Dimethyl carbonate dropwise adding system for producing polycarbonate diol

Abstract

The utility model discloses a dimethyl carbonate dropping system for polycarbonate diol production, which comprises a head tank, two dropping pipes arranged side by side are connected to the bottom of the head tank, flow control components are respectively mounted on the dropping pipes, the bottom ends of the two dropping pipes are connected with a left port and a right port of a tee joint, and the left port and the right port of the tee joint are respectively connected with the head tank. An instant heating part, a fixed end pipe and a liquid distribution ring pipe which are communicated with the tee joint are sequentially mounted at the bottom of the tee joint, the instant heating part comprises an inner pipe body and an outer pipe body which are coaxially arranged, and the two ends of the inner pipe body and the two ends of the outer pipe body are fixedly connected with flanges respectively; a closed clamping cavity of an annular structure is formed between the outer wall of the inner pipe body and the inner wall of the outer pipe body, and a spiral heating pipe is installed in the closed clamping cavity. According to the utility model, materials can be preheated and heated in the flowing process, so that the energy consumption is reduced; the problem of over-high local concentration caused by poor dispersibility of the dropping material can be solved; the problem that the whole dropwise adding system cannot work after a dropwise adding pipeline goes wrong is solved.

Description

Technical Field

[0001] The utility model relates to a dimethyl carbonate dropping system for the production of polycarbonate diol, belonging to the technical field of material dropping. Background Technique

[0002] The production processes of polycarbonate diol include phosgene method, ring-opening polymerization method of cyclic carbonate, copolymerization method of carbon dioxide and epoxide, and transesterification method. In the process of producing polycarbonate diol by transesterification method, dimethyl carbonate needs to be dropped through a dropping system.

[0003] The dimethyl carbonate dropping system drops materials from a high-level tank above the reaction kettle, and the dropped liquid enters the reaction kettle from the upper cover of the reaction kettle through a flow control device by gravity.

[0004] The existing dimethyl carbonate dropping system has the following deficiencies in the use process:

[0005] 1. The materials need to be preheated during dropping. Currently, the preheating of the dropped materials is through the jacket outside the high-level tank. After the materials in the inner cavity of the high-level tank are all preheated through the jacket, they are dropped. This preheating method consumes a large amount of energy. Sometimes only part of the materials in the high-level tank need to be dropped, and the overall heating method is not economical.

[0006] 2. During the dropping process, the materials often form very large liquid drops or a stream of liquid drops into the reaction kettle, which results in poor dispersion of the dropped materials and too high local concentration, thus leading to problems of uneven or too fast reaction and affecting the product quality.

[0007] 3. The dropping pipelines of the dropping system generally have a single structure. When problems occur in the dropping pipelines, the entire dropping system cannot work.

[0008] In summary, it is obvious that the existing technology has inconveniences and defects in actual use, so it is necessary to improve. Content of the Utility Model

[0009] Aiming at the deficiencies in the background technique, the utility model provides a dimethyl carbonate dropping system for the production of polycarbonate diol, which can realize preheating and temperature rise of the materials during the flowing process, reduce energy consumption; can solve the problem of poor dispersion of the dropped materials resulting in too high local concentration; and can solve the problem that the entire dropping system cannot work when problems occur in the dropping pipelines.

[0010] To solve the above technical problems, the utility model adopts the following technical solutions:

[0011] Dimethyl carbonate dropping system for polycarbonate diol production, including a high-level tank. The bottom of the high-level tank is connected with two side-by-side dropping pipes, and flow control components are respectively installed on the dropping pipes. The bottoms of the two dropping pipes are connected to the left and right ports of a tee. The bottom of the tee is successively installed with an immediate heating component, a fixed-end pipe and a liquid distribution ring pipe connected to it. The immediate heating component includes an inner pipe body and an outer pipe body arranged coaxially. The two ends of the inner pipe body and the outer pipe body are respectively fixedly connected with flanges. An annular sealed clamping cavity is formed between the outer wall of the inner pipe body and the inner wall of the outer pipe body, and a spiral heating pipe is installed inside the sealed clamping cavity. A plurality of flow disturbance plates are installed inside the inner pipe body.

[0012] Further, the immediate heating component is arranged vertically, and the two ends of the immediate heating component are connected to the tee and the fixed-end pipe through flanges.

[0013] Further, the fixed-end pipe penetrates through the top wall of the reaction kettle vertically and is fixedly connected to the top wall of the reaction kettle.

[0014] Further, the liquid distribution ring pipe is installed at the top of the inner cavity of the reaction kettle and is fixedly connected to the bottom end of the fixed-end pipe. A plurality of liquid distribution holes are arranged at the bottom of the pipe wall of the liquid distribution ring pipe.

