Multi-stage gas-liquid separator for closed liquid ring vacuum unit

Abstract

The invention discloses a multistage gas-liquid separator for a closed liquid ring vacuum unit, which comprises a cylinder, two ends of the cylinder are open structures and are respectively sealed and sealed through a window cover plate and an end cover, and the inner side of the window cover plate is provided with a liquid level window for monitoring the internal liquid level; the swirler is mounted at the top end of the barrel through a connecting pipe, a spiral disc and a central shaft are arranged in a shell of the swirler, a gas input port is formed in the side wall of the shell, and a liquid supplementing hole is formed in the central shaft; the invention belongs to the technical field of gas-liquid separation, and achieves the technical effects that four-stage separation means of rotational flow centrifugal separation, gravity settling, porous filtration and coil pipe condensation cooling are integrated, so that the gas-liquid separation efficiency and the recovery rate of a working solution are remarkably improved; the compact structural design reduces pipeline connection and occupied area, an indirect cooling mode avoids mixing of a cooling medium and a working solution, and the reliability and the energy-saving performance of the system are improved.

Description

Technical Field

[0001] This invention relates to the field of gas-liquid separation technology, and more specifically to a multi-stage gas-liquid separator for closed-loop liquid ring vacuum units. Background Technology

[0002] A liquid ring vacuum pump is a vacuum device that uses a liquid (usually water or coolant) as the working medium to form a liquid ring for pumping. In a closed-loop system, after the gas is pumped out by the liquid ring vacuum pump, the discharged gas usually contains a large number of fine liquid droplets and vapor. If these liquids cannot be effectively separated and cooled, it will not only cause continuous loss of the system's working fluid, but also lead to a decrease in the efficiency of the vacuum pump, and even cause equipment overheating, cavitation and other failures. Existing gas-liquid separators mostly use a single cyclone or gravity separation method, which has limited separation effect, especially under high humidity or high flow rate conditions, which can easily lead to liquid entrainment. In addition, traditional condensers are mostly independent components, requiring additional piping connections, which are complex in structure, occupy a large space, and have low energy utilization. Currently, as industries increasingly demand energy conservation, stable operation, and ease of maintenance, the limitations of traditional separation methods are becoming more and more apparent. Under high load or continuous operation conditions, incomplete separation leading to working fluid escape not only increases the cost of replenishment and wastewater treatment, but the escaped liquid may also corrode downstream pipelines or affect subsequent processes. Working fluid temperature runaway directly threatens vacuum pump performance; temperature rise reduces vacuum level, exacerbates cavitation, and shortens pump lifespan. Therefore, the industry urgently needs a compact device that highly integrates functions such as efficient multi-stage separation, active condensation cooling, automatic working fluid reflux, and intelligent liquid level control to fundamentally optimize the operating efficiency of closed-loop liquid ring vacuum systems. Therefore, to address the shortcomings of existing requirements, we propose a multi-stage gas-liquid separator for closed-loop liquid ring vacuum units. Summary of the Invention

[0003] Therefore, the present invention provides a multi-stage gas-liquid separator for closed-loop liquid ring vacuum units to solve the above-mentioned problems in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: According to a first aspect of the invention, a multi-stage gas-liquid separator for a closed-loop liquid ring vacuum unit includes a separator body that internally defines an integrated separation chamber. The cyclone separation section is located at the upstream inlet of the separation chamber and is used to receive the gas-liquid mixture from the liquid ring vacuum pump and achieve primary gas-liquid separation by using centrifugal force. The gravity settling section is fluidly connected to the cyclone separation section, providing an expansion and deceleration space for the gas after primary separation, so that the droplets can achieve secondary separation under the action of gravity. The filtration and interception section is located downstream of the gravity settling section and is used to intercept and condense the fine droplets carried in the gas through collision, thereby achieving three-stage separation. The condensation and cooling section is located downstream of the filtration and interception section and is immersed in the working fluid collected at the bottom of the separation chamber. It is used to indirectly cool the working fluid and condense and precipitate the residual vapor in the gas, thereby achieving four-stage separation. A gas outlet is located at the top of the separation chamber to discharge the dried gas after multi-stage separation. The working fluid return port is located at the bottom of the separation chamber and is used to guide the cooled working fluid back to the liquid ring vacuum pump to form a closed circulation loop for the working fluid. And a liquid level maintenance unit, which is connected to the lower part of the filter interception section on the side wall of the separation chamber, for maintaining the working fluid within a predetermined liquid level range.

