Special device for preventing tail gas from entraining lactide

Abstract

A special device for preventing tail gas from carrying lactide comprises a tank body, a heater, a buffer tank, a condenser and a trapper are sequentially installed in the tank body from bottom to top, a pipe opening communicated with an outlet of the trapper is formed in the middle of the top face of the tank body, and the pipe opening is connected with a tail gas output port through a tail gas output pipe. The tail gas outlet is connected with a vacuum pump inlet; a tail gas input port is formed in one side wall of the tank body at the buffer tank, a chilled water inlet and a chilled water outlet are respectively formed in two side walls of the tank body at the condenser, a low-pressure steam inlet is formed in the outer wall surface of the tank body at the heater, and a condensed water outlet and a condensed liquid outlet are respectively formed in the bottom of the tank body at the heater. By means of mutual cooperation among the buffer tank, the heater, the condenser, the catcher and other components, lactide can be conveniently removed, lactide enters the vacuum pump after being removed, the vacuum pump is protected, the service life of the vacuum pump is prolonged, and smoothness of whole production is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical environmental protection equipment, in particular to a special device for preventing tail gas from carrying lactide. Background Art

[0002] Polylactic acid is a new type of biodegradable material. During its synthesis or depolymerization process, an intermediate, lactide, will be produced behind the reactor. Lactide is solid at room temperature, with a melting point of 93-95°C, a boiling point of 216°C, and it sublimates. In the process of lactide production, it is necessary to quickly gasify and remove the lactide produced at high temperature and high vacuum to ensure the normal reaction, and then separate the lactide by condensation. Because the exhaust gas flow rate is relatively fast under high vacuum, and because of the sublimation of lactide, there will be a trace amount of lactide in the exhaust gas. If these lactides are brought into the vacuum pump, they will condense into solids in the vacuum pump, causing damage to the vacuum pump, which will affect production at the least and cause accidents at the worst. Therefore, all the lactide remaining in the exhaust gas must be removed. Utility Model Content

[0003] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a special device for preventing the entrainment of lactide in the tail gas, so as to conveniently remove the lactide entrained in the tail gas and allow it to enter the vacuum pump after removal, while also protecting the vacuum pump and greatly improving the working reliability.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A special device for preventing tail gas from carrying lactide comprises a tank body, wherein a heater, a buffer tank, a condenser and a catcher are sequentially installed inside the tank body from bottom to top, a pipe opening connected to the catcher outlet is arranged in the middle of the top surface of the tank body, the pipe opening is connected to the tail gas outlet through a tail gas outlet pipe, and the tail gas outlet is connected to the inlet of a vacuum pump; a tail gas inlet is arranged on one side wall of the tank body at the buffer tank, a chilled water inlet and a chilled water outlet are respectively arranged on both side walls of the tank body at the condenser, a low-pressure steam inlet is arranged on the outer wall surface of the tank body at the heater, and a condensed water outlet and a condensate outlet are respectively arranged on the bottom of the tank body at the heater.

[0006] As a further improvement of the above technical solution:

[0007] The heater adopts multiple evenly distributed heating tubes.

[0008] The heating pipe is directly connected to the condensate outlet.

[0009] The condensate outlet is directly connected to the pipe wall at the bottom of the tank.

[0010] The catcher is made of stainless steel wire mesh.

[0011] The beneficial effects of the utility model are as follows:

[0012] The utility model has a compact and reasonable structure and is easy to operate. Through the cooperation between the buffer tank, the heater, the condenser, the catcher and other components, the removal of lactide can be easily completed. The lactide enters the vacuum pump only after removal, which protects the vacuum pump, prolongs the service life of the vacuum pump and ensures the smoothness of the entire production.

[0013] The utility model can conveniently remove the residual lactide in the tail gas, prevent it from entering the vacuum pump, and ensure the normal production.

[0014] The utility model is provided with a heater, and when the equipment is blocked, steam is introduced to heat and melt, so that the equipment can resume production, and solidified lactide can also be melted, bringing convenience to the subsequent removal work.

[0015] The utility model is provided with a buffer tank, a condenser, a catcher and the like, which can effectively intercept lactide in the tail gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Among them: 1. exhaust gas output pipe; 2. exhaust gas output port; 3. tank body; 4. catcher; 5. condenser; 6. chilled water outlet; 7. chilled water inlet; 8. buffer tank; 9. exhaust gas inlet; 10. low-pressure steam inlet; 11. heater; 12. condensed water outlet; 13. condensate outlet. DETAILED DESCRIPTION

[0018] The specific implementation of the utility model is described below in conjunction with the accompanying drawings.

