outlet.

[0040] This invention creates a functional cylinder within a cold hydrazine cylinder, with a set of heat exchange components installed both inside and outside the functional cylinder. This allows the gaseous phase entering the cold hydrazine cylinder to sequentially exchange heat with the corresponding heat exchange components in the heat exchange spaces between the inner heat exchange components, between the inner heat exchange components and the functional cylinder, between the outer heat exchange components and the functional cylinder, and between the outer heat exchange components and the cold hydrazine cylinder. This forces the gaseous material to prolong its residence time inside the cold hydrazine, enhancing the heat exchange effect. At the same time, it saves on the consumption of cooling medium, reducing equipment operating costs. Because condensable gases condense more fully, it reliably ensures the stability of the vacuum system.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cold hydrazine suitable for liquid removal at the inlet of a vacuum pump, characterized in that: The device includes a cold hydrazine cylinder (1), which has an air inlet (2) at the top, a condensate outlet (3) at the bottom, and a gas outlet (4) in the middle. A functional cylinder (5) is located at the top of the inner side of the cold hydrazine cylinder (1), dividing the inner cavity of the cold hydrazine cylinder (1) into an inner heat exchange chamber (6) and an outer heat exchange chamber (7). A through-hole (8) is located on the side wall of the functional cylinder (5) connecting the inner heat exchange chamber (6) and the outer heat exchange chamber (7). A collection pipe (9) extending to the bottom of the cold hydrazine cylinder (1) is located at the bottom of the functional cylinder (5). The inner heat exchange chamber... 6) An internal heat exchange component (10) is installed inside, and an external heat exchange component (11) is installed inside the external heat exchange chamber (7). Heat exchange spaces (12) are formed sequentially between the inner side of the internal heat exchange component (10), between the internal heat exchange component (10) and the functional cylinder (5), between the external heat exchange component (11) and the functional cylinder (5), and between the external heat exchange component (11) and the cold hydrazine cylinder (1). The air inlet (2) extends to the heat exchange space (12) inside the internal heat exchange component (10), and a sealing plate (14) is provided between the air inlet (2) and the internal heat exchange component (10).

2. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 1, characterized in that: The internal heat exchange assembly (10) includes a coiled internal heat exchange tube (16), with internal heat exchange medium pipes (17) at both ends of the internal heat exchange tube (16), and the internal heat exchange medium pipes have an internal heat exchange tube interface (18) extending outward from the cold hydrazine cylinder (1).

3. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 2, characterized in that: The inner sleeve (15) is fixed to the functional cylinder (5) by the inner support (19).

4. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 1, characterized in that: The external heat exchange assembly (11) includes an outer jacket (20), an external heat exchange tube (21) is coiled in the outer jacket (20), and an external heat exchange medium pipe (22) is provided at both ends of the external heat exchange tube (21). The external heat exchange medium is connected to the external heat exchange tube interface (23) with the externally extended cold hydrazine cylinder (1).

5. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 4, characterized in that: The outer jacket (20) is fixed to the cold hydrazine cylinder (1) by an outer support (24).

6. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 1, characterized in that: A condensate collection tube support (25) is provided between the collection tube (9) and the inner wall of the cold hydrazine cylinder (1).

7. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 1, characterized in that: The lower part of the cold hydrazine cylinder (1) is provided with support legs (26).

8. The cold hydrazine for dehydration at the inlet of a vacuum pump according to claim 1, characterized in that: The side wall of the cold hydrazine cylinder (1) is provided with a level gauge port (27).

9. A cold hydrazine suitable for dehydration at the inlet of a vacuum pump according to any one of claims 1 to 8, characterized in that: The gas outlet is provided with a filtration structure (28), which includes a guide tube (29) corresponding to the gas outlet, and a baffle (30) is installed inside the guide tube.

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