A pressure measuring tube cleaning device in a pre-shrinking process

Abstract

The application relates to a pressure measuring pipe cleaning device in a pre-shrinking process, and belongs to the technical field of chemical engineering and polymerization reaction equipment. By switching of a valve group, the measuring pipeline can be mechanically cleaned under the condition that a process system is completely isolated, the production continuity and equipment utilization are greatly improved, the mechanical piston rod pushing and scraping mode is adopted, compared with pure gas blowing, the cleaning effect of residues which are viscous, solidified or seriously attached to the pipe wall is better and more thorough, multiple valve control and nitrogen blowing / back pressure functions are designed, the process medium is prevented from leaking during the cleaning process, the cleaning operation is carried out in a controllable pressure environment, the risks caused by pressure mutation are avoided, and air is prevented from entering the process system, the pressure measuring, blowing and mechanical cleaning functions are integrated in a modular device, the structure design is reasonable, the shaft alignment ensures smooth cleaning action, and installation and maintenance are convenient.

Description

Technical Field

[0001] This invention relates to the field of chemical and polymerization reaction equipment technology, specifically to a device for online cleaning of pressure measuring pipelines connected to reaction equipment in chemical production processes such as pre-shrinking processes. Background Technology

[0002] In chemical processes such as the prepolymerization of polymers like PET and nylon, real-time pressure monitoring within the reactor is crucial. The common practice is to connect a pressure measuring instrument via a tap pipe leading from the reactor or main pipeline. However, in high-temperature, high-viscosity process environments, material vapors or oligomers can easily condense, crystallize, or adhere within the pressure measuring pipeline, gradually clogging or contaminating the pressure transmission channels. This can lead to inaccurate pressure measurements, uncontrolled reactions, and even safety hazards. The traditional solution is to shut down the plant for disassembly and cleaning, which severely impacts production continuity and efficiency.

[0003] Existing pressure measuring devices with purging functions exist, but most are complex in structure, have limited purging effect, and are difficult to completely remove solidified or heavily adhered residues. Furthermore, sudden depressurization or reverse flow of the purging medium may interfere with the main process pipeline. Therefore, there is an urgent need for a device that can effectively and controllably clean pressure measuring pipelines without interrupting the main process or affecting normal pressure measurement. Summary of the Invention

[0004] The present invention mainly addresses the technical problems existing in the prior art by providing a pressure testing tube cleaning device in the pre-shrinking process.

[0005] The above-mentioned technical problems of this utility model are mainly solved by the following technical solution: a pressure measuring tube cleaning device in a pre-shrinking process, comprising a tap tube, a measuring tube and a cleaning tube, wherein both the tap tube and the measuring tube include a main tube, a tap branch tube is led out from the main tap tube of the tap tube, the measuring tube is connected to the tap branch tube, a first measuring branch tube and a second measuring branch tube are led out from the measuring tube, the cleaning tube includes a connecting part and a cleaning piston rod, the cleaning tube is connected to the measuring tube through the connecting part, the connecting part is a hollow structure, a connecting head is provided at one end near the measuring tube, the cleaning piston passes through the connecting part, the diameter of the cleaning piston is smaller than the inner diameter of the connecting part, a filler is filled between the two, and a pressure cap is installed at the end of the connecting part away from the measuring tube to compress the filler.

[0006] Preferably, the tap branch pipe in the tap tube has an angle of 40° to 60° with the tap main pipe, a first valve is connected between the main pipe of the measuring tube and the tap branch pipe of the tap tube, and a second valve is connected between the main pipe of the measuring tube and the connection part of the cleaning tube.

[0007] Preferably, a first pressure gauge is connected to the first measuring branch of the measuring tube, a third valve is connected to the second measuring branch, a three-way pipe is connected to the third valve, and a fourth valve and a second pressure gauge are connected to the other two ports of the three-way pipe.

[0008] Preferably, the main pipe and the cleaning pipe in the tap branch and the measuring end are on the same straight line.

[0009] Preferably, the fourth valve is used to connect to an external nitrogen pipeline.

[0010] Preferably, the two ends of the tap main pipe are used to connect the reactor and the feed pipeline, respectively.

[0011] The beneficial effects of this utility model are: by switching the valve group, the measuring pipeline can be mechanically cleaned while completely isolating the process system, which greatly improves production continuity and equipment utilization.

[0012] Compared to simple gas purging, the mechanical piston rod scraping method is more effective and thorough in removing viscous, solidified, or heavily adhered residues from the pipe wall.

[0013] The system incorporates multiple valve controls and nitrogen purging / backpressure functions to ensure that the process medium does not leak during the cleaning process. The cleaning operation is carried out under a controllable pressure environment, avoiding the risks caused by sudden pressure changes and preventing air from entering the process system.

