A tubular mixer for the preparation of p-nitroaniline

Abstract

The application discloses a tubular mixer for preparing p-nitroaniline, which comprises an outer tube, a middle tube, an inner tube, an ammonia water feeding pipe connected to the left end of the middle tube, a feeding plate for closing the right end of the outer tube and having spray ports uniformly distributed on the left end surface, a p-nitrochlorobenzene feeding pipe connected to the outer circumferential surface of the feeding plate, a plurality of truncated hollow sections arranged in sequence along the left-right direction on the middle tube, a rotating ring assembled at each truncated hollow section and rotationally and sealingly connected to the middle tube at the left and right ends, axial flow blades arranged on the inner circumferential surface of each rotating ring and uniformly distributed along the circumferential direction of the rotating ring, a stirring rod arranged on the outer circumferential surface of each rotating ring, and a plurality of flow uniformizing plates sleeved on the middle tube, uniformly distributed through holes and arranged in sequence along the left-right direction. The tubular mixer for preparing p-nitroaniline can realize sufficient mixing of p-nitrochlorobenzene and ammonia water, improve the mixing efficiency and mixing effect, and finally improve the production efficiency and product quality of p-nitroaniline.

Description

Technical Field

[0001] This invention relates to a tubular mixer for preparing p-nitroaniline. Background Technology

[0002] p-Nitroaniline is an extremely important intermediate in the dye industry. Currently, there is a method for preparing p-nitroaniline, which includes the following steps: p-nitrochlorobenzene and ammonia are fed into a tubular mixer for mixing; the mixed material output from the tubular mixer is fed into a tubular reactor for high-temperature and high-pressure reaction; the material output from the tubular reactor after the high-temperature and high-pressure reaction is fed into a low-pressure reactor for ammonia release; the material output from the low-pressure reactor after ammonia release is fed into a separation vessel for separation; finally, the separated material is centrifuged and washed to obtain p-nitroaniline.

[0003] The mixing efficiency and effect of p-nitrochlorobenzene and ammonia water will affect the final production efficiency and product quality of p-nitroaniline. Although existing tubular mixers can mix p-nitrochlorobenzene and ammonia water, their mixing efficiency and effect need to be improved. Summary of the Invention

[0004] This invention provides a tubular mixer for preparing p-nitroaniline, comprising: an outer tube horizontally positioned along the left-right direction and closed at both ends; a middle tube internally embedded in the outer tube, coaxial with the outer tube, closed at the left end and open at the right end; an inner tube internally embedded in the middle tube, coaxial with the middle tube, with its left end penetrating the left end of the middle tube and its right end penetrating the right end of the outer tube; an ammonia water supply pipe externally connected to the left end of the middle tube; an ammonia water high-pressure delivery pump (located outside the outer tube) mounted on the ammonia water supply pipe; a spray plate sealing the right end of the outer tube, coaxial with the outer tube, penetrated by the inner tube, and with spray nozzles evenly distributed on its left end face; a p-nitrochlorobenzene supply pipe externally connected to the outer circumference of the spray plate; a p-nitrochlorobenzene high-pressure delivery pump (located outside the outer tube) mounted on the p-nitrochlorobenzene supply pipe; and multiple truncated sections arranged at equal intervals along the left-right direction on the middle tube. The system comprises: rotating rings mounted at each cut-off section, coaxial with the central tube and with their left and right ends rotatably sealed to the central tube; axial flow blades evenly distributed along the circumference of the inner circumference of each rotating ring; stirring rods mounted on the outer circumference of each rotating ring; multiple flow equalizing plates mounted on the central tube, coaxial with the central tube, with through holes evenly distributed along the left and right directions and arranged at equal intervals along the left and right directions; a feed hopper connected to the left end of the inner tube, coaxial with the inner tube and with its large diameter end facing left; a left cone block fixed on the inner surface of the left end of the outer tube, coaxial with the outer tube, with its small diameter end facing right and extending into the large diameter end of the feed hopper; and a right cone block fixed on the left end face of the flow equalizing plate, coaxial with the flow equalizing plate, with its small diameter end facing left and extending into the right end of the inner tube; the flow equalizing plates and rotating rings are alternately arranged on the central tube; the through holes of each flow equalizing plate have the same diameter, and the density of the through holes in each flow equalizing plate gradually increases from right to left.

