A device for sampling polyoxymethylene powder

Abstract

The utility model belongs to the powder sampling technical field, concretely relates to a kind of formaldehyde powder leakage sampling device of preventing polymerization, including the sampling storage box being communicated with storage tank, still including powder recovery tank, waste gas absorption tank, the sampling storage box is sequentially divided into coaxial upper cone cylinder, middle cylinder and lower cone cylinder from top to bottom, the upper cone cylinder is connected between the discharge port of storage tank by feed pipe, lower cone cylinder is connected between powder recovery tank by discharge pipe;The taper surface of the upper cone cylinder is provided with exhaust port, the hard anti-bending pipe is installed in this exhaust port, the anti-bending pipe is connected with a flexible exhaust pipe, the end of the flexible exhaust pipe is immersed below the liquid level of waste gas absorption tank;The junction of the middle cylinder and lower cone cylinder is provided with horizontal sieve plate, the sieve plate is provided with a plurality of hollow holes, the central position of the sieve plate is provided with recessed mounting groove, the open sampling bottle is clamped in the mounting groove;First valve, second valve are sequentially installed in the feed pipe from top to bottom, third valve is provided on the discharge pipe.The utility model is simple, low risk, low pollution.

Description

Technical Field

[0001] This utility model belongs to the field of powder sampling technology, specifically relating to a powder leakage prevention sampling device. Background Technology

[0002] In the production of polyoxymethylene (POM), powder quality is a key control indicator affecting product performance and requires strict monitoring through frequent sampling and analysis at the production site. Currently, the industry commonly uses an open sampling method, which involves directly opening the sampling valve connected to the reaction equipment, allowing the powder and high-temperature, high-pressure gas to be ejected together into an open environment for collection. However, this method has the following significant drawbacks:

[0003] 1. Difficulty in sampling operation: Due to the high internal pressure of the reaction system (usually up to 0.5~2.0 MPa) and high temperature (100~200°C), when the sampling valve is opened, the powder will form a high-speed jet stream with the high-temperature gas, causing the material to scatter and making it difficult to collect effectively, thus affecting the accuracy of analysis.

[0004] 2. High safety risks: The sprayed gas contains unreacted formaldehyde monomers, oligomers and a small amount of organic solvents. These substances are toxic, irritating and flammable. Direct exposure to the environment can cause occupational health hazards such as respiratory damage and skin irritation to operators, and there is also a risk of fire and explosion.

[0005] 3. Environmental pollution: Open emissions can cause harmful substances to spread, pollute the air in the production area, and may deposit on the surface of surrounding equipment, causing corrosion or long-term pollution, increasing cleaning and maintenance costs.

[0006] 4. Equipment wear and tear: The violent ejection of high-temperature and high-pressure materials can easily cause erosion of the sampling valve and downstream pipelines, shortening the service life of the equipment and increasing the maintenance frequency and production costs.

[0007] Currently, some companies are attempting to use simple sealed containers to receive samples, but this still cannot effectively solve problems such as incomplete collection and complex operation caused by high-pressure jetting. Therefore, there is an urgent need to develop a safe, efficient, and environmentally friendly polyoxymethylene powder sampling device and method to overcome the shortcomings of existing technologies and meet the requirements of modern chemical production for safety, environmental protection, and refined operation. Utility Model Content

[0008] This invention provides a sampling device for preventing leakage of polyoxymethylene powder that is simple to use, low in risk, and low in pollution.

[0009] The present invention provides a sampling device for preventing leakage of polyoxymethylene powder, comprising a sampling and storage box connected to a storage tank, a powder recovery tank, and a waste gas absorption tank. The sampling and storage box is divided into a coaxial upper cone, a middle cone, and a lower cone from top to bottom. The upper cone is connected to the outlet of the storage tank via a feed pipe, and the lower cone is connected to the powder recovery tank via a discharge pipe. An exhaust port is provided on the conical surface of the upper cone, and a rigid anti-bend pipe is installed on the exhaust port. The anti-bend pipe is connected to a flexible exhaust pipe, the end of which is submerged below the liquid surface of the waste gas absorption tank. A horizontal sieve plate is provided at the junction of the middle cone and the lower cone. The sieve plate has several perforated holes, and a recessed mounting groove is provided at the center of the sieve plate. An open sampling bottle is placed in the mounting groove. A first valve and a second valve are installed on the feed pipe from top to bottom, and a third valve is provided on the discharge pipe.

