CN216890737U

CN216890737U - Caprolactam high-efficient gasification piece-rate system

Info

Publication number: CN216890737U
Application number: CN202220742202.3U
Authority: CN
Inventors: 史秦博苑
Original assignee: Shaanxi Keyuan Environmental Protection Energy Saving Technology Co ltd
Current assignee: Shaanxi Keyuan Environmental Protection Energy Saving Technology Co ltd
Priority date: 2022-04-01
Filing date: 2022-04-01
Publication date: 2022-07-05
Anticipated expiration: 2032-04-01

Abstract

The caprolactam high-efficiency gasification separation system consists of a falling film heater and a separation tower, wherein the falling film heater is connected with the lower part of the separation tower, a liquid drop remover is arranged in the separation tower, and an air draft device is arranged on the separation tower and continuously drafts air to the falling film heater; and a liquid collecting chamber is arranged at the lower part of the falling film heater. The utility model has the advantage of solving the problems of processing the distilled caprolactam organic materials and easily polymerizing and fluctuating quality of the heat-sensitive organic matters in the heating process in the traditional chemical process.

Description

Caprolactam high-efficient gasification piece-rate system

Technical Field

The utility model relates to a caprolactam purification system in a chemical process, in particular to a caprolactam high-efficiency gasification separation system.

Background

In chemical production, many places in the process need to separate or purify organic liquid containing many components, light components in the organic liquid are generally subjected to tower rectification process treatment, and materials containing heavy component impurities are distilled, while the conventional distillation process generally adopts treatment technologies of bottom heating, material evaporation and top condensation, and distillation and refining for heat-sensitive materials or materials with high rectification requirements are not easy to achieve by the method, the yield of single set of distillation is limited, and the distillation process is often completed by matching of a plurality of sets of distillation devices.

For example, in the implemented refining and preparation process of caprolactam, the conventional technology for rectifying caprolactam adopts a tower bottom tubular heating technology, the vaporization process of caprolactam at the bottom needs to overcome the liquid pressure in a pipe, so that the difference between the heating temperature and the vaporization temperature is large, the caprolactam is easy to deteriorate and polymerize, the heating pipe of equipment is easy to scale and block, the product quality is difficult to control, frequent cleaning is needed, the requirement on the quality of operating personnel is high, the production cost is increased, and in addition, the rectification residual liquid is easy to form dead corners. The utility model adopts heating and vaporizing as a unit, gas defoaming and condensing as a unit, and the vaporizing unit adopts film evaporation, so that the defects of the traditional process can be effectively avoided, not only can the rectification be continuously carried out, but also the vaporization pushing temperature required in the treatment process is very low, the caprolactam deterioration can be effectively avoided, the temperature fluctuation in the distillation process is small, the product quality is stable, the requirement of large-scale distillation can be met, the control is easier, and the low cost of the refining process is realized.

Summary of the utility model

The utility model provides a caprolactam high-efficiency gasification separation system, which aims to solve the problems of treatment of distilled caprolactam organic materials and easy polymerization and quality fluctuation of a thermosensitive organic matter heating process in the traditional chemical process.

The technical processing scheme of the utility model is as follows: a caprolactam high-efficiency gasification separation system comprises a falling film heater and a separation tower, wherein the falling film heater is connected with the lower part of the separation tower, a liquid drop remover is arranged in the separation tower, and an air draft device is arranged on the separation tower and continuously drafts air to the falling film heater;

and a liquid collecting chamber is arranged at the lower part of the falling film heater.

Further, the droplet remover divides the separation column into an upper portion and a lower portion, and the diameter of the lower portion is 0.15 to 0.6 times the diameter of the upper portion.

Furthermore, a liquid discharge valve is arranged on the liquid collection chamber.

Furthermore, a limiter is arranged in the liquid collection chamber, the liquid discharge valve is an electric control liquid discharge valve, and the limiter is connected with the liquid discharge valve.

And the liquid discharge valve is communicated with a liquid inlet at the upper end of the falling film heater through a circulating pump in a stepping mode.

Furthermore, the lower part of the separation tower is provided with a heat preservation device.

