Pressure vacuum breaking device

Abstract

The invention discloses a pressure vacuum breaking device, and belongs to the technical field of liquid cargo ship transportation. A backflow pipe assembly of the pressure vacuum breaking device is connected with a sealing cavity in an outer cylinder assembly through a non-return element, and the backflow pipe assembly is further connected with the sealing cavity through an inner liquid sealing assembly. Therefore, when the pressure value of the ship cargo hold is larger than the set maximum pressure value, the sealing liquid automatically flows back to the backflow pipe assembly and does not overflow, the purpose that the pressure vacuum breaking device does not need to be filled with the sealing liquid for the second time after being filled with the sealing liquid for the first time is achieved, and the maintenance cost and the cleaning cost of the pressure vacuum breaking device can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid cargo ship transportation, and in particular to a pressure-vacuum breaker. BACKGROUND

[0002] During the loading and unloading of liquid cargo in a liquid cargo ship, when the external temperature changes, the diesel oil and other cargos in the cargo hold may volatilize into gas, causing the pressure in the cargo hold to change. Without corresponding adjustment measures, serious accidents such as fire and explosion may occur. Therefore, a riser, a pressure-vacuum valve, and a pressure-vacuum breaker are needed to balance the pressure in the cargo hold. The pressure-vacuum breaker is the last line of defense for balancing the pressure in the cargo hold.

[0003] The pressure-vacuum breaker is usually connected to an inert gas main pipeline, and the positive pressure set value is generally not more than +21kPag, and the vacuum set value is generally -7kPag. Before use, the pressure-vacuum breaker usually needs to be filled with sealing solution. When the cargo hold is over-pressurized or the vacuum degree is too high, the liquid sealing function of the device is released, and the downstream cargo hold is directly connected to the atmosphere, thereby releasing the over-pressurization or breaking the vacuum. The existing pressure-vacuum breaker is irreversible in the above process. After triggering the over-pressurization protection action, the sealing solution in the device leaks onto the deck, and at this time, the sealing solution needs to be refilled to continue using the device, thereby increasing the cleaning and maintenance costs. SUMMARY

[0004] The embodiments of the present application provide a pressure-vacuum breaker, which can reduce the maintenance cost and cleaning cost of using the pressure-vacuum breaker, to at least partially solve the above technical problems.

[0005] To achieve the above-mentioned purpose, according to the first aspect of the present application, a pressure-vacuum breaker is provided. The pressure-vacuum breaker comprises an outer cylinder assembly, the outer cylinder assembly is used to be installed to a ship, and an inner part of the outer cylinder assembly is provided with a sealed cavity used to be connected to a cargo hold of the ship and used to inject a sealing liquid. The pressure-vacuum breaker further comprises an inner liquid seal assembly, at least a part of the inner liquid seal assembly is embedded in the sealed cavity, and the inner liquid seal assembly is in sealed connection with the outer cylinder assembly, and the part of the inner liquid seal assembly embedded in the sealed cavity is spaced apart from a bottom wall of the sealed cavity. The pressure-vacuum breaker further comprises a return pipe assembly, the return pipe assembly is connected to the sealed cavity through a check element, and the return pipe assembly is connected to the inner liquid seal assembly. The check element is configured to allow the sealing liquid in the return pipe assembly to flow into the sealed cavity and to hinder the sealing liquid in the sealed cavity from flowing back to the return pipe assembly.

[0006] Optionally, the inner liquid seal assembly comprises an inner liquid seal tube, the inner liquid seal tube is embedded in the sealed cavity, and the height of the check element is lower than the bottom of the inner liquid seal tube.

[0007] Optionally, the return pipe assembly comprises a main return pipe and a sight glass pipe, the main return pipe is in communication with the inner liquid seal tube and the sight glass pipe respectively, the sight glass pipe is connected to the sealed cavity through the check element, and the sight glass pipe is used for allowing a user to observe the liquid level therein.

[0008] Optionally, the outer cylinder assembly comprises a cylinder body, a base and a main pipe interface, the sealed cavity is arranged in the cylinder body, the base is arranged at the bottom of the cylinder body and is used for being mounted to the ship, and the main pipe interface is arranged on the cylinder body and is used for connecting the sealed cavity to the cargo hold of the ship, wherein the opening pressure of the check element is configured to be smaller than the pressure corresponding to the difference between the bottom of the main pipe interface and the liquid level of the sealing liquid in the sealed cavity under normal pressure.

[0009] Optionally, the return pipe assembly further comprises a bend pipe section, the sight glass pipe is connected to the check element through the bend pipe section.

[0010] Optionally, the outer cylinder assembly further comprises a main sight glass, the main sight glass is arranged on the side wall of the cylinder body and is used for allowing a user to observe the liquid level in the sealed cavity.

[0011] Optionally, the inner liquid seal assembly comprises an inner liquid seal tube, the inner liquid seal tube is embedded in the sealed cavity, the bottom of the sight glass pipe and the bottom of the main sight glass are lower than the bottom of the inner liquid seal tube, and the top of the sight glass pipe and the top of the main sight glass are higher than the bottom of the main pipe interface.

