A protective device for ammonia storage tank breather valve vent nozzle

Abstract

The utility model discloses a kind of protective devices for ammonia storage tank breather valve vent pipe orifice, belong to chemical industry environmental protection equipment technical field, including horn mouth part, wire mesh demister, liquid baffle, spray nozzle, metal mesh type firestop core, front collection bag and rear collection bag, horn mouth part is connected at the breather valve vent pipe end, for reducing gas flow rate;Wire mesh demister is located in the straight pipe portion downstream of horn mouth part, for intercepting liquid droplet entrained in gaseous ammonia;Liquid baffle is located at the rear side of wire mesh demister, for gas-liquid baffle separation;Spray nozzle is located at the top of straight pipe portion, into desalted water to absorb gaseous ammonia;Metal mesh type firestop core is integrated in the rear end of wire mesh demister, for blocking fire source;Front collection bag and rear collection bag are respectively located at the front and rear side of wire mesh demister, connected to recovery tank by drainage pipeline.The five-stage protection mechanism of flared deceleration→wire mesh demisting→spray absorption→fire prevention and explosion prevention→two-stage collection, realize the efficient recovery and safety control of ammonia.

Description

Technical Field

[0001] This utility model belongs to the field of chemical environmental protection equipment technology, and in particular relates to a protective device for the vent pipe of the breather valve of an ammonia storage tank, used to recover the escaped ammonia gas, eliminate safety hazards and environmental pollution. Background Technology

[0002] The liquid ammonia tank area of ​​a certain enterprise's chemical ammonia synthesis unit contains two atmospheric pressure ammonia storage tanks with a capacity of 10,000 tons, which are classified as a Class I major hazard source. The ammonia storage tanks store liquid ammonia at a temperature of -33℃. A breather valve is installed on the top of the ammonia storage tank to balance the tank pressure. During daily production, when the pressure of the ammonia storage tank exceeds 0.0065 MPa, the breather valve automatically opens to release the gas in the ammonia storage tank to reduce the pressure inside the tank. When the breather valve is vented, gaseous liquid ammonia is released from the vent pipe, along with a trace amount of liquid ammonia. Especially in summer when the temperature is high, the liquid ammonia in the ammonia storage tank is heated and partially evaporates, and is released into the atmosphere through the breather valve. The existing atmospheric pressure ammonia storage tank directly releases ammonia-containing gas into the atmosphere when the breather valve is vented, which has the following main problems: (1) There is a safety hazard, as releasing ammonia gas can easily cause poisoning of inspection personnel; (2) There is environmental pollution, as the strong ammonia smell on site pollutes the surrounding environment; (3) There is a waste of resources, as the direct release of liquid ammonia causes economic losses. Utility Model Content

[0003] Technical problem solved: In response to the problems existing in the background technology, this utility model provides a protective device for the vent pipe of the breather valve of an ammonia storage tank. Through a five-level protection mechanism of flaring and deceleration → wire mesh defoaming → spray absorption → flame arrest and explosion prevention → dual-stage collection, it achieves efficient recovery and safe control of ammonia.

[0004] Technical solution: The present invention provides a protective device for the vent pipe of a breather valve of an ammonia storage tank, comprising:

[0005] The flared end is connected to the vent pipe port of the breathing valve, and its diameter is radially enlarged to more than 1.5 times the original diameter to reduce the gas flow rate.

[0006] A wire mesh demister, wherein the wire mesh demister is located in the straight pipe section downstream of the flared end, and is used to intercept liquid droplets entrained in gaseous ammonia;

[0007] A baffle plate, located behind the wire mesh demister, is inclined and its height is 1 / 3 of the pipe diameter, and is used for gas-liquid flow separation.

[0008] A spray nozzle is located at the top of the straight pipe section and is used to introduce demineralized water to absorb gaseous ammonia.

[0009] A metal mesh flame arrestor core is integrated into the rear end of a wire mesh demister to block fire sources.

