Method for accumulating activated carbon on upper tube plate of converter and enabling gas to uniformly enter tube nest of converter in calcium carbide method polyvinyl chloride production

Abstract

The invention discloses a method for accumulating activated carbon on an upper tube plate of a converter and enabling gas to uniformly enter a tube nest of the converter in calcium carbide method polyvinyl chloride production, and belongs to the technical field of polyvinyl chloride production. The method comprises the following steps: placing an activated carbon check ring on the upper tube plate of the converter, and laying glass wool cloth at the bottom end in the activated carbon check ring; a circular-truncated-cone-shaped activated carbon layer is stacked on the glass wool cloth; gas such as acetylene gas and hydrogen chloride gas or gas such as acetylene gas, hydrogen chloride gas and vinyl chloride enters an upper sealing head of the converter through a gas inlet of the converter; due to the fact that the thickness of the activated carbon layer is consistent, the gas amount of acetylene gas, hydrogen chloride gas and the like or acetylene gas, hydrogen chloride gas, vinyl chloride and the like entering each tube nest of the converter from the gas inlet in the upper portion of the converter is uniform, and the situation that the gas inlet amount of some tube nests is large, and the gas inlet amount of some tube nests is small is avoided.

Description

Technical Field

[0001] This invention belongs to the field of polyvinyl chloride production technology, specifically relating to a method for depositing activated carbon on the upper tube sheet of a converter in the calcium carbide method of polyvinyl chloride production, so that gas can enter the converter tubes uniformly. Background Technology

[0002] Gases such as acetylene and hydrogen chloride, or a combination of acetylene, hydrogen chloride, and vinyl chloride, enter the converter. Catalysts packed in the converter's tubes catalyze the reaction, causing acetylene and hydrogen chloride to react and produce vinyl chloride. Activated carbon is deposited (laid) on the converter's upper tube sheet to adsorb impurities, chemical substances, or particulate matter carried in the gas entering the converter.

[0003] The existing technology has the following problems: 1. Activated carbon is deposited on the upper tube sheet of the converter, forming a conical or frustum-shaped pile. Acetylene and hydrogen chloride gases enter the converter tubes through this conical or frustum-shaped activated carbon layer, where they are converted into vinyl chloride under the action of a catalyst. Because the activated carbon is piled in a conical or frustum-shaped pile, the gas encounters varying resistance as the pile thickness varies, resulting in uneven gas flow into the converter tubes. Thinner piles at the edges of the conical or frustum-shaped piles result in lower resistance and a larger gas flow into the lower tubes; conversely, thicker piles at the center result in higher resistance and a smaller gas flow into the lower tubes. Larger gas flow leads to more vigorous reactions and higher temperatures, while smaller flow results in lower production efficiency.

[0004] 2. The reaction between acetylene and hydrogen chloride gases is exothermic within the converter tubes. The required reaction temperature is between 120-180℃. Above 180℃, the catalyst deactivates rapidly. The reaction temperature detection point is approximately one-third of the distance between the center of the converter and the outermost tube. However, because the outer tubes have a larger intake volume and their reaction temperature is higher than the detection point, and the detection point is not located there, the measured temperature is not representative. Furthermore, using the detection point temperature to control the intake volume would cause the catalyst in the outermost tubes of the converter to overheat, leading to rapid catalyst deactivation.

[0005] 3. The catalyst in the edge tubes quickly loses its activity due to overheating, resulting in high acetylene content at the converter outlet. This is considered a sign of reduced catalyst activity across the entire converter, necessitating its scrapping. However, the catalyst in the middle tubes receives less gas, meaning many catalysts within the converter do not reach the scrapping stage. This leads to catalyst waste. Summary of the Invention

[0006] To address the problems mentioned in the background section, this invention provides a method for uniformly introducing gas into the converter tubes by depositing activated carbon on the upper tube sheet during the calcium carbide process for polyvinyl chloride production. This method ensures uniform gas intake and features a simple structure.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for uniformly introducing gas into the converter tubes by depositing activated carbon on the upper tube sheet during the calcium carbide process for polyvinyl chloride production, characterized by comprising the following steps: S1. Place an activated carbon baffle on the upper tube sheet of the converter, and lay glass fiber cloth at the bottom inside the activated carbon baffle. S2. Stack frustum-shaped activated carbon layers on glass fiber cloth; Gases such as S3, acetylene, and hydrogen chloride, or acetylene, hydrogen chloride, and vinyl chloride, enter the upper head of the converter through the converter gas inlet. S4. The gas passes through the stacked frustum-shaped activated carbon layer and enters the converter tube containing the catalyst. The catalyst in the converter tube catalyzes the reaction of acetylene and hydrogen chloride to produce vinyl chloride.