[0012] Optionally, the outer cylinder assembly comprises a cylinder body, a base and a main pipe interface, the sealed cavity is arranged in the cylinder body, the base is arranged at the bottom of the cylinder body and is used for being mounted to the ship, and the main pipe interface is arranged on the cylinder body and is used for connecting the sealed cavity to the cargo hold of the ship, wherein the inner liquid seal assembly comprises an inner liquid seal tube, the inner liquid seal tube is embedded in the sealed cavity, and the bottom of the inner liquid seal tube is close to the base relative to the bottom of the main pipe interface.

[0013] Optionally, the length of the inner liquid seal tube matches the set maximum pressure value of the cargo hold of the ship, and the distance between the bottom of the inner liquid seal tube and the bottom of the main pipe interface matches the set minimum pressure value of the cargo hold of the ship.

[0014] Optionally, the inner liquid seal assembly further comprises a liquid surface stabilizing baffle, the liquid surface stabilizing baffle is connected to the outer periphery of the inner liquid seal tube, and the liquid surface stabilizing baffle is arranged close to the bottom of the main pipe interface in the height direction.

[0015] Optionally, the pressure vacuum break device further comprises an accumulated liquid disc, the accumulated liquid disc is connected to the inner liquid seal tube and the return pipe assembly respectively, and the accumulated liquid disc is used for containing the sealing liquid transmitted by the inner liquid seal tube when the pressure value of the cargo hold of the ship is greater than the set maximum pressure value.

[0016] Optionally, the volume of the sump is greater than the volume of the inner liquid seal tube.

[0017] Optionally, the bottom of the sump is provided with a backflow port connected with the backflow pipe assembly, and the height of the backflow port is lower than the rest of the bottom.

[0018] Optionally, the end of the sump away from the outer cylinder assembly is provided with an opening; the inner liquid seal assembly further comprises a cover arranged at the end of the inner liquid seal tube away from the base, the cover is located at the opening; and a rain cover is detachably connected with the cover, and the rain cover covers the gap between the cover and the sump, the inner liquid seal tube and the backflow pipe assembly are in communication with the external environment through the gap between the cover and the sump.

[0019] Optionally, the inner liquid seal assembly further comprises a fireproof net arranged between the inner liquid seal tube and the cover.

[0020] Optionally, the outer cylinder assembly comprises a cylinder body provided with a sealed cavity inside, and a liquid discharge valve arranged near the bottom of the cylinder body, the liquid discharge valve is used to discharge the sealing liquid in the sealed cavity.

[0021] The pressure vacuum breaker of the embodiment of the present application, the backflow pipe assembly is connected with the sealed cavity in the outer cylinder assembly through the check element, and the backflow pipe assembly is further connected with the sealed cavity through the inner liquid seal assembly. When the pressure value of the ship cargo hold is less than the set minimum pressure value, the sealing liquid in the inner liquid seal assembly and the backflow pipe assembly is squeezed into the sealed cavity under the action of the external atmospheric pressure, the external air enters the sealed cavity through the inner liquid seal assembly and escapes to the ship cargo hold, so that the pressure value of the ship cargo hold is increased, and the vacuum environment of the ship cargo hold is broken. When the pressure value of the ship cargo hold is greater than the set maximum pressure value, the sealing liquid in the sealed cavity is transmitted to the backflow pipe assembly through the inner liquid seal assembly under the action of the pressure, and the check element prevents the sealing liquid in the sealed cavity from directly flowing back to the backflow pipe assembly, and the ship cargo hold is in communication with the outside through the inner liquid seal assembly, so that the pressure value of the ship cargo hold is decreased. In this way, when the pressure value of the ship cargo hold is greater than the set maximum pressure value, the sealing liquid automatically flows back to the backflow pipe assembly and does not overflow, so that the pressure vacuum breaker does not need to be refilled after the initial filling of the sealing liquid, and the maintenance cost and cleaning cost of using the pressure vacuum breaker are reduced.

[0022] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0023] For a more complete understanding of the present application and the advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which like numbers represent like parts.

[0024] Figure 1 is a structural schematic diagram of an embodiment of the pressure vacuum breaker of the present application; Figure 2 is a structural schematic diagram of an embodiment of the liquid level stabilizing baffle of the present application; Figure 3 is a structural schematic diagram of an embodiment of the liquid accumulation tray of the present application; Figure 4 is a structural schematic diagram of an embodiment of the pressure vacuum breaker of the present application in a state where the pressure value of the cargo hold of the ship is higher than the atmospheric pressure; Figure 5 is a structural schematic diagram of an embodiment of the pressure vacuum breaker of the present application in a state where the pressure value of the cargo hold of the ship is lower than the atmospheric pressure; Figure 6 is a structural schematic diagram of an embodiment of the pressure vacuum breaker of the present application in a state where the pressure value of the cargo hold of the ship is lower than the set minimum pressure value; Figure 7 is a structural schematic diagram of an embodiment of the pressure vacuum breaker of the present application in a state where the pressure value of the cargo hold of the ship reaches the set maximum pressure value; Figure 8 is a structural schematic diagram of an embodiment of the pressure vacuum breaker of the present application in a state where the pressure value of the cargo hold of the ship is higher than the set maximum pressure value; Figure 9 is a structural schematic diagram of another embodiment of the pressure vacuum breaker of the present application in a state where the pressure value of the cargo hold of the ship is higher than the atmospheric pressure.

