Polyformaldehyde stabilizing device

Abstract

The utility model relates to the technical field of polyformaldehyde production, in particular to a polyformaldehyde stabilizing device which comprises a stabilizing tank, a first feeding end of the stabilizing tank is fixedly communicated with an alkali liquor feeding pipeline, a second feeding end of the stabilizing tank is fixedly communicated with a polyformaldehyde powder feeding pipeline, and a third feeding end of the stabilizing tank is fixedly communicated with a desalted water feeding pipeline. A stirrer is fixedly mounted in the stabilizing tank, a circulating pipeline is fixedly communicated between a first discharging end at the lower part of the stabilizing tank and a fourth feeding end at the upper part of the stabilizing tank, a circulating pump is fixedly mounted on the circulating pipeline, a second discharging end at the lower part of the stabilizing tank is fixedly communicated with a material delivery pipeline, and a conveying pump is fixedly mounted on the material delivery pipeline. The device is reasonable and compact in structure and convenient to use, greatly reduces the content of free formaldehyde in finished polyformaldehyde, reduces unstable end groups and active molecules remaining in polyformaldehyde powder, greatly improves the thermal stability of the product and guarantees the quality of the final product, and has the characteristics of safety, labor saving, simplicity, convenience and high efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of polyformaldehyde production, and is a polyformaldehyde stabilization device. Background Art

[0002] Traditional polyformaldehyde products are prone to decomposition during preheating due to the presence of unstable end groups. In order to improve the thermal stability of polyformaldehyde, alkali is generally added for treatment. In the process of conventional addition of organic liquid alkali, polyformaldehyde powder is not stirred, and the material residence time cannot be accurately controlled. The material residence time is between 5min and 30min. The alkali solution cannot be accurately controlled, and the pH value fluctuates between 8.0 and 10.5, resulting in uneven stabilization of polyformaldehyde powder, more residual active molecules, and unstable end groups between 1.5 and 2.5%. Unstable end groups are prone to form free formaldehyde gas during the melt granulation process, thereby forming tiny protrusions, affecting the appearance of polyformaldehyde pellets. Free formaldehyde will be released during the later deep processing of polyformaldehyde, and will adhere to the mold in the form of film scale, affecting the precision of the product and damaging the mold; in addition, free formaldehyde will be released, affecting the air quality of the processing plant, and employees will be prone to occupational diseases in the long term. Summary of the invention

[0003] The utility model provides a polyformaldehyde stabilization device, which overcomes the deficiencies of the prior art and can effectively solve the problems of unreasonable structural setting, imprecise control and incomplete stabilization of the prior polyformaldehyde stabilization device.

[0004] The technical scheme of the utility model is achieved through the following measures: a polyformaldehyde stabilization device, comprising a stabilization tank, a first feed end of the stabilization tank is fixedly connected with an alkali solution feed pipeline, a second feed end of the stabilization tank is fixedly connected with a polyformaldehyde powder feed pipeline, a third feed end of the stabilization tank is fixedly connected with a desalted water feed pipeline, an agitator is fixedly installed in the stabilization tank, a circulation pipeline is fixedly connected between a first discharge end at the bottom of the stabilization tank and a fourth feed end at the top, a circulation pump is fixedly installed on the circulation pipeline, a second discharge end at the bottom of the stabilization tank is fixedly connected with a material delivery pipeline, a delivery pump is fixedly installed on the material delivery pipeline, a flow meter is fixedly installed on the alkali solution feed pipeline, a liquid level meter is fixedly installed on the stabilization tank, and a pH detector is fixedly installed on the material delivery pipeline between the pipeline outlet of the material delivery pipeline and the delivery pump.

[0005] The following are further optimizations and / or improvements to the above utility model technical solution:

[0006] There are multiple agitators, and the blades of the agitators are self-lifting blades.

[0007] A first solenoid valve is fixedly installed between the alkali liquid feed pipeline inlet and the alkali liquid feed pipeline between the flow meter, a first spare pipeline is fixedly connected between the alkali liquid feed pipelines before and after the first solenoid valve, and a linkage control is set between the first solenoid valve and the flow meter.

[0008] A second solenoid valve is fixedly installed on the desalted water feed pipeline, a second spare pipeline is fixedly connected between the desalted water pipelines before and after the second solenoid valve, and interlocking control is arranged between the first solenoid valve and the second solenoid valve and the pH detector.

