Liquid seal device for a quench tank breather valve

Abstract

The utility model relates to a kind of liquid seal device of quenching water tank breathing valve, belong to methanol to olefin technical field.It is by quenching water tank, liquid seal tank and diaphragm pump composition;Quenching water tank top is equipped with breathing valve and second field pressure gauge, and breathing valve breathes mouth is connected to the bottom of liquid seal tank by pipeline, second check valve is installed on the pipeline, and breathing valve suction circuit is formed with atmosphere connection;First stop valve is installed with atmosphere connection in the top of liquid seal tank, and liquid overflow outlet is arranged in the middle lower part of liquid seal tank side;Liquid discharge pipeline and liquid inlet pipeline are arranged in the bottom of liquid seal tank, first field pressure gauge, second stop valve and liquid discharge guide are sequentially installed on liquid discharge pipeline, and diaphragm pump is connected by first check valve, third stop valve and liquid inlet pipeline;Absorption liquid is added in liquid seal tank.The utility model structure is simple, easy to maintain, effectively solve the problem that traditional breathing valve cannot handle harmful ingredients in waste gas, with remarkable environmental protection effect.

Description

Technical Field

[0001] This utility model belongs to the field of methanol-to-olefins technology, specifically relating to a liquid seal device for a breather valve of a quench water tank. Background Technology

[0002] Methanol to Olefins (MTO) is an important chemical process that converts methanol into low-carbon olefins such as ethylene and propylene. In this process, wastewater such as quench water and concentrate is typically stored in a quench water tank for treatment before being discharged. To maintain stable pressure within the quench water tank (pressure fluctuations are caused by factors such as changes in the tank level or ambient temperature), a breather valve is usually installed on the top of the tank. However, because the gas inside the quench water tank contains a high concentration of non-methane hydrocarbons, traditional breather valve designs cannot effectively handle these hydrocarbon compounds, resulting in direct emissions into the atmosphere and causing environmental pollution. Existing breather valves are usually only used to regulate tank pressure and lack the function of treating harmful components in the waste gas. Therefore, there is an urgent need for a device that can effectively absorb hydrocarbon compounds in the breather valve's exhaled gas to reduce environmental pollution and meet environmental protection requirements. Utility Model Content

[0003] To address the aforementioned problems, developing a highly efficient, economical, and easy-to-maintain breather valve liquid seal device is of great significance for reducing harmful gas emissions in the methanol-to-olefins process. This invention proposes a quench water tank breather valve liquid seal device that can promptly and effectively reduce the content of non-methane total hydrocarbons in the breather valve's exhaled air, thereby reducing environmental pollution.

[0004] The present invention discloses a liquid sealing device for a breather valve of a quench water tank, comprising a quench water tank (1), a liquid sealing tank (3), and a diaphragm pump (10). A breather valve (2) and a second field pressure gauge (13) are installed on the top of the quench water tank (1). The breather port of the breather valve (2) is connected to the bottom of the liquid sealing tank (3) through a pipeline. A second check valve (11) connected to the atmosphere is installed on the pipeline to form a breather valve intake circuit. A first shut-off valve (4) connected to the atmosphere is installed on the top of the liquid sealing tank (3). A drain overflow port (12) is provided on the lower middle part of the side of the liquid sealing tank (3). A drain pipeline and an inlet pipeline are provided at the bottom of the liquid sealing tank (3). A first field pressure gauge (6), a second shut-off valve (5), and a drain drain (7) are installed sequentially on the drain pipeline. The diaphragm pump (10) is connected to the inlet pipeline through the first check valve (9), the third shut-off valve (8), and the inlet pipeline. An absorbent liquid is added to the liquid sealing tank (3).

[0005] Furthermore, the absorbent is water, sodium hypochlorite aqueous solution, surfactant solvent (fatty alcohol polyoxyethylene ether, alkyl sulfate, etc.) or organic solvent (white oil, silicone oil, etc.);

[0006] The aforementioned quench water tank (1) has a volume of 2000 m³ in the methanol-to-olefins process. 3 Fixed-roof tank;

[0007] The breathing valve (2) is a DN600 LF8178-24-133-FO type breathing valve;

[0008] The liquid-sealed tank (3) is a vertical tank with a volume of 30L;

[0009] The first shut-off valve (4), the second shut-off valve (5), and the third shut-off valve (8) are DN20 straight-through shut-off valves;

[0010] The first field pressure gauge (6) and the second field pressure gauge (13) are pressure gauges with a range of 0 to 6 kPa;

[0011] The drain valve (7) is a DN20 shut-off valve drain valve;

[0012] The first check valve (9) is a DN20 lift check valve;

[0013] The second check valve (11) is a DN20 wafer check valve;

[0014] The diaphragm pump (10) is a QBK-25PF metering pump.

