Sampling device for refined polyether polyol

Abstract

The utility model relates to the technical field of polyether polyol sampling, and particularly discloses a sampling device for refined polyether polyol, which comprises a refining tank, and the bottom of the refining tank is connected with a filtering system through a second pipeline; the top of the refining tank is connected with the vacuum dehydration system through a first pipeline; one side of the lower end of the refining tank is connected with a circulating pipeline, a pump B and a sampler are mounted on the circulating pipeline, and the pipeline close to an inlet and an outlet of the sampler is connected with a nitrogen purging system through a third pipeline; and the circulating pipeline is also connected with a pressure control system. The nitrogen purging system is additionally arranged, so that the risk that the sampler is blocked by salt particles is reduced, and the process production stability is improved. According to the device, the circulating pipeline is additionally arranged, so that waste discharge during sampling each time is avoided, the product yield is improved, and the environmental pollution is reduced. Pressure control is additionally arranged at the outlet of the circulating pipeline pump, so that the emptying guarantee of the circulating pipeline is further increased; and the circulation pipeline blocking risk is reduced.

Description

Technical Field

[0001] This utility model relates to the field of polyether polyol sampling technology, specifically a sampling device for refined polyether polyols. Background Technology

[0002] Polyether polyols are an important raw material for the production of polyurethane foam. Various types of catalysts are used in the production process. Conventional catalysts include alkali metals such as KOH or NaOH; bimetallic complexes (DMCs) are also used; and novel phosphazenes are employed. Phosphazene catalysts have only been reported in experimental research and have not been used industrially. Due to their high efficiency and the fact that they do not require purification, DMC catalysts are increasingly being used by companies to produce polyether polyols. Studies have found that the viscosity of polyether polyols produced using DMC catalysis is slightly higher than that produced using alkali catalysis. Furthermore, alkali catalysis remains the preferred process for synthesizing polyether polyols for certain special applications. However, because the crude polyether polyol obtained after alkali-catalyzed polymerization easily contains alkaline metal ions, if the content of potassium, sodium, and other metal ions in the polyether polyol is too high when reacting with isocyanates to produce polyurethane, the reaction will be violent, and the polyurethane product will be scrapped due to agglomeration. Therefore, crude polyether polyols need to undergo purification to remove potassium, sodium, and other metal ions.

[0003] Existing refining tanks have a sampler at the bottom. Usually, during operation, to avoid the influence of previous batch samples and dead corners of the agitator, the operator will drain a large amount of liquid before taking a sample. If multiple additions of acidic substances are required for adjustment, multiple drainages will result in a large loss of product. At the same time, since the sampler is at the bottom of the refining tank, there is a risk of blockage after dehydration, which may lead to production abnormalities. Therefore, a sampling device for refining polyether polyols is provided. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a sampling device for refined polyether polyols, thereby solving the problems mentioned in the background section.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a sampling device for refined polyether polyols, comprising a refining tank, the bottom of which is connected to a filtration system via a second pipeline;

[0006] The top of the refining tank is connected to the vacuum dehydration system via a first pipeline;

[0007] A circulation pipeline is connected to one side of the lower end of the refining tank. A pump B and a sampler are installed on the circulation pipeline. The pipeline near the inlet and outlet of the sampler is connected to the nitrogen purging system through a third pipeline. A pressure control system is also connected to the circulation pipeline.

[0008] As a preferred embodiment of this invention, a stirring rod is installed inside the refining tank, and a motor is connected to the top of the stirring rod.

[0009] As a preferred embodiment of this utility model, a valve D is installed on the third pipeline.

[0010] As a preferred embodiment of this invention, the pressure control system is connected to the pipeline at the outlet of pump B.

[0011] As a preferred embodiment of this utility model, a pump A is installed on the second pipeline, a valve B is installed on the second pipeline near the inlet of the pump A, and a valve C is installed on the second pipeline near the outlet of the pump A.

[0012] As a preferred embodiment of this utility model, valve A is installed on the first pipeline.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This device reduces the risk of the sampler being blocked by salt particles by adding a nitrogen purging system, thereby improving the stability of the production process.

[0015] This device avoids waste discharge during each sampling by adding a circulation pipeline, thereby improving product yield and reducing environmental pollution.

[0016] This device purges the circulating pipeline after sampling to return the sample material to the refining tank, thereby improving product yield. In addition, pressure control is added to the outlet of the circulating pipeline pump to further ensure the evacuation of the circulating pipeline and reduce the risk of circulation pipeline blockage. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] In the diagram: 1-First pipeline; 2-Valve A; 3-Refining tank; 4-Pump A; 5-Sampler; 6-Nitrogen purging system; 7-Pump B; 8-Pressure control system; 9-Circulation pipeline; 10-Stirring rod; 11-Valve B; 12-Second pipeline; 13-Valve C; 14-Filtration system; 15-Vacuum dehydration system; 16-Third pipeline. Detailed Implementation

[0019] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more definite definition of the scope of protection of the present invention.

