1、 Project Description

　　PVB, also known as polyvinyl butyral in Chinese, is a polymer material that is a semi transparent film, non-toxic, odorless, non corrosive, and non flammable. It has good transparency, insulation, weather resistance, wear resistance, water resistance, oil resistance, and aging resistance, and has special adhesion and transparency properties for inorganic and organic glass. It can be used as a interlayer material for safety glass and as other transparent materials.

2、 Overview of PVB dedicated rotary flash dryer

　　According to the material characteristics of PVB, a rotating flash dryer is used to dry PVB. The entire equipment uses steam heating, with a drying processing capacity of 800Kg/h, and can dry wet materials with an initial moisture content of 35% to below 1.5%. As the materials are heat sensitive, the main machine of the dryer is jacketed with water cooling. Due to the low temperature of the materials, the inlet air temperature is lower, so a section is added to the main tower to extend the drying time of the materials, The material contact area of the entire system is made of stainless steel, while the rest is made of carbon steel. The exhaust gas treatment system mainly consists of a cyclone separator, a bag filter, and an induced draft fan. The dust in the exhaust gas is treated through the cyclone separator and bag filter.

3、 Principle of PVB dedicated rotary flash dryer

　　The material of the PVB dryer enters the dryer through a spiral feeder. Under the strong action of the high-speed rotating mixer, the material is dispersed due to impact, friction, and shear. The block material is quickly crushed, fully in contact with hot air, heated, and dried. The dehydrated dry powder material rises with the hot gas, and the grading ring intercepts large particles. Small particles are discharged from the center of the ring outside the dryer and recycled by a cyclone separator. Undry or large materials are thrown towards the wall by centrifugal force, and then fall back to the bottom for crushing and drying. Due to the rotating flow of gas-solid two phases, the inertia of the solid phase is greater than that of the gas phase, and the relative velocity between the solid and gas phases is relatively high, which enhances the heat transfer properties between the two phases. Therefore, the production intensity of this machine is high.

4、 Characteristics of PVB dedicated rotary flash dryer

　　a. In the high-temperature area of the lower part of the dryer, thermosensitive materials do not come into direct contact with the hot surface and are equipped with special devices to solve the problem of coking discoloration of thermosensitive materials.

　　b. Due to the high air velocity in the drying room and the short residence time of materials, it achieves high efficiency, speed, small equipment, and large output.

　　c. The installation of ceramic separator rings and swirl plates on the upper part of the drying chamber can control the particle size and temperature of the outlet materials to meet the requirements for the final water particle size of different materials.

　　d. Due to the low temperature of the material, the inlet air temperature is lower, so an additional section is added to the main tower to extend the drying time of the material.