Phthalic anhydride rectification device

Abstract

The utility model discloses a phthalic anhydride rectifying device which comprises a rectifying tower, an outlet pipeline arranged at the top of the rectifying tower, a condensing device connected with the outlet pipeline, an intermediate storage tank connected with the condensing device through a pipeline and a finished product storage tank connected with the intermediate storage tank through a pipeline, the condenser is horizontally arranged, a first sealing head and a second sealing head are arranged at the two ends of the condenser, a shell is arranged in the middle of the condenser, a first gas phase inlet and a first liquid phase outlet are formed in the first sealing head, a second gas phase inlet and a second liquid phase outlet are formed in the second sealing head, and a condensation pipe is arranged in the shell.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical equipment, in particular to a phthalic anhydride rectification device. Background Art

[0002] Phthalic anhydride, with the chemical formula C8H4O3, molecular weight of 148.116, and CAS number 85-44-9, is an important chemical intermediate, mainly formed by intramolecular dehydration of phthalic acid to form a cyclic anhydride. By-products such as phthalide, maleic anhydride, benzoic acid, and citraconic anhydride are generated in the reaction. Therefore, obtaining phthalic anhydride that meets the quality requirements requires a rectification device. When the rectification device operates, the high-temperature gas components at the top of the tower need to be condensed by a condenser for collection. Heat exchange occurs between the high-temperature gas and the low-temperature circulating cooling water in the condenser. In the existing condenser, the high-temperature gas always flows in from one end of the condenser. During operation, the temperature difference at this end is large, and corrosion and material fatigue are likely to occur, while the corrosion and material fatigue at the other end are relatively light. The existing condensers are all inclined or vertically arranged to facilitate the entry of gas and the outflow of liquid, which shortens the overall service life of the condenser. Content of the Utility Model

[0003] In view of this, the utility model provides a phthalic anhydride rectification device.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A phthalic anhydride rectification device includes a rectification tower, an outlet pipeline arranged at the top of the rectification tower, a condensation device connected to the outlet pipeline, an intermediate storage tank connected to the condensation device through a pipeline, and a finished product storage tank connected to the intermediate storage tank through a pipeline. It is characterized in that the condensation device includes a condenser, the condenser is horizontally arranged, with a first head and a second head at both ends, a shell in the middle, a first gas phase inlet and a first liquid phase outlet on the first head, a second gas phase inlet and a second liquid phase outlet on the second head, and a condensation pipe in the shell.

[0006] Further, a first circulating water outlet and a second circulating water outlet are arranged on the upper side of the shell along the axis, and a first circulating water inlet and a second circulating water inlet are arranged on the lower side of the shell along the axis.

[0007] Further, a first baffle plate is provided at each end inside the shell. The first baffle plate is a circular plate with notches at the upper and lower ends, and upper and lower notches are formed between the first baffle plate and the shell; several second baffle plates are provided in the middle of the shell. The second baffle plate is a circular plate with a notch at one end, and the notches between the second baffle plate and the shell are alternately arranged at the top and bottom of the shell.

[0008] Further, a plurality of condensing tubes are arranged inside the shell, round holes are formed in the baffle plate, and the condensing tubes can pass through the round holes.

[0009] Further, a first baffle is arranged on one side of the shell corresponding to the notch on the first baffle plate relative to the middle of the shell, and a second baffle is arranged on one side of the shell corresponding to the notch under the first baffle plate relative to the middle of the shell.

[0010] Further, the upper end of the first baffle is an arc surface, and the lower end is a plane. The arc surface is hinged to the shell through a hinge, and the plane end is lapped on the upper end of the side of the first baffle plate close to the middle of the shell.

[0011] Further, the upper end surface of the second baffle is a plane, and the lower end is an arc surface. The plane is hinged to the lower end of the first baffle plate through a hinge.

[0012] Further, a stop block is arranged inside the shell corresponding to the second baffle, and the stop block can prevent the second baffle from moving towards the middle of the shell.

[0013] Further, an opening is formed in the first baffle, and the area of the opening is 1 / 8 - 1 / 5 of the area of the lower notch.

[0014] Further, a first gas-phase inlet valve is arranged on the pipeline of the first gas-phase inlet, and a second gas-phase inlet valve is arranged on the pipeline of the second gas-phase inlet; a first liquid-phase outlet valve is arranged on the pipeline of the first liquid-phase outlet, and a second liquid-phase outlet valve is arranged on the pipeline of the second liquid-phase outlet; a first circulating water inlet valve is arranged on the pipeline of the first circulating water inlet, and a second circulating water inlet valve is arranged on the pipeline of the second circulating water inlet; a first circulating water outlet valve is arranged on the pipeline of the first circulating water outlet, and a second circulating water outlet valve is arranged on the pipeline of the second circulating water outlet; a finished product receiving valve and a reflux control valve are arranged on the pipeline of the intermediate storage tank outlet.