[0005] Furthermore, the swirling separation section includes a swirler housing with a tangential gas inlet, and a flow guide component disposed within the housing to create a strong swirling flow field and swirl separate the tangentially flowing mixture.

[0006] Furthermore, the lower part of the hydrocyclone shell has a tapered, constricted structure.

[0007] Furthermore, the flow guiding component is a helical blade arranged around a central axis.

[0008] Furthermore, the central shaft is provided with a liquid replenishment channel along the axial direction.

[0009] Furthermore, the filtering and interception section includes one or more porous metal filter plates that are detachably mounted on the cross braces inside the separation chamber.

[0010] Furthermore, the condensation cooling section includes a metal heat exchange coil coiled at the bottom of the separation chamber.

[0011] Furthermore, the metal heat exchange coil is made of copper or stainless steel.

[0012] Furthermore, the separator body consists of a horizontally arranged cylindrical body and cover plates sealed at both ends.

[0013] Furthermore, the working fluid return port is located on the cover plate on the downstream side.

[0014] Furthermore, the liquid level maintaining unit includes an overflow port disposed on the side wall of the separation chamber, the position of which corresponds to the upper limit of the predetermined liquid level range.

[0015] Furthermore, the bottom of the separation chamber is provided with support feet for fixing the gas-liquid separator.

[0016] The present invention has the following advantages: 1. This multi-stage gas-liquid separator for closed-loop liquid ring vacuum units integrates a cyclone separator, a volume expander, a detachable porous metal mesh plate, and a spiral coil cooler into a single horizontal cylinder. This design achieves structural compactness, significantly reducing the piping, valves, and floor space required for traditional multi-device series connections, thus lowering system complexity and potential leakage risks. This integrated design not only simplifies the installation process but also ensures a smooth and natural airflow path, optimizing pressure drop loss. 2. This multi-stage gas-liquid separator for closed-loop liquid ring vacuum units uses a cyclone separator as the first stage to efficiently remove most of the liquid droplets. Subsequently, the gas velocity decreases sharply within the expanded gas flow chamber, achieving secondary sedimentation through gravity. Following this, a porous metal mesh plate precisely intercepts and condenses fine mist droplets. Finally, the residual vapor of the gas flowing through the cooling working fluid space is completely condensed on the low-temperature metal coil surface and within the cooling liquid space. These four interconnected and progressively deepening separation stages reduce the liquid entrainment rate at the gas outlet to an extremely low level and significantly improve the working fluid recovery rate, thereby greatly reducing the system's operating medium consumption and maintenance frequency. 3. This multi-stage gas-liquid separator for closed-loop liquid ring vacuum units indirectly cools the recovered working fluid through an internal coil and utilizes the negative pressure of the pump itself to achieve automatic closed-loop circulation of the working fluid. This design ensures that the working fluid returning to the pump is always within a suitable temperature range, effectively preventing pump efficiency degradation and cavitation damage caused by overheating of the working fluid, and greatly enhancing the operational stability and service life of the entire vacuum unit. At the same time, user-friendly designs such as a visible liquid level window, a removable filter, and overflow protection make equipment status monitoring, maintenance, and fault prevention intuitive and simple, improving the operability and reliability of the equipment. Attached Figure Description

[0017] Figure 1 This is a front view of a multi-stage gas-liquid separator for a closed-loop liquid ring vacuum unit proposed in this invention; Figure 2 for Figure 1 A side view diagram; Figure 3 This is a schematic cross-sectional view of the hydrocyclone casing; Figure 4 This is a schematic cross-sectional view of the cylinder. Figure 5 for Figure 4 A side view diagram; Figure 6 for Figure 1 A schematic diagram of its breakdown.

