An automatic exhaust valve and a cavitation protection device for the unloading pump of a chemical liquid oil tanker.
By designing an automatic venting valve and a liquid level sensing system, the problem of cavitation during the unloading of liquid oil tankers was solved, achieving automatic venting and protection of the unloading pump, avoiding cavitation and dry running, and ensuring the stability and environmental friendliness of the unloading process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LANGFANG HUILAI PETROLEUM PROD CO LTD
- Filing Date
- 2025-07-16
- Publication Date
- 2026-05-26
AI Technical Summary
During the unloading process of liquid oil tank trucks, cavitation is prone to occur, which can lead to cavitation and dry running of the unloading pump and damage to sealing components. Existing exhaust valves have problems with lag and sensitivity to impurities, resulting in gas retention or seal failure.
Design an automatic venting valve and a cavitation protection device for unloading pumps of chemical liquid tank trucks, including an automatic venting assembly and a buffer storage tank. The automatic venting is achieved by using a float-limiting guide post and a conical plug dynamic seal to sense the liquid level. Combined with a liquid level transmitter, the speed of the unloading pump is controlled to prevent cavitation and dry running of the unloading pump.
The automatic exhaust valve adjusts automatically according to changes in liquid level to prevent gas stagnation, protect the unloading pump from cavitation and dry running, ensure the impeller chamber of the unloading pump is full of liquid, and prevent environmental pollution.
Smart Images
Figure CN224284260U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of petrochemical storage and transportation technology, and in particular to an automatic exhaust valve and a pump anti-cavitation protection device for unloading pumps of chemical liquid oil tankers. Background Technology
[0002] Before unloading, liquid oil tankers inevitably need to be filled with pumps and emptied. During the unloading process, as the liquid level in the tanker decreases, the unloading pump is prone to cavitation, especially for media with low density. This can cause cavitation and other problems in the unloading pump, resulting in pump vibration and dry running. In severe cases, it can also cause the pump body to overheat and damage to sealing components such as mechanical seals.
[0003] In addition, existing exhaust valves may have problems such as hysteresis and sensitivity to impurities, which may cause gas to stagnate in the system or fail to seal. Utility Model Content
[0004] To address the aforementioned problems, this utility model aims to provide an automatic exhaust valve and a cavitation protection device for the unloading pump of a chemical liquid oil tanker.
[0005] The technical solution of this utility model is as follows:
[0006] On the one hand, an automatic venting valve is provided, including a housing and an automatic venting assembly disposed within the housing;
[0007] The housing includes a detachably connected upper housing and a lower housing, with an outlet pipe at the center of the top of the housing and an inlet pipe at the center of the bottom of the housing;
[0008] The automatic venting assembly includes a conical cavity fixed sealing body and a float limiting guide post, a conical plug dynamic sealing body, and a float connected in sequence. The conical cavity fixed sealing body includes a body and a fluid channel penetrating the body. The fluid channel includes a conical section and a cylindrical section. The end of the conical section with a smaller inner diameter is connected to the cylindrical section. The outer diameter of the float limiting guide post is smaller than the inner diameter of the cylindrical section, and the conical plug dynamic sealing body is matched with the conical section.
[0009] When a liquid medium enters the housing, the float can float in the liquid medium and allow the conical plug dynamic seal to enter the fluid channel under the action of the float limiting guide post to form a seal with the conical cavity fixed seal; when the liquid medium inside the housing decreases and venting is required, the float can cause the conical plug dynamic seal to leave the fluid channel under its own weight, thus releasing the seal.
[0010] Preferably, the upper housing and the lower housing are detachably connected by flange bolts.
[0011] Preferably, both the outlet pipe and the inlet pipe have threads on their outer surfaces.
[0012] Preferably, the conical plug dynamic sealing body is fitted with an elastic sealing ring.
[0013] Preferably, multiple elastic sealing rings are provided.
[0014] Preferably, a plurality of the elastic sealing rings are arranged at equal intervals on the conical plug dynamic sealing body.
[0015] Preferably, the immersion depth of the float in the liquid medium is half the diameter of the float.
[0016] On the other hand, a cavitation protection device for unloading pump of chemical liquid oil tanker is also provided, including a buffer storage tank and an unloading pump. The buffer storage tank is equipped with a level gauge, which is connected to a level transmitter, and the level transmitter is connected to the unloading pump.
