CN209836041U

CN209836041U - Benzoic acid refining device

Info

Publication number: CN209836041U
Application number: CN201920572284.XU
Authority: CN
Inventors: 李仁峰
Original assignee: Jujube Guipu Material Ltd Company
Current assignee: Jujube Guipu Material Ltd Company
Priority date: 2019-04-24
Filing date: 2019-04-24
Publication date: 2019-12-24
Anticipated expiration: 2029-04-24

Abstract

The utility model discloses a refining plant of benzoic acid relates to benzoic acid purification field. Aiming at the problems of multiple equipment and complex structure in the prior art, a whole set of refining device special for benzoic acid is provided. Comprises a crystallization tower, a finished product tank, a first storage tank, a second storage tank and a condensing tank; the crystallization tower is provided with a crystal hanging frame which is longitudinally arranged, and the crystallization frame effectively improves the yield of finished products. The upper part of the crystallization tower is communicated with the condensing tank through a pipeline and then communicated with the second storage tank; the lower part of the crystallization tower is respectively communicated with the finished product tank and the first storage tank through another pipeline below the screen. The device has the advantages of simple structure, convenient maintenance, high yield of finished products and simple pipeline connection.

Description

Benzoic acid refining device

Technical Field

The utility model relates to a benzoic acid's purification field especially relates to a benzoic acid's refining plant.

Background

The benzoic acid has good bacteriostatic action and can be used as industrial raw materials, feed bacteriostatic agents and even intermediates of pharmaceutical products.

The GC purity of crude benzoic acid is about 92.1 percent, the GC purity of industrial benzoic acid is more than 98.5 percent, and the GC purity of high-quality medical benzoic acid is as high as 99.8 percent. As medical needs increase, the purity requirements for benzoic acid are becoming higher and higher. When the GC purity is as high as 98.5%, the refining equipment is very expensive, and the product yield is directly influenced because the process is complicated and the connecting pipelines between the equipment are too many.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems existing in the prior art, the utility model aims to provide a benzoic acid refining device with simple structure and convenient maintenance.

A refining plant of benzoic acid, include: the system comprises a crystallization tower, a finished product tank, a first storage tank, a second storage tank and a condensing tank; the crystallization tower is provided with an inner cavity, the bottom of the inner cavity is provided with a table-shaped screen, the center of the inner cavity is longitudinally provided with a crystal hanging frame, the upper end of the crystal hanging frame is fixedly connected with the top of the inner cavity, and the discharge end at the upper part of the inner cavity is communicated with a condensing tank through a pipeline and then communicated with a second storage tank; the discharge end at the lower part of the inner cavity is respectively communicated with the finished product tank and the first storage tank through another pipeline below the screen; the finished product tank, the first storage tank and the second storage tank are horizontally arranged side by side, and the height of the feeding end is lower than that of the discharging end at the lower part of the crystallization tower; the height of the feed end of the condensing tank is lower than that of the discharge end at the upper part of the crystallization tower, and the height of the discharge end of the condensing tank is higher than that of the feed end of the second storage tank.

A refining plant of benzoic acid, the first time heating can make the melting point be less than the impurity of benzoic acid and discharge to first storage tank from the bottom. The second heating can leave impurities with a melting point higher than that of the benzoic acid above the screen, and the high-purity benzoic acid is discharged to a finished product tank. The third heating can change the residual benzoic acid into gas state and discharge the gas state into a condensing tank from the upper part of the crystallization tower, and crystal beads can be formed when the gas meets a crystal hanging frame with relatively low temperature in the rising process. Because the benzoic acid is easier to crystallize than the residual impurities, the substances hung on the crystal rack are basically the benzoic acid, and more impurities are discharged from the upper part of the crystallization tower along with other benzoic acid. The yield of the benzoic acid can be effectively improved only by heating and melting the benzoic acid hung on the crystal rack for collection. The device has the advantages of simple structure, convenient maintenance, high yield of finished products and simple pipeline connection.

Preferably, the crystal hanging frame is of a hollow structure; the crystallization tower is also provided with a cold mass pipe communicated with the upper end of the crystal hanging frame. Can let the gaseous cooling of flowing through near hanging crystal frame faster to hanging crystal frame inside input condensing medium, like cold air or cold liquid through cold matter pipe, the crystallization volume is higher, further promotes the finished product yield.