[0014] The pressure measurement, purging, and mechanical cleaning functions are integrated into a modular device. The reasonable structural design and axis alignment ensure smooth cleaning operations and facilitate installation and maintenance.

[0015] Two pressure gauges are installed, one for process pressure monitoring and the other for cleaning / purging pressure monitoring. They do not interfere with each other and provide more comprehensive process information. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of the cleaning tube of this utility model.

[0017] In the diagram: 1. Tap pipe; 101. Tap main pipe; 102. Tap branch pipe; 2. Measuring pipe; 201. Measuring main pipe; 202. First measuring branch pipe; 203. Second measuring branch pipe; 3. Cleaning pipe; 301. Connecting part; 302. Cleaning piston rod; 303. Connector; 304. Packing; 305. Gland; 306. Push head; 4. First pressure gauge; 5. Second pressure gauge; 6. First valve; 7. Second valve; 8. Third valve; 9. T-connector; 10. Fourth valve. Detailed Implementation

[0018] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0019] Example: A pressure testing tube cleaning device in a pre-shrinking process, such as Figures 1-2 As shown, the device includes a tap tube 1, a measuring tube 2, and a cleaning tube 3. Both the tap tube 1 and the measuring tube 2 include a main tube. A tap branch tube 102 is led out from the main tap tube 101 of the tap tube 1. The measuring tube 2 is connected to the tap branch tube 102. A first measuring branch tube 202 and a second measuring branch tube 203 are led out from the measuring tube 2. The cleaning tube 3 includes a connecting part 301 and a cleaning piston rod 302. The cleaning tube 3 is connected to the measuring tube 2 through the connecting part 301. The connecting part 301 has a hollow structure and a connector 303 is provided at one end near the measuring tube 2. The cleaning piston passes through the connecting part 301. The diameter of the cleaning piston is smaller than the inner diameter of the connecting part 301. A filler 304 is filled between the two. A pressure cap 305 is installed at the end of the connecting part 301 away from the measuring tube 2 to press the filler 304 tightly.

[0020] The tap branch pipe 102 in the tap tube 1 has an angle of 40° to 60° with the tap main pipe 101. A first valve 6 is connected between the main pipe of the measuring tube 2 and the tap branch pipe 102 of the tap tube 1, and a second valve 7 is connected between the main pipe of the measuring tube 2 and the connection part 301 of the cleaning tube 3.

[0021] A first pressure gauge 4 is connected to the first measuring branch 202 of the measuring tube 2, a third valve 8 is connected to the second measuring branch 203, a three-way pipe 9 is connected to the third valve 8, and a fourth valve 10 and a second pressure gauge 5 are connected to the other two ports of the three-way pipe 9.

[0022] The tap branch pipe 102, the main pipe in the measuring end, and the cleaning pipe 3 are on the same straight line; the fourth valve 10 is used to connect to the external nitrogen pipeline; the two ends of the tap main pipe 101 are used to connect the reactor and the feeding pipeline, respectively.

[0023] The principle of this utility model: Normal pressure measurement state: Close the second valve 7 and the third valve 8, and open the first valve 6. At this time, the process pressure in the reactor is transmitted to the first pressure gauge 4 through the tap pipe 1, the tap branch pipe 102, the first valve 6 and the measuring pipe 2 for continuous online pressure monitoring.

[0024] Cleaning Preparation Status: When cleaning is required, first close the first valve 6 to disconnect from the process side. Then, open the second valve 7 and the fourth valve 10. Introduce external nitrogen gas through the fourth valve 10, the tee pipe 9, and the third valve 8 into the main pipe of the measuring pipe 2 and the connection 301 of the cleaning pipe 3 for purging and pressure testing (monitored by the second pressure gauge 5). This step can initially remove loose residues and provide a clean or controlled pressure environment for subsequent mechanical cleaning.

[0025] Cleaning Operation Status: After preparation, maintain a certain nitrogen back pressure (or close the fourth valve 10 and the third valve 8 as needed). The operator (or via a drive device) pushes the cleaning piston rod 302, moving it towards the measuring tube 2. The pusher 306 (if present) at the front end of the cleaning piston rod 302 enters and scrapes across the entire inner wall of the main pipe of the measuring tube 2, mechanically scraping away any adhered or solidified residues and pushing them back towards the process side (blocked by the first valve 6) or discharging them by other means (such as opening the third valve 8 at a specific step).

[0026] Recovery status: After cleaning is complete, fully retract the cleaning piston rod 302 into the connection 301 of the cleaning pipe 3. Close the second valve 7 to isolate the cleaning channel. Then open the first valve 6, and the device will return to normal pressure measurement status, allowing continued monitoring of process pressure.