[0015] To address the issue of high non-methane hydrocarbon (NMR) content in the exhaled gas from the quench water tank's breather valve in existing methanol-to-olefins (MTO) processes, this invention addresses this problem by installing a liquid-sealed tank at the breather valve's inlet. The absorbent liquid within the tank washes the exhaled gas, reducing its NMR content and minimizing environmental pollution. The breather valve's inlet pipeline is connected to the atmosphere via a second check valve, ensuring direct atmospheric intake and preventing direct release of NMR into the atmosphere during exhalation. The liquid-sealed tank features an overflow outlet to prevent gas from being trapped when full. A pressure gauge connected to the bottom of the tank allows for real-time monitoring of the tank's bottom pressure, preventing backflow of liquid into the breather valve due to higher pressure at the bottom than in the quench water tank.

[0016] This utility model has a simple structure, is easy to maintain, and effectively solves the problem that traditional breather valves cannot handle harmful components in exhaust gas, thus having a significant environmental protection effect.

[0017] The working process of this utility model:

[0018] like Figure 1As shown, when the pressure of the second field pressure gauge (13) is lower than 1.1 kPa, the breather valve (2) needs to inhale, and the atmosphere enters the breather valve (2) through the second check valve (11); when the pressure of the second field pressure gauge (13) is higher than 1.5 kPa (due to changes in the pressure inside the tank caused by the inlet / outlet of the quench water tank or changes in the external temperature), the exhaled gas from the breather valve (2) enters the liquid seal tank (3) through the pipeline, and after the gas is washed by the liquid seal, it is released into the atmosphere through the opened first shut-off valve (4). When the liquid seal tank (3) is filled with liquid, the diaphragm pump (10) is started and the third shut-off valve (8) is opened, and the absorbent enters the liquid seal tank (3) through the first check valve (9) and the third shut-off valve (8). When the liquid level in the liquid seal tank (3) is high, the absorbent is discharged through the overflow port (12); after the liquid seal tank (3) is filled with liquid, the diaphragm pump (10) is stopped and the third shut-off valve (8) is closed. The bottom pressure of the liquid seal tank (3) is measured in real time by the first field pressure gauge (6). When the pressure is higher than the pressure of the second field pressure gauge (13), the second shut-off valve (5) is opened to drain the liquid through the drain guide (7) until the pressure of the first field pressure gauge (6) is lower than that of the second field pressure gauge (13). The function of the first check valve (9) is to prevent liquid backflow from causing the diaphragm pump to reverse or the absorption liquid to leak.

[0019] Advantages of this utility model:

[0020] (1) Effective absorption of hydrocarbon compounds: Through the water or other absorbent liquid in the liquid seal tank, non-methane total hydrocarbon compounds in the breather can be effectively absorbed, reducing the pollution of the environment by exhaust gas emissions;

[0021] (2) Simple structure and easy maintenance: The device has a simple structure and is easy to install. The liquid seal effect and liquid seal pressure can be easily maintained through the liquid overflow port and liquid drain.

[0022] (3) Wide range of applications: This device is not only suitable for the quench water tank in the methanol-to-olefins process, but also for other scenarios where there is a breather valve that emits harmful gases;

[0023] (4) Adjustable liquid seal pressure: A local pressure gauge and a drain guide are added to the bottom of the liquid seal tank. The liquid level of the liquid seal tank can be adjusted in real time according to the pressure of the quench water tank to prevent liquid backflow to the breather valve. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0025] Figure 1This is a schematic diagram of the process of the liquid seal device for the breather valve of the quench water tank according to the present invention;

[0026] Figure 2 A comparison of the non-methane total hydrocarbon content in the exhaust gas from the quench water tank before and after the installation of the breather valve liquid seal device in the 1.8 million tons / year methanol-to-olefins process (non-methane total hydrocarbon content was measured by gas chromatography). Detailed Implementation

[0027] Example 1

[0028] The present invention discloses a liquid seal device for a breather valve of a quench water tank, comprising a quench water tank (1), a liquid seal tank (3), and a diaphragm pump (10); a breather valve (2) and a second field pressure gauge (13) are installed on the top of the quench water tank (1), and the breather port of the breather valve (2) is connected to the bottom of the liquid seal tank (3) through a pipeline, and a second check valve (11) connected to the atmosphere is installed on the pipeline to form the breather valve's air intake circuit; a diaphragm pump (10) is installed on the top of the liquid seal tank (3). The liquid seal tank (3) is equipped with a first shut-off valve (4) connected to the atmosphere, and a drain overflow port (12) is provided in the lower middle part of the side of the liquid seal tank (3). A drain line and an inlet line are provided at the bottom of the liquid seal tank (3). A first field pressure gauge (6), a second shut-off valve (5) and a drain drain (7) are installed in sequence on the drain line. A diaphragm pump (10) is connected to the inlet line via a first check valve (9), a third shut-off valve (8) and an inlet line. Absorbent liquid water is added to the liquid seal tank (3).

