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November 15, 2019
Application of eight drying equipments in chemical and pharmaceutical industry
Drying equipment is very widely used in industry, and the use of drying equipment is needed in many fields. Also, drying equipment also plays an important role in the pharmaceutical industry. Today, the author will bring eight kinds of drying equipment in the chemical and pharmaceutical industry. The application of eight drying equipments in chemical and pharmaceutical industry is analyzed.
(1) Belt drier
The belt dryer consists of several independent units. Each unit segment includes a circulating fan, heating device, fresh air intake system and exhaust gas system separately or publicly. The operation parameters of the drying medium quantity, temperature, humidity and tail gas circulation can be controlled independently, so as to ensure the reliability and operation conditions of the dry machine. The dryer is flexible in operation, wet in feed, and dry in the completely sealed box. The working conditions are good and the dust leakage is avoided. The drying of flaky, striped and granular materials with good air permeability is especially suitable for dehydrated vegetables, Chinese herbal medicine and other materials with high water content and material temperature which is not allowed to be high.
(2)Roller scraper dryer
The roller scraper is a continuous operating equipment for drying the liquid material or strip material attached to the outer wall of the cylinder by a rotating cylinder. The drying material is poured into the receiving tank of the drum dryer by the upper trough. The drying cylinder rotates at the prescribed speed under the drive of the transmission device. The material is formed by a membrane device and a material film is formed on the wall surface of the roller. The tube is continuously fed into the heating medium, and the body is heated by the tube wall to vaporize the wet partition of the film, and then the material will be scraped through the scraper, and the material is spirally transported to the tank to carry on the packing. The wet fraction removed by evaporation can be introduced into the corresponding treatment device by the closed cover, which is generally water vapor, and can be directly put into the atmosphere by the exhaust pipe at the top of the cover. The machine is mainly used for treating liquid materials, which can be heated and dried through steam, hot water or hot oil, and can also be cooled by cooling water. According to different material properties and process requirements, immersion, sprinkling, grinding and auxiliary feeding methods are adopted.
(3) Hollow blade dryer (blade dryer)
The hollow blade dryer is also called the leaf dryer, which is mainly composed of a W shell with a jacket and two hollow propeller blades and a transmission device. The shaft is lined with hollow blades, and the shaft ends are provided with rotary joints imported by thermal medium. The heat required for drying moisture is transported to the material by the inner wall and the hollow blade wall of the W groove with a jacket. During the drying process, the hollow shaft with hollow blades is used to heat the material while stirring the material, so that the heating surface can be renewed. It is a continuous conduction heating dryer. The heating medium is steam, hot water or heat conduction oil. The heating medium is inserted into the shell and two hollow blade shaft, and the material is heated and dried in the way of conduction heating. The structure of different material hollow paddles is different. The machine is suitable for handling all kinds of paste, granular and powdery materials with good thermal stability. Under special conditions, it can also dry heat sensitive materials and recover solvents in the drying process. The drying or cooling of materials such as carbon black, light calcium carbonate, titanium dioxide, barium carbonate, nitrile uric acid, gypsum, clay, manganese dioxide, nylon and polyester chips, polyethylene and polypropylene (recovery solvent) are used.
(4)Vacuum rake dryer
When the material is in contact with the shell wall, the surface is constantly updated, and the dry material is heated indirectly by the steam (or hot water and heat conduction oil), but the moisture of the material is vaporized, and the vaporized moisture is pumped away from the vacuum pump in time. The drying material is heated indirectly by the heat carrier, so that the moisture in the material is vaporized, and the vaporized water is discharged in time by the vacuum pump.
In the range of 400 ~ 700mmHg, the pressure of water vapor on the surface of the dried material is much greater than that of the evaporation space in the dryer shell. Thus, it is beneficial to the discharge of moisture and surface moisture in the dried material, which is conducive to the movement of the water molecules of the dried material and the purpose of drying. The vacuum rake dryer is suitable for heat sensitive materials, materials easily oxidized at high temperature or easy to be made in drying, as well as materials recovered from steam in drying. Typical dry materials include sodium acrylonsulfonate, CMC, phthalocyanine blue, dye intermediate, carboxymethyl starch, maltodextrin, anthraquinone sulfonic acid, etc.
(5)Double conical rotary vacuum dryer
The double cone rotary vacuum dryer is slightly olive like, covered with two ends, and has two axes in the middle to support the body. The body has a jacket to heat, and the body can be rotated when drying, so that the material and the wall of the device are constantly changed and contact, so that the material in the vacuum oven mainly depends on the heating tube and the heat efficiency is low. Rotary vacuum dryer has been widely applied in fine chemical industry and medicine. It is not suitable for materials with high viscosity or strong adhesion during rotary process. The equipment is mainly used for the concentration, mixing, drying of powdery, granular and fibrous materials in the pharmaceutical, chemical and food industries, as well as dry materials (such as biochemical products). It is more suitable for the drying of oxidizable, volatile, thermosensitive and toxic materials and materials that are not allowed to destroy the crystal.
(6) Spray dryer
Spray drying is the most widely used technology in liquid forming and drying industry. It is most suitable for producing powdery and granular solid products from solution, emulsion, suspension and paste liquid raw materials. Therefore, spray drying is an ideal process when the particle size distribution, residual water content, accumulation density and particle shape must conform to the precise standard.
After evaporation, the evaporation temperature of volatiles contained in material evaporation can be reduced, which is suitable for drying all kinds of heat sensitive and easily oxidized materials. This device is often used as a casing or other housing for vacuum operation, and heat or hot water and heat transfer oil are used for heating by heating plate or heating tube. It is suitable for batch production in small batch.
The oven is a general drying equipment. It is widely applied in pharmaceutical, chemical and food industries. Heating, curing, drying and dehydration of materials and products in light industry, heavy industry and other industries. Such as raw material, raw medicine, Chinese herbal medicine, extract, powder, granule, granule, water pill, packing bottle, pigment dyestuff, dehydrated vegetable, dried melon fruit, sausage, plastic resin, electrical components, baking varnish, etc.
(8)Rotary flash dryer
The dry material is entered into the drying chamber through the spiral input device, crushed by the stirring paddle in the lower part of the dryer. The material after the crushing is fully exposed to the hot air, and flows upward and dried under the dual action of the mixing paddle and the air distributor. The filter size of the classifier and the qualified material of the humidity are dried downward until the dry. So far.
Product features: dry speed. The dryer can be completed in 1-10 seconds, and the material residence time can be adjusted. It can be adjusted between 1-500s, suitable for the drying of heat sensitive materials; a variety of feeding devices for selection, continuous and stable feeding, no bridge erection, high speed of air in the drying room, short stay time, effectively preventing material sticking and heat sensitive material from deteriorating; the drying chamber is equipped with classification ring and swirling piece, material fineness and end. The moisture can be controlled and the drying strength is high.