[0027] The main pipe 101 of the tap pipe 1 is installed horizontally, with its two ends connected to the reactor (not shown in the figure) and the downstream process pipeline, respectively. The tap branch pipe 102 extends obliquely upward from the main pipe 101 at an angle of approximately 50°.

[0028] The end of the tap branch pipe 102 is threaded to the first valve 6 (ball valve). The other end of the first valve 6 is connected to the main measuring pipe 201 of the measuring pipe 2. The ends of the tap branch pipe 102 are collinear. The first measuring branch pipe 202 extends to the left from the main measuring pipe 201, on which the first pressure gauge 4 (mechanical pressure gauge) is installed. The second measuring branch pipe 203 extends to the right from the main measuring pipe 201, and is connected in sequence to the third valve 8 (stop valve) and a three-way pipe 9. One horizontal port of the three-way pipe 9 is connected to the fourth valve 10 (stop valve, external nitrogen line), and the other port is connected to the second pressure gauge 5 (electronic pressure sensor).

[0029] At the other end of the measuring main pipe 201 opposite to the first valve 6, a second valve 7 (ball valve) is connected via a threaded connector 303. The other end of the second valve 7 is connected to the connecting part 301 of the cleaning pipe 3 via another connector. The connecting part 301 is a hollow cylinder, and its axis is strictly aligned with the axis of the measuring main pipe 201. The cleaning piston rod 302 passes through the connecting part 301, and its front end is provided with a pusher 306 made of polytetrafluoroethylene. The outer diameter of the pusher 306 is slightly smaller than the inner diameter of the measuring main pipe 201. Graphite filler 304 is filled between the cleaning piston rod 302 and the inner wall of the connecting part 301, and the connection is sealed by a threaded cap 305.

[0030] During cleaning, follow the steps outlined above for valve switching and nitrogen purging. Push the cleaning piston rod 302; its front end, the pusher 306, will reciprocate several times within the measuring main pipe 201, effectively scraping away any prepolymer adhering to the pipe wall. After cleaning, reset the device to restore its normal pressure measurement function.

[0031] Finally, it should be noted that the above embodiments are merely representative examples of this utility model. Obviously, this utility model is not limited to the above embodiments and can have many variations. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model should be considered to fall within the protection scope of this utility model.

Claims

1. A pressure measuring tube cleaning device for a pre-shrinking process, comprising a tap tube (1), a measuring tube (2), and a cleaning tube (3), characterized in that: Both the tap tube (1) and the measuring tube (2) include a main tube. A tap branch tube (102) is led out from the tap main tube (101) of the tap tube (1). The measuring tube (2) is connected to the tap branch tube (102). A first measuring branch tube (202) and a second measuring branch tube (203) are led out from the measuring tube (2). The cleaning tube (3) includes a connecting part (301) and a cleaning piston rod (302). The cleaning tube (3) passes through... The connecting part (301) is connected to the measuring tube (2). The connecting part (301) is a hollow structure. A connector (303) is provided at one end near the measuring tube (2). The cleaning piston passes through the connecting part (301). The diameter of the cleaning piston is smaller than the inner diameter of the connecting part (301). A filler (304) is filled between the two. A pressure cap (305) is installed at the end of the connecting part (301) away from the measuring tube (2) to press the filler (304) tightly.

2. The pressure testing tube cleaning device in the pre-shrinking process according to claim 1, characterized in that: The tap branch pipe (102) in the tap pipe (1) has an angle of 40° to 60° with the tap main pipe (101). A first valve (6) is connected between the main pipe of the measuring pipe (2) and the tap branch pipe (102) of the tap pipe (1). A second valve (7) is connected between the main pipe of the measuring pipe (2) and the connection part (301) of the cleaning pipe (3).

3. The pressure testing tube cleaning device in the pre-shrinking process according to claim 2, characterized in that: The first measuring branch (202) of the measuring tube (2) is connected to a first pressure gauge (4), the second measuring branch (203) is connected to a third valve (8), the third valve (8) is connected to a three-way pipe (9), and the other two ports of the three-way pipe (9) are connected to a fourth valve (10) and a second pressure gauge (5).

4. The pressure testing tube cleaning device in the pre-shrinking process according to claim 3, characterized in that: The tap branch pipe (102), the main pipe in the measuring end, and the cleaning pipe (3) are on the same straight line.

5. The pressure testing tube cleaning device in the pre-shrinking process according to claim 3, characterized in that: The fourth valve (10) is used to connect to an external nitrogen pipeline.

6. The pressure testing tube cleaning device in the pre-shrinking process according to claim 1, characterized in that: The two ends of the tap main pipe (101) are used to connect the reactor and the feed pipeline, respectively.

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