[0025] Explanation of reference signs: 1 - outer cylinder assembly; 11 - sealed cavity; 12 - cylinder body; 13 - base; 14 - main pipeline interface; 15 - liquid discharge valve; 16 - first mounting flange; 17 - main view window; 2 - inner liquid seal assembly; 21 - inner liquid seal pipe; 22 - liquid level stabilizing baffle; 221 - liquid stabilizing hole; 23 - cover; 24 - rain cover; 25 - fireproof net; 26 - second mounting flange; 3 - return pipe assembly; 31 - main return pipe; 32 - view window pipe; 33 - elbow pipe section; 4 - check element; 5 - liquid accumulation tray; 51 - return port; 52 - opening. DETAILED DESCRIPTION

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0027] To address the technical problem of sealing solution leakage within existing pressure vacuum rupture devices after triggering overpressure protection, this application provides a pressure vacuum rupture device. The pressure vacuum rupture device includes an outer cylinder assembly for installation on a ship. The outer cylinder assembly has an internal sealed cavity for communication with the ship's cargo hold, where a sealing liquid is injected. The pressure vacuum rupture device also includes an inner liquid seal assembly, at least a portion of which is embedded in the sealed cavity and is sealed to the outer cylinder assembly. The portion of the inner liquid seal assembly embedded in the sealed cavity is spaced apart from the bottom wall of the sealed cavity. The pressure vacuum rupture device further includes a return pipe assembly, which is connected to the sealed cavity via a check element and is also connected to the inner liquid seal assembly. The check element is configured to allow sealing liquid in the return pipe assembly to flow into the sealed cavity while preventing sealing liquid in the sealed cavity from flowing back to the return pipe assembly. This is described in detail below.

[0028] Please see Figure 1 , Figure 1 This is a schematic diagram of an embodiment of the pressure vacuum breaking device of this application.

[0029] In one embodiment, the pressure vacuum rupture device can be applied to scenarios such as liquid cargo ships, where it can balance the pressure in the ship's cargo hold. The pressure vacuum rupture device includes an outer cylinder assembly 1, which is used for installation on the ship. The outer cylinder assembly 1 provides the mounting base for the pressure vacuum rupture device and the ship; specifically, it can be installed on the ship's deck, etc. The outer cylinder assembly 1 has a sealed cavity 11 inside, which connects to the ship's cargo hold and is used to inject a sealing liquid. The pressure vacuum rupture device also includes an inner liquid seal assembly 2, at least a portion of which is embedded in the sealed cavity 11, and the inner liquid seal assembly 2 is sealed to the outer cylinder assembly 1. The portion of the inner liquid seal assembly 2 embedded in the sealed cavity 11 is spaced apart from the bottom wall of the sealed cavity 11. The partial embedding of the inner liquid seal assembly 2 into the sealed cavity 11 and its separation from the bottom wall creates an initial liquid seal structure to ensure sealing under normal conditions, while also reserving space for the flow of the sealing liquid and pressure balance, ensuring that the adjustment function can be triggered in case of abnormal pressure. The pressure vacuum breaking device also includes a return pipe assembly 3, which is connected to the sealing cavity 11 via a check element 4, and is also connected to the inner liquid seal assembly 2. The check element 4 is configured to allow the sealing liquid in the return pipe assembly 3 to flow into the sealing cavity 11 while preventing the sealing liquid in the sealing cavity 11 from flowing back to the return pipe assembly 3.

[0030] In this embodiment, after the initial filling of the sealing liquid, the sealing liquid in the sealing cavity 11 submerges the bottom of the portion of the inner liquid seal assembly 2 embedded in the sealing cavity 11, constructing an initial liquid seal structure to ensure sealing under normal conditions. The sealing liquid can be a water-glycol solution, etc., and is not limited here. When the pressure value of the ship's cargo hold is less than the set minimum pressure value, under the action of external atmospheric pressure, the sealing liquid in the inner liquid seal assembly 2 and the return pipe assembly 3 is forced into the sealing cavity 11. External air enters the sealing cavity 11 through the inner liquid seal assembly 2 and escapes into the ship's cargo hold, causing the pressure value of the ship's cargo hold to rise and breaking the vacuum environment of the ship's cargo hold. When the pressure value of the ship's cargo hold is greater than the set maximum pressure value, under the action of pressure, the sealing liquid in the sealing cavity 11 is transferred to the return pipe assembly 3 through the inner liquid seal assembly 2, while the check element 4 prevents the sealing liquid in the sealing cavity 11 from flowing directly back to the return pipe assembly 3. The ship's cargo hold is connected to the outside through the inner liquid seal assembly 2, causing the pressure value of the ship's cargo hold to drop.