Preferably, the crystal hanging frame comprises an outer tube and an inner tube which extend longitudinally and are coaxially sleeved, and the upper ends of the outer tube and the inner tube are fixedly connected with the top of the inner cavity; a plurality of branch pipes transversely extend out of the outer pipe, and one end of each branch pipe is closed while the other end is communicated with the outer pipe; the length of the inner pipe is less than that of the outer pipe, and the lower end of the inner pipe is open and communicated with the outer pipe; the cold pipe extends between the outer pipe and the inner pipe; the crystallization tower is also provided with a return pipe communicated with the inner pipe. The flowing loop of the condensing medium is formed in the crystal hanging frame, so that the temperature control of the crystal hanging frame is more accurate, and the purity of the crystal is more accurately controlled.

Preferably, the branch pipes are distributed along the longitudinal direction, and the adjacent branch pipes are arranged in a staggered mode. The gas can be raised to form turbulent flow, which is helpful for improving the crystallization rate.

Drawings

FIG. 1 is a schematic structural view of a benzoic acid refining apparatus according to the present invention;

FIG. 2 is a schematic diagram of the structure of the crystal hanging frame of the crystallization tower.

Reference numerals: 10-a crystallization tower, 11-a crystal hanging frame, 12-a cold pipe, 13-a return pipe, 14-an outer pipe, 15-an inner pipe, 16-a branch pipe and 17-a screen; 21-a finished product tank, 22-a first storage tank and 23-a second storage tank; 30-condensation tank.

Detailed Description

As shown in fig. 1 and 2, the refining device for benzoic acid of the present invention comprises: a crystallization tower 10, a finished product tank 21, a first storage tank 22, a second storage tank 23 and a condensing tank 30; the crystallization tower 10 is provided with an inner cavity, the bottom of the inner cavity is provided with a table-shaped screen 17, the center of the inner cavity is longitudinally provided with a crystal hanging frame 11, the upper end of the crystal hanging frame 11 is fixedly connected with the top of the inner cavity, and the discharge end at the upper part of the inner cavity is communicated with a second storage tank 23 after being communicated with a condensation tank 30 through a pipeline; the discharge end at the lower part of the inner cavity is respectively communicated with a finished product tank 21 and a first storage tank 22 below the screen 17 through another pipeline; the finished product tank 21, the first storage tank 22 and the second storage tank 23 are horizontally arranged side by side, and the heights of the feeding ends are all lower than the height of the discharging end at the lower part of the crystallization tower 10; the height of the feeding end of the condensing tank 30 is lower than that of the discharging end at the upper part of the crystallizing tower 10, and the height of the discharging end of the condensing tank 30 is higher than that of the feeding end of the second storage tank 23.

The crystal hanging frame 11 is of a hollow structure; the crystallization tower 10 is also provided with a cold mass pipe 12 communicated with the upper end of the crystal hanging frame 11.

The crystal hanging frame 11 comprises an outer tube 14 and an inner tube 15 which extend longitudinally and are coaxially sleeved, and the upper ends of the outer tube 14 and the inner tube 15 are fixedly connected with the top of the inner cavity; a plurality of branch pipes 16 transversely extend out of the outer pipe 14, and one end of each branch pipe 16 is closed, and the other end of each branch pipe 16 is communicated with the outer pipe 14; the length of the inner pipe 15 is less than that of the outer pipe 14, and the lower end of the inner pipe is opened and communicated with the outer pipe 14; the cold mass pipe 12 extends between the outer pipe 14 and the inner pipe 15; the crystallization tower 10 is also provided with a return pipe 13 communicated with an inner pipe 15.

The branch pipes 16 are distributed along the longitudinal direction, and the adjacent branch pipes 16 are arranged in a staggered mode.

