^{Analysis of eight kinds of drying equipment in the chemical and pharmaceutical industry applications}

Abstracts:

Drying equipment in the use of industry is very wide, many fields need to use the use of drying equipment, the same, drying equipment in the pharmaceutical industry also has an important role. Today, I will bring eight kinds of drying equipment in the chemical and pharmaceutical industry. Analysis of eight kinds of drying equipment in the chemical and pharmaceutical industry.

(1) Vacuum harrow dryer

Drying materials from the vacuum harrow dryer shell above the middle of the accession, in the constant rotation of the rake teeth of the mixing, materials and shell wall contact, the surface is constantly updated, the material to be dried by the steam (or hot water, heat conduction oil) indirect heating, but the material vaporization of moisture, vaporization of water by the vacuum pump pumped out in time. The material to be dried is indirectly heated by the heat carrier, so that the moisture in the material is vaporized, and the vaporized moisture is timely discharged by the vacuum pump.

Due to the high operating vacuum, generally within the range of 400-700mmHg, the water vapor pressure on the surface of the dried material is much larger than the water vapor pressure in the evaporation space within the drier shell. Thus, it is favorable to the discharge of internal moisture and surface moisture of the dried material and the movement of water molecules of the dried material to achieve the purpose of drying. Vacuum harrow dryer is suitable for materials which are heat-sensitive, easy to oxidize under high temperature or easy to slate when drying, as well as materials whose steam discharged in drying must be recovered. Typical drying materials are sodium acryl sulfonate, CMC, phthalocyanine blue, dye intermediates, carboxymethyl starch, maltodextrin, anthraquinone sulfonic acid, etc.

(2)Double cone rotary vacuum dryer

The body of double cone rotary vacuum dryer is slightly like olive shape, with cover at both ends and two shafts in the middle to support the body. There is a jacket to heat the body, and the body can rotate when drying, so that the material and the wall are often replaced with the contact, overcoming the shortcomings of low thermal efficiency in the vacuum oven, in which the material mainly relies on the conduction of the heating cylinder. The rotary vacuum dryer has been widely used in fine chemicals, pharmaceuticals, etc. It is not suitable for materials with high viscosity or strong adhesion in the rotary process. This equipment is mainly used in medicine, chemical industry, food and other industries of powder, granular and fibrous materials, concentration, mixing, drying and low-temperature drying of materials (such as biochemical products, etc.), more suitable for easy oxidation, volatile, heat-sensitive strong stimulation, toxic materials and do not allow the destruction of the crystal of the drying of materials.

(3)Drum scraper dryer

Drum scraper dryer is a continuous operation equipment through the rotation of the cylinder, in the way of heat conduction, will be attached to the cylinder wall of the liquid phase materials or band materials, drying. The liquid material to be dried and processed flows into the receiving trough of the drum dryer from the high level trough. The drying drum is driven by the transmission device and rotates according to the specified speed. Material by the film device, in the drum wall to form a film. Cylinder continuous through the heating medium, heating cylinder, heat transfer from the cylinder wall so that the film of moisture vaporization, and then through the scraper will meet the drying requirements of the material scraped, through the spiral conveyor to the storage tank, packaging. The moisture removed by evaporation, depending on its nature, can be introduced into the corresponding treatment device through the closed cover; generally water vapor, can be released directly to the atmosphere by the exhaust pipe on the top of the cover. The machine is mainly used to deal with liquid materials, both through the steam, hot water or hot oil heating and drying, but also through the cold water cooling sheet. According to the nature of different materials and process requirements using immersion, spraying, grinding auxiliary feeding methods.

(4)Vacuum oven

Due to decompression, the evaporation of volatiles contained in the material evaporation temperature can be reduced, suitable for a variety of heat-sensitive, easy to oxidize the material drying. This device is often a garden cylinder or other shell that can bear the vacuum operation, inside the electric heat or hot water, heat conduction oil through the heating plate or heating tube for heating, suitable for small batch intermittent production.

Oven is a general drying equipment, applicable to a wider range, is a disk rack type batch drying equipment, used in pharmaceutical, chemical, food. Light industry, heavy industry and other industries materials and products of heating curing, drying and dehydration. Such as raw materials, raw drugs, Chinese medicine tablets, extracts, powder, granules, punch, water pills, packaging bottles, pigments and dyes, dehydrated vegetables, dried fruits and vegetables, sausages, plastic resins, electrical components, baking paint and so on.
(5) Spray dryer

Spray drying is a liquid process forming and drying industry ^ widely used process. It is suitable for generating powdery and granular solid products from solutions, emulsions, suspensions and pasty liquid raw materials. Spray drying is therefore an ideal process when the particle size distribution, residual moisture content, bulk density and particle shape of the finished product must meet standards.

(6) Hollow paddle dryer (blade dryer)

Hollow paddle dryer, also known as blade dryer, mainly consists of W-shaped shell with jacket and two hollow paddle shaft and transmission device. The shaft is arranged with hollow blades, and the end of the shaft is equipped with a rotary joint for heat medium introduction. The heat required for drying moisture is conducted to the material by the inner wall of the W-shaped trough with jacket and the wall of the hollow blades. During the drying process, the hollow shaft with hollow blades heats the material and stirs the material at the same time, thus renewing the heating surface. It is a kind of continuous conduction heating dryer. The heating medium is steam, hot water or thermal oil. The heating medium passes into the shell jacket and two hollow paddle shafts to heat and dry the materials by conduction heating, and the structure of hollow paddle shafts is different for different materials.

The machine is suitable for processing various kinds of paste, granular, powder and other thermally stable materials, under special conditions can also dry heat-sensitive materials and recovery of solvents in the drying process. Commonly used in carbon black, light calcium carbonate, titanium dioxide, barium carbonate, nitrile uric acid, gypsum, clay, manganese dioxide, nylon and polyester slices, polyethylene, polypropylene (recovery of solvents), and other materials such as drying or cooling.

(7) Belt dryer

Belt dryer consists of several independent unit sections. Each unit section includes circulating fan, heating device, separate or common fresh air intake system and exhaust system. The number of drying media, temperature, humidity and exhaust gas circulation amount of operating parameters, can be independently controlled, thus ensuring the reliability of the work of the belt dryer and the optimization of operating conditions. With the flexible operation of the belt dryer, the wet material is fed and the drying process is carried out in a completely sealed box, with better labor conditions and avoiding the leakage of dust. It is used for drying flakes, strips and granular materials with good permeability, and it is especially suitable for dehydrated vegetables, Chinese medicine tablets and other materials with high water content and material temperature not allowed to be high.

(8) Rotary flash dryer

The material to be dried enters into the drying room through the spiral input device, and is crushed by the stirring paddle in the lower part of the dryer, the crushed material and the hot air are fully contacted, and the material is ^moved and dried under the double action of the stirring paddle and the airflow distributor, and the qualified material with qualified granularity and humidity is rotated and dried downward after the screening of the grader, until it is qualified.

Product features: fast drying speed. 1-10 seconds to complete the dryer; material residence time can be adjusted. Can be adjusted between 1-500s, suitable for drying heat-sensitive materials; a variety of feeding devices for choice, feeding continuous and stable, will not produce the phenomenon of bridging; drying chamber circumferential gas velocity is high, the material residence time is short, effectively preventing the material from sticking to the wall and heat-sensitive material deterioration; drying chamber equipped with grading ring and cyclone piece, the fineness of the material and the final moisture can be adjustable and controllable; drying intensity is high.