[0015] The beneficial effects of the present utility model are as follows:

[0016] The phthalic anhydride rectifying device provided by the present utility model includes a rectifying tower, an outlet pipeline arranged at the top of the rectifying tower, a condensing device connected to the outlet pipeline, an intermediate storage tank connected to the condensing device through a pipeline, and a finished product storage tank connected to the intermediate storage tank through a pipeline. The condensing device includes a condenser, the condenser is horizontally arranged, a first head and a second head are arranged at both ends, a shell is arranged in the middle, a first gas-phase inlet and a first liquid-phase outlet are arranged on the first head, a second gas-phase inlet and a second liquid-phase outlet are arranged on the second head, and condensing tubes are arranged inside the shell. The first gas-phase inlet and the second gas-phase inlet can be used alternately, so that both ends of the condenser work alternately in an environment with a large temperature difference, thereby increasing the service life. Description of the Drawings

[0017] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic structural diagram of the phthalic anhydride rectification device of the present utility model;

[0019] Figure 2 is Figure 1 The enlarged structural diagram at the position A shown;

[0020] Figure 3 It is a schematic structural diagram of the condenser in the present utility model;

[0021] Figure 4 It is a schematic structural diagram of the first baffle plate in the present utility model;

[0022] Figure 5 It is a schematic structural diagram of the second baffle plate in the present utility model;

[0023] Figure 6 It is a schematic structural diagram of the first baffle in the present utility model;

[0024] Figure 7 It is a schematic structural diagram of the second baffle in the present utility model;

[0025] In the figure: 100, phthalic anhydride rectification device; 1, rectification tower; 11, outlet pipeline; 111, first gas-phase inlet valve; 112, second gas-phase inlet valve; 2, condensation device; 21, condenser; 211, first head; 2111, first gas-phase inlet; 2112, first liquid-phase outlet; 2113, first fixing plate; 212, second head; 2121, second gas-phase inlet; 2122, second liquid-phase outlet; 2123, second fixing plate; 213, housing; 2131, third fixing plate; 2132, fourth fixing plate; 2133, second baffle plate; 2134, first baffle plate; 21341, first baffle; 21342, second baffle; 2135, first circulating water outlet; 2136, second circulating water outlet; 2137, first circulating water inlet; 2138, second circulating water inlet; 2139, condensation tube; 214, bolt; 22, first circulating water outlet valve; 23, second circulating water outlet valve; 24, first liquid-phase outlet valve; 25, second liquid-phase outlet valve; 26, first circulating water inlet valve; 27, second circulating water inlet valve; 3, intermediate storage tank; 31, finished product receiving valve; 32, reflux control valve; 4, finished product storage tank. Specific embodiments

[0026] Now, the present utility model will be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present utility model in a schematic manner, so it only shows the components related to the present utility model.

[0027] AsFigures 1 - 3 As shown in the figure, the present utility model provides a phthalic anhydride rectification device 100, which includes a rectification tower 1, a condensation device 2, an intermediate storage tank 3 and a finished product storage tank 4. An outlet pipeline 11 is provided at the top of the rectification tower 1, and is connected to the condensation device through the outlet pipeline 11. The condensation device 2 and the intermediate storage tank 3 are connected by a pipeline, and the intermediate storage tank 3 and the finished product storage tank 4 are connected by a pipeline.