[0017] The buffer storage tank is connected to the tank truck quick interface via the tank truck unloading pipeline, connected to the oil and gas recovery interface via the gas phase pressure relief pipeline, and connected to the unloading pump via the unloading pump inlet pipeline.
[0018] The housing cavity of the unloading pump is connected to the oil and gas recovery interface through the second gas phase pressure relief pipeline, and the output end of the unloading pump is connected to the unloading outlet pipeline.
[0019] Both the first gas phase pressure relief pipeline and the second gas phase pressure relief pipeline are equipped with a shut-off valve and an exhaust valve. The exhaust valve is an automatic exhaust valve as described above and is located at one end near the oil and gas recovery interface.
[0020] Preferably, the gas phase pressure relief line is connected to the top of the buffer storage tank.
[0021] Preferably, the top of the automatic vent valve on the second gas phase pressure relief pipeline is at a lower level than the top of the buffer storage tank.
[0022] The beneficial effects of this utility model are:
[0023] The automatic exhaust valve of this invention can automatically exhaust or seal according to the liquid level of the liquid medium inside the housing, thus preventing gas from stagnating in the system.
[0024] The anti-cavitation protection device of this utility model, by setting up a buffer storage tank and a level transmitter, allows the unloading pump to automatically adjust its speed according to the liquid level in the buffer tank, thereby regulating the pumping flow rate and ensuring that the liquid level in the buffer storage tank is always full. This effectively avoids cavitation and dry running of the unloading pump. By setting up an automatic exhaust valve connected to the oil and gas recovery interface, it can realize automatic exhaust during operation and automatic priming before starting the unloading pump. At the same time, it can also centrally process the oil and gas discharged during operation, avoiding direct discharge of oil and gas into the atmosphere and causing environmental pollution. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of the structure of the automatic exhaust valve of this utility model;
[0027] Figure 2 This is a schematic diagram of the anti-cavitation protection device for the unloading pump of a chemical liquid oil tanker according to this utility model.
[0028] The numbers in the diagram are: 1-tank truck quick interface, 2-buffer storage tank, 3-level gauge, 4-level transmitter, 5-shut-off valve, 6-vent valve, 7-oil and gas recovery interface, 8-unloading pump, 9-unloading outlet pipeline;
[0029] 601-Outlet pipe, 602-Shell, 603-Float limit guide post, 604-Conical cavity fixed seal, 605-Elastic sealing ring, 606-Conical plug moving seal, 607-Flange bolt, 608-Float ball, 609-Inlet pipe. Detailed Implementation
[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and technical features described in this application can be combined with each other. It should also be pointed out that, unless otherwise indicated, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terms "comprising" or "including" and similar words used in this utility model refer to elements or objects preceding the word that encompass the elements or objects listed following the word and their equivalents, without excluding other elements or objects.
[0031] On the one hand, such as Figure 1As shown, this utility model provides an automatic exhaust valve, including a housing 602 and an automatic exhaust assembly disposed within the housing 602;
[0032] The housing 602 includes a detachably connected upper housing and a lower housing. An outlet pipe 601 is provided at the center of the top of the housing 602, and an inlet pipe 609 is provided at the center of the bottom of the housing 602.
[0033] The automatic venting assembly includes a conical cavity fixed seal body 604 and a float limiting guide post 603, a conical plug dynamic seal body 606, and a float 608 connected in sequence. The conical cavity fixed seal body 604 includes a body and a fluid channel penetrating the body. The fluid channel includes a conical section and a cylindrical section. The end of the conical section with a smaller inner diameter is connected to the cylindrical section. The outer diameter of the float limiting guide post 603 is smaller than the inner diameter of the cylindrical section, and the conical plug dynamic seal body 606 is matched with the conical section.
[0034] When liquid medium enters the housing 602, the float 608 can float in the liquid medium and allow the conical plug dynamic seal 606 to enter the fluid channel under the action of the float limiting guide post 603 to form a seal with the conical cavity fixed seal 604; when the liquid medium inside the housing 602 decreases and venting is required, the float 608 can cause the conical plug dynamic seal 606 to leave the fluid channel and release the seal under its own weight.
