BF3 and DOX pre-reaction device

Abstract

The invention belongs to the technical field of synthesis of copolyformaldehyde, and particularly relates to a BF3 and DOX pre-reaction device which comprises a BF3 feeding port, a DOX feeding port, a heat tracing pipe, a baffle, a flow guide pipe and a mixture discharging port. According to the BF3 and DOX pre-reaction device provided by the invention, a plurality of groups of baffles and flow guide pipes are arranged, so that BF3 and DOX which respectively enter from the two feeding holes are more fully contacted, the reaction of a subsequent mixture and TOX is more complete, the reaction speed is higher, and the production efficiency of polyformaldehyde is improved.

Description

Technical Field

[0001] The invention relates to the technical field of synthesizing copolymer formaldehyde, and in particular to a BF3 and DOX pre-reaction device. Background Art

[0002] Polyoxymethylene (POM), full name polyoxymethylene resin, is a linear polymer with no side chains, high density, and high crystallinity. It has excellent heat resistance, wear resistance, oil resistance, peroxide resistance, and fatigue resistance.

[0003] POM is divided into two categories, namely homopolymer and copolymer, and my country is a major producer and consumer of copolymer.

[0004] The basic process of domestic copolymer formaldehyde production technology is: formaldehyde (HCHO) is used as raw material to synthesize trioxymethylene (TOX) and dioxolane (DOX) respectively, and trioxymethylene and dioxolane are ring-opening polymerized to generate copolymer formaldehyde under the condition of boron trifluoride (BF3) as initiator. In the step of TOX and DOX reacting, if TOX, DOX and BF3 are directly mixed for reaction, DOX and initiator BF3 are not in sufficient contact, resulting in slow reaction speed and low production efficiency. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a BF3 and DOX pre-reaction device, the purpose of which is to solve the problem that TOX, DOX and BF3 are directly mixed for reaction, and DOX and the initiator BF3 are not in sufficient contact, resulting in a slow reaction speed and low production efficiency.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A BF3 and DOX pre-reaction device comprises a device body, wherein the device body is provided with a BF3 inlet, a DOX inlet and a mixture outlet; a guide tube is provided inside the device body, and baffles are provided on the inner wall of the device body and the guide tube; and a heating pipe is provided outside the device body.

[0008] Furthermore, the BF3 inlet and the DOX inlet are located at the top of the device body, and the mixture outlet is located at the bottom of the device body.

[0009] Furthermore, the baffles are in multiple groups.

[0010] In certain embodiments, baffles are alternately disposed on both sides of the internal fluid linear path of the device body.

[0011] Furthermore, there are multiple flow guide pipes.

[0012] In certain embodiments, a flow guide tube is provided at the end of the internal fluid straight path of the device body.

[0013] Furthermore, the number of baffles and guide tubes can be increased or decreased according to the feed flow rate.

[0014] Furthermore, the BF3 feed port is connected to the BF3 input pipeline.

[0015] In certain embodiments, the BF3 feed port is connected to the BF3 input pipeline by a metal hose.

[0016] Furthermore, a check valve is provided on the BF3 input pipeline.

[0017] Furthermore, the DOX feed port is connected to the DOX input pipeline.

[0018] In certain embodiments, the DOX feed port is connected to the DOX input pipe by a metal hose.

[0019] Furthermore, the DOX input pipeline is provided with a filter and a flow indicating controller.

[0020] A copolymer formaldehyde preparation system comprises the above-mentioned BF3 and DOX pre-reaction device, wherein the mixer is provided with a mixture feed port, a nitrogen inlet, a TOX feed port and a TOX mixture discharge port, the mixture feed port of the mixer is connected to the mixture discharge port of the BF3 and DOX pre-reaction device, and the nitrogen inlet is connected to a nitrogen input pipeline and a DOX input pipeline containing an antioxidant.