[0028] The condensation device includes a condenser 21, which is horizontally arranged, with a first head 211 and a second head 212 provided at both ends respectively, and a condenser housing 213 in the middle. A first gas phase inlet 2111, a first liquid phase outlet 2112 and a first fixing plate 2113 are provided on the first head 211. A second gas phase inlet 2121, a second liquid phase outlet 2122 and a second fixing plate 2123 are provided on the second head 212. Third fixing plates 2131 and fourth fixing plates 2132 are provided at both ends of the condenser housing 213 respectively. A number of condenser tubes 2139 are arranged inside, and the condenser tubes 2139 sequentially pass through the first fixing plate 2113, the third fixing plate 2131, the fourth fixing plate 2132 and the second fixing plate 2123, connecting the first head 211, the housing 213 and the second head 212. The first head 211 and the housing 213 are fixed by bolts 214 around the first fixing plate 2113 and the third fixing plate 2131. The second head 211 and the housing 213 are fixed by bolts 214 around the second fixing plate 2123 and the fourth fixing plate 2132. A first circulating water outlet 2135 and a second circulating water outlet 2136 are provided at both ends of the upper side of the housing 213 along the axial direction. A first circulating water inlet 2137 and a second circulating water inlet 2138 are provided at both ends of the lower side of the housing 213 along the axial direction. A number of baffle plates are arranged inside the housing 213. Circular holes for the condenser tubes 2139 to pass through are provided in the middle of the baffle plates. Among them, the two ends are the first baffle plates 2134. As Figure 4 shown, the first baffle plate 2134 is a circular plate with notches at both the upper and lower ends. A circular hole for the condenser tube 2139 to pass through is provided inside the first baffle plate. The middle part is the second baffle plate 2133. As Figure 5 shown, the second baffle plate 2133 is a circular plate with a notch at one end, and also has a circular hole for the condenser tube 2139 to pass through. When the second baffle plate 2133 is arranged, the direction of the notch is alternately placed at the top and bottom of the axial direction of the housing 213, which can cause the water flow to form a baffle when passing through, increasing the cooling effect. After the first baffle plate 2134 is installed on the housing 213, upper and lower notches appear correspondingly. A first baffle 21341 is provided at the position corresponding to the housing 213 inside the upper notch (close to the middle side of the housing 213). The shape is as Figure 6As shown in the figure, an opening 2136 is provided inside the first baffle 21341. The water passing area of the opening 2136 is 1 / 8 - 1 / 5 of the water passing area of the upper notch. The upper end arc surface of the first baffle 21341 is movably connected to the housing 213 through a hinge, and the lower end plane is lapped on the first baffle plate 2134. Water flow can wash open the first baffle from the outside and be blocked from passing through from the inside; a second baffle 21342 is provided outside the lower notch (the side away from the middle of the housing 213), and the shape is as Figure 7 shown. The upper end plane of the second baffle 21342 is movably connected to the first baffle plate 2134 through a hinge, and a stopper (not shown in the figure) is provided on the lower end arc surface corresponding to the housing 213. Cooperating with the stopper, water flow can pass through when flowing through the second baffle 21342 from the middle of the housing 213, and is blocked when flowing into the second baffle 21342 from both ends of the housing 213.

[0029] A first gas phase inlet valve 111 is provided on the pipeline connecting the first gas phase inlet 2111 of the condenser 21, and a second gas phase inlet valve 112 is provided on the pipeline of the second gas phase inlet 2121; a first circulating water outlet valve 22 is provided on the pipeline of the first circulating water outlet 2135, and a second circulating water outlet valve 23 is provided on the pipeline of the second circulating water outlet 2136; a first circulating water inlet valve 26 is provided on the pipeline of the first circulating water inlet 2137, and a second circulating water inlet valve 27 is provided on the pipeline of the second circulating water inlet 2138; a first liquid phase outlet valve 24 is provided on the pipeline of the first liquid phase outlet 2112, and a second liquid phase outlet valve 25 is provided on the pipeline of the second liquid phase outlet 2122.

[0030] When the phthalic anhydride rectification device 100 is in operation, the first gas phase inlet valve 111 is opened, and the second gas phase inlet valve 112 is closed; the first circulating water inlet valve 26 is opened, and the second circulating water inlet valve 27 is closed; the second circulating water outlet valve 23 is opened, and the first circulating water outlet valve 22 is closed; the second liquid phase outlet valve 25 is opened, and the first liquid phase outlet valve 24 is closed. At this time, the circulating water enters the housing 213 from the second circulating water inlet 2138, passes through the upper notch of the left - hand first baffle plate, washes open the first baffle 21341, and then passes through several second baffle plates 2133 in sequence. A small part of the circulating water flows through the opening 21361 of the right - hand first baffle 21341 and flows out through the first circulating water outlet 2135. Most of the circulating water passes through the lower notch of the right - hand first baffle plate 2134, washes open the second baffle 21342, and after being deflected, flows out of the housing 213 through the first circulating water outlet 2135. The phthalic anhydride distilled from the top of the tower passes through the first gas phase inlet valve 111, the first head 211, the condenser tube 2139, the second head 212, and the second liquid phase outlet 2122 in sequence in the pipeline and enters the intermediate storage tank 3. A finished product receiving valve 31 and a reflux control valve 32 are provided on the outlet pipeline of the intermediate storage tank 3 to adjust the flow rate into the finished product storage tank 4 and the reflux ratio into the rectification tower 1 respectively.