[0035] In the above embodiments, the exhaust principle of the automatic exhaust valve is as follows:
[0036] Gas enters the housing 602 through inlet pipe 609. The gas cannot cause the float 608 to rise, and it exits through outlet pipe 601 into the corresponding collection device, thus achieving automatic venting. When liquid medium enters the housing 602 through inlet pipe 609, the float rises as the liquid level increases. Under the action of the float limiting guide post 603, the automatic venting assembly enters the fluid channel. When the conical plug moving seal 606 contacts the conical plug stationary seal 604, a seal is formed, and the venting valve closes. Conversely, when the liquid medium inside the housing 602 decreases, the float 608 descends, the conical plug moving seal 606 leaves the fluid channel, releasing the seal, and the venting valve resumes its venting function.
[0037] In one specific embodiment, the upper housing and the lower housing are detachably connected by flange bolts 607, and the outer surfaces of the outlet pipe 601 and the inlet pipe 609 are both threaded.
[0038] In one specific embodiment, an elastic sealing ring 605 is fitted onto the conical plug-shaped dynamic sealing body 606. Optionally, multiple elastic sealing rings 605 are provided, and the multiple elastic sealing rings 605 are equally spaced on the conical plug-shaped dynamic sealing body 606.
[0039] In the above embodiments, by providing the elastic sealing ring 605, the sealing performance between the conical cavity fixed sealing body 604 and the conical plug moving sealing body 606 can be further enhanced, preventing the liquid medium in the housing 602 from entering the fluid channel of the cylindrical section.
[0040] In one specific embodiment, the immersion depth of the float 608 in the liquid medium is half the diameter of the float 608.
[0041] In the above embodiments, the use of a float with this buoyancy can prevent the float from being too small to form a seal between the conical cavity fixed seal 604 and the conical plug moving seal 606, allowing the liquid medium to pass through the fluid channel of the cylindrical section; it can also prevent the float from being too large to release the seal under its own weight.
[0042] On the other hand, such as Figure 2 As shown, this utility model also provides a protection device for preventing air cavitation of the unloading pump of a chemical liquid oil tanker, including a buffer storage tank 2 and an unloading pump 8. The buffer storage tank 2 is equipped with a level gauge 3, which is connected to a level transmitter 4. The level transmitter 4 is connected to the unloading pump 8.
[0043] The buffer storage tank 2 is connected to the tank truck quick interface 1 via the tank truck unloading pipeline, connected to the oil and gas recovery interface 7 via the gas phase pressure relief pipeline, and connected to the unloading pump 8 via the unloading pump inlet pipeline.
[0044] The housing cavity of the unloading pump 8 is connected to the oil and gas recovery interface 7 through the gas phase pressure relief pipeline 2, and the output end of the unloading pump 8 is connected to the unloading outlet pipeline 9.
[0045] Both the first gas phase pressure relief pipeline and the second gas phase pressure relief pipeline are equipped with a shut-off valve 5 and an exhaust valve 6. The exhaust valve 6 is an automatic exhaust valve as described above and is located at one end near the oil and gas recovery interface 7.
[0046] In the above embodiment, the liquid level gauge 3 can monitor the liquid level in the buffer storage tank 2, and the liquid level transmitter 4 can transmit signals remotely. The rotational speed of the unloading pump 8 is controlled based on the liquid level in the buffer storage tank, thus adjusting the pumping flow rate of the unloading pump 8 to ensure the liquid level in the buffer storage tank 2 is maintained, keeping the impeller chamber of the unloading pump 8 always full and effectively preventing cavitation and dry running. It should be noted that controlling the pump speed via a liquid level transmitter is existing technology; the specific structure and control method will not be described in detail here.
[0047] In one specific embodiment, the first gas phase pressure relief line is connected to the top of the buffer storage tank 2, and the top of the automatic vent valve on the second gas phase pressure relief line is at a lower level than the top of the buffer storage tank 2.
[0048] In one specific embodiment, the workflow of using this utility model is as follows:
[0049] The oil tanker is connected to the oil tanker quick interface 1, the oil and gas recovery interface 7 is connected to the oil and gas recovery tank, and the unloading outlet pipeline 9 is connected to the unloading oil storage tank.
[0050] When the unloading valve of the tanker truck is opened, the anti-cavitation protection device of the unloading pump of this utility model starts to automatically fill the pump and vent air. When the height of the liquid level gauge 3 is higher than the height of the automatic vent valve on the gas phase pressure relief pipeline 2, the unloading pump 8 is started and the unloading operation begins. At this time, the automatic vent valve on the gas phase pressure relief pipeline 2 is in the automatic closed state.