[0009] A third solenoid valve is fixedly installed on the material delivery pipeline, a third backup pipeline is fixedly connected between the material delivery pipelines before and after the first solenoid valve, and a chain control is arranged between the third solenoid valve and the liquid level meter.

[0010] The utility model has a reasonable and compact structure and is easy to use. It greatly reduces the content of free formaldehyde in the finished polyformaldehyde product, reduces unstable end groups and active molecules remaining in the polyformaldehyde powder, greatly improves the thermal stability of the product and the quality of the final product, and has the characteristics of safety, labor saving, simplicity and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 This is a schematic diagram of the process flow of the utility model.

[0012] The codes in the accompanying drawings are: 1 is a stabilization tank, 2 is an alkali solution feed pipeline, 3 is a polyoxymethylene powder feed pipeline, 4 is a desalted water feed pipeline, 5 is a stirrer, 6 is a circulation pipeline, 7 is a circulation pump, 8 is a material delivery pipeline, 9 is a delivery pump, 10 is a flow meter, 11 is a liquid level meter, 12 is a pH detector, 13 is a first solenoid valve, 14 is a first spare pipeline, 15 is a second solenoid valve, 16 is a second spare pipeline, 17 is a third solenoid valve, and 18 is a third spare pipeline. DETAILED DESCRIPTION

[0013] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical solution of the present invention and actual conditions.

[0014] In the present invention, unless otherwise specified, the equipment and devices used are all the equipment and devices known and used in the art.

[0015] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached manual. Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.

[0016] The present invention is further described below in conjunction with the embodiments and drawings:

[0017] Embodiment 1: As attached Figure 1 As shown, the polyformaldehyde stabilization device includes a stabilization tank 1, a first feed end of the stabilization tank 1 is fixedly connected with an alkali solution feed pipeline 2, a second feed end of the stabilization tank 1 is fixedly connected with a polyformaldehyde powder feed pipeline 3, a third feed end of the stabilization tank 1 is fixedly connected with a desalted water feed pipeline 4, an agitator 5 is fixedly installed in the stabilization tank 1, a circulation pipeline 6 is fixedly connected between the first discharge end at the bottom and the fourth feed end at the top of the stabilization tank 1, a circulation pump 7 is fixedly installed on the circulation pipeline 6, a second discharge end at the bottom of the stabilization tank 1 is fixedly connected with a material delivery pipeline 8, a delivery pump 9 is fixedly installed on the material delivery pipeline 8, a flow meter 10 is fixedly installed on the alkali solution feed pipeline 2, a liquid level meter 11 is fixedly installed on the stabilization tank 1, and a pH detector 12 is fixedly installed on the material delivery pipeline 8 between the pipeline outlet of the material delivery pipeline 8 and the delivery pump 9.

[0018] The above polyoxymethylene stabilization device can be further optimized and / or improved according to actual needs:

[0019] Embodiment 2: It is different from Embodiment 1 in that: Figure 1 As shown, there are multiple stirrers 5, and the blades of the stirrer 5 are self-elevating blades. The self-elevating blades can ensure that the polyoxymethylene powder and the alkaline solution form a suspension, effectively achieving the purpose of removing unstable end groups.

[0020] Embodiment 3: It differs from Embodiment 1 to Embodiment 2 in that: Figure 1 As shown, a first solenoid valve 13 is fixedly installed between the inlet of the alkali liquid feed pipeline 2 and the alkali liquid feed pipeline 2 between the flow meter 10, a first backup pipeline 14 is fixedly connected between the alkali liquid feed pipeline 2 before and after the first solenoid valve 13, and a linkage control is set between the first solenoid valve 13 and the flow meter 10.

[0021] Embodiment 4: It differs from Embodiments 1 to 3 in that: Figure 1 As shown, a second solenoid valve 15 is fixedly installed on the desalted water feed pipeline 4, a second standby pipeline 16 is fixedly connected between the desalted water pipelines before and after the second solenoid valve 15, and a linkage control is provided between the first solenoid valve 13 and the second solenoid valve 15 and the pH detector 12. The addition amount of alkali solution and desalted water is adjusted by the opening of the first solenoid valve 13 and the second solenoid valve 15, and the pH of the discharge of the stabilization tank 1 is controlled between 8.8 and 9.2.

