The internal renovation of the rotary dryer is very important. The internal renovation investment of the dryer is not large and relatively simple, but it is necessary to understand the construction principle of the dryer, the types of drying materials, and the situation of the supporting dust collector, and develop a feasible renovation plan based on daily experience. The general steps of the renovation method are:

（1） The rotary dryer is equipped with a central X-shaped lifting plate to reduce thermal voids, extend material retention time, improve heat exchange efficiency, and reduce the loss of high-temperature gases.

The installation position can start from the middle of the dryer (or later) and install 3-5 sets of lifting plates in sequence towards the head end, with a spacing of 0.5-1m and 6 X-shaped lifting plates per set. But it cannot be installed within 3 meters near the head end (due to the high moisture content, high viscosity, and low temperature of the newly added material, which can easily cause adhesion), otherwise it will affect the overall drying efficiency.

（2） The rotary dryer removes the spiral conveying blades at the feeding end and replaces them with triangular ribs, which can be made of 6mm thick steel plate. The short right angle edge is at the same height as the feeding end retaining ring and welded firmly. The long right angle edge is 800mm long and welded firmly to the drying inner cylinder at intervals of 50mm, naturally forming a conical feeder. Its function is to slow down the flow rate of materials in high temperature zones, fully absorb heat, improve heat exchange rate, and reduce the temperature at the front end of the dryer to avoid burning out the cylinder and stopper ring.

（3） Modify the angle of the feeding pipe, as long as it does not affect the feeding, try to raise the feeding cylinder as much as possible, and the upper end should not be in contact with the dryer stopper ring. However, the insertion into the cylinder should not be too long, and the feeding point can be controlled within 200mm of the stopper ring. To prevent the front end from running out of material and the temperature from burning out the blocking ring and cylinder, raising the discharge chute not only facilitates the circulation of high-temperature gas but also prevents the chute from being burned out. The material naturally falls to form a curtain and comes into direct contact with the high-temperature gas, thereby increasing the heat exchange rate.

（4） Modify the L-shaped lifting plate at approximately 1/3 of the cylinder length of the low-temperature drying belt at the tail of the machine. Generally, the L-shaped lifting plate is fixed vertically at a 90 ° angle and can be welded around the circumference at angles of 30, 90, and 120. By rotating the dryer in this way, the material distribution area of the lifting plate is large at different spatial heights, and the heat exchange rate is high.

Whether a dryer is of high quality and high yield fundamentally depends on achieving a balance between air, fire, and material.

Firstly, determine whether the dust removal ventilation, dryer specifications, model and modification impact, and the heating capacity of the combustion furnace are compatible.

Secondly, we need to strengthen our operations:

① The addition should be uniform to prevent excessive fluctuations in moisture content;

② The temperature adjustment of the heat source should be timely, and the furnace temperature and exhaust gas temperature should be kept stable;

③ Ventilation and dust removal equipment should operate normally to ensure balanced air volume and pressure. Only by mastering these points can we achieve high yield and low consumption through strong winds, large materials, and large fires.