[0005] The advantages and beneficial effects of the present invention are as follows: It provides a tubular mixer for preparing p-nitroaniline, which can achieve thorough mixing of p-nitrochlorobenzene and ammonia water, and can improve mixing efficiency and mixing effect, thereby ultimately improving the production efficiency and product quality of p-nitroaniline. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the present invention. Detailed Implementation

[0007] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0008] The specific technical solution of this invention is as follows: like Figure 1 As shown, a tubular mixer for preparing p-nitroaniline includes: an outer tube 11 placed horizontally in the left-right direction and closed at both ends; a middle tube 12 built into the outer tube 11, coaxial with the outer tube 11, closed at the left end and open at the right end; an inner tube 13 built into the middle tube 12, coaxial with the middle tube 12, with its left end penetrating the left end of the middle tube 12 and its right end penetrating the right end of the outer tube 11; an ammonia water supply pipe 21 connected to the left end of the middle tube 12; and an ammonia water high-pressure delivery pump installed on the ammonia water supply pipe 21. (The ammonia high-pressure delivery pump is located outside the outer pipe 11), a spray plate 3 that is coaxial with the outer pipe 11, penetrated by the inner pipe 13, and has spray nozzles 31 evenly distributed on its left end face, a p-nitrochlorobenzene supply pipe 22 connected to the outer circumference of the spray plate 3, a p-nitrochlorobenzene high-pressure delivery pump (located outside the outer pipe 11) installed on the p-nitrochlorobenzene supply pipe 22, and multiple cut-off sections arranged at equal intervals along the left and right directions on the middle pipe 12. The components include rotating rings 41 located at each cut-off section, coaxial with the central tube 12, and rotatably and sealingly connected to the central tube 12 at both ends; axial flow blades evenly distributed along the circumference of each rotating ring 41 on its inner circumferential surface; stirring rods 42 on the outer circumferential surface of each rotating ring 41; multiple flow equalizing plates 5 mounted on the central tube 12, coaxial with the central tube 12, evenly distributed with through holes extending in the left and right directions, and arranged at equal intervals in the left and right directions; and externally connected to the left end of the inner tube 13, coaxial with the inner tube 13. The feed hopper 6, with its large diameter end facing left, is fixed on the inner surface of the left end of the outer tube 11, coaxial with the outer tube 11, with its small diameter end facing right and extending into the large diameter end of the feed hopper 6. The feed hopper 6 also has a left cone block 71 fixed on the left end face of the flow equalization plate 5, coaxial with the flow equalization plate 5, with its small diameter end facing left and extending into the right end of the inner tube 13. The flow equalization plate 5 and the rotating ring 41 are alternately arranged on the middle tube 12. The through holes of each flow equalization plate 5 have the same diameter, and the distribution density of the through holes of each flow equalization plate 5 gradually increases from right to left.

