Wiped film evaporator is a kind of evaporation and distillation equipment that uses a scraper system to force liquid to form a film for evaporation or distillation. It can also perform unit operations such as deodorization, defoaming reaction, heating and cooling. It has been used in the following fields for the purposes of evaporation, concentration, desolventization, steam stripping, reaction, degassing, deodorization (gas) smell, etc., and has achieved good results:
Chinese and Western medicines: antibiotics, sugar solution, Chinese herbal medicines such as Leigongteng and Astragalus, intermediates such as methylimidazole and mononitrile amines;
Light industrial food: fruit juice, gravy, pigment, flavor, spice, enzyme preparation, lactic acid, xylose, starch sugar, potassium sorbate;
Grease daily chemicals: lecithin, VE, cod liver oil, oleic acid, glycerin, fatty acid, waste lubricating oil, alkyl polyglycoside, alcohol ether sulfate, etc.;
Synthetic resins: polyamide resin, epoxy resin, paraformaldehyde, PPS (polypropylene sebacate), PBT, propylene formate;
Synthetic fiber: PTA, DMT, carbon fiber, polyether polyol, etc.;
Petrochemical: TDI, MDI, trimethylhydroquinone, trimethylolpropane, sodium hydroxide, etc.;
Pesticide biology: acetochlor, pretilachlor, chlorpyrifos, furanol, clomazone, and other herbicides, insecticides, herbicides, and acaricides;
Waste water: inorganic salt wastewater, etc.
The wiped film evaporator is a new type of film that is forced to form a film by a rotary wiper, and flows at a high speed, has high heat transfer efficiency, short residence time (about 10-50 seconds), and can perform falling film evaporation under vacuum conditions. Device. The material enters the evaporator radially from the top of the heating zone; it is distributed to the heating wall of the evaporator through the distributor, and then the rotating film scraper scrapes the material continuously and uniformly on the heating surface into a liquid film of uniform thickness and spirals. Push down. In this process, the rotating film wiper ensures that the continuous and uniform liquid film produces high-speed turbulence, and prevents the liquid film from coking and scaling on the heating surface, thereby increasing the overall transfer coefficient. The light component is evaporated to form a steam flow which rises through the vapor-liquid separator to the external condenser directly connected to the evaporator; the recombined component is discharged from the cone at the bottom of the evaporator. Method for processing heat sensitive materials:
1. The raw materials are transported to the upper tank by the pump, and then flow through the flow meter into the middle of the rectification tower, and the valve opening and closing degree is controlled by the flow rate;
2. The vapor phase components in the rectification tower enter the condenser from the top of the tower, and are liquefied under the action of condensed water; under the control of the reflux ratio controller, part of the condensate flows back to the top of the rectification tower and part of the light components In the liquid storage tank;
3. The liquid components in the rectification tower enter the wiped film evaporator from the bottom of the tower, and are distributed as a liquid film on the inner surface of the evaporator under the action of the scraper. When heated by the heat transfer oil, the material becomes a liquid film. The vapor phase of the volatile components returns to the rectification tower body again, and performs mass and heat transfer with the liquid phase flowing down from the top of the tower. The unvolatile part in the evaporator flows out under the action of gravity and is transported. The pump enters the heavy component storage tank;
4. Light and heavy components can be sampled and analyzed from the bottom of the corresponding liquid storage tank respectively;
5. The condenser is connected to the vacuum pump through the buffer tank to provide a vacuum environment for the entire system.