[0021] Furthermore, the TOX input pipeline and the mixture discharge port of the BF3 and DOX pre-reaction device are connected to the connected pipeline by a metal hose.

[0022] Furthermore, the antioxidant is a hindered phenol antioxidant.

[0023] In certain embodiments, a check valve is provided on the nitrogen input pipeline.

[0024] In certain embodiments, a check valve is provided on the DOX input pipeline containing the antioxidant.

[0025] Furthermore, the TOX feed port is connected to a TOX input pipeline.

[0026] Furthermore, the TOX input pipeline is provided with a filter and a flow indicating controller.

[0027] In certain embodiments, the temperature of the heat tracer is maintained at 30-70°C, preferably 50°C.

[0028] The present invention has the following beneficial effects:

[0029] The BF3 and DOX pre-reaction device provided by the present invention allows BF3 and DOX to be mixed in advance for pre-reaction, so that the initiator BF3 and DOX are in contact more fully, thereby avoiding the problem of insufficient contact between DOX and the initiator BF3 when BF3, DOX and TOX are directly mixed, resulting in a reduced reaction rate.

[0030] The BF3 and DOX pre-reaction device provided by the present invention is provided with multiple groups of baffles and guide tubes, so that the BF3 and DOX entering from two feed ports can contact more fully, ensure that the subsequent mixture reacts with TOX more completely, the reaction speed is faster, and the copolymerization efficiency is improved (about 10-15%). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the copolymerization system.

[0032] Figure 2 Schematic diagram of the BF3 and DOX pre-reaction device.

[0033] In the figure, 1. BF3 input pipeline, 2. DOX input pipeline, 3. Nitrogen input pipeline, 4. DOX input pipeline containing antioxidant, 5. TOX input pipeline, 6. BF3 and DOX pre-reaction device, 7. Mixer, 11. Check valve of BF3 input pipeline, 12. Flow indicating controller of BF3 input pipeline, 21. Filter of DOX input pipeline, 22. Flow indicating controller of DOX input pipeline, 31. Check valve of nitrogen input pipeline, 41. Check valve of DOX input pipeline, 51. Filter of TOX input pipeline, 52. Flow indicating control of TOX input pipeline, 61. BF3 feed port, 62. DOX feed port, 63. Baffle, 64. Mixture discharge port, 65. Heat tracing pipe, 66. Guide pipe, 67. Device body. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0035] Example 1

[0036] like Figure 1 , 2 As shown, a BF3 and DOX pre-reaction device includes a device body 67, wherein the device body 67 is provided with a BF3 feed port 61, a DOX feed port 62 and a mixture discharge port 64; a guide tube 66 is provided inside the device body 67, and a baffle 63 is provided on the inner wall of the device body 67 and the guide tube 66; a heating pipe 65 is provided outside the device body 67.

[0037] In this embodiment, the BF3 feed port 61 is connected to the BF3 input pipeline 1 by a metal hose. The BF3 input pipeline 1 is provided with a check valve 11 and a flow indicating controller 12 to prevent the BF3 gas from flowing back and detect the BF3 flow.

[0038] In this embodiment, the DOX feed port 62 is connected to the DOX input pipeline 2 by a metal hose. The DOX input pipeline 2 is provided with a filter 21 and a flow indicating controller 22, which can monitor and control the DOX flow rate to avoid insufficient mixing and contact between part of the DOX and the initiator BF3 due to excessive DOX flow.

[0039] In this embodiment, baffles 63 are alternately arranged on both sides of the internal fluid straight path, which is conducive to more complete mixing of DOX and initiator BF3.

[0040] In this embodiment, a flow guide tube 66 is provided at the end of the internal fluid straight path.

[0041] In this embodiment, the temperature of the heating pipe 65 is maintained at 50°C.