[0051] As the liquid level in level gauge 3 increases, level transmitter 4 remotely controls unloading pump 8 to increase its speed until level transmitter 4 reaches the set value, at which point unloading pump 8 operates at full frequency. As the medium in the tanker truck decreases, and buffer tank 2 cannot reach full level, level transmitter 4 controls unloading pump 8 to decrease its speed, thereby reducing the amount pumped from buffer tank 2 and maintaining a balance between inflow and outflow. As the liquid level in buffer tank 2 continues to drop, the unloading frequency continues to decrease until level transmitter 4 reaches the lower limit of the set value. At this point, unloading pump 8 automatically stops, indicating that the medium in the tanker truck has been completely unloaded, and the unloading operation is complete, awaiting the next operation. After the unloading operation is finished, shut-off valves 5 on the two gas phase pressure relief pipelines are closed to effectively isolate the unloading process from the oil and gas recovery system.
[0052] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.
Claims
1. An automatic vent valve characterized in that, Includes a housing and an automatic exhaust assembly disposed within the housing; The housing includes a detachably connected upper housing and a lower housing, with an outlet pipe at the center of the top of the housing and an inlet pipe at the center of the bottom of the housing; The automatic venting assembly includes a conical cavity fixed sealing body and a float limiting guide post, a conical plug dynamic sealing body, and a float connected in sequence. The conical cavity fixed sealing body includes a body and a fluid channel penetrating the body. The fluid channel includes a conical section and a cylindrical section. The end of the conical section with a smaller inner diameter is connected to the cylindrical section. The outer diameter of the float limiting guide post is smaller than the inner diameter of the cylindrical section, and the conical plug dynamic sealing body is matched with the conical section. When a liquid medium enters the housing, the float can float in the liquid medium and allow the conical plug dynamic seal to enter the fluid channel under the action of the float limiting guide post to form a seal with the conical cavity fixed seal; when the liquid medium inside the housing decreases and venting is required, the float can cause the conical plug dynamic seal to leave the fluid channel under its own weight, thus releasing the seal.
2. The automatic vent valve of claim 1, wherein The upper housing and the lower housing are detachably connected by flange bolts.
3. The automatic vent valve of claim 1, wherein Both the outlet pipe and the inlet pipe have threads on their outer surfaces.
4. The automatic vent valve of claim 1, wherein An elastic sealing ring is fitted onto the conical plug dynamic sealing body.
5. The automatic exhaust valve according to claim 4, characterized in that, Multiple elastic sealing rings are provided.
6. The automatic exhaust valve according to claim 5, characterized in that, Multiple elastic sealing rings are arranged at equal intervals on the conical plug dynamic sealing body.
7. The automatic exhaust valve according to any one of claims 1-6, characterized in that, The immersion depth of the float in the liquid medium is half the diameter of the float.
8. A cavitation protection device for an unloading pump of a chemical liquid oil tanker, characterized in that, It includes a buffer storage tank and an unloading pump. The buffer storage tank is equipped with a level gauge, which is connected to a level transmitter. The level transmitter is connected to the unloading pump. The buffer storage tank is connected to the tank truck quick interface via the tank truck unloading pipeline, connected to the oil and gas recovery interface via the gas phase pressure relief pipeline, and connected to the unloading pump via the unloading pump inlet pipeline. The housing cavity of the unloading pump is connected to the oil and gas recovery interface through the second gas phase pressure relief pipeline, and the output end of the unloading pump is connected to the unloading outlet pipeline. Both the first gas phase pressure relief pipeline and the second gas phase pressure relief pipeline are equipped with a shut-off valve and an exhaust valve. The exhaust valve is an automatic exhaust valve as described in any one of claims 1-7 and is located at one end near the oil and gas recovery interface.
9. The anti-cavitation protection device for the unloading pump of a chemical liquid oil tanker according to claim 8, characterized in that, The gas phase pressure relief pipeline is connected to the top of the buffer storage tank.
10. The anti-cavitation protection device for the unloading pump of a chemical liquid oil tanker according to claim 8 or 9, characterized in that, The top of the automatic vent valve on the second gas phase pressure relief pipeline is at a lower level than the top of the buffer storage tank.