Sulfur dioxide recovery device

Abstract

The sulfur dioxide recovery device comprises a first-stage heat exchanger and a second-stage heat exchanger, the secondary heat exchanger is used for further cooling the feed gas; the third-stage heat exchanger is used for further cooling the feed gas; the primary separator is used for separating feed gas into a gas phase and a liquid phase, a liquid phase outlet of the primary separator is connected with a first liquid phase discharge pipe, the first liquid phase discharge pipe is connected with a product storage tank, a gas phase outlet of the primary separator is connected with an expansion machine, and a gas outlet of the expansion machine is connected with a secondary separator; a liquid phase outlet of the secondary separator is connected with a second liquid phase discharge pipe, the second liquid phase discharge pipe is connected with a product storage tank, and a gas phase outlet of the secondary separator is connected with a tail gas discharge pipe. The sulfur dioxide recovery device disclosed by the utility model can be used for separating and recovering discharged tail gas, is energy-saving and environment-friendly, and has higher economic value and social value. The utility model has the advantages of simple structure, stability and reliability.

Description

Technical Field

[0001] The utility model relates to a gas recovery device, in particular to a sulfur dioxide recovery device. Background Art

[0002] Sulfur dioxide is the most common and simplest sulfur oxide. Its chemical formula is SO2. It is a colorless, transparent gas with a pungent odor. It is soluble in water, ethanol, and ether. Sulfur dioxide is one of the main air pollutants. It is emitted during volcanic eruptions and is also produced in many industrial processes. When sulfur dioxide dissolves in water, it forms sulfurous acid. If sulfurous acid is further oxidized, sulfuric acid is quickly and efficiently generated.

[0003] Sulfur dioxide is mainly used to produce sulfur trioxide, sulfuric acid, sulfite, thiosulfate, and is also used as a fumigant, preservative, disinfectant, reducing agent, etc. Sulfur dioxide is a reductive bleaching agent allowed for use in China. It has a bleaching effect on food and a strong inhibitory effect on oxidases in plant foods.

[0004] In industry, sulfur dioxide can be obtained by burning sulfur ore. After the reaction gas is purified and liquefied, it can produce sulfur dioxide products with corresponding quality requirements. The tail gas produced by the above process contains a large amount of SO2, which will seriously pollute the environment if it is directly discharged into the atmosphere. Utility Model Content

[0005] The utility model aims to provide a sulfur dioxide recovery device.

[0006] The sulfur dioxide recovery device of the utility model comprises:

[0007] A primary heat exchanger for cooling the raw gas to reduce its temperature;

[0008] A secondary heat exchanger for further cooling the raw gas, connected to the primary heat exchanger through a pipeline;

[0009] A third-stage heat exchanger for further cooling the raw gas, connected to the second-stage heat exchanger through a pipeline;

[0010] A primary separator is used to separate the raw gas into gas phase and liquid phase, the liquid phase outlet of the primary separator is connected to the first liquid phase discharge pipe, the first liquid phase discharge pipe is connected to the product storage tank, the gas phase outlet of the primary separator is connected to the air inlet of the expander, the air outlet of the expander is connected to the secondary separator, the liquid phase outlet of the secondary separator is connected to the second liquid phase discharge pipe, the second liquid phase discharge pipe is connected to the product storage tank, the gas phase outlet of the secondary separator is connected to the tail gas discharge pipe, the tail gas discharge pipe passes through the third-stage heat exchanger and the first-stage heat exchanger in sequence, so that the tail gas in the tail gas discharge pipe provides cooling for the third-stage heat exchanger and the first-stage heat exchanger.

[0011] In the sulfur dioxide recovery device of the utility model, a first throttle valve is arranged on the first liquid phase discharge pipe, and a second throttle valve is arranged on the second liquid phase discharge pipe.

[0012] The sulfur dioxide recovery device of the utility model further comprises a refrigeration system, wherein the refrigeration system comprises:

[0013] A compressor used to compress the refrigerant,

[0014] A water cooler for cooling the refrigerant, connected to the outlet of the compressor through a pipeline;

[0015] A precooler for further cooling the refrigerant, connected to the water cooler through a pipeline;

[0016] A third throttle valve is used for throttling and reducing the pressure of the refrigerant, wherein the inlet of the third throttle valve is connected to the outlet of the precooler, and the outlet of the third throttle valve is connected to the air inlet of the compressor through a return line, so that the refrigerant circulates between the compressor and the third throttle valve, and the return line passes through the secondary heat exchanger and the precooler in sequence, so that the refrigerant in the return line provides cooling capacity for the secondary heat exchanger and the precooler.

[0017] The sulfur dioxide recovery device of the utility model can separate and recover the discharged tail gas, save energy and protect the environment, and has great economic value and social value. The advantages of the utility model are: simple structure, stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the sulfur dioxide recovery device of the utility model. DETAILED DESCRIPTION

[0019] Sulfur dioxide is easy to liquefy. Because sulfur dioxide is a polar molecule with a large relative molecular mass and strong intermolecular forces, it has a low boiling point and is easy to liquefy.