The utility model has the advantages that 1) according to the physical and chemical characteristics of caprolactam and the characteristics of chemical equipment, the treatment method is obtained on the basis of fully considering and applying the characteristics of chemical materials and treatment processes, utilizes the melting flow property of caprolactam, the adaptability of falling film evaporation equipment to flowing materials and the adaptability of falling film evaporation to caprolactam (heat-sensitive substances), gasifies the caprolactam and separates the caprolactam from liquid by a distillation separation mode of instant heating and instant discharge, and is carried out under the action of air draft (vacuum pumping), taking the falling film as an example, during the distillation separation, the liquid containing the caprolactam enters the film tube from the upper end, the liquid is adhered to the inner surface of the film tube or the surface of the film by the van der Waals force of water molecules and moves downwards due to the gravity action of the liquid, namely, the liquid is fed from the upper end of the film tube or the upper end of the film, and moves from the upper end to the lower end along the surface of the film, the problem of last feeding is solved, and gas receives convulsions effort to remove along the membrane tube is middle, realizes the instant separation of gasification and non-gasification liquid for the separating rate of gas and liquid, thereby the effect that makes the separation is more outstanding.

2) The process method for processing the caprolactam material combines the process steps of heating, evaporation, concentration, crystallization, separation, filtration, condensation or steam compression and the like, and has the advantages of simple method and strong controllability.

3) The evaporation temperature in the falling film evaporation equipment can be as low as 115 ℃ and 135 ℃, and compared with the existing evaporation temperature of 160 ℃, the energy is greatly saved.

4) The pressure requirement of the separation tower is not high, 0-10 KPa can be used, the flow speed of the gas in the separation tower is only required, the control method is realized by changing the ratio of the upper diameter to the lower diameter of the separation tower, the flow speed of the gas for removing liquid drops is greater than the flow speed of the gas for condensation separation, and is generally 1: 0.15-0.6.

5) the falling film heater, especially the falling film heater, in the caprolactam high-efficiency gasification separation system has the biggest difference from the structure of the existing falling film heater that the air draft in the separation tower can continuously enter the falling film heater, but the air draft in the separation tower in the prior art generally does not enter the falling film heater, and even if the structure can enter, the air draft in the separation tower can be blocked by the liquid which is not gasified in the use process.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a schematic view of the liquid level control of the plenum.

FIG. 3 is a process flow diagram during use of the present invention.

As shown in the figure, the device comprises a separation tower 1, a liquid drop remover 2, an air draft device 4, a falling film heater 5, a liquid collecting chamber 6, a liquid discharge valve 7, a limiter 8, a circulating pump 9 and a heat preservation device 10.

Detailed Description

As shown in fig. 1, a caprolactam high-efficiency gasification separation system comprises a falling film heater 5 and a separation tower 1, wherein the falling film heater 5 is connected with the lower part of the separation tower 1, a liquid drop remover 2 is arranged in the separation tower 1, an air draft device 4 is arranged on the separation tower 1, the air draft device 4 continuously drafts air to the falling film heater 4, preferably, the liquid drop remover 2 divides the separation tower 1 into an upper part and a lower part, and the diameter of the lower part is 0.15-0.6 times of the diameter of the upper part;

a liquid collecting chamber 6 is arranged at the lower part of the falling film heater 5, and a liquid discharging valve 7 is preferably arranged on the liquid collecting chamber 6.

As in fig. 2, be equipped with stopper 8 in the drip chamber 6, flowing back valve 7 is automatically controlled flowing back valve, stopper 8 with flowing back valve 7 connect, when the liquid level in the drip chamber 6 exceeded stopper 8, triggered stopper 8 work, make flowing back valve 7 start and carry out the flowing back, with the liquid discharge in the drip chamber 6, prevent that falling film heater 5 lower part liquid from compiling too much, hinder updraft ventilator 4 convulsions and get into falling film heater 5 through knockout tower 1, set up drip chamber 6 and can collect the liquid that falling film heater 5 did not evaporate and in time discharge the liquid in drip chamber 6 with flowing back valve 7.

Preferably, the liquid discharge valve 7 is communicated with a liquid inlet at the upper end of the falling film heater 5 through a circulating pump 9, and the liquid in the liquid collecting chamber 6 can be pumped back to the falling film heater 5 through the circulating pump 9 for re-evaporation.

Preferably, the lower part of the separation tower 1 is provided with a heat preservation device 10, and the heat preservation device 10 arranged at the lower part of the separation tower 1 can preserve the heat of the gas entering the separation tower 1 to prevent the gas from losing temperature too fast.

The working method comprises the following steps: as shown in fig. 3, a caprolactam high-efficiency gasification separation process is carried out by heating gasification A and liquid drop removal separation C under the air draft state;

heating and gasifying A, wherein a falling film heating mode is adopted for caprolactam materials, and gasified gas flows under the guidance of air draft effect to be separated from unvaporized liquid;

and removing and separating C by liquid drops, vaporizing caprolactam to remove liquid drops (removing the liquid drops is C1), and condensing and separating (condensing and separating into C2) to obtain organic matters.