[0010] The front and rear collection bags are located on the front and rear sides of the wire mesh demister, respectively, and are connected to the recovery tank through the drain line.

[0011] Preferably, the connection between the flared end and the venting pipe of the breathing valve is welded, and the flaring angle is 15°-30°.

[0012] Preferably, the baffle plate is a deflector structure with an inclination angle of 45°-60°.

[0013] Preferably, the wire mesh demister uses a multi-layer densely woven stainless steel wire mesh with a mesh density of ≥200 mesh.

[0014] Preferably, the demineralized water spray direction of the spray nozzle is arranged opposite to the airflow direction.

[0015] Preferably, the housing of the protective device is made of 304 stainless steel.

[0016] Preferably, the baffle plate and its connecting pipe are detachably connected to the end of the straight pipe section via a flange connection end.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention achieves efficient ammonia recovery and safe control through a five-stage protection mechanism: flared deceleration, wire mesh defoaming, spray absorption, flame arrest and explosion prevention, and dual-stage collection. Through wire mesh interception and spray absorption, the amount of gaseous ammonia escaping is reduced by more than 95%, and the ammonia recovery rate is ≥90%. The metal mesh flame arrestor core can prevent open flame backfire, conforming to GB / T13347-2010 standards and improving the explosion-proof safety of the device. The flange connection supports quick disassembly for convenient maintenance.

[0019] This invention also has other beneficial effects, which are described in the embodiments section of the specification and will not be repeated here. Attached Figure Description

[0020] Figure 1 This is a front view of the structure of the protective device of this utility model;

[0021] Figure 2 for Figure 1 Right view of the structure of the central protective device.

[0022] Attached reference numerals: 1. Breathing valve vent pipe; 2. Flared mouth section; 3. Straight pipe section; 4. Front collection bag; 5. Rear collection bag; 6. Wire mesh demister; 7. Metal mesh flame arrestor core; 8. Liquid baffle; 9. Vent port; 10. Spray nozzle; 11. Drainage line; 12. Recovery tank. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the following will be described in conjunction with the accompanying drawings. Figures 1-2 The technical solutions of the embodiments of this utility model are clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model are within the protection scope of this utility model.

[0024] like Figures 1-2 As shown, this utility model discloses a protective device for the vent pipe of an ammonia storage tank's breather valve, comprising a flared mouth section 2, a front collection bag 4, a rear collection bag 5, a wire mesh demister 6, a metal mesh flame arrestor 7, a liquid baffle 8, and a spray nozzle 10. The housing of the protective device is made of 304 stainless steel to prevent oxidation and corrosion. The flared mouth section 2 is connected to the vent pipe 1 of the breather valve, and its diameter is radially enlarged to more than 1.5 times the original diameter to reduce the gas flow rate; the connection A between the flared mouth section 2 and the vent pipe 1 of the breather valve is welded, and the flare angle is 15°-30°. The wire mesh demister 6 is located in the straight pipe section 3 downstream of the flared mouth section 2 to intercept liquid droplets entrained in gaseous ammonia.

[0025] The baffle plate 8 is located behind the wire mesh demister 6. It can be installed at an angle, with a height of 1 / 3 of the pipe diameter, for gas-liquid flow separation. A vent 9 is formed at the top of the baffle plate 8. The baffle plate 8 is a baffle structure with an inclination angle of 45°-60°. It should be noted that it can also be installed as follows: Figure 1 The vertical structure shown tends to result in significant gas-liquid flow velocity loss. Therefore, a baffle structure with an inclined rearward orientation is more effective in reducing airflow resistance. The baffle plate 8 and its connecting pipe are detachably connected to the end of the straight pipe section 3 via flange connection end B, facilitating the disassembly and replacement of the internal structure of the protection device.

[0026] A spray nozzle 10 is located at the top of the straight pipe section 3, through which demineralized water is introduced to absorb gaseous ammonia. In a preferred embodiment, the demineralized water spray direction of the spray nozzle 10 is arranged opposite to the airflow direction to obtain a better absorption effect.