[0031] In this embodiment, when the pressure in the cargo hold exceeds the set maximum pressure, the sealing liquid automatically flows back to the return pipe assembly 3 without overflowing. This achieves the goal of eliminating the need for secondary filling of the sealing liquid after the initial filling of the pressure vacuum breaking device, thereby reducing the maintenance and cleaning costs of using the pressure vacuum breaking device.

[0032] In one embodiment, the outer cylinder assembly 1 includes a cylinder 12, a base 13, and a main pipeline interface 14. A sealed cavity 11 is provided inside the cylinder 12. The base 13 is mounted on the bottom of the cylinder 12 and is used for mounting to a ship. The main pipeline interface 14 is disposed on the cylinder 12, and the sealed cavity 11 is connected to the ship's cargo hold through the main pipeline interface 14. Specifically, the main pipeline interface 14 may be disposed on the side of the cylinder 12. The inner liquid seal assembly 2 includes an inner liquid seal tube 21, which is embedded in the sealed cavity 11. The inner liquid seal tube 21 extends vertically along the direction of gravity. Specifically, the bottom of the inner liquid seal tube 21 is spaced apart from the bottom wall of the sealed cavity 11.

[0033] The check valve element 4 is lower than the bottom of the inner liquid seal pipe 21, which prevents the cargo hold from connecting to the external environment through the return pipe assembly 3 when the pressure in the cargo hold is lower than the set minimum pressure, thus preventing premature breaking of the vacuum environment in the cargo hold. Specifically, when the pressure in the cargo hold is lower than the set minimum pressure, the liquid level in the inner liquid seal pipe 21 drops under the pressure difference, and the liquid level in the return pipe assembly 3 drops simultaneously. The sealing liquid in the inner liquid seal pipe 21 and the return pipe assembly 3 is forced into the sealing cavity 11, and the liquid level in the sealing cavity 11 rises. Until the liquid level in the inner liquid seal pipe 21 drops to the bottom of the inner liquid seal pipe 21, outside air enters the sealing cavity 11 along the inner liquid seal pipe 21 and forms bubbles at the bottom of the inner liquid seal pipe 21, which rise to the liquid surface in the sealing cavity 11 and escape. They then connect to the downstream cargo hold through the main pipeline interface 14, thereby breaking the vacuum environment in the cargo hold. The height of the check element 4 is lower than the bottom of the inner liquid seal pipe 21, so that the outside air along the return pipe assembly 3 not only has to overcome the opening pressure of the check element 4, but also the pressure caused by the liquid level difference between the check element 4 and the bottom of the inner liquid seal pipe 21. Therefore, it can prevent the ship's cargo hold from being connected to the external environment through the return pipe assembly 3, which would cause the vacuum environment of the ship's cargo hold to be broken in advance.

[0034] The opening pressure of the check element 4 is configured to be less than the pressure corresponding to the liquid level difference between the bottom of the main pipeline interface 14 and the sealing liquid in the sealing cavity 11 under normal pressure. This embodiment ensures the normal functioning of the check element 4 by reasonably setting its opening pressure.

[0035] Furthermore, a first mounting flange 16 is provided at the end of the cylinder 12 away from the base 13, and a second mounting flange 26 is provided at the inner liquid seal pipe 21. The cylinder 12 and the inner liquid seal pipe 21 are sealed together by the first mounting flange 16 and the second mounting flange 26.

[0036] In one embodiment, the length of the inner liquid seal pipe 21 is matched to the set maximum pressure value of the ship's cargo hold. This embodiment, by reasonably setting the length of the inner liquid seal pipe 21, ensures that when the pressure value of the ship's cargo hold exceeds the set maximum pressure value, the pressure action can guarantee that the sealing liquid in the sealing cavity 11 is squeezed through the inner liquid seal pipe 21 to the return pipe assembly 3, ensuring that the ship's cargo hold is connected to the outside through the inner liquid seal pipe 21, thus reducing the pressure value of the ship's cargo hold. If the length of the inner liquid seal pipe 21 is too short, the ship's cargo hold will connect to the outside before the pressure value reaches the set maximum pressure value; conversely, if the length of the inner liquid seal pipe 21 is too long, the ship's cargo hold will exceed the set maximum pressure value before connecting to the outside, resulting in excessive pressure in the ship's cargo hold and potentially causing safety problems.

[0037] The bottom of the inner liquid seal pipe 21 is close to the base 13 relative to the bottom of the main pipeline interface 14, so that the distance between the bottom of the inner liquid seal pipe 21 and the bottom of the main pipeline interface 14 matches the set minimum pressure value of the ship's cargo hold. This embodiment ensures that the sealing liquid in the sealing cavity 11 will not overflow the bottom of the main pipeline interface 14 and enter the ship's cargo hold when the pressure value of the ship's cargo hold is less than the set minimum pressure value. If the distance between the bottom of the inner liquid seal pipe 21 and the bottom of the main pipeline interface 14 is too small, the sealing liquid in the sealing cavity 11 will overflow the bottom of the main pipeline interface 14 and enter the ship's cargo hold when the pressure value of the ship's cargo hold is less than the set minimum pressure value.