The working principle of the benzoic acid refining device is as follows, firstly, the crude benzoic acid to be refined is put into the crystallization tower 10 and heated to a melting point slightly lower than that of benzoic acid, such as 120-122 ℃. Crystals of benzoic acid will remain above the screen 17 and partially dissolved benzoic acid, together with impurities with a lower melting point, will flow below the screen 17. The valve of the first storage tank 22 is opened, and the valve of the first storage tank 22 is closed after the first storage tank 22 is drained through a pipeline for storage. The temperature in the crystallization tower 10 is further increased to a temperature slightly higher than the melting point of benzoic acid, for example, to 123 ℃ to 124 ℃, most of benzoic acid is molten, and impurities with a melting point higher than that of benzoic acid are substantially retained above the screen 17. The valve of the finished product tank 21 is opened, the high purity benzoic acid is discharged into the finished product tank 21 to be stored, and then the valve of the finished product tank 21 is closed. The heating is continued to boil and gasify the benzoic acid in the crystallization tower 10, for example, the benzoic acid is heated to 250 ℃ to 260 ℃, and the mixed gas of the benzoic acid and impurities rises to the top of the crystallization tower 10 and is discharged to the condensing tank 30 through a pipeline for cooling. And in the process of gas rising, introducing a condensing medium into the crystal hanging rack 11 to cool the mixed gas. The temperature of the crystal hanging rack 11 is controlled to be slightly lower than the melting point of benzoic acid, the crystal on the crystal hanging rack 11 is basically pure benzoic acid, and relatively more impurities in the gas are discharged into the condensing tank 30. The condensed material is discharged to the second storage tank 23 through a pipe to be stored after passing through the condensation tank 30. Controlling the temperature of the crystallization tower 10, stopping the input of the condensing medium of the crystal hanging rack 11, melting the crystals on the crystal hanging rack 11 and gathering the crystals below the screen 17, and opening a valve of a finished product tank 21 for collection. The refining process of the benzoic acid is completed, and compared with the prior art, the collecting efficiency and the finished product yield of the benzoic acid are obviously improved. Especially, the yield of the finished product can reach 25.67 percent when the GC purity is 99.7 percent. Meanwhile, according to the common knowledge, the skilled person can change the corresponding temperature range in each process step by reducing or increasing the pressure in the crystallization tower so as to adapt to different purity of the finished product.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes are intended to fall within the scope of the claims.

Claims

1. A benzoic acid refining device, characterized by comprising: a crystallization tower (10), a finished product tank (21), a first storage tank (22), a second storage tank (23) and a condensing tank (30);

the crystallization tower (10) is provided with an inner cavity, the bottom of the inner cavity is provided with a table-shaped screen (17), the center of the inner cavity is longitudinally provided with a crystal hanging frame (11), the upper end of the crystal hanging frame (11) is fixedly connected with the top of the inner cavity, and the discharge end at the upper part of the inner cavity is communicated with a condensing tank (30) through a pipeline and then communicated with a second storage tank (23); the discharge end at the lower part of the inner cavity is respectively communicated with a finished product tank (21) and a first storage tank (22) through another pipeline below the screen (17);

the finished product tank (21), the first storage tank (22) and the second storage tank (23) are horizontally arranged side by side, and the heights of the feeding ends are all lower than the height of the discharging end at the lower part of the crystallization tower (10); the height of the feed end of the condensing tank (30) is lower than that of the discharge end at the upper part of the crystallization tower (10), and the height of the discharge end of the condensing tank (30) is higher than that of the feed end of the second storage tank (23).

2. The benzoic acid refining device according to claim 1, wherein the crystal hanger (11) is a hollow structure; the crystallization tower (10) is also provided with a cold pipe (12) which is communicated with the upper end of the crystal hanging frame (11).

3. The benzoic acid refining device according to claim 2, wherein the crystal hanging rack (11) comprises an outer tube (14) and an inner tube (15) which extend longitudinally and are coaxially sleeved, and the upper ends of the outer tube (14) and the inner tube (15) are fixedly connected with the top of the inner cavity; a plurality of branch pipes (16) transversely extend out of the outer pipe (14), and one end of each branch pipe (16) is closed, and the other end of each branch pipe is communicated with the outer pipe (14); the length of the inner pipe (15) is less than that of the outer pipe (14), and the lower end of the inner pipe is opened and communicated with the outer pipe (14); the cold mass pipe (12) extends between the outer pipe (14) and the inner pipe (15); the crystallization tower (10) is also provided with a return pipe (13) communicated with the inner pipe (15).

4. A refining apparatus for benzoic acid according to claim 3, characterized in that said branches (16) are longitudinally distributed and adjacent branches (16) are staggered.