The Introduction to Evaporator (one)

The vapor generated in the heating chamber carries a large amount of liquid foam. After reaching the evaporation chamber in a larger space, these liquids can be separated from the vapor by the function of self-condensation or demister. Usually the demister is located at the top of the evaporation chamber.

 

The evaporator is divided into three types according to operating pressure: normal pressure, pressurized and decompressed. According to the movement status of the solution in the evaporator:

 

(1) Circulation type. The boiling solution passes through the heating surface many times in the heating chamber, such as central circulation tube type, hanging basket type, external heating type, leven type and forced circulation type.

(2) One-way type. The boiling solution passes through the heating surface once in the heating chamber, and the concentrated liquid is discharged without circulating flow, such as rising film type, falling film type, stirring film type and centrifugal film type.

 

(3) Direct contact type. The heating medium directly contacts the solution to transfer heat, such as submerged combustion evaporator. During the operation of the evaporation device, a large amount of heating steam is consumed. To save heating steam, a multi-effect evaporation device and steam recompression evaporator can be used. Evaporator is widely used in chemical industry, light industry and other departments.

 

The evaporator used in medicine and volatile inhaled anesthetics are all liquid at room temperature. The evaporator can effectively evaporate the volatile anesthetic liquid into gas, and can accurately adjust the concentration of the anesthetic vapor output. The evaporation of anesthetics requires heat, and the temperature around the evaporator is the main factor that determines the evaporation rate of volatile anesthetics. Contemporary anesthesia machines widely use temperature-flow compensation evaporators, that is, when the temperature or fresh gas flow changes, the automatic compensation mechanism can keep the evaporation rate of volatile inhaled anesthetics constant, thus ensuring that the inhaled anesthetics leave the evaporator The output concentration is stable. Due to different physical characteristics such as boiling point and saturated vapor pressure of different volatile inhalation anesthetics, the evaporator has drug specificity. Such as enflurane evaporator, isoflurane evaporator, ethanol evaporation, etc., can not be common to each other. The evaporator of the modern anesthesia machine is mostly placed outside the anesthesia breathing loop, and a separate oxygen gas flow is connected to it, and the evaporated inhalation anesthetic drug vapor is mixed with the main gas flow before being inhaled by the patient.

 

Species of evaporator

1. According to the evaporation method

 

Natural evaporation. That is, the solution evaporates at a temperature below the boiling point, such as seawater drying salt. In this case, the solvent vaporizes at a low rate because the solvent only vaporizes on the surface of the solution.

 

Boiling evaporation. Heating the solution to the boiling point is to make it evaporate in boiling state. Industrial evaporation operations are basically of this type.

 

2. According to heating method

 

Direct heat source heating. It is the evaporation process of mixing fuel and air to make the high-temperature flame and flue gas produced by its combustion directly sprayed into the evaporated solution through the nozzle to heat the solution and vaporize the solvent. The equipment you need to use at this time is vacuum clamp, vacuum adapter and distillation column.

 

Indirect heat source heating. The walls of the container are passed to the evaporated solution. That is, the heat transfer process in the partition wall heat exchanger.

 

3. According to operating pressure

 

It can be divided into normal pressure, pressurized and reduced pressure (vacuum) evaporation operations. Obviously, heat-sensitive materials, such as antibiotic solutions, fruit juices, etc. should be carried out under reduced pressure. The high-viscosity materials should be heated by pressurized high-temperature heat source (such as thermal oil, molten salt, etc.) for evaporation.

 

4. According to the number of effects

 

It can be divided into single-effect and multi-effect evaporation. If the secondary steam produced by evaporation is directly condensed and no longer used, it is called single-effect evaporation. If the secondary steam is used as the next effect heating steam, and multiple evaporators are connected in series, the evaporation process is multi-effect evaporation.

 

Features of evaporator

 

The evaporator has a metal circular basin with an inner diameter of φ200mm and a height of about 100 mm.

 

The evaporator is a metal circular structure, the inner wall should be smooth, and the evaporator blade must not have defects such as burrs or bumps.

 

All parts in contact with water should be smooth, and the welding seams of their joints should be tight and firm, and there should be no water leakage.

 

The assembly of the evaporator parts and components should be correct, and there must be no looseness, deformation and other defects that affect the use.

 

The protective layer applied to the parts and components of the evaporator shall be firm, uniform and smooth, and shall not have defects such as delamination and corrosion.

 

The evaporator and the installation frame should be easy to install, and can make the evaporator not disconnected due to the influence of wind during normal use.

 

Accessories: one measuring cup with scale, one water reservoir, one mounting frame, one wire mesh cover (anti-bird drinking water, user can choose).

 

Working principle of falling film evaporator

 

Falling film evaporation is to add the feed liquid from the upper tube box of the heating chamber of the falling film evaporator, and evenly distribute it to each heat exchange tube through the liquid distribution and film forming device. Under the induction of gravity and vacuum and the action of airflow, it flows into a uniform film from top to bottom. The equipment you need to use at this time are vacuum stainless steel clamps, vacuum adapter fittings and vacuum extractor.

 

During the flow process, it is heated and vaporized by the shell-side heating medium, and the generated steam and the liquid phase enter the separation chamber of the evaporator together. Falling film evaporator is in charge of separating substances from the mixture. In cannabis-processing process, falling film evaporator is to get ethanol evaporated. In this way, we can get purer falling film evaporator cbd, and ethanol can also be recycled with the help of FFE evaporator.

 

The main body of the equipment is composed of Ⅰ, Ⅱ, Ⅲ effect heaters, separators, heat pressure pumps, condensers, sterilizers, insulation pipes, material pumps, water pumps and instrument cabinets. This evaporator is made of high-quality stainless steel evaporator in contact with materials.