[0038] Please refer to the following: Figure 2 , Figure 2 This is a schematic diagram of the structure of an embodiment of the liquid level stabilizing baffle of this application.

[0039] In one embodiment, the inner liquid seal assembly 2 further includes a liquid level stabilizing baffle 22. The liquid level stabilizing baffle 22 is connected to the outer periphery of the inner liquid seal pipe 21, and is positioned close to the bottom of the main pipeline interface 14 in the height direction. Furthermore, the top surface of the liquid level stabilizing baffle 22 is flush with the bottom of the main pipeline interface 14. In this way, when the pressure in the ship's cargo hold is less than a set minimum pressure value, the liquid level stabilizing baffle 22 can stabilize the liquid level of the sealing liquid in the sealing cavity 11, minimizing the possibility that the liquid level of the sealing liquid in the sealing cavity 11 exceeds the bottom of the main pipeline interface 14, thus preventing the sealing liquid in the sealing cavity 11 from entering the ship's cargo hold through the main pipeline interface 14.

[0040] Specifically, the liquid level stabilizing baffle 22 has multiple liquid stabilizing holes 221. The liquid level stabilizing baffle 22 can be an annular plate surrounding the outer periphery of the inner liquid seal pipe 21. The multiple liquid stabilizing holes 221 are distributed circumferentially along the liquid level stabilizing baffle 22, and each liquid stabilizing hole 221 also extends radially along the liquid level stabilizing baffle 22. The multiple liquid stabilizing holes 221 cooperate to stabilize the liquid level of the sealing liquid in the sealing cavity 11.

[0041] In one embodiment, the pressure vacuum breaking device further includes a liquid collection tray 5, which is connected to the inner liquid seal pipe 21 and the return pipe assembly 3. The liquid collection tray 5 is used to contain the sealing liquid transmitted from the inner liquid seal pipe 21 when the pressure value in the ship's cargo hold exceeds a set maximum pressure value.

[0042] The accumulator tray 5 is located near the end of the inner liquid seal pipe 21 away from the outer cylinder assembly 1. When the pressure in the ship's cargo hold exceeds the set maximum pressure, the sealing fluid in the sealing cavity 11 is forced into the inner liquid seal pipe 21 under pressure. The level of the sealing fluid in the inner liquid seal pipe 21 continues to rise until it is pushed into the accumulator tray 5. The accumulator tray 5 can store the sealing fluid overflowing from the inner liquid seal pipe 21, avoiding the need for secondary filling of sealing fluid due to leakage and avoiding unnecessary cleaning work.

[0043] Furthermore, the volume of the accumulator tray 5 is larger than the volume of the inner liquid seal tube 21. In other words, the accumulator tray 5 in this embodiment has a larger volume, which can provide sufficient storage space to store the sealing liquid overflowing from the inner liquid seal tube 21, thereby minimizing the need for secondary filling of sealing liquid due to leakage and avoiding unnecessary cleaning work.

[0044] Please refer to the following: Figure 3 , Figure 3 This is a schematic diagram of the structure of an embodiment of the fluid collection tray of this application.

[0045] In one embodiment, the bottom of the liquid collection tray 5 is provided with a return port 51 connected to the return pipe assembly 3, and the height of the return port 51 is lower than the rest of the bottom of the tray. In this way, under the action of gravity, the sealing liquid overflowing into the liquid collection tray 5 can flow into the return pipe assembly 3 through the return port 51.

[0046] Specifically, the accumulating tray 5 is sealed and welded to the inner liquid seal tube 21. An opening is made at the edge of the accumulating tray 5 to form a return port 51. The accumulating tray 5 is welded to the return tube assembly 3, so that the return port 51 communicates with the return tube assembly 3. The bottom of the accumulating tray 5 has a slope, so that the height of the return port 51 is lower than the rest of the tray bottom.

[0047] In one embodiment, the end of the liquid collection tray 5 facing away from the outer cylinder assembly 1 has an opening 52. The inner liquid seal assembly 2 also includes a shield 23, which covers the end of the inner liquid seal tube 21 away from the base 13, and the shield 23 is located at the opening 52. The inner liquid seal assembly 2 also includes a rain cover 24, which is detachably connected to the shield 23, and the rain cover 24 is configured to cover the gap between the shield 23 and the liquid collection tray 5. The inner liquid seal tube 21 and the return pipe assembly 3 communicate with the external environment through the gap between the shield 23 and the liquid collection tray 5.