[0008] Further, in the present invention, a method for uniformly introducing gas into the converter tube array by depositing activated carbon on the converter upper tube sheet in the production of polyvinyl chloride via the calcium carbide method includes a converter upper head, wherein a converter upper tube sheet is installed at the lower end of the inner interior of the converter upper head, an activated carbon baffle is placed at the upper end of the converter upper tube sheet, a glass fiber cloth is laid flat on the activated carbon baffle, a frustum-shaped activated carbon layer is laid flat on the upper end of the glass fiber cloth, a converter gas inlet is opened at the top of the converter upper head, and a plurality of converter tubes are arranged at the bottom end of the converter upper tube sheet.

[0009] Furthermore, in this invention, the height of the stacked frustum-shaped activated carbon layer is flush with the height of the activated carbon retaining ring, and the upper surface of the stacked frustum-shaped activated carbon layer is flat and without protrusions.

[0010] Furthermore, in this invention, the outer diameter of the activated carbon retaining ring is smaller than the inner diameter of the converter upper end cap, and the activated carbon retaining ring does not contact the inner wall surface of the converter upper end cap.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. Because the activated carbon layer has a uniform thickness, the amount of gas such as acetylene and hydrogen chloride, or acetylene, hydrogen chloride, and vinyl chloride, entering each tube of the converter from the upper inlet of the converter is uniform, and will not cause some tubes to have a large amount of gas entering while others have a small amount of gas entering. 2. The temperature detected by the converter temperature measuring tube is representative of the reaction temperature of each tube, avoiding rapid deactivation of the catalyst in the edge tubes, solving the problem of uneven air intake in each tube of the converter, solving the problem of inconsistent use of catalyst in each tube of the converter, and solving the problem of the temperature detection point not being representative. 3. This invention solves the long-standing problem in the industry where the acetylene content at the converter outlet is high (mistakenly attributed to low catalyst activity), and the catalyst is disposed of as waste after being unloaded, but the catalyst content is still very high when tested. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is an enlarged view of part of the structure of the present invention; Figure 3 This is a schematic diagram of the activated carbon retaining ring structure of the present invention.

[0013] In the diagram: 1. Gas inlet of the converter; 2. Upper end cap of the converter; 3. Upper tube sheet of the converter; 4. Converter tubes; 5. Stacked frustum-shaped activated carbon layer; 6. Activated carbon retaining ring. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Example 1 Please see Figure 1-3 The present invention provides the following technical solution: a method for depositing activated carbon on the upper tube sheet of a converter and uniformly introducing gas into the converter tubes during the calcium carbide process for polyvinyl chloride production, comprising the following steps: S1. Place an activated carbon baffle 6 on the upper tube plate 3 of the converter, and lay glass fiber cloth at the bottom inside the activated carbon baffle 6. S2. Stack a frustum-shaped activated carbon layer 5 on the glass fiber cloth; Gases such as S3, acetylene, and hydrogen chloride, or acetylene, hydrogen chloride, and vinyl chloride, enter the upper head 2 of the converter through the gas inlet 1. S4. The gas passes through the stacked frustum-shaped activated carbon layer 5 and enters the converter tube 4 containing the catalyst. The catalyst in the converter tube 4 catalyzes the reaction of acetylene and hydrogen chloride to produce vinyl chloride.

[0016] Specifically, a method for producing polyvinyl chloride using the calcium carbide method, in which activated carbon is deposited on the upper tube sheet of a converter and gas is uniformly introduced into the converter tubes, includes an upper converter head 2, an upper converter tube sheet 3 installed at the lower end of the upper converter head 2, an activated carbon baffle 6 placed at the upper end of the upper converter tube sheet 3, a layer of glass fiber cloth laid flat on the activated carbon baffle 6, a frustum-shaped activated carbon layer 5 laid flat on the upper end of the glass fiber cloth, a converter gas inlet 1 opened at the top of the upper converter head 2, and several converter tubes 4 arranged at the bottom of the upper converter tube sheet 3.

