CN119633415A - A method for improving evaporation efficiency of vacuum evaporation process - Google Patents

Abstract

A method for improving the evaporation efficiency of a vacuum evaporation process comprises the following steps: in a vacuum zone of a vacuum evaporator, a solution is dispersed into droplets by physical methods such as spraying and atomization, and a large number of small droplets are continuously maintained, so that the surface area of the solution is large and the evaporation rate is effectively improved; air or other safe gas is introduced into the vacuum zone of the vacuum evaporator at a certain speed to reduce the vapor pressure of water and accelerate the evaporation of water in the solution; the flow of air drives the water vapor to quickly leave the surface of the solution, accelerates the evaporation rate of the liquid, and forms a gas cycle to improve the evaporation efficiency of the vacuum evaporation process.

Description

Method for improving evaporation efficiency of vacuum evaporation process

Technical Field

A method for improving the evaporation efficiency of a vacuum evaporation process relates to a method for improving the evaporation efficiency of the vacuum evaporation process.

Background

In industrial production, some evaporation, concentration and other treatment processes are widely adopted due to the advantages of low energy consumption, high evaporation speed and the like, and the vacuum evaporation treatment process is a universal evaporation and concentration method. The key technological parameters of the vacuum evaporation process include solution temperature, vacuum degree, evaporator volume and solution surface area, the parameters actually controlled in production practice are parameters which are easy to realize such as temperature, vacuum degree and the like, the size of the evaporator determines the solution surface area and cannot be increased at will under the influence of factors such as equipment cost and the like, so that the existing vacuum evaporation process keeps better evaporation efficiency and cost advantage, but has not been improved essentially for a long time in the aspects of further improving the evaporation efficiency and the like, and meanwhile, the existing vacuum evaporation process is difficult to be effectively adapted to and efficiently finish treatment for solutions with high solution viscosity, high solution acidity and solid phase matters separated from liquid in the evaporation process.

Disclosure of Invention

The invention provides a method for improving the evaporation efficiency of a vacuum evaporation process, aiming at the problems of improving the production efficiency and the selectivity of a treatment solution in the vacuum evaporation process, which is characterized in that:

In a vacuum area of the vacuum evaporator, the solution is dispersed into liquid drops by continuous physical methods such as spraying, atomizing and the like, and a large number of small liquid drops are continuously kept in a state of existence, the more the liquid drops are, the smaller the volume is, the larger the surface area of the solution is, and the evaporation speed is effectively improved by increasing the surface area of the solution under the same conditions of temperature and vacuum degree.

Introducing gas circulation, namely introducing air or other safe gas into a vacuum area of the vacuum evaporator at a certain speed, so that on one hand, the vapor pressure of water is reduced, the evaporation of water in solution can be accelerated, on the other hand, the flow of air drives the evaporated vapor to rapidly separate from the surface of the solution, the evaporation speed of the liquid is accelerated, the gas brings the vapor out of the vacuum area of the vacuum evaporator, and the gas with water separated at normal pressure is introduced into the vacuum area, so that the gas circulation is formed, and the evaporation efficiency of the vacuum evaporation process is improved.

Drawings

Description figure 1 is a schematic diagram of the vacuum zone structure of a vacuum evaporator, and the meaning of the figure representation is:

1.2, a pipeline for conveying liquid to spray and disperse treatment;

3. a solution outlet for conveying the solution to spray or heat treatment on the evaporator;

5. liquid in the evaporator, 6, the surface of the liquid in the evaporator, 7, sprayed liquid drops;

8. 9, evaporating steam to flow to a schematic arrow;

10. The solids crystallized from the solution settle to the bottom of the evaporator and 11. Solids outlet.

Detailed Description

Example 1

Distilled water production using tap water

Vacuum area of vacuum evaporator phi 100 mm by 350mm

The liquid level of the vacuum area is 80mm, and tap water is continuously supplemented in the evaporation process to keep the liquid level unchanged.

The evaporation process conditions are that the vacuum degree is-40 kPa to-65 kPa, and the evaporation temperature is 75 ℃ to 85 ℃.

During evaporation, water was pumped from the vacuum zone to a dispersion pipe at a rate of 0.5L per minute and dispersed into the vacuum zone through 20 holes of 2mm diameter in the dispersion pipe.

The distilled water amount evaporated per minute reaches 3.0mL, and the distilled water yield is improved by 50% compared with 2.0mL per minute without dispersion treatment.

Example two

Distilled water production using tap water

Vacuum area of vacuum evaporator phi 100 mm by 350mm

The liquid level of the vacuum area is 80mm, and tap water is continuously supplemented in the evaporation process to keep the liquid level unchanged.

The evaporation process conditions are that the vacuum degree is-40 kPa to-65 kPa, and the evaporation temperature is 75 ℃ to 85 ℃.

The solution was withdrawn from the vacuum zone during evaporation and sent to a dispersion pipe at a rate of 0.5L per minute and dispersed into the vacuum zone through 20 holes of 2mm diameter in the dispersion pipe.

And (3) introducing circulating air into the vacuum area in the evaporation process, wherein the speed of the air entering the vacuum area is 1L/min, the mixture of the air and the water vapor circulates out of the vacuum area, the water vapor is condensed into water drops under normal pressure, and after the water drops are centrifugally separated, the air enters the vacuum area of the vacuum evaporator again to form air circulation.

The distilled water amount evaporated per minute reaches 3.5mL to 3.8L, and the speed of the produced distilled water is improved by 75% to 90% compared with 2.0mL per minute without dispersing treatment and gas circulation.

Claims (2)

1. In the vacuum area of the vacuum evaporator, the solution is dispersed into droplets and a large number of small droplets are continuously maintained through continuous spraying, atomization and other physical methods. The more droplets there are and the smaller the volume, the larger the surface area of the solution. Under the same temperature and vacuum conditions, the increased surface area of the solution effectively increases the evaporation rate. 2. Introduce gas circulation: Introduce air or other safe gases into the vacuum area of the vacuum evaporator at a certain speed. On the one hand, it reduces the vapor pressure of water and accelerates the evaporation of water in the solution. On the other hand, the flow of air drives the evaporated water vapor to quickly leave the surface of the solution, accelerating the evaporation rate of the liquid. The gas takes out water vapor from the vacuum area of the vacuum evaporator, and the gas that separates the water at normal pressure is then introduced into the vacuum area, forming a gas circulation to improve the evaporation efficiency of the vacuum evaporation process.