[0048] When the pressure in the ship's cargo hold is lower than the set minimum pressure, outside air enters the inner liquid seal pipe 21 and the return pipe assembly 3 through the gap between the shield 23 and the accumulator 5. The sealing liquid in the inner liquid seal pipe 21 and the return pipe assembly 3 is forced into the sealing cavity 11. Outside air enters the sealing cavity 11 through the inner liquid seal pipe 21 and escapes into the ship's cargo hold, causing the pressure in the ship's cargo hold to rise and breaking the vacuum environment in the ship's cargo hold. When the pressure in the ship's cargo hold is higher than the set maximum pressure, the sealing liquid in the sealing cavity 11 is forced into the inner liquid seal pipe 21 under pressure. The liquid level in the inner liquid seal pipe 21 continues to rise until it is pushed into the accumulator 5. The ship's cargo hold is connected to the gap between the shield 23 and the accumulator 5 through the inner liquid seal pipe 21, thus communicating with the outside, causing the pressure in the ship's cargo hold to drop, playing an overpressure protection role.

[0049] Optionally, the rain cover 24 can be fixed to the cover 23 by fasteners such as screws, so as to achieve a detachable connection between the rain cover 24 and the cover 23.

[0050] In one embodiment, please continue to refer to Figure 1 The inner liquid seal assembly 2 also includes a fireproof mesh 25, which is positioned between the inner liquid seal tube 21 and the shield 23. The fireproof mesh 25 can be made of stainless steel wire mesh, etc. In scenarios where there are flames or sparks on a ship's deck, when the flames or sparks come into contact with the fireproof mesh 25, the excellent thermal conductivity of stainless steel will rapidly disperse the heat, causing a sharp drop in flame temperature. This prevents the flame from continuing to burn and spread. Simultaneously, the fine mesh can physically divide the flame, cutting off the combustion chain. This ensures that the pressure vacuum breaking device meets fire safety requirements.

[0051] In one embodiment, the reflux pipe assembly 3 includes a main reflux pipe 31 and a viewing window pipe 32. The main reflux pipe 31 is connected to both the inner liquid seal pipe 21 and the viewing window pipe 32. Specifically, both the main reflux pipe 31 and the viewing window pipe 32 extend along the height direction of the pressure vacuum breaking device. The viewing window pipe 32 is installed on the main reflux pipe 31 via a flange. The main reflux pipe 31 is connected to the reflux port 51 of the liquid collection tray 5, and then connected to the inner liquid seal pipe 21 via the liquid collection tray 5. The viewing window pipe 32 is connected to the sealed cavity 11 via a check element 4, and the viewing window pipe 32 is used for the user to observe the liquid level therein. Further, the reflux pipe assembly 3 also includes a bend section 33, through which the viewing window pipe 32 is connected to the check element 4.

[0052] It should be noted that when the pressure in the ship's cargo hold is lower than the set minimum pressure, the sealing liquid in the inner liquid seal pipe 21 and the viewing window pipe 32 is forced into the sealing cavity 11. In this embodiment, the bottom of the viewing window pipe 32 is lower than the bottom of the inner liquid seal pipe 21, so that when the pressure in the ship's cargo hold is lower than the set minimum pressure, the level of the sealing liquid in the return pipe assembly 3 can be normally observed through the viewing window pipe 32. Furthermore, in this embodiment, the top of the viewing window pipe 32 is higher than the bottom of the main pipeline interface 14, so that the level of the sealing liquid in the return pipe assembly 3 can be normally observed through the viewing window pipe 32 when the sealing liquid is initially added.

[0053] The outer cylinder assembly 1 also includes a main viewing window 17, which is located on the side wall of the cylinder 12. The main viewing window 17 is used by the user to observe the liquid level in the sealed cavity 11. The top of the main viewing window 17 is close to the top of the sight glass 32, and the bottom of the main viewing window 17 is close to the bottom of the sight glass 32. That is, the main viewing window 17 and the sight glass 32 provide a relatively consistent field of view, which is convenient for the operator to observe the liquid level of the sealing liquid in the return pipe assembly 3 and the outer cylinder assembly 1. Both the main viewing window 17 and the sight glass 32 are marked with corresponding scales, which is convenient for the operator to quantify the liquid level of the sealing liquid.

[0054] In one embodiment, the outer cylinder assembly 1 further includes a drain valve 15, which is located near the bottom of the cylinder 12. The drain valve 15 is used to drain the sealing liquid in the sealing cavity 11. When the pressure vacuum breaking device is initially filled with sealing liquid, the pressure vacuum breaking device is open to the atmosphere. Open the rain cover 24 and add sealing liquid to the accumulator 5. Under the action of gravity, the sealing liquid is added to the sealing cavity 11 of the cylinder 12 along the return pipe assembly 3. Observe the main viewing window 17 to determine whether the filling is in place. If the filling is excessive, the excess sealing liquid can be drained through the drain valve 15. At this time, the liquid level of the sealing cavity 11 and the inner liquid sealing pipe 21 are the same, and the liquid level of the sealing liquid in the return pipe assembly 3 is slightly higher than the former two. The drain valve 15 is normally sealed with a plug. When it is necessary to drain the sealing liquid in the sealing cavity 11, the plug can be removed.

[0055] The working process of the pressure vacuum breaking device according to the embodiments of this application is described below.