[0010] Beneficial effects: (1) Safety protection: The combination of flexible exhaust pipe and waste gas absorption tank (such as containing 10% sodium sulfite absorption liquid) completely neutralizes harmful gases such as formaldehyde, avoiding the risk of operators coming into contact with toxic substances and explosion; (2) Precise sampling: Dual valves control the feed flow rate in stages, and the positioning design of the sieve plate and sampling bottle ensures the representativeness of the sample and reduces the error caused by high pressure injection; the whole process is carried out in the sampling device, and the operators will not be directly exposed to the powder environment, reducing the risk of respiratory damage and skin irritation to the operators; (3) The use of "rigid anti-bend pipe + flexible exhaust pipe" dual exhaust structure The rigid anti-bend tube's integrated bending section design ensures that the flexible tube hangs naturally, completely solving the problem of bending and clogging of traditional flexible tubes; (4) Sampling is simple and easy to operate: the hinged sampling door, stainless steel valve and integrated structure improve durability and simplify the sampling process, which is suitable for the high-frequency sampling needs of polyoxymethylene production; (5) Multi-valve control enables accurate sampling, the sealing design prevents pollution, the coaxial inlet / outlet reduces residue, the waste gas absorption tank ensures environmental safety, and the discharge pipe recovers residual materials to improve resource utilization. The overall structure is compact and easy to operate, which is suitable for efficient and safe sampling of polyoxymethylene powder.

[0011] Furthermore, the anti-bend pipe includes an integrally formed straight pipe section and a bent pipe section. A filter screen is installed inside the straight pipe section to effectively intercept large dust particles and prevent the anti-bend pipe from clogging. The bent pipe section has a bend, and the end of the bend connects to the flexible exhaust pipe. The rigid bend design ensures that the flexible exhaust pipe hangs down naturally without bending, reducing gas flow resistance and completely solving the problem of poor exhaust caused by bending of traditional flexible pipes.

[0012] Furthermore, a sampling door is hinged to the wall of the intermediate cylinder. This allows for single-handed operation for opening and closing, improving sampling efficiency.

[0013] Furthermore, the waste gas absorption tank is filled with 10% sodium sulfite absorption solution. The sodium sulfite solution has a high chemical neutralization efficiency for formaldehyde, and the pH value of the solution is stable at 8-9, avoiding acid corrosion of the equipment.

[0014] Furthermore, the first, second, and third valves are all stainless steel ball valves. Gradient control controls the feed flow rate, preventing sample stratification caused by high-pressure jetting.

[0015] Furthermore, the sampling and storage box is made of stainless steel, which improves corrosion resistance and is suitable for humid and acidic conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an embodiment of the polyoxymethylene powder leakage prevention sampling device of this utility model;

[0017] Attached reference numerals: 1. Storage tank; 2. Powder recovery tank; 3. Waste gas absorption tank; 4. Sampling and storage box; 4-1. Upper cone; 4-2. Middle cone; 4-3. Lower cone; 4-4. Sampling gate; 5. First valve; 6. Second valve; 7. Third valve; 8. Anti-bend pipe; 8-1. Filter screen; 9. Flexible exhaust pipe; 10. Sieve plate; 11. Sampling bottle. Detailed Implementation

[0018] This embodiment, in conjunction with the accompanying drawings, provides a detailed description of the connection relationships and functions of each part.

[0019] like Figure 1 As shown, a sampling device for preventing polyoxymethylene powder leakage includes a powder recovery tank 2, a waste gas absorption tank 3, and a sampling and storage box 4. The sampling and storage box 4 is provided with an inlet, an outlet, and an exhaust port.

[0020] The sampling and storage box 4 is made of 2mm thick 304 stainless steel plate. From top to bottom, it consists of an upper conical cylinder 4-1 (which can be a conical or square cone shape), an intermediate cylinder 4-2 (which is circular), and a lower conical cylinder 4-3 (which can be a conical or square cone shape). The inlet is located at the center of the upper conical cylinder 4-1, and the outlet is located at the center of the lower conical cylinder 4-3. The inlet and outlet are coaxially aligned. A rigid inlet pipe is installed on the inlet, and the upper end of the inlet pipe is connected to the outlet of the target storage tank 1. A first valve 5 and a second valve 6 are installed on the inlet pipe from top to bottom. A rigid outlet pipe is installed on the outlet, and the lower end of the outlet pipe is connected to the powder recovery tank 2. A third valve 7 is installed on the outlet pipe.