The heating temperature in the step A of heating and gasifying is 115-135 ℃, namely the heating temperature of the film evaporator in the film heating mode is 115-135 ℃.

The step C of removing and separating the liquid drops is completed in a separating tower 1, an air draft device 4 (generally a vacuum pump) is connected to the separating tower 1, namely the step C1\ C2 is completed in the separating tower 1, and the top pressure of the separating tower 1 is 0-10 KPa.

Be equipped with the liquid drop remover 2 in knockout tower 1 (knockout tower 1 is connected with the equipment of convulsions, and the outside convulsions of air extraction equipment makes the caprolactam that adopts the membrane heating mode to heat gasification after the gasification by the induced draft guide flow to knockout tower 1), liquid drop remover 2 will knockout tower 1 divide into upper portion and lower part, the lower part diameter is 0.15-0.6 times of upper portion diameter, and gaseous speed that flows on upper portion is 0.15-0.6 times of lower part promptly.

The working principle is as follows: caprolactam material is heated and gasified by falling film, and then is separated from unvaporized liquid under the guide of air draft, gasified gas enters from the lower part of the separation tower 1, liquid drops of the gas are removed by the liquid drop remover 2, organic matters are separated after the condensation of the upper part of the separation tower 1, and the speed is faster than the speed of air separation of the organic matters by gas condensation before the contact with the liquid drop remover 2.

Taking a falling film heating mode (single) as an example, a continuous gasification separation test of 1000L of caprolactam liquid is carried out for 24 hours, the gasification process is not subjected to boiling under the temperature of 115-135 ℃ (the temperature of a film tube) and the absolute pressure of 40mm mercury, the gas cooling temperature is 80-90 ℃, the index of the recovered caprolactam is 290 extinction: 0.032, 390 color: 4.5, acidity: 1.76-1.78mmol/kg, no iron detected, cyclohexanone oxime content: 18-21mk/kg, volatile alkali: 0.38-0.4 mmol/kg.

Taking a falling film heating mode (single) as an example, a continuous gasification separation test of 1800 liters of caprolactam liquid is carried out for 48 hours, the gasification process is not subjected to boiling under the conditions that the temperature is 115-135 ℃ (the heating temperature of a film tube) and the absolute pressure is 30mm Hg, the gas cooling temperature is 80-90 ℃, the index of the recovered caprolactam is 290 extinction: 0.032, 390 color: 4.5, acidity: 1.76-1.79mmol/kg, no iron detected, cyclohexanone oxime content: 17-21mk/kg, volatile alkali: 0.38-0.41 mmol/kg.

Taking a falling film heating mode (three and one are parallel) as an example, a 2700L caprolactam liquid continuous gasification separation test is carried out for 24 hours, the gasification process is not subjected to boiling under the temperature of 115-plus-135 ℃ (the heating temperature of a film tube) and the absolute pressure of 30-45mm mercury, the gas cooling temperature is 80-90 ℃, the index of the recovered caprolactam is 290 extinction: 0.032, 390 color: 4.5, acidity: 1.76-1.80mmol/kg, no iron detected, cyclohexanone oxime content: 17-21mk/kg, volatile alkali: 0.38-0.41 mmol/kg.

The indexes of the recovered caprolactam are almost the same, and the utility model is effective for separating caprolactam by gasification.

Claims

1. A caprolactam high efficiency gasification piece-rate system, characterized by: the system consists of a falling film heater and a separation tower, wherein the falling film heater is connected with the lower part of the separation tower, a liquid drop remover is arranged in the separation tower, an air draft device is arranged on the separation tower, and the air draft device continuously drafts air to the falling film heater;

2. The high-efficiency caprolactam gasification and separation system as claimed in claim 1, which is characterized in that: the droplet remover divides the separation column into an upper portion and a lower portion, and the diameter of the lower portion is 0.15 to 0.6 times the diameter of the upper portion.

3. The high-efficiency caprolactam gasification and separation system as claimed in claim 1, which is characterized in that: and a liquid discharge valve is arranged on the liquid collecting chamber.

4. The high-efficiency caprolactam gasification and separation system as claimed in claim 3, which is characterized in that: and a limiter is arranged in the liquid collection chamber, the liquid discharge valve is an electric control liquid discharge valve, and the limiter is connected with the liquid discharge valve.

5. The high-efficiency caprolactam gasification and separation system as claimed in claim 3 or 4, which is characterized in that: and the liquid discharge valve is communicated with a liquid inlet at the upper end of the falling film heater through a circulating pump.

6. The high-efficiency caprolactam gasification and separation system as claimed in claim 1, which is characterized in that: and the lower part of the separation tower is provided with a heat preservation device.