[0056] 1. During normal operation, the pressure in the ship's cargo holds lies between the set minimum and maximum pressure values. For example... Figure 4 As shown, if the pressure in the ship's cargo hold is higher than atmospheric pressure, the liquid level of the sealing liquid in the sealed cavity 11 inside the cylinder 12 will decrease under the action of pressure difference, while the liquid level of the sealing liquid in the inner liquid seal pipe 21 will increase. Due to the action of the check element 4, the liquid level of the sealing liquid in the return pipe assembly 3 will remain unchanged.

[0057] 2. For example Figure 5 As shown, during normal operation, if the pressure in the ship's cargo hold is lower than atmospheric pressure, the liquid level of the sealing liquid in the inner liquid seal pipe 21 drops under the action of pressure difference, and the liquid level of the sealing liquid in the return pipe assembly 3 drops synchronously. The sealing liquid is forced into the sealing cavity 11, and the liquid level of the sealing liquid in the sealing cavity 11 rises.

[0058] 3. For example Figure 6 As shown, when the pressure in the ship's cargo hold is lower than the set minimum pressure, the liquid level of the sealing liquid in the inner liquid seal pipe 21 drops to the bottom of the inner liquid seal pipe 21, while the liquid level of the sealing liquid in the sealing cavity 11 rises to the position of the liquid level stabilizing baffle 22. Outside air enters the sealing cavity 11 along the inner liquid seal pipe 21, forming bubbles at the bottom of the inner liquid seal pipe 21, which then rise to the surface of the sealing liquid in the sealing cavity 11 and escape. This escapes and connects to the downstream ship's cargo hold through the main pipeline interface 14, thus breaking the vacuum. Under the action of the liquid level stabilizing baffle 22, the sealing liquid in the sealing cavity 11 will not fluctuate or overflow to the main pipeline interface 14. The liquid level of the sealing liquid in the return pipe assembly 3 drops synchronously. Due to the opening pressure of the check valve element 4, the liquid level of the sealing liquid in the return pipe assembly 3 is slightly higher than the bottom of the inner liquid seal pipe 21.

[0059] 4. For example Figure 7 As shown, when the pressure in the ship's cargo hold reaches the set maximum pressure value, the liquid level of the sealing fluid in the sealing cavity 11 drops to the bottom of the inner liquid seal pipe 21, and the liquid level of the sealing fluid in the inner liquid seal pipe 21 rises to the top of the inner liquid seal pipe 21. As the pressure in the ship's cargo hold continues to rise, as... Figure 8 As shown, the sealing liquid in the inner liquid seal pipe 21 is pushed into the accumulator 5. Gas in the ship's cargo hold is connected to the atmosphere through the inner liquid seal pipe 21 and the fireproof mesh 25, providing overpressure protection. As the pressure in the ship's cargo hold decreases, the liquid in the accumulator 5 flows back to the sealing cavity 11 under gravity, forming... Figure 1 The state shown.

[0060] 5. Based on scenarios 2 and 3 above, if the pressure in the ship's cargo hold rises above atmospheric pressure, then as follows: Figure 9As shown, the liquid level of the sealing liquid in the inner liquid seal pipe 21 and the sealing cavity 11 is related to... Figure 4 The situation is consistent. However, due to the action of the check element 4, the liquid level of the sealing liquid in the return pipe assembly 3 cannot rise again. Based on the above scenario, when the pressure in the ship's cargo hold drops below atmospheric pressure again, the opening of the check element 4 not only needs to overcome the original pressure (the opening pressure when there is no liquid level difference on both sides of the check element 4), but also needs to offset the pressure corresponding to the liquid level difference between the sealing cavity 11 and the return pipe assembly 3. Therefore, the situation where the check element 4 abnormally opens and prematurely breaks the vacuum under the vacuum condition of the ship's cargo hold will not occur.

[0061] The situation where the check valve element 4 abnormally opens and prematurely breaks the vacuum refers to a situation where, under vacuum conditions in the ship's cargo hold, outside air directly enters the sealed cavity 11 through the return pipe assembly 3 and the check valve element 4, forming bubbles at the bottom of the outer cylinder and escaping to the liquid surface. These bubbles then connect to the downstream ship's cargo hold through the main pipeline interface 14, causing premature vacuum breaking. However, due to the presence of the check valve element 4, the resistance that outside gas needs to overcome to enter the sealed cavity 11 from the return pipe assembly 3 is always higher than the resistance to enter the sealed cavity 11 from the inner liquid seal pipe 21, thus preventing this situation from occurring. In the above embodiment, the design of the viewing window tube 32 connected to the check valve element 4 via a bend section 33 further increases the resistance that outside gas needs to overcome to enter the sealed cavity 11 from the return pipe assembly 3, further reducing the risk of the check valve element 4 abnormally opening and prematurely breaking the vacuum.

[0062] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0063] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0064] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0065] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A pressure vacuum breaking device, characterized in that, include: An outer cylinder assembly for installation on a ship, the outer cylinder assembly having an internal sealed cavity for communication with the ship's cargo hold, the sealed cavity being used for injecting a sealing liquid; An inner liquid seal assembly is at least partially embedded in the sealing cavity, and the inner liquid seal assembly is sealed to the outer cylinder assembly, wherein the portion of the inner liquid seal assembly embedded in the sealing cavity is spaced apart from the bottom wall of the sealing cavity; as well as A return pipe assembly is connected to the sealed cavity via a check element, and the return pipe assembly is connected to the inner liquid seal assembly; wherein the check element is configured to allow the sealing liquid in the return pipe assembly to flow into the sealed cavity while preventing the sealing liquid in the sealed cavity from flowing back to the return pipe assembly.

