Development status and characteristics of drying equipment for inorganic salt industry

The overall requirements are high thermal efficiency, low energy consumption, simple configuration, convenient control, small footprint, and safe and hygienic operation environment. At present, the commonly used drying equipment in the inorganic salt industry are: rotary tube dryers, rotary indirect heating dryers, disc continuous dryers, and air dryers (also divided into pulse air flow, air flow rotation, positive and negative pressure secondary air flow drying ), Rotary Flash Dryer, Rotary Drum Dryer, Spray Dryer (Also divided into Granulator, Powder, Centrifugal, Pressure Type), Vibrating Fluid Bed Dryer, Static Vacuum Dryer, Hot Air Circulating Dryer, Oven Type , Paddle-type vacuum dryer, boiling dryer (horizontal, vertical) and so on.

These drying equipments provide guarantees for product quality, but there are problems with tail gas collection. Due to the ever-increasing production of nano-scale products, the original particle size is becoming smaller and smaller, the potential moisture content of the paste-like material is increased, and the company is continuously developing toward large-scale and large-scale production. The companies are eager to combine drying equipment. In particular, some large tonnage products, such as precipitated calcium carbonate, currently produce more than 3 million tons of the country's total, the smallest production line has an annual output of 10,000 tons, and the scale of 100,000 tons requires five sets of drying equipment, and a company in Guangxi plans to obtain 500,000 tons. According to the current level of drying equipment, the amount of “dust” collected from the tail gas after the drying of the equipment is large regardless of the floor space of the equipment.

According to the pulse bag filter commonly used in the industry, the operating environment is very bad and must be taken to solve it. Therefore, we hope that the equipment development unit will focus on solving two problems: one is the problem of drying of paste-like fine objects with high moisture content, and the other is that the exhaust gas after the object is dried will receive “dust” industrial hygiene problems. The calcium carbonate industry is still used as an example. For more than 200 companies across the country, in the selection of drying equipment, basic rotary indirect heating dryers, disc-type continuous dryers, rotary column dryers, etc. are used. Although the production efficiency is met, energy consumption is met. Both the dust and the tail gas were not ideal. Once a calcium carbonate enterprise had a white layer of calcium carbonate powder on the ground and roof, it was even white on the desks and chairs in the office. This aspect had management problems. What's more important is that the tail gas after drying is not close to "dust." Recently, this industry introduced DuPont's dust removal equipment, which basically solved the problem.

Therefore, the combined drying equipment should include: providing heat source equipment, primary and secondary drying equipment, and tail gas collection “dust” equipment, etc. It is hoped that equipment manufacturers and research institutes will make a fuss about high thermal efficiency, low energy consumption, simple configuration, and convenient control. , Make a fuss about the combination drying equipment, serve others, develop yourself. If the calcium carbonate industry solves the problem of drying and achieves high efficiency and environmental friendliness, other types of drying problems will be solved.