[0009] The present invention relates to a tubular mixer for preparing p-nitroaniline, the working principle of which is as follows: A high-pressure ammonia pump pumps ammonia into the middle pipe 12 along the ammonia supply pipe 21, and a high-pressure p-nitrochlorobenzene pump pumps p-nitrochlorobenzene into the spray plate 3 along the p-nitrochlorobenzene supply pipe 22. p-Nitrochlorobenzene pumped into the spray plate 3 is sprayed out from the spray nozzle 31 on the left end face of the spray plate 3. Ammonia water pumped into the middle tube 12 flows from left to right in the inner cavity of the middle tube 12. The ammonia water flowing out from the right end of the middle tube 12 mixes with the p-nitrochlorobenzene sprayed from the spray nozzle 31. The mixture flows from right to left in the inner cavity between the middle tube 12 and the outer tube 11. The mixture flowing to the left end of the outer tube 11 flows from left to right in the inner tube 13. The mixture flowing out from the right end of the inner tube 13 is fed into the pipeline reactor for high temperature and high pressure reaction, and then continues to produce p-nitroaniline. The ammonia water pumped into the middle pipe 12 flows from left to right in the inner cavity of the middle pipe 12, which drives the axial flow blades to rotate the rotating ring 41, and then the rotating ring 41 drives the stirring rod 42 to rotate; the mixed material flows from right to left in the inner cavity between the middle pipe 12 and the outer pipe 11, and is stirred by the stirring rod 42, which improves the mixing efficiency and mixing effect of p-nitrochlorobenzene and ammonia water. The arrangement of the right cone block 72, the flow equalization plate 5, the left cone block 71, the feed hopper 6, etc., will also improve the mixing efficiency and mixing effect of p-nitrochlorobenzene and ammonia water; As can be seen from the above, the tubular mixer of the present invention for preparing p-nitroaniline can achieve thorough mixing of p-nitrochlorobenzene and ammonia water, and can improve mixing efficiency and mixing effect, thereby ultimately improving the production efficiency and product quality of p-nitroaniline.

[0010] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A tubular mixer for preparing p-nitroaniline, characterized in that, include: An outer pipe, horizontally aligned and closed at both ends, is housed within the outer pipe; a middle pipe, horizontally aligned and closed at the left end, with the right end open, is housed within the outer pipe; an inner pipe, horizontally aligned and connected to the middle pipe, with its left end penetrating the left end of the middle pipe and its right end penetrating the right end of the outer pipe; an ammonia supply pipe connected to the left end of the middle pipe; an ammonia high-pressure delivery pump mounted on the ammonia supply pipe; a spray plate, horizontally aligned with the axis along the left and right, with the inner pipe penetrating it and spray nozzles evenly distributed on its left end face; a p-nitrochlorobenzene supply pipe connected to the outer circumference of the spray plate; a p-nitrochlorobenzene high-pressure delivery pump mounted on the p-nitrochlorobenzene supply pipe; and multiple... Each section has a cut-off gap, a rotating ring assembled at each cut-off gap, coaxial with the central tube and with its left and right ends respectively connected to the central tube in a rotating seal, axial flow blades evenly distributed along the circumference of each rotating ring on its inner circumference, stirring rods evenly distributed on the outer circumference of each rotating ring, multiple flow equalization plates arranged sequentially along the left and right directions, coaxial with the central tube and with through holes evenly distributed along the left and right directions, a feed hopper connected to the left end of the inner tube with its large diameter end facing left, a left cone block fixed on the inner surface of the left end of the outer tube with its small diameter end facing right and extending into the large diameter end of the feed hopper, and a right cone block fixed on the left end face of the flow equalization plate with its small diameter end facing left and extending into the right end of the inner tube.

2. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The flow equalization plate and the rotating ring are alternately arranged on the central tube.

3. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The through-hole diameters of each flow equalizer plate are the same, and the density of through-hole distribution in each flow equalizer plate gradually increases from right to left.

4. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The multiple cut-off segments are arranged sequentially at equal intervals along the left and right directions on the central tube.

5. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The multiple flow equalizers are arranged sequentially at equal intervals along the left and right directions on the central tube.

6. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The middle tube, spray plate, and left cone block are all coaxial with the outer tube.

7. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The inner tube and the middle tube are coaxial.

8. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The feed hopper and the inner tube are coaxial.

9. The tubular mixer for preparing p-nitroaniline according to claim 1, characterized in that, The right cone block is coaxial with the flow equalization plate.

Images