[0021] The exhaust port is located on the conical surface of the upper cone 4-1, and is connected to a stainless steel anti-bend pipe 8. This anti-bend pipe includes an integrally formed straight pipe section and a bent pipe section. A filter screen 8-1 is installed inside the straight pipe section to block large particles of dust. The bent pipe section has a bend, and the end of the bend is connected to a flexible exhaust pipe 9. This allows the flexible exhaust pipe 9 to hang naturally without bending, avoiding gas blockage problems caused by bending or even breaking of the flexible pipe. The waste gas absorption tank 3 contains a 10% sodium sulfite absorption liquid, and the exhaust end of the flexible exhaust pipe 9 is submerged below the surface of the absorption liquid.

[0022] Inside the sampling and storage box 4, a horizontal sieve plate 10 is provided at the junction between the intermediate cylinder 4-2 and the lower conical cylinder 4-3. The sieve plate 10 has several perforations, and a recessed mounting groove is located at the center of the sieve plate 10 (opposite to the feed inlet). An open sampling bottle 11 is placed in the mounting groove. A sampling port is opened on the wall of the intermediate cylinder 4-2, and a sampling door 4-4 is hinged to the sampling port.

[0023] The first valve 5, the second valve 6, and the third valve 7 are all stainless steel ball valves.

[0024] The usage process of this embodiment is as follows:

[0025] (1) Replacement stage

[0026] Close the sampling door 4-4 of the sampling collection box 4, and open the first valve 5, the second valve 6, and the third valve 7 to fully disperse the powder in the air.

[0027] (2) Sampling stage:

[0028] Close valves 5, 6, and 7. Open sampling door 4-4 and place sampling bottle 11 into the mounting slot of sampling collection box 4. Close sampling door 4-4. Then open valves 5, 6, and 7. Powder enters sampling bottle 11 from storage tank 1 through the feed pipe. After sampling, close valves 5, 6, and 7, let stand for at least 1 minute, and then remove sampling bottle 11.

[0029] (3) Exhaust treatment:

[0030] The waste gas generated during the sampling process is introduced into the waste gas absorption tank 3 through the flexible exhaust pipe 9 and is neutralized by 10% sodium sulfite absorption liquid.

[0031] (4) Residual material recycling:

[0032] Open the third valve 7, and the residual powder will be discharged from the discharge pipe to the powder recovery tank 2 to avoid waste.

[0033] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A sampling device for preventing leakage of polyoxymethylene powder, comprising a sampling and storage box connected to a storage tank, characterized in that: It also includes a powder recovery tank and a waste gas absorption tank. The sampling and storage box is divided into a coaxial upper cone, a middle cylinder, and a lower cone from top to bottom. The upper cone is connected to the outlet of the storage tank through a feed pipe, and the lower cone is connected to the powder recovery tank through a discharge pipe. An exhaust port is provided on the conical surface of the upper cone. A rigid anti-bend pipe is installed on the exhaust port and connected to a flexible exhaust pipe. The end of the flexible exhaust pipe is submerged below the liquid surface of the waste gas absorption tank. A horizontal sieve plate is provided at the junction of the middle cylinder and the lower cone. The sieve plate has several hollow holes, and a recessed mounting groove is provided at the center of the sieve plate. An open sampling bottle is placed in the mounting groove. A first valve and a second valve are installed on the feed pipe from top to bottom, and a third valve is provided on the discharge pipe.

2. The sampling device for preventing leakage of polyoxymethylene powder according to claim 1, characterized in that: The anti-bend pipe includes an integrally formed straight pipe section and a bent pipe section. A filter screen is installed inside the straight pipe section, and the bent pipe section has a bend. The end of the bent pipe is connected to the flexible exhaust pipe.

3. The sampling device for preventing leakage of polyoxymethylene powder according to claim 2, characterized in that: A sampling door is hinged to the wall of the intermediate cylinder.

4. The sampling device for preventing leakage of polyoxymethylene powder according to claim 3, characterized in that: The waste gas absorption tank is filled with a 10% sodium sulfite absorption solution.

5. The sampling device for preventing leakage of polyoxymethylene powder according to claim 4, characterized in that: The first valve, the second valve, and the third valve are all stainless steel ball valves.

6. The sampling device for preventing leakage of polyoxymethylene powder according to claim 5, characterized in that: The sampling and storage box is made of stainless steel.

Images