Because the amount of the dryer is related to the bulk density of the material (refers to the mass of the material per unit volume), in general, the proportion of the material in the design of the dryer is calculated according to 0.6g /cm3. If the proportion exceeds this, on the one hand, it will affect the drying efficiency of the material; On the other hand, long running will reduce the service life of motor, turbine reducer, sprocket, chain, bearing, etc. In general, the filling rate of the double cone rotary vacuum dryer (the ratio of the actual filling volume to the volume of the drying cylinder) is usually between 30% and 50%, and the vacuum cover in the double cone dryer cannot be covered, otherwise the drying rate will be affected. 

In actual production application, when filling the vacuum, the double cone rotating vacuum drying opportunities such as vacuum tube bending, gland injury, filtering, head of the phenomenon such as deformation and fracture, this is because in the process of drying in the air into the tank recoil filter head, has reached the higher vacuum degree within the tanks, can lead to positive and negative air shock and damage the vacuum system. Therefore, after drying the material needs to empty the tank, when empting must use the empting valve to control the flow, that is, the valve is opened a little, to be gradually reduced in the tank vacuum degree and then slowly increase; Or add a pressure reducing valve to control the flow of air. 

The double cone rotary vacuum dryer often has the problem of too low or too high vacuum in the drying process, which will not only affect the drying efficiency and quality of the material, but also affect the production safety of the workshop. Although the higher the vacuum degree, the more conducive to the evaporation of water at low temperature, but too high vacuum degree is not conducive to heat conduction, affect the drying effect of the material. 

In the actual production, if the use and maintenance of the glass lined liner of the rotary cylinder is not correct, it is easy to be damaged. Especially for acidic and alkaline materials, the drying discharge is not clean, the material is easy to wall, damage the bladder inside the cylinder, and affect the service life of the dryer. To solve such problems, we only need to choose the right dryer according to the nature of the material. During the use of the material, the material is clean and inspected regularly, and at the same time, maintenance and cleaning should be carried out. 

In the dryer, in use process due to the drying machine of the anchor is loose, damage of worm gear reducer (gearbox), bearing damage, the chain is too loose or too tight and other reasons caused by noise is too big, for the damage of the reducer, bearing and chain, just regular check and pay attention to add lubricating oil, malfunction in time, the preventive maintenance. 

Inlet and outlet leakage is generally caused by adhesive or damage to the sealing strip, as long as the material on the surface is cleaned up or the sealing strip is replaced. In the actual production management of the workshop, preventive maintenance work should be done, and wearing parts should be replaced in advance. 

In actual production, if there is material wall, it will not only affect the mass and heat transfer inside the dryer, thus affecting the nature of the whole batch of materials, resulting in unqualified products, but also affect the service life of the dryer. In order to alleviate the wall problem of materials in the double cone rotary vacuum dryer, the following research and discussion are carried out on the solution: 

According to the specific properties of the material, the double-cone rotary vacuum dryer is coated with a special protective layer to prevent the material from forming walls. But this requires higher requirements for the coating, on the one hand, must consider the physical properties of the coating; On the other hand, we must consider whether cross-contamination will occur. 

In the process of drying, adding inert medium ball and material mixing, can effectively reduce the material wall, but in the selection of medium ball in the process, to fully consider the shape of the medium ball on the dryer liner, but also to consider the separation and recycling process with the material in the later period. 

According to the nature of the material, before drying, optimization of drying machine feeding, temperature rise, speed and other steps, can also effectively reduce the degree of material wall. But for special materials, to optimize the steps of drying machine feeding, temperature rise, speed and so on, it is necessary to carry out the relevant orthogonal optimization test to obtain the drying conditions. In general, it is better to use variable temperature drying, that is, the temperature is low at the initial stage of drying, and the temperature is gradually increased to improve the drying speed. 

This method is mainly from the process of changing the crystal structure of the material, changing the crystallization of the material or the process of dissolving, can fundamentally eliminate the wall of the material, but at the same time of changing the process, there is a greater risk for the quality and nature of the material, and fundamentally change the process, difficult. 

Before drying each batch of wet materials, add a certain amount of the previous batch of dry materials, using mixed drying method, can effectively eliminate the wall of materials, but also improve the drying efficiency of materials.