[0018] In the diagram: 1. Cylinder; 101. Sight window cover; 102. Liquid level sight window; 103. End cap; 104. Annular sealing gasket; 105. Exhaust port; 106. Overflow pipe; 107. Working fluid circulation return port; 108. Horizontal plate; 109. Perforated metal mesh plate; 110. Working fluid chamber; 111. Airflow chamber; 2. Metal coil; 201. Cooling water inlet; 202. Cooling water outlet; 3. Hydrocyclone; 301. Hydrocyclone housing; 302. Gas inlet; 303. Central shaft; 304. Spiral disc; 305. Liquid replenishment hole; 306. Connecting pipe; 4. Support foot; Detailed Implementation

[0019] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1; Reference Figure 1 - Figure 6 A multi-stage gas-liquid separator for a closed-loop liquid ring vacuum unit includes a cylindrical body 1, both ends of which are open. A viewing window cover 101 and an end cap 103 are respectively bolted to both ends of the cylindrical body 1. Annular sealing gaskets 104 are provided between the viewing window cover 101 and the cylindrical body 1, and between the end cap 103 and the cylindrical body 1. A liquid level viewing window 102 is installed on the inner side of the viewing window cover 101 for visually monitoring the internal working fluid level. To provide stable support, support feet 4 are fixedly installed on both sides of the bottom of the outer wall of the cylinder 1, which facilitates the installation and fixation of the equipment; The top two sides of the cylinder 1 are respectively connected to a connecting pipe 306 and an exhaust pipe 105, both of which are connected to the inside of the cylinder 1. The top of the connecting pipe 306 is connected to a hydrocyclone 3 for primary gas-liquid separation. The hydrocyclone 3 includes a hydrocyclone shell 301, the bottom output end of which is connected to the connecting pipe 306. The lower part of the inner wall of the hydrocyclone shell 301 is designed as a conical structure with a decreasing diameter from top to bottom, which is conducive to the collection and guidance of the separated liquid. A central shaft 303 is fixed at the top of the inside of the hydrocyclone shell 301. A spiral disc 304 is provided between the outer wall of the central shaft 303 and the inner wall of the shell 301. When the gas-liquid mixture enters tangentially from the gas inlet 302, a high-speed rotating flow field is formed under the guidance of the spiral disc 304. The droplets are thrown towards the inner wall of the shell under the action of centrifugal force and flow downward along the wall, realizing the initial centrifugal separation. A liquid replenishment hole 305 is opened on the central shaft 303 to replenish the working fluid when the liquid level is too low. Inside the upper part of the cylinder 1, horizontal plates 108 are fixedly installed on both sides of its inner wall, forming a stable mesh plate support; a perforated metal mesh plate 109 is installed on the support, thereby dividing the inside of the cylinder 1 into an upper airflow chamber 111 and a lower working liquid chamber 110; the airflow chamber 111 is used to contain the gas after primary separation and provide it with sufficient gravity settling space; the working liquid chamber 110 is used to collect the separated liquid and contain the cooling components; A metal coil 2 is arranged inside the working fluid chamber 110. Its input end is a cooling water inlet 201 and its output end is a cooling water outlet 202, both of which are connected and fixed to the end cap 103. The metal coil 2 is usually made of copper or stainless steel and is filled with cooling water (such as chilled water or ethylene glycol solution). It indirectly exchanges heat with the liquid in the working fluid chamber 110 through the tube wall. This process can effectively reduce the temperature of the working fluid, prevent the vacuum pump from becoming less efficient or cavitating due to overheating of the working fluid, and also condense the residual vapor in the gas flow, achieving deep gas-liquid separation and temperature control. On the end cap 103, below the cooling water inlet 201 and outlet 202, a working fluid circulation return port 107 is also provided; the working fluid circulation return port 107 is connected to the liquid ring vacuum pump inlet (usually under negative pressure) through a pipeline, so that the cooled working fluid after separation can automatically and continuously flow back to the vacuum pump under the action of pressure difference, forming a closed loop, ensuring the stability of the total amount of working fluid in the system, and maintaining the efficient and stable operation of the vacuum pump; An overflow pipe 106 is installed on the side wall of the cylinder 1. One end of the overflow pipe 106 is connected to the working liquid chamber 110, and a valve can be installed at the other end. The overflow pipe 106 is used to set and maintain the highest safe liquid level in the working liquid chamber to prevent the liquid level from being too high and affecting the gas separation effect or entering the exhaust pipe. In operation: During operation, the wet saturated gas-liquid mixture from the liquid ring vacuum pump first enters the hydrocyclone 3 through the gas inlet 302, where it generates a high-speed vortex under the action of the spiral disc 304, completing the primary separation based on centrifugal force; the separated gas, carrying a small amount of liquid droplets, enters the airflow chamber 111 above the cylinder 1 through the connecting pipe 306; in this chamber, the airflow velocity decreases, and larger liquid droplets settle into the working liquid chamber 110 under the action of gravity, completing the secondary gravity separation; the gas continues to flow downwards, passing through the porous metal mesh plate 109; the porous metal mesh plate 109 separates the gas through collision, The system intercepts and condenses the fine droplets and mist in the gas, achieving three-stage filtration and separation while also providing flow stabilization and noise reduction. Subsequently, as the gas flows through the space of the cooled working fluid, the residual vapor comes into contact with the low-temperature metal coil 2 and the cooled working fluid and is condensed, achieving four-stage condensation separation. Finally, the dried gas is discharged through the exhaust pipe 105. All the separated and collected working fluids are collected in the working fluid chamber 110, and after cooling, they are returned to the vacuum pump through the working fluid circulation return port 107, forming a highly efficient closed system with controllable liquid level, controlled temperature, and working fluid recycling.