[0019] like Figure 1 As shown, the special device for preventing exhaust gas from carrying lactide in this embodiment comprises a tank body 3, wherein a heater 11, a buffer tank 8, a condenser 5 and a trap 4 are sequentially installed inside the tank body 3 from bottom to top, a pipe opening connected to the outlet of the trap 4 is arranged in the middle position of the top surface of the tank body 3, the pipe opening is connected to the exhaust gas outlet 2 through the exhaust gas outlet pipe 1, and the exhaust gas outlet 2 is connected to the inlet of the vacuum pump; an exhaust gas inlet 9 is arranged on one side wall of the tank body 3 located at the buffer tank 8, a chilled water inlet 7 and a chilled water outlet 6 are respectively arranged on both side walls of the tank body 3 located at the condenser 5, a low-pressure steam inlet 10 is arranged on the outer wall surface of the tank body 3 located at the heater 11, and a condensed water outlet 12 and a condensate outlet 13 are respectively arranged on the bottom of the tank body 3 located at the heater 11.

[0020] The heater 11 adopts a plurality of uniformly distributed heating tubes.

[0021] The heating pipe is directly connected to the condensed water outlet 12 .

[0022] The condensate outlet 13 is directly connected to the pipe wall at the bottom of the tank body 3 .

[0023] The catcher 4 is made of stainless steel wire mesh.

[0024] The utility model is provided with a buffer tank 8, which can effectively reduce the exhaust gas flow rate and realize gas-liquid separation.

[0025] The utility model is provided with a condenser 5, which uses chilled water to further reduce the temperature of the tail gas, so that the lactide in the tail gas continues to be condensed and separated.

[0026] The utility model is provided with a catcher 4, which adopts a metal wire mesh structure to further intercept the trace lactide remaining in the tail gas.

[0027] The utility model is provided with a heater 11. When lactide solidifies in the equipment and causes blockage, steam is introduced to heat the equipment so that the lactide is melted and removed, thereby ensuring that the equipment continues to operate.

[0028] In the actual working process, under normal circumstances, the tail gas enters the buffer tank 8 from the tail gas input port 9, and then enters the condenser 5 for condensation separation. After separation, it enters the trap 4 to further intercept the trace lactide remaining in the tail gas, and then the treated tail gas is output to the vacuum pump. After a period of use, the lactide will solidify, which is easy to cause equipment clogging. At this time, the heater 11 is started to work, and steam is introduced from the low-pressure steam inlet 10. By heating, the lactide is melted and removed, and then the above work is repeated to discharge the tail gas. The overall operation is convenient, the working reliability is good, and the lactide in the tail gas can be conveniently and quickly removed.

[0029] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. Any form of modification can be made within the protection scope of the utility model.

Claims

1. A special device for preventing tail gas from carrying lactide, characterized in that: The invention comprises a tank body (3), wherein a heater (11), a buffer tank (8), a condenser (5) and a catcher (4) are sequentially installed inside the tank body (3) from bottom to top; a pipe opening connected to the catcher (4) outlet is arranged in the middle of the top surface of the tank body (3); the pipe opening is connected to the exhaust gas outlet (2) through an exhaust gas outlet pipe (1); the exhaust gas outlet (2) is connected to the inlet of a vacuum pump; a side wall of the tank body (3) located at the buffer tank (8) is provided with an exhaust gas inlet (9); a side wall of the tank body (3) located at the condenser (5) is provided with a chilled water inlet (7) and a chilled water outlet (6); an outer wall of the tank body (3) located at the heater (11) is provided with a low-pressure steam inlet (10); and a condensed water outlet (12) and a condensate outlet (13) are provided at the bottom of the tank body (3) located at the heater (11).

2. A special device for preventing tail gas from carrying lactide as claimed in claim 1, characterized in that: The heater (11) adopts a plurality of evenly distributed heating tubes.

3. A special device for preventing tail gas from carrying lactide as claimed in claim 2, characterized in that: The heating pipe is directly connected to the condensed water outlet (12).

4. A special device for preventing tail gas from carrying lactide as claimed in claim 1, characterized in that: The condensate outlet (13) is directly connected to the pipe wall at the bottom of the tank body (3).

5. A special device for preventing tail gas from carrying lactide as claimed in claim 1, characterized in that: The catcher (4) is made of stainless steel wire mesh.

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