[0029] The exhalation process of the quench water tank breather valve in the 1.8 million tons / year methanol-to-olefins process is as follows: Before the breather valve (2) is put into operation, the diaphragm pump (10) is started and the third shut-off valve (8) is opened. The water used for liquid sealing enters the liquid sealing tank (3) from the bottom through the inlet pipeline with the second check valve (9) and the third shut-off valve (8). In order to prevent the liquid in the liquid sealing tank (3) from flowing back into the breather valve (2), the second shut-off valve (5) is opened and the liquid level in the liquid sealing tank (3) is adjusted to 1.3 kPa by the drain drain (7) to drain the liquid. During normal production, the pressure of the quench water tank (1) is 1.5 kPa. When the pressure of the quench water tank (1) is higher than 1.5 kPa, the breather valve (2) starts to exhale. The exhaled exhaust gas enters the liquid sealing tank (3) from the bottom through the pipeline. After being washed by the water used for liquid sealing, it is emptied through the opened first shut-off valve (4).

[0030] like Figure 2 As shown, sampling and testing revealed that before the installation of the liquid seal device on the quench water tank's breather valve, the content of non-methane total hydrocarbons in the exhaust gas exhaled by the breather valve (2) was 153562.4 mg / m³. 3After the installation of the liquid seal device for the breather valve of the quench water tank, the exhaust gas exhaled by the breather valve (2) is washed with water in the liquid seal tank (3) and discharged from the first shut-off valve (4). The content of non-methane total hydrocarbons in the exhaust gas is 48812.6 mg / m³. 3 The analysis results show that after installing the liquid seal device on the breather valve of the quench water tank, the content of non-methane total hydrocarbons in the exhaust gas exhaled by the breather valve decreased to about 31% of the previous level, significantly reducing the impact on the environment.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various variations and modifications can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0032] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0033] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0034] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A liquid seal device for a breather valve of a quench water tank, characterized in that: It consists of a quench water tank (1), a liquid seal tank (3), and a diaphragm pump (10); a breather valve (2) and a second field pressure gauge (13) are installed on the top of the quench water tank (1), and the breather port of the breather valve (2) is connected to the bottom of the liquid seal tank (3) through a pipeline. A second check valve (11) connected to the atmosphere is installed on the pipeline to form a breather valve intake circuit; a first shut-off valve (4) connected to the atmosphere is installed on the top of the liquid seal tank (3), and a drain overflow port (12) is provided on the lower middle part of the side of the liquid seal tank (3); a drain pipeline and a liquid inlet pipeline are provided at the bottom of the liquid seal tank (3), and a first field pressure gauge (6), a second shut-off valve (5), and a drain guide (7) are installed in sequence on the drain pipeline. The diaphragm pump (10) is connected through the first check valve (9), the third shut-off valve (8), and the liquid inlet pipeline; an absorbent is added to the liquid seal tank (3).

2. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The absorbent is water, sodium hypochlorite aqueous solution, surfactant solvent or organic solvent.

3. The liquid seal device for the breather valve of a quench water tank as described in claim 2, characterized in that: The surface-active solvent is fatty alcohol polyoxyethylene ether or alkyl sulfate, and the organic solvent is white oil or silicone oil.

4. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The quench water tank (1) is a 2000m³ tank used in the methanol-to-olefins process. 3 Fixed-top tank.

5. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The breathing valve (2) is a DN600 LF8178-24-133-FO type breathing valve.

6. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The liquid seal tank (3) is a vertical tank with a volume of 30L.

7. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The first shut-off valve (4), the second shut-off valve (5), and the third shut-off valve (8) are DN20 straight-through shut-off valves.

8. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The first field pressure gauge (6) and the second field pressure gauge (13) are pressure gauges with a range of 0 to 6 kPa.

9. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The drain valve (7) is a DN20 shut-off valve drain valve, the first check valve (9) is a DN20 lift check valve, and the second check valve (11) is a DN20 wafer check valve.

10. The liquid seal device for the breather valve of a quench water tank as described in claim 1, characterized in that: The diaphragm pump (10) is a QBK-25PF type metering pump.

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