Drying equipment is widely used in industry. It is necessary to use drying equipment in many fields. Similarly, drying equipment also plays an important role in the pharmaceutical industry. Today, the author will introduce the application of eight drying equipment in the chemical and pharmaceutical industry. The application of eight kinds of drying equipment in the chemical and pharmaceutical industry is analyzed.

(1) Belt dryer

　　The belt dryer is composed of several independent unit sections. Each unit section includes circulating fan, heating device, separate or public fresh air extraction system and tail gas exhaust system. The number of drying media, temperature, humidity and tail gas circulation operation parameters can be independently controlled to ensure the reliability of the belt dryer and the optimization of operating conditions. The belt dryer has flexible operation, wet material feeding, and the drying process is carried out in a fully sealed box. The working conditions are good, and the leakage of dust is avoided. It is suitable for drying of flaky, strip and granular materials with good permeability, especially for dehydrated vegetables, Chinese herbal pieces and other materials with high water content and material temperature not allowed to be high.

(2) Drum scraper dryer

　　The drum scraper dryer is a continuous operation equipment that dries the liquid phase materials or ribbon materials attached to the outer wall of the cylinder by means of heat conduction through a rotating cylinder. The material liquid to be dried flows into the receiving tank of the drum dryer from the high-level tank. The drying drum is driven by the driving device and rotates at the specified speed. The material forms a material film on the drum wall by the film distribution device. The heating medium is continuously introduced into the cylinder to heat the cylinder. The moisture content of the material film is vaporized by the heat transfer of the cylinder wall, and then the materials that meet the drying requirements are scraped off by the scraper, and then spiral transported to the storage tank for packaging. The moisture removed by evaporation can be introduced into the corresponding treatment device through the closed cover according to its nature; Generally, it is water vapor, which can be directly discharged into the atmosphere through the exhaust pipe on the top of the hood. This machine is mainly used to process liquid materials, which can be heated and dried by steam, hot water or hot oil, and cooled by cold water. According to different material properties and process requirements, immersion type, spray type, grinding auxiliary type and other feeding methods can be used.

(3) Hollow paddle dryer

　　The hollow blade dryer, also known as the blade dryer, is mainly composed of a W-shaped shell with a jacket, two hollow blade shafts and a transmission device. Hollow blades are arranged on the shaft, and the shaft end is equipped with a rotary joint for the introduction of thermal medium. The heat required for drying water is transferred to the material by the inner wall of the W-shaped groove with jacket and the hollow blade wall. During the drying process of the material, the hollow shaft with hollow blades heats the material while stirring it, so as to update the heating surface. It is a continuous conduction heating dryer. The heating medium is steam, hot water or heat transfer oil. The heating medium is introduced into the jacket of the shell and the two hollow propeller shaft to heat and dry the material in the way of conduction heating. The structure of the hollow propeller shaft of different materials is different. This machine is suitable for processing various paste, granular, powder and other materials with good thermal stability. Under special conditions, it can also dry heat-sensitive materials and recover solvent in the drying process. It is often used for drying or cooling carbon black, light calcium carbonate, titanium dioxide, barium carbonate, cyanuric acid, gypsum, clay, manganese dioxide, nylon and polyester chips, polyethylene, polypropylene (recycled solvent) and other materials.

(4) Vacuum rake dryer

　　The dry material is added from the middle of the shell of the vacuum rake dryer. With the stirring of the continuously rotating rake teeth, the surface of the material is constantly updated when it contacts with the shell wall. The dried material is indirectly heated by steam (or hot water, heat transfer oil), but the material moisture vaporizes, and the vaporized moisture is timely removed by the vacuum pump. The dried material is indirectly heated by the heat carrier to vaporize the moisture in the material, and the vaporized moisture is discharged by the vacuum pump in time.

　　Due to the high operating vacuum, generally in the range of 400~700mmHg, the water vapor pressure on the surface of the dried material is far greater than the water vapor pressure in the evaporation space inside the dryer shell. This is conducive to the discharge of internal and surface moisture of the dried material, and the movement of water molecules of the dried material, so as to achieve the purpose of drying. The vacuum rake dryer is applicable to materials that are heat sensitive, easy to oxidize under high temperature or easy to harden during drying, and materials that must be recovered from the steam discharged during drying. Typical drying materials include sodium propylene sulfonate, CMC, phthalocyanine blue, dye intermediate, carboxymethyl starch, maltodextrin, anthraquinone sulfonic acid, etc.

(5) Double cone rotary vacuum dryer

　　The body of the double-cone rotary vacuum dryer is slightly olive shaped, with covers at both ends and two shafts in the middle to support the body. The body is equipped with a jacket for heating, and the body can rotate during drying, so that the material and the wall of the body are often replaced and contacted, which overcomes the disadvantage of low thermal efficiency due to the material in the vacuum oven mainly relying on the heating cylinder for conduction. Rotary vacuum dryer has been widely used in fine chemicals, medicine and other fields. It is not suitable for materials with high viscosity or strong adhesion in the rotary process. This equipment is mainly used for the concentration, mixing and drying of powder, granular and fibrous materials in the pharmaceutical, chemical, food and other industries, as well as materials that need to be dried at low temperature (such as biochemical products). It is more suitable for the drying of materials that are easy to oxidize, volatile, highly sensitive to heat, toxic materials and materials that are not allowed to damage crystals.

(6) Spray dryer

　　Spray drying is a process widely used in liquid forming and drying industries^ It is suitable for generating powder and granular solid products from solution, lotion, suspension and paste liquid raw materials. Therefore, when the particle size distribution, residual moisture content, bulk density and particle shape of the finished product must meet the standard of ^, spray drying is a very ideal process.

(7) Vacuum oven

　　Since the evaporation temperature of volatile matter contained in material evaporation can be reduced after decompression, it is suitable for drying various heat-sensitive and oxide-prone materials. This device is usually a cylinder or other shell that can be operated under vacuum. It is heated by electric heating or hot water, heat transfer oil through heating plate or heating pipe, and is suitable for small batch batch batch production.

　　The oven is a general drying equipment with a wide range of applications. It belongs to the plate-type intermittent drying equipment and is used 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 materials, crude drugs, Chinese herbal medicines, extracts, powders, granules, granules, water pills, packaging bottles, pigment dyes, dehydrated vegetables, dried fruits and melons, sausages, plastic resins, electrical components, baking paint, etc.

(8) Rotary flash dryer

　　The dried material enters the drying chamber through the screw feeder and is crushed by the mixing paddle at the lower part of the dryer. The crushed material fully contacts with the hot air, flows upward and dries under the dual action of the mixing paddle and the air flow distributor. The material that passes the screening size and humidity of the classifier is rotated downward and dried until it is qualified.

　　Product features: fast drying speed. The dryer can be completed in 1-10 seconds; The residence time of materials can be adjusted. It can be adjusted between 1-500s and is suitable for drying heat-sensitive materials; Various feeding devices are available for selection, feeding is continuous and stable, and bridging will not occur; The drying chamber has high circumferential gas velocity and short residence time of materials, effectively preventing materials from adhering to the wall and heat sensitive materials from deteriorating; The drying chamber is equipped with a grading ring and a swirl plate, and the fineness and final moisture of the material can be adjusted and controlled; High drying strength.