[0020] like Figure 1 As shown, the sulfur dioxide recovery device of the utility model comprises:

[0021] The primary heat exchanger E3 is used to cool the raw gas to reduce its temperature;

[0022] The secondary heat exchanger E4 for further cooling the raw gas is connected to the primary heat exchanger through a pipeline;

[0023] The third-stage heat exchanger E5 for further cooling the raw gas is connected to the second-stage heat exchanger through a pipeline;

[0024] A primary separator V1 is used to separate the raw gas into gas phase and liquid phase, the liquid phase outlet of the primary separator is connected to the first liquid phase discharge pipe 10, the first liquid phase discharge pipe is connected to the product storage tank V3, the gas phase outlet of the primary separator is connected to the air inlet of the expander ET1, the air outlet of the expander is connected to the secondary separator V2, the liquid phase outlet of the secondary separator is connected to the second liquid phase discharge pipe 20, the second liquid phase discharge pipe is connected to the product storage tank, the gas phase outlet of the secondary separator is connected to the tail gas discharge pipe 30, the tail gas discharge pipe 30 passes through the third-stage heat exchanger and the first-stage heat exchanger in sequence, so that the tail gas in the tail gas discharge pipe provides cooling for the third-stage heat exchanger and the first-stage heat exchanger.

[0025] In the sulfur dioxide recovery device of the utility model, a first throttle valve V10 is arranged on the first liquid phase discharge pipe, and a second throttle valve V20 is arranged on the second liquid phase discharge pipe.

[0026] The sulfur dioxide recovery device of the utility model further comprises a refrigeration system, wherein the refrigeration system comprises:

[0027] Compressor C1 for compressing refrigerant,

[0028] A water cooler E1 for cooling the refrigerant is connected to the outlet of the compressor through a pipeline;

[0029] A precooler E2 for further cooling the refrigerant, connected to the water cooler through a pipeline;

[0030] The third throttle valve V30 is used for throttling and reducing the pressure of the refrigerant. The inlet of the third throttle valve is connected to the outlet of the precooler E2, and the outlet of the third throttle valve is connected to the air inlet of the compressor through the return line 50, so that the refrigerant circulates between the compressor and the third throttle valve.

[0031] In the sulfur dioxide recovery device of the utility model, the return pipeline 50 passes through the secondary heat exchanger and the precooler in sequence, so that the refrigerant in the return pipeline provides cooling capacity for the secondary heat exchanger and the precooler.

[0032] The working process of the sulfur dioxide recovery device of the utility model:

[0033] The raw gas enters the primary heat exchanger E3, the secondary heat exchanger E4, and the tertiary heat exchanger E5 for cooling, and then enters the primary separator V1. The liquid phase at the bottom of the separator is throttled by the first throttle valve V10 and sent to the product storage tank V3. The gas phase at the top of the separator enters the expander ET1 for expansion and cooling, and then enters the secondary separator V2. The liquid phase at the bottom of the separator is throttled by the second throttle valve V20 and sent to the product storage tank V3. The gas phase at the top of the separator enters the tertiary heat exchanger E5 and the primary heat exchanger E3 in turn. After heat exchange and reheating, the tail gas exits the device.

[0034] After being pressurized by the refrigeration compressor C1, the refrigerant is cooled to 40°C by the water cooler E1 and enters the precooler E2. After precooling, it is throttled and depressurized by the third throttle valve V30, and after heat exchange with the secondary heat exchanger E2, it enters the precooler E2 and then returns to the compressor inlet.

[0035] The sulfur dioxide recovery device of the utility model comprises the following equipment: a heat exchanger, a refrigerator, an expander, a separator and related valves and pipelines.

[0036] In the sulfur dioxide recovery device of the utility model, the heat exchanger can be a plate-fin heat exchanger, a plate heat exchanger, a coiled-tube heat exchanger, a shell-and-tube heat exchanger or a related combination.

[0037] The sulfur dioxide recovery device of the utility model can separate and recover the discharged tail gas, save energy and protect the environment, and has great economic value and social value. The advantages of the utility model are: simple structure, stable and reliable.

[0038] In the sulfur dioxide recovery device of the utility model, the expander can be a turbine type or a screw type.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A sulfur dioxide recovery device, characterized in that: include: A primary heat exchanger for cooling the raw gas to reduce its temperature; A secondary heat exchanger for further cooling the raw gas, connected to the primary heat exchanger through a pipeline; A third-stage heat exchanger for further cooling the raw gas is connected to the second-stage heat exchanger through a pipeline; A primary separator is used to separate the raw gas into gas phase and liquid phase, the liquid phase outlet of the primary separator is connected to the first liquid phase discharge pipe, the first liquid phase discharge pipe is connected to the product storage tank, the gas phase outlet of the primary separator is connected to the air inlet of the expander, the air outlet of the expander is connected to the secondary separator, the liquid phase outlet of the secondary separator is connected to the second liquid phase discharge pipe, the second liquid phase discharge pipe is connected to the product storage tank, the gas phase outlet of the secondary separator is connected to the tail gas discharge pipe, the tail gas discharge pipe passes through the third-stage heat exchanger and the first-stage heat exchanger in sequence, so that the tail gas in the tail gas discharge pipe provides cooling for the third-stage heat exchanger and the first-stage heat exchanger.

2. The sulfur dioxide recovery device according to claim 1, characterized in that: The first liquid phase discharge pipe is provided with a first throttle valve, and the second liquid phase discharge pipe is provided with a second throttle valve.

3. The sulfur dioxide recovery device according to claim 2, characterized in that: Also included is a refrigeration system, the refrigeration system comprising: A compressor used to compress the refrigerant, A water cooler for cooling the refrigerant, connected to the outlet of the compressor through a pipeline; A precooler for further cooling the refrigerant, connected to the water cooler through a pipeline; A third throttle valve is used for throttling and reducing the pressure of the refrigerant, wherein the inlet of the third throttle valve is connected to the outlet of the precooler, and the outlet of the third throttle valve is connected to the air inlet of the compressor through a return line, so that the refrigerant circulates between the compressor and the third throttle valve, and the return line passes through the secondary heat exchanger and the precooler in sequence, so that the refrigerant in the return line provides cooling capacity for the secondary heat exchanger and the precooler.

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