WZ type external heating vacuum evaporator
WZ type external circulation vacuum evaporator is a natural circulation type evaporator operated under a vacuum system
The WZ model has one effect, two effect, and three effect series specifications, namely WZI-50003000200015001000500250; WZII-5000，3000，2000，1000，； WZIII-5000，3000，2000，1000，500。
This product is a new product designed by Shanghai Pharmaceutical Design Institute East China Economic and Technological Cooperation Development Company in 1986 based on imported prototypes and further improved, and officially transferred to our company for designated production. There are five specifications for single effect, and it was appraised as a new equipment technology achievement by Jiangsu Provincial Pharmaceutical Corporation in 1989. The WZ-1000 model has been exported to Thailand.
·The evaporation capacity of WZI-1000 model is 1000-1200kg/h
·The evaporation capacity of WZI-500 model is 500-600kg/h
·The evaporation capacity of WZI-250 model is 250-300kg/h
This product is a universal evaporation device. It can be used to evaporate both aqueous solutions and solutions for recovering organic solvents; It can be operated under vacuum or atmospheric pressure.
·purpose·
The WZ evaporator can be widely used for the evaporation and concentration of water or organic solvent solutions in industries such as medicine, food, chemical, and light industry. Specially suitable for thermosensitive materials (such as water and alcohol extracts from traditional Chinese medicine production, antibiotic alcohol solutions, milk, fruit juice, etc.), low-temperature continuous concentration under vacuum conditions can ensure product quality.
·The WZ evaporator has the following structural characteristics·
To prevent material contamination, all parts in contact with the material are made of high-quality stainless steel.
In order to improve the efficiency of gas-liquid separation and also have the functions of foam removal and anti entrainment, a two-stage separation and capture method is adopted: firstly, the vapor-liquid tangent enters the evaporation tank to utilize centrifugal force and sedimentation inside the tank; Second, the top of the evaporator is equipped with an efficient air filter screen layer. Third, an impact liquid trap is added to prevent the loss of the feed liquid entrained by the secondary steam. Even the feed liquid that is prone to generate foam (such as the Chinese medicine liquid containing saponins) can achieve satisfactory separation effect.
For easy cleaning, a quick opening top cover is installed on top of the heater. A circular spray cleaning water pipe is installed on the upper part of the gas filter screen inside the evaporator. And a manhole shall be provided on the evaporation tank body for cleaning the inner wall of the tank.
For easy observation during operation, light holes and mirrors are installed on the top of the heater and evaporator.
Compared with the commonly used rising film, falling film, and rising falling film evaporators in China, the WZ type evaporator belongs to the circulation type evaporator, with a higher concentration ratio of the feed liquid and less fouling inside the tube. For example, when used to concentrate traditional Chinese medicine decoction, the specific gravity can reach d=1.25 without scaling inside the tube.
·principle·
The WZ type external circulation vacuum evaporation device is mainly composed of a tubular heater, an evaporation tank, a circulation tube, and other ancillary equipment.
After the liquid is heated to its boiling point inside the heater tube, some of the water vaporizes, converting thermal energy into upward kinetic energy; At the same time, due to the significant difference in density between the vapor-liquid mixture in the heating tube and the non boiling liquid in the circulation tube, natural circulation of the liquid is induced by the expansion kinetic energy and density difference (the circulation speed of the liquid in the heating tube is less than 1m/s). The more heat the liquid is subjected to, the better the boiling, and the faster its circulation speed. Due to evaporation under vacuum, the evaporation temperature of the liquid can be controlled below 50 ℃. The secondary steam evaporated is collected by a wire mesh demister and a liquid trap, and then condensed by the water spray of a hydraulic jet pump before being carried away. After centrifugal rotation, the liquid in the evaporation tank returns to the lower part of the heater along the outer circulation pipe for recirculation heating and evaporation. This process repeats heating and evaporation (15-20 minutes), and when the required concentration is reached, discharge begins.
The liquid trap can be omitted for the evaporation of the feed liquid that is not easy to produce foam.
·process·

A-heater B-evaporator C-liquid trap
D-water jet pump E-multi-stage water pump F-water tank