[0042] Example 2

[0043] like Figure 1 , 2 As shown, a copolymer formaldehyde production system includes the BF3 and DOX pre-reaction device 6 and the mixer 7 described in Example 1, the mixer is provided with a mixture inlet, a nitrogen inlet, a TOX inlet and a TOX mixture outlet, the mixture inlet of the mixer is connected to the mixture outlet 64 of the BF3 and DOX pre-reaction device, the nitrogen inlet is connected to the nitrogen input pipeline 3 and the DOX input pipeline 4 containing an antioxidant.

[0044] In this embodiment, a check valve 31 is provided on the nitrogen input pipeline 3 to prevent nitrogen from flowing back.

[0045] In this embodiment, a check valve 41 is provided on the DOX input pipeline 4 containing the antioxidant to prevent the material from flowing back.

[0046] In this embodiment, a filter 51 and a flow indicator control 52 are provided on the TOX input pipeline 5, which can monitor and control the DOX flow rate to prevent the DOX flow rate from being too large or too small so that the POM quality is unqualified.

[0047] In this embodiment, the nitrogen gas input pipeline 3 , the DOX input pipeline 4 containing the antioxidant, and the TOX input pipeline 5 are mixed by a mixer 7 .

[0048] In this embodiment, the discharge pipeline of the mixer 7 and the pipeline connected to the discharge port 64 of the mixture of BF3 and DOX pre-reaction device are connected by a metal hose.

[0049] In summary, the BF3 and DOX pre-reaction device provided by the present invention is provided with two feed inlets, namely, a BF3 feed inlet 61 and a DOX feed inlet 62. The initiator BF3 and DOX are fully contacted through the baffle 63 and the guide tube 66 inside the device. After being fully mixed and pre-reacted, they leave through the mixture discharge port 64 and enter the mixer together with TOX to react, thereby accelerating the reaction speed and improving the production efficiency.

Claims

1. A BF3 and DOX pre-reaction device, characterized in that, The device comprises a device body, wherein the device body is provided with a BF3 inlet, a DOX inlet and a mixture outlet; a flow guide pipe is provided inside the device body, and baffles are provided on the inner wall of the device body and the flow guide pipe; and a heating pipe is provided outside the device body.

2. The BF3 and DOX pre-reaction device according to claim 1, characterized in that: The baffles are in multiple groups, and the flow guide pipes are in multiple groups.

3. The BF3 and DOX pre-reaction device according to claim 1, characterized in that: Baffles are alternately arranged on both sides of the straight path of the internal fluid of the device body; and a flow guide pipe is arranged at the end of the straight path of the internal fluid of the device body.

4. The BF3 and DOX pre-reaction device according to claim 1, characterized in that: The BF3 inlet and the DOX inlet are located at the top of the device body, and the mixture outlet is located at the bottom of the device body.

5. The BF3 and DOX pre-reaction device according to claim 1, characterized in that: The BF3 feed port is connected to the BF3 input pipeline; the DOX feed port is connected to the DOX input pipeline.

6. The BF3 and DOX pre-reaction device according to claim 1, characterized in that: The BF3 input pipeline is provided with a check valve; the DOX input pipeline is provided with a filter and a flow indicating controller.

7. A copolymerization system, characterized in that: It comprises the BF3 and DOX pre-reaction device and the mixer according to any one of claims 1 to 6, wherein the mixer is provided with a mixture inlet, a nitrogen inlet, a TOX inlet and a TOX mixture outlet, the mixture inlet of the mixer is connected to the mixture outlet of the BF3 and DOX pre-reaction device, and the nitrogen inlet is connected to a nitrogen input pipeline and a DOX input pipeline containing an antioxidant.

8. The copolymerization oxymethylene production system according to claim 7, characterized in that: The nitrogen input pipeline is provided with a check valve, and the DOX input pipeline containing an antioxidant is provided with a check valve.

9. The copolymerization oxymethylene production system according to claim 7, characterized in that: The TOX feed port is connected to the TOX input pipeline.

10. The copolymerization acetal production system according to claim 7, characterized in that: The TOX input pipeline is provided with a filter and a flow indicating controller.

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