[0015] Further, the spiral heating pipe is wound around the outside of the main body of the inner pipe body.

[0016] Further, the sealed clamping cavity is filled with a heat-conducting medium.

[0017] Further, a medium filling port is arranged on the outer wall above the main body of the outer pipe body.

[0018] Further, a plurality of flow disturbance plates are arranged vertically in a staggered manner. The flow disturbance plates are in a semi-circular structure, and the arc-shaped edges of the flow disturbance plates are fixedly connected to the inner wall of the inner pipe body.

[0019] Further, the inner diameter of the inner pipe body is equal to the inner diameter of the fixed-end pipe.

[0020] After the present utility model adopts the above technical solutions, compared with the prior art, it has the following advantages:

[0021] By setting the immediate heating component, the present utility model enables the material to be preheated and heated up during the flowing process. The immediate heating component can work as long as it is powered on, with convenient operation and less energy consumption.

[0022] By setting two dropping pipes, one for use and one for standby, the present utility model prevents the problem that the entire dropping system cannot work after a problem occurs in one dropping pipeline.

[0023] In the present utility model, the material is dispersed through a number of liquid distribution holes provided on the liquid distribution ring pipe, avoiding the problem that the dropping feed forms very large liquid droplets or a stream of liquid droplets dripping into the system, resulting in too high local concentration.

[0024] The present utility model will be described in detail below in conjunction with the accompanying drawings and embodiments. Description of the Drawings

[0025] Figure 1 is the installation schematic diagram of the present utility model;

[0026] Figure 2 is the structural schematic diagram of the present utility model;

[0027] Figure 3 is the internal structural schematic diagram of the instant heating component.

[0028] In the figure, 1 - high-level tank, 2 - dropping tube, 3 - flow control component, 4 - three-way, 5 - instant heating component, 51 - inner tube body, 52 - outer tube body, 53 - sealed clamping cavity, 54 - spiral heating tube, 55 - medium filling port, 56 - flow disturbing piece, 6 - fixed end tube, 7 - liquid distribution ring pipe, 8 - reaction kettle. Specific Embodiments

[0029] For a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described with reference to the accompanying drawings.

[0030] As Figures 1 - 3 collectively shown, the present utility model provides a dimethyl carbonate dropping system for polycarbonate diol production, including a high-level tank 1. The bottom of the high-level tank 1 is connected with two dropping tubes 2 arranged side by side. Flow control components 3 are respectively installed on the dropping tubes 2. The bottom ends of the two dropping tubes 2 are connected to the left and right ports of a three-way 4.

[0031] The bottom of the three-way 4 is successively installed with an instant heating component 5, a fixed end tube 6, and a liquid distribution ring pipe 7 that are communicated with it.

[0032] The instant heating component 5 is arranged in the vertical direction. The two ends of the instant heating component 5 are connected to the three-way 4 and the fixed end tube 6 through flanges.

[0033] The fixed end tube 6 penetrates through the top wall of the reaction kettle 8 in the vertical direction and is fixedly connected to the top wall of the reaction kettle 8.

[0034] The liquid distribution ring pipe 7 is installed at the top of the inner cavity of the reaction kettle 8 and is fixedly connected to the bottom end of the fixed end tube 6. A number of liquid distribution holes are provided at the bottom of the pipe wall of the liquid distribution ring pipe 7.

[0035] By setting a number of liquid distribution holes to disperse the dripping feed material, it is avoided that the dripping feed material forms very large droplets or a jet of liquid flowing into the system, resulting in the problem of too high local concentration.

[0036] The instant heating component 5 includes an inner tube body 51 and an outer tube body 52 arranged coaxially. Both ends of the inner tube body 51 and the outer tube body 52 are fixedly connected to flanges respectively.

[0037] An annular sealed clamping cavity 53 is formed between the outer wall of the inner tube body 51 and the inner wall of the outer tube body 52. A spiral heating tube 54 is installed inside the sealed clamping cavity 53, and the spiral heating tube 54 is wound around the outside of the main body of the inner tube body 51.

[0038] The sealed clamping cavity 53 is filled with a heat-conducting medium. After the spiral heating tube 54 is powered on, the heat-conducting medium is heated up, and then the material flowing in the inner cavity of the inner tube body 51 is uniformly heated up.

[0039] A medium filling port 55 is provided on the outer wall above the main body of the outer tube body 52.