2. The pressure vacuum breaking device according to claim 1, characterized in that, The internal liquid seal assembly includes an internal liquid seal tube embedded in the sealing cavity, and the height of the check element is lower than the bottom of the internal liquid seal tube.

3. The pressure vacuum breaking device according to claim 1, characterized in that, The reflux pipe assembly includes a main reflux pipe and a viewing window pipe. The main reflux pipe is connected to the inner liquid seal pipe and the viewing window pipe respectively. The viewing window pipe is connected to the sealed cavity through the check element. The viewing window pipe is used for the user to observe the liquid level inside.

4. The pressure vacuum breaking device according to claim 3, characterized in that, The outer cylinder assembly includes: The cylindrical body has the sealed cavity inside; A base, installed at the bottom of the cylinder, is used for mounting to a ship; and A main pipeline interface is provided in the cylinder, and the sealed cavity is connected to the ship's cargo hold through the main pipeline interface; The opening pressure of the check valve element is configured to be less than the pressure corresponding to the liquid level difference between the bottom of the main pipeline interface and the sealing liquid in the sealed cavity under normal pressure.

5. The pressure vacuum breaking device according to claim 3, characterized in that, The return pipe assembly also includes a bend, through which the window pipe is connected to the check element.

6. The pressure vacuum breaking device according to claim 4, characterized in that, The outer cylinder assembly also includes: A main viewing window is located on the side wall of the cylinder, and the main viewing window is used for the user to observe the liquid level in the sealed cavity.

7. The pressure vacuum breaking device according to claim 6, characterized in that, The inner liquid seal assembly includes an inner liquid seal tube embedded in the sealing cavity; the bottom of the viewing window tube and the bottom of the main viewing window are lower than the bottom of the inner liquid seal tube, and the top of the viewing window tube and the top of the main viewing window are higher than the bottom of the main pipeline interface.

8. The pressure vacuum breaking device according to claim 1, characterized in that, The outer cylinder assembly includes: The cylindrical body has the sealed cavity inside; A base, installed at the bottom of the cylinder, is used for mounting to a ship; and A main pipeline interface is provided in the cylinder, and the sealed cavity is connected to the ship's cargo hold through the main pipeline interface; The inner liquid seal assembly includes an inner liquid seal tube, which is embedded in the sealing cavity, and the bottom of the inner liquid seal tube is close to the base relative to the bottom of the main pipeline interface.

9. The pressure vacuum breaking device according to claim 8, characterized in that, The length of the inner liquid seal pipe is matched to the maximum pressure value set in the ship's cargo hold, and the distance between the bottom of the inner liquid seal pipe and the bottom of the main pipeline interface is matched to the minimum pressure value set in the ship's cargo hold.

10. The pressure vacuum breaking device according to claim 8, characterized in that, The inner liquid seal assembly also includes a liquid level stabilizing baffle, which is connected to the outer periphery of the inner liquid seal tube and is positioned close to the bottom of the main pipeline interface in the height direction.

11. The pressure vacuum breaking device according to claim 8, characterized in that, The pressure vacuum breaking device also includes a liquid collection tray, which is connected to the inner liquid seal pipe and the return pipe assembly respectively; the liquid collection tray is used to contain the sealing liquid transmitted from the inner liquid seal pipe when the pressure value in the ship's cargo hold is greater than the set maximum pressure value.

12. The pressure vacuum breaking device according to claim 11, characterized in that, The volume of the liquid accumulation tray is greater than the volume of the inner liquid seal tube.

13. The pressure vacuum breaking device according to claim 11, characterized in that, The bottom of the liquid collection tray has a return port that is connected to the return pipe assembly, and the height of the return port is lower than the rest of the bottom of the tray.

14. The pressure vacuum breaking device according to claim 11, characterized in that, The end of the liquid collection tray opposite to the outer cylinder assembly has an opening; The internal liquid seal assembly further includes: A shield, covering the end of the inner liquid seal tube away from the base, the shield being located at the opening; and A rain cover is detachably connected to the shield, and the rain cover covers the gap between the shield and the liquid collection tray. The inner liquid seal tube and the return tube assembly are in communication with the external environment through the gap between the shield and the liquid collection tray.

15. The pressure vacuum breaking device according to claim 14, characterized in that, The inner liquid seal assembly also includes a fireproof mesh, which is disposed between the inner liquid seal tube and the shield.

16. The pressure vacuum breaking device according to claim 1, characterized in that, The outer cylinder assembly includes: The cylindrical body, wherein the sealed cavity is provided inside; and A drain valve is located near the bottom of the cylinder and is used to drain the sealing liquid in the sealed cavity.

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