[0017] Specifically, the height of the stacked frustum-shaped activated carbon layer 5 is the same as the height of the activated carbon retaining ring 6, and the upper surface of the stacked frustum-shaped activated carbon layer 5 is flat and without protrusions.

[0018] By adopting the above technical solutions, the uniformity and stability of the air intake are ensured, preventing excessive differences from occurring.

[0019] Specifically, the outer diameter of the activated carbon retaining ring 6 is smaller than the inner diameter of the upper end cap 2 of the converter, and the activated carbon retaining ring 6 does not contact the inner wall surface of the upper end cap 2 of the converter.

[0020] By adopting the above technical solution, the inner diameter of the activated carbon retaining ring 6 is determined to include all the tube ports of the upper end cap 2 of the converter.

[0021] The working principle and usage process of this invention: In use, acetylene and hydrogen chloride gases, or acetylene, hydrogen chloride, and vinyl chloride gases, enter the upper head 2 of the converter through the gas inlet 1. A glass fiber cloth is laid on the upper tube sheet 3 of the converter, and a frustum-shaped activated carbon layer 5 is stacked on the glass fiber cloth. The gas passes through the stacked frustum-shaped activated carbon layer 5 and enters the converter tube 4 containing the catalyst. Catalysis is achieved through the catalyst packed in the converter tube 4, where acetylene and hydrogen chloride react to produce vinyl chloride. The activated carbon retaining ring 6 serves two purposes: first, it encloses the stacked frustum-shaped activated carbon layer 5, preventing it from entering the converter cylinder flange during catalyst replacement and reassembly of the upper head 2, thus preventing flange seal failure; second, the stacked frustum-shaped activated carbon layer 5 has a flat surface, ensuring a consistent gas entry path into the converter tube 4, preventing some converter tubes from having a large gas intake while others have a small intake.

[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for uniformly introducing gas into the converter tubes by depositing activated carbon on the upper tube sheet during the calcium carbide process for polyvinyl chloride production, characterized in that: Includes the following steps: S1. Place an activated carbon baffle (6) on the upper tube sheet (3) of the converter, and lay glass fiber cloth at the bottom inside the activated carbon baffle (6); S2. Stack frustum-shaped activated carbon layers on glass fiber cloth (5). S3, acetylene and hydrogen chloride gas, or acetylene, hydrogen chloride and vinyl chloride gas, enter the upper head (2) of the converter through the converter gas inlet (1); S4. The gas passes through the stacked frustum-shaped activated carbon layer (5) and enters the converter tube (4) containing the catalyst. The catalyst in the converter tube (4) catalyzes the reaction of acetylene and hydrogen chloride to produce vinyl chloride.

2. The method for producing polyvinyl chloride by calcium carbide method in which activated carbon is deposited on the tube sheet of the converter and the gas is uniformly introduced into the converter tubes in the process of calcium carbide production, as described in claim 1, is characterized in that: The converter includes a converter upper end cap (2), a converter upper tube sheet (3) is installed at the lower end of the converter upper end cap (2), an activated carbon baffle (6) is placed at the upper end of the converter upper tube sheet (3), glass fiber cloth is laid flat at the bottom of the inner part of the activated carbon baffle (6), a stacked frustum-shaped activated carbon layer (5) is laid flat at the top of the glass fiber cloth, a converter gas inlet (1) is opened at the top of the converter upper end cap (2), and several converter tubes (4) are provided at the bottom of the converter upper tube sheet (3).

3. The method for uniformly introducing gas into the converter tubes by depositing activated carbon on the upper tube sheet in the calcium carbide process for polyvinyl chloride production, as described in claim 2, is characterized in that: The height of the stacked frustum-shaped activated carbon layer (5) is the same as the height of the activated carbon retaining ring (6), and the upper surface of the stacked frustum-shaped activated carbon layer (5) is flat and without protrusions.

4. The method for producing polyvinyl chloride by calcium carbide method in which activated carbon is deposited on the tube sheet of the converter and the gas enters the converter tubes uniformly, as described in claim 2, is characterized in that: The outer diameter of the activated carbon retaining ring (6) is smaller than the inner diameter of the upper end cap (2) of the converter, and the activated carbon retaining ring (6) does not contact the inner wall surface of the upper end cap (2) of the converter.

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