[0031] After running for a period of time, close the first gas-phase inlet valve 111 and open the second gas-phase inlet valve 112; close the first circulating water inlet valve 26 and open the second circulating water inlet valve 27; close the second circulating water outlet valve 23 and open the first circulating water outlet valve 22; close the second liquid-phase outlet valve 25 and open the first liquid-phase outlet valve 24. At this time, the circulating water enters the housing 213 from the first circulating water inlet 2137, passes through the upper notch of the first baffle at the right end, flushes open the first baffle 21341, and then passes through a number of second baffles 2133 in sequence. A small part of the circulating water flows into the first circulating water outlet 2135 through the opening 21361 of the first baffle 21341 at the left end, and most of the circulating water passes through the lower notch of the first baffle 2134 at the left end, flushes open the second baffle 21342, and after a baffle, flows out of the housing 213 through the first circulating water outlet 2135. The phthalic anhydride distilled from the top of the tower passes through the second gas-phase inlet valve 112, the second head 212, the condenser tube 2139, the first head 211, and the first liquid-phase outlet 2112 in sequence in the pipeline and enters the intermediate storage tank 3. A finished product receiving valve 31 and a reflux control valve 32 are provided on the outlet pipeline of the intermediate storage tank 3 to adjust the flow rate into the finished product storage tank 4 and the reflux ratio into the distillation column 1 respectively.

[0032] The technical solution disclosed by the present utility model, by providing a first gas-phase inlet 2111 and a second gas-phase inlet 2121, a first liquid-phase outlet 2112 and a second liquid-phase outlet 2122 on the condenser 21, and cooperating with the first circulating water inlet 2137 and the second circulating water inlet 2138, the first circulating water outlet 2135 and the second circulating water outlet 2136, can enable the two ends of the condenser to alternately work in an environment with a large temperature difference, increasing the service life.

[0033] Inspired by the above ideal embodiments according to the present utility model, through the above description, relevant staff can completely make various changes and modifications without departing from the scope of the present utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A phthalic anhydride distillation device, comprising a distillation tower, an outlet pipeline arranged at the top of the distillation tower, a condensing device connected to the outlet pipeline, an intermediate storage tank connected to the condensing device pipeline, and a finished product storage tank connected to the intermediate storage tank pipeline, characterized in that: The condensing device includes a condenser, which is horizontally arranged, with a first head and a second head at both ends, and a shell in the middle, the first head is provided with a first gas phase inlet and a first liquid phase outlet, the second head is provided with a second gas phase inlet and a second liquid phase outlet, a condenser is provided in the shell, the shell is provided with a first circulating water outlet and a second circulating water outlet along the axial upper side, and the shell is provided with a first circulating water inlet and a second circulating water inlet along the axial lower side.

2. The phthalic anhydride distillation device according to claim 1, characterized in that: A first baffle is provided at each end of the shell, the first baffle is a circular plate with notches at the upper and lower ends, and upper and lower notches are formed between the first baffle and the shell; a plurality of second baffles are provided in the middle of the shell, the second baffle is a circular plate with a notch at one end, and the notches between the second baffle and the shell are alternately arranged at the top and bottom of the shell.

3. The phthalic anhydride distillation device according to claim 2, characterized in that: A plurality of condensing tubes are arranged in the shell, and a circular hole is arranged on the baffle, through which the condensing tubes can pass.

4. The phthalic anhydride distillation device according to claim 2, characterized in that: A first baffle is provided in the shell at a position corresponding to the notch on the upper part of the first baffle plate relative to the middle side of the shell, and a second baffle is provided in the shell at a position corresponding to the notch on the lower part of the first baffle plate relative to the middle side of the shell.

5. The phthalic anhydride distillation device according to claim 4, characterized in that: The upper end of the first baffle is an arc surface, and the lower end is a plane. The arc surface is hinged to the shell through a hinge, and the plane end overlaps the upper end of a surface of the first baffle close to the middle of the shell.

6. The phthalic anhydride distillation device according to claim 4, characterized in that: The upper end surface of the second baffle is a plane, and the lower end is a curved surface. The plane is hinged to the lower end of the first baffle through a hinge.

7. The phthalic anhydride distillation device according to claim 6, characterized in that: A stopper is provided in the shell at a position corresponding to the second baffle, and the stopper can prevent the second baffle from moving toward the middle of the shell.

8. The phthalic anhydride distillation device according to claim 4, characterized in that: The first baffle is provided with an opening, and the area of ​​the opening is 1 / 8-1 / 5 of the area of ​​the lower notch.

9. The phthalic anhydride distillation device according to claim 8, characterized in that: A first gas phase inlet valve is provided on the pipeline of the first gas phase inlet, and a second gas phase inlet valve is provided on the pipeline of the second gas phase inlet; a first liquid phase outlet valve is provided on the pipeline of the first liquid phase outlet, and a second liquid phase outlet valve is provided on the pipeline of the second liquid phase outlet; a first circulating water inlet valve is provided on the first circulating water inlet pipeline, and a second circulating water inlet valve is provided on the second circulating water inlet pipeline; a first circulating water outlet valve is provided on the first circulating water outlet pipeline, and a second circulating water outlet valve is provided on the second circulating water outlet pipeline; a finished product receiving valve and a reflux control valve are provided on the intermediate storage tank outlet pipeline.

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