Spray Granulation Rotary Dryer

The rotary granulator is a rotary equipment that realizes the granulation function of calcium chloride dihydrate: the seed crystals are in the rotary granulator, and are sprinkled on the built-in fluid bed dryer as the cylinder rotates, and fall from the fluid bed dryer to form the material cascade. The calcium chloride solution enters the rotary granulator through the pipeline, and directly contacts the material cascade after being melted by the nozzle. The solution wraps on the surface of the seed crystals, and solidifies on the surface of the seed crystals as the temperature decreases. After multiple contacts, wrapping and solidification with the solution, the particle size of the seed crystals continues to increase, and they are discharged at the tail of the rotary granulator.

The rotary granulator is equipped with a shovelling plate to sprinkle the seed crystals into the fluid bed dryer. Hot air is introduced into the bottom of the fluid bed dryer to remove free water and part of the crystal water on the surface of the material.

• On the side of the rotary granulator that is perpendicular to the material cascade, multiple nozzles using single-fluid spray are installed. After the seed crystal contacts, wraps and solidifies with the solution for many times, the particle size continues to increase, and it is discharged from the tail of the rotary granulator after drying. The granulator can remove free water and a small amount of crystal water on the surface of the material after granulation by introducing hot air at the bottom of the built-in fluid bed dryer.

• The material particles after granulation and drying are discharged from the tail of the rotary machine, and after screening, the qualified particles enter the cooling equipment, and then enter the packaging system after cooling; and the coarse particles are crushed and returned to the rotary granulator together with the fine particles for recycling as seed crystals.

• The rotary granulator uses ambient air as the drying medium. The air is pressurized by the blower and enters the air heat exchanger. It fully exchanges heat with the low-pressure steam. After heating to the process setting temperature, it enters the rotary granulator to participate in the drying process. The steam condenses and flows back to the condensate pipe network. After completing the drying task, the cooled air carries some fine powder and moisture, and first enters the cyclone to separate the fine powder in the exhaust gas. The exhaust gas after dust removal then enters the wet scrubber for washing, and is finally discharged through the system induced draft fan.
  

1. Compared with the existing production process of calcium chloride dihydrate flakes, the calcium chloride dihydrate granulation technology has obvious energy-saving effect. The system uses high-concentration calcium chloride solution (69%) as raw material, and directly dehydrates and granulates into spherical products in one step, eliminating the flake process of the traditional calcium chloride dihydrate flake production process. The heat of the raw calcium liquid is fully utilized, and the steam consumption is greatly reduced;

2. The calcium chloride dihydrate granules produced are solid spheres, the particles are uniform, the fluidity is good, the anti-hardening ability is strong, and the bulk density is 930kg/m³, which is about 30% higher than the calcium chloride dihydrate flake, which can reduce the packaging and export transportation costs;

3. The dried product adopts rotary cooling technology, which has low power consumption and indirect heat exchange, avoids product moisture absorption, and provides an operating cycle;

4. The system adopts rotary granulation technology, which integrates material granulation and drying functions, has reliable and stable operating conditions, low power consumption, and a continuous and stable operating cycle of >40 days;

5. The material moves in the rotary granulator by the rotation of the granulator, and does not require a large amount of wind to provide power. The system installed power is low.

Applicable material: Calcium chloride