[0027] The metal mesh flame arrestor core 7 is integrated at the rear end of the wire mesh demister 6 to block the fire source; the metal mesh flame arrestor core can block open flame flashback, which meets the GB / T13347-2010 standard and improves the explosion-proof safety of the device.

[0028] The front collection bag 4 and the rear collection bag 5 are respectively located on the front and rear sides of the wire mesh demister 6, and are connected to the recovery tank 12 through the drain line 11. The wire mesh demister 6 uses multi-layer densely woven stainless steel wire mesh with a mesh density ≥200 mesh. The liquid ammonia solution collected in the wire mesh demister 6 can be collected into the recovery tank 12 through the drain line for recycling. After wire mesh interception and spray absorption, the amount of gaseous ammonia emitted is reduced by more than 95%, and the ammonia recovery rate is ≥90%.

[0029] The working principle or method of this utility model:

[0030] This invention increases the diameter of the flared nozzle, reducing the airflow velocity. After the airflow impacts the wire mesh demister, the liquid ammonia is intercepted and stored in the front collection bag. The gaseous ammonia passing through the wire mesh demister is absorbed by the demineralized water spray nozzle at the top. The demineralized airflow encounters a baffle plate at the nozzle, which deflects and intercepts the gaseous ammonia, allowing it to be absorbed and then collected in the rear collection bag, thus achieving ammonia recovery and preventing ammonia from being released into the atmosphere. The device also includes a metal mesh flame arrestor to prevent an ignition source from entering the ammonia storage tank through the breather valve vent in case of an accident.

[0031] The above are preferred embodiments of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A protective device for the vent pipe of a breather valve in an ammonia storage tank, characterized in that, include: The flared mouth (2) is connected to the port of the breathing valve vent pipe (1), and its diameter is radially enlarged to more than 1.5 times the original diameter to reduce the gas flow rate. A wire mesh demister (6) is located in the straight pipe section (3) downstream of the flared mouth section (2) and is used to intercept liquid droplets entrained in gaseous ammonia. A baffle plate (8) is located behind the wire mesh demister (6). It is inclined and its height is 1 / 3 of the diameter of the pipe opening. It is used for gas-liquid baffle separation. Spray nozzle (10), the spray nozzle (10) is located at the top of the straight pipe section (3), and demineralized water is introduced to absorb gaseous ammonia; Metal mesh flame arrestor core (7), which is integrated at the rear end of the wire mesh demister (6) and is used to block the fire source; The front collection bag (4) and the rear collection bag (5) are respectively located on the front and rear sides of the wire mesh demister (6) and connected to the recovery tank (12) through the drain line (11).

2. The protective device for the vent pipe of the breather valve of an ammonia storage tank according to claim 1, characterized in that, The connection (A) between the flared mouth (2) and the vent pipe (1) of the breathing valve is welded, and the flaring angle is 15°-30°.

3. The protective device for the vent pipe of the breather valve of an ammonia storage tank according to claim 1, characterized in that, The baffle plate (8) is a baffle structure with an inclination angle of 45°-60°.

4. The protective device for the vent pipe of the breather valve of an ammonia storage tank according to claim 3, characterized in that, The wire mesh demister (6) uses a multi-layer densely woven stainless steel wire mesh with a mesh density of ≥200 mesh.

5. The protective device for the vent pipe of the breather valve of an ammonia storage tank according to claim 1, characterized in that, The desalination spray direction of the spray nozzle (10) is arranged opposite to the airflow direction.

6. The protective device for the vent pipe of the breather valve of an ammonia storage tank according to claim 1, characterized in that, The housing of the protective device is made of 304 stainless steel.

7. The protective device for the vent pipe of the breather valve of an ammonia storage tank according to claim 1, characterized in that, The baffle plate (8) and its connecting pipe are detached and connected to the end of the straight pipe section (3) via the flange connection end (B).

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