[0040] A plurality of flow disturbance vanes 56 are installed inside the inner tube body 51. The plurality of flow disturbance vanes 56 are arranged staggeredly in the vertical direction. The flow disturbance vanes 56 are in a semi-circular structure, and the arc-shaped edges of the flow disturbance vanes 56 are fixedly connected to the inner wall of the inner tube body 51. By setting the flow disturbance vanes 56, the flowing speed of the dripping feed material is reduced, so as to facilitate sufficient heat absorption and temperature rise.

[0041] The inner diameter of the inner tube body 51 is equal to the inner diameter of the fixed-end tube 6.

[0042] The specific working principle of the present utility model:

[0043] The material in the high-level tank 1 enters the tee 4, the instant heating component 5, the fixed-end tube 6 and the liquid distribution ring pipe 7 in sequence through the dripping tube 2, and then enters the reaction kettle 8. The dripping process is precisely controlled by the flow control component 3.

[0044] By setting the instant heating component, the present utility model enables the material to be preheated and heated up during the flowing process. The instant heating component can work as long as it is powered on, with convenient operation and less energy consumption.

[0045] By setting two dripping tubes, one for use and one for backup, the present utility model prevents the problem that the entire dripping system cannot work after a problem occurs in one dripping pipeline.

[0046] The material in the present utility model is dispersed through a number of liquid distribution holes provided on the liquid distribution ring pipe, avoiding the problem that the dripping feed material forms very large droplets or a jet of liquid flowing into the system, resulting in too high local concentration.

[0047] The above is an example of the best implementation mode of the present utility model. The parts not described in detail are all common general knowledge in the art. The protection scope of the present utility model shall be subject to the content of the claims. Any equivalent transformation based on the technical inspiration of the present utility model is also within the protection scope of the present utility model.

Claims

1. A dimethyl carbonate dropping system for the production of polycarbonate diol, characterized in that: It includes a high-level tank (1). Two dropping pipes (2) arranged side by side are connected to the bottom of the high-level tank (1). Flow control components (3) are respectively installed on the dropping pipes (2). The bottom ends of the two dropping pipes (2) are connected to the left and right ports of a tee (4). The bottom of the tee (4) is successively installed with an instant heating component (5), a fixed-end pipe (6), and a liquid distribution ring pipe (7) connected to it. The instant heating component (5) includes an inner pipe body (51) and an outer pipe body (52) arranged coaxially. The two ends of the inner pipe body (51) and the outer pipe body (52) are respectively fixedly connected to flanges. An annular closed clamping cavity (53) is formed between the outer wall of the inner pipe body (51) and the inner wall of the outer pipe body (52). A spiral heating pipe (54) is installed inside the closed clamping cavity (53). A plurality of flow disturbance vanes (56) are installed inside the inner pipe body (51).

2. The dimethyl carbonate dropping system for the production of polycarbonate diol according to claim 1, wherein: The instant heating component (5) is arranged vertically. The two ends of the instant heating component (5) are connected to the tee (4) and the fixed-end pipe (6) through flanges.

3. The dimethyl carbonate dropping system for the production of polycarbonate diol according to claim 2, wherein: The fixed-end pipe (6) penetrates through the top wall of the reaction kettle (8) vertically and is fixedly connected to the top wall of the reaction kettle (8).

4. The dimethyl carbonate dropping system for producing polycarbonate diol according to claim 3, characterized in that: The liquid distribution ring pipe (7) is installed at the top of the inner cavity of the reaction kettle (8) and is fixedly connected to the bottom end of the fixed-end pipe (6). A number of liquid distribution holes are provided at the bottom of the pipe wall of the liquid distribution ring pipe (7).

5. The dimethyl carbonate dropping system for the production of polycarbonate diol according to claim 1, characterized in that: The spiral heating pipe (54) is wound around the outside of the main body of the inner pipe body (51).

6. The dimethyl carbonate dropping system for producing polycarbonate diol according to claim 1, wherein: The closed clamping cavity (53) is filled with a heat-conducting medium.

7. The dimethyl carbonate dropping system for polycarbonate diol production according to claim 1, characterized in that: A medium filling port (55) is provided on the outer wall above the main body of the outer pipe body (52).

8. The dimethyl carbonate dropping system for polycarbonate diol production according to claim 1, characterized in that: A plurality of flow disturbance vanes (56) are arranged staggered vertically. The flow disturbance vanes (56) are in a semi-circular structure, and the arc-shaped edges of the flow disturbance vanes (56) are fixedly connected to the inner wall of the inner pipe body (51).

9. The dimethyl carbonate dropping system for polycarbonate diol production according to claim 1, characterized in that: The inner diameter of the inner pipe body (51) is equal to the inner diameter of the fixed-end pipe (6).

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