[0021] By integrating four-stage separation methods—cyclone centrifugal separation, gravity sedimentation, porous filtration, and coil condensation cooling—the gas-liquid separation efficiency and working fluid recovery rate are significantly improved. The compact structural design reduces piping connections and floor space, and the indirect cooling method avoids mixing of the cooling medium and working fluid, improving system reliability and energy efficiency. Visualized liquid level monitoring, removable filter screens, and automatic liquid replenishment and overflow protection functions ensure stable operation and easy maintenance. It is particularly suitable for closed-loop liquid ring vacuum units and other similar industrial systems with strict requirements for working fluid loss and gas dryness.

Claims

1. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum units, characterized in that include: The separator body defines an integrated separation chamber. The cyclone separation section is located at the upstream inlet of the separation chamber and is used to receive the gas-liquid mixture from the liquid ring vacuum pump and achieve primary gas-liquid separation by using centrifugal force. The gravity settling section is fluidly connected to the cyclone separation section, providing an expansion and deceleration space for the gas after primary separation, so that the droplets can achieve secondary separation under the action of gravity. The filtration and interception section is located downstream of the gravity settling section and is used to intercept and condense the fine droplets carried in the gas through collision, thereby achieving three-stage separation. The condensation and cooling section is located downstream of the filtration and interception section and is immersed in the working fluid collected at the bottom of the separation chamber. It is used to indirectly cool the working fluid and condense and precipitate the residual vapor in the gas, thereby achieving four-stage separation. A gas outlet is located at the top of the separation chamber to discharge the dried gas after multi-stage separation. The working fluid return port is located at the bottom of the separation chamber and is used to guide the cooled working fluid back to the liquid ring vacuum pump to form a closed circulation loop for the working fluid. And a liquid level maintenance unit, which is connected to the lower part of the filter interception section on the side wall of the separation chamber, for maintaining the working fluid within a predetermined liquid level range.

2. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 1, characterized in that The cyclone separation section includes a cyclone housing with a tangential gas inlet, and a flow guide component disposed within the housing to form a strong cyclone flow field and to cyclone separate the tangentially flowing mixture.

3. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 2, characterized in that The lower part of the hydrocyclone shell has a tapered, constricted structure.

4. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 3, characterized in that The flow guiding component is a spiral blade arranged around a central axis.

5. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 4, characterized in that The central shaft is provided with a fluid replenishment channel along its axial direction.

6. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 5, characterized in that The filtration and interception section includes one or more porous metal filter plates that are detachably mounted on the cross braces inside the separation chamber.

7. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 6, characterized in that The condensation cooling section includes a metal heat exchange coil coiled at the bottom of the separation chamber.

8. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 7, characterized in that The metal heat exchange coil is made of copper or stainless steel.

9. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 1, characterized in that The separator body consists of a horizontally positioned cylindrical body and cover plates sealed at both ends.

10. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 9, characterized in that The working fluid return port is located on the cover plate on the downstream side.

11. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 1, characterized in that The liquid level maintenance unit includes an overflow pipe disposed on the side wall of the separation chamber, the position of which corresponds to the upper limit of the predetermined liquid level range.

12. A multi-stage gas-liquid separator for closed-loop liquid ring vacuum sets according to claim 11, characterized in that The bottom of the separation chamber is provided with support feet for fixing the gas-liquid separator.

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