[0020] Example: Please refer to Figure 1 This utility model provides a technical solution: a sampling device for refined polyether polyol, including a refining tank 3, the bottom of which is connected to a filtration system 14 via a second pipeline 12;

[0021] The top of the refining tank 3 is connected to the vacuum dehydration system 15 via the first pipeline 1;

[0022] A circulation pipeline 9 is connected to the lower end of the refining tank 3 to avoid waste discharge during each sampling. A pump B7 and a sampler 5 are installed on the circulation pipeline 9 for sampling. The pipelines near the inlet and outlet of the sampler 5 are connected to the nitrogen purging system 6 through a third pipeline 16. The nitrogen purging system 6 reduces the risk of the sampler 5 being blocked by salt particles and improves the stability of the process. A pressure control system 8 is also connected to the circulation pipeline 9 to further ensure the evacuation of the circulation pipeline 9 and reduce the risk of blockage in the circulation pipeline.

[0023] The refining tank 3 is equipped with a stirring rod 10, and a motor is connected to the top of the stirring rod 10.

[0024] A valve D is installed on the third pipeline 16 to open or close the connection between the nitrogen purging system 6 and the circulation pipeline 9.

[0025] The pressure control system 8 is connected to the pipeline at the outlet of pump B7.

[0026] Pump A4 is installed on the second pipeline 12. Valve B11 is installed on the second pipeline 12 near the inlet of pump A4, and valve C13 is installed on the second pipeline 12 near the outlet of pump A4.

[0027] A valve A2 is installed on the first pipeline 1 to control the connection between the first pipeline 1 and the vacuum dehydration system 15.

[0028] Working Principle: A sampling device for refined polyether polyols. The specific process mainly involves adding a fixed amount of acidic substance and demineralized water to the refining tank 3. The purpose of adding demineralized water is to precipitate alkali metal salts from the polyether polyol. Then, the crude polyether polyol, neutralized to a suitable degree, is dehydrated through a vacuum dehydration system 15, causing salt particles to continuously precipitate. After the moisture content is qualified, it is sent to the downstream filtration system 14 for filtration via pump A4. Finally, a qualified polyether polyol product is obtained. The key steps in the refining process are controlling the refining process by adjusting the amount of acidic substance added, the acid-base neutralization temperature, and the neutralization time. As production batches increase, the amount of salt particles in the system gradually increases, causing the required amount of acidic substance to change continuously. This is to ensure that the material in the refining tank 3 has a suitable pH and acidity / alkalinity before dehydration.

[0029] This device adds a circulation line 9, pump B7, and sampler 5 downstream of the refining tank 3. Each time a sample is taken before dehydration, the material in the refining tank 3 passes through the sampler 5, pump B7, and circulation line 9 before returning to the bottom of the refining tank 3. After circulating in this manner for a certain period, the material at the bottom of the refining tank 3 is thoroughly mixed with the material in the upper and middle parts, ensuring that the sampled material is representative. This method eliminates the need for pre-drainage, reducing product loss. A nitrogen purging system 6 is added to the front and rear ends of the sampler 5. After sampling, nitrogen purging is used to purge any remaining material from the front and rear ends of the sampler 5 and the circulation line back into the refining tank 3. To ensure that the material in the circulation line 9 is emptied after sampling, a pressure control system 8 is added to the outlet of pump B7 to monitor whether the material in the circulation line 9 has been emptied into the refining tank 3.

[0030] The above embodiments merely illustrate the implementation of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A sampling device for refined polyether polyols, comprising a refining tank (3), characterized in that: The bottom of the refining tank (3) is connected to the filtration system (14) via a second pipeline (12); The top of the refining tank (3) is connected to the vacuum dehydration system (15) via the first pipeline (1); A circulation pipeline (9) is connected to one side of the lower end of the refining tank (3). A pump B (7) and a sampler (5) are installed on the circulation pipeline (9). The pipeline near the inlet and outlet of the sampler (5) is connected to the nitrogen purging system (6) through a third pipeline (16). A pressure control system (8) is also connected to the circulation pipeline (9).

2. The sampling device for refined polyether polyols according to claim 1, characterized in that: The refining tank (3) is equipped with a stirring rod (10), and a motor is connected to the top of the stirring rod (10).

3. The sampling device for refined polyether polyols according to claim 1, characterized in that: Valve D is installed on the third pipeline (16).

4. The sampling device for refined polyether polyols according to claim 1, characterized in that: The pressure control system (8) is connected to the pipeline at the outlet of pump B (7).

5. The sampling device for refined polyether polyols according to claim 1, characterized in that: A pump A (4) is installed on the second pipeline (12), a valve B (11) is installed on the second pipeline (12) near the inlet of the pump A (4), and a valve C (13) is installed on the second pipeline (12) near the outlet of the pump A (4).

6. The sampling device for refined polyether polyols according to claim 1, characterized in that: Valve A (2) is installed on the first pipeline (1).

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