[0022] Embodiment 5: It differs from Embodiments 1 to 4 in that: Figure 1As shown, a third solenoid valve 17 is fixedly installed on the material delivery pipeline 8, a third backup pipeline 18 is fixedly connected between the material delivery pipelines 8 before and after the first solenoid valve 13, and a linkage control is set between the third solenoid valve 17 and the liquid level meter 11.

[0023] As required, valves and instruments are fixedly installed on each pipeline of the polyformaldehyde stabilization device to enable its normal operation.

[0024] When in use, desalted water is introduced into the stabilization tank 1. When the liquid level is about 60%, the agitator 5 is started, the first electromagnetic valve 13 is opened, and the amount of alkali solution added is adjusted to control the pH of the system between 8.8 and 9.2. The polyoxymethylene powder is transported into the stabilization tank 1, and the circulation pump 7 is started. After the material circulates for 35 to 40 minutes, the third electromagnetic valve 17 is opened to transport the material to the outside. The utility model can effectively achieve stabilization, reduce the content of unstable end groups, and reduce the unstable end groups of the product to less than 1%.

[0025] The utility model improves the stabilization efficiency through the stirring operation by modifying the original stabilization equipment; and avoids the degradation and decomposition of the product caused by excessive alkali solution by adjusting and controlling the alkali solution and accurately measuring the amount of alkali solution. In addition, by controlling the stirring rate and the discharge flow rate, the residence time of the polyformaldehyde powder can be effectively controlled to ensure that the alkali solution and the active molecules are fully contacted during the entire stabilization process, which plays a role in comprehensive inactivation, greatly improves the inactivation efficiency and reduces the amount of alkali solution used. Through the extreme stabilization treatment of the polyformaldehyde powder, the release of free formaldehyde in the finished product is greatly reduced.

[0026] The above technical features constitute the embodiments of the present utility model, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A polyoxymethylene stabilization device, characterized in that It includes a stabilizing tank, a first feed end of the stabilizing tank is fixedly connected with an alkali solution feed pipeline, a second feed end of the stabilizing tank is fixedly connected with a polyformaldehyde powder feed pipeline, a third feed end of the stabilizing tank is fixedly connected with a desalted water feed pipeline, an agitator is fixedly installed in the stabilizing tank, a circulation pipeline is fixedly connected between a first discharge end at the bottom of the stabilizing tank and a fourth feed end at the top, a circulation pump is fixedly installed on the circulation pipeline, a second discharge end at the bottom of the stabilizing tank is fixedly connected with a material delivery pipeline, a delivery pump is fixedly installed on the material delivery pipeline, a flow meter is fixedly installed on the alkali solution feed pipeline, a liquid level meter is fixedly installed on the stabilizing tank, and a pH detector is fixedly installed on the material delivery pipeline between the pipeline outlet of the material delivery pipeline and the delivery pump.

2. The polyoxymethylene stabilization device according to claim 1, characterized in that There are multiple agitators, and the blades of the agitators are self-lifting blades.

3. The polyoxymethylene stabilization device according to claim 1 or 2, characterized in that A first solenoid valve is fixedly installed between the alkali liquid feed pipeline inlet and the alkali liquid feed pipeline between the flow meter, a first spare pipeline is fixedly connected between the alkali liquid feed pipelines before and after the first solenoid valve, and a linkage control is set between the first solenoid valve and the flow meter.

4. The polyoxymethylene stabilization device according to claim 3, characterized in that A second solenoid valve is fixedly installed on the desalted water feed pipeline, a second spare pipeline is fixedly connected between the desalted water pipelines before and after the second solenoid valve, and interlocking control is arranged between the first solenoid valve and the second solenoid valve and the pH detector.

5. The polyoxymethylene stabilization device according to claim 1, 2 or 4, characterized in that A third solenoid valve is fixedly installed on the material delivery pipeline, a third spare pipeline is fixedly connected between the material delivery pipelines before and after the first solenoid valve, and a chain control is arranged between the third solenoid valve and the liquid level meter.

6. The polyoxymethylene stabilization device according to claim 3, characterized in that A third solenoid valve is fixedly installed on the material delivery pipeline, a third spare pipeline is fixedly connected between the material delivery pipelines before and after the first solenoid valve, and a chain control is arranged between the third solenoid valve and the liquid level meter.

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