1．Introduction to rotary dryer

The rotary dryer is also called a drum dryer because the cylinder rotates driven by the gear during the working process. Since its launch, it has been praised by all walks of life and can be widely used in metallurgy, mining, building materials, and chemical fertilizers. , coal and other industries, it can be used to dry various starch residues, sawdust, straw, kaolin, clay, sand, mineral powder, coal slime and other materials. It can also adapt to a wide range of material shapes, such as: lump, powder It is suitable for materials in various states such as shapes and granules. It is especially suitable for large-volume continuous and rapid drying operations. It does not require secondary processing operations and has high economic benefits and value.

2．Rotary dryer performance characteristics

The technical process structure design of the rotary dryer fully considers the nature of the drying feed, and a special design is made on the internal structure of the cylinder, which not only improves the thermal efficiency, but also effectively avoids the sticking and over-drying of materials in the dryer. Its structural characteristics are that it is divided into six sections along the axial direction. The first section is a large-angle guide plate; the second section is an inclined lifting plate; the third section is a movable grate-type wing; and the fourth section is a cleaning device. Arc-shaped lifting plate; the fifth section is an arc-shaped grate-type lifting plate with automatic cleaning device; the sixth section is an area without lifting plates to control dust flying. In addition, the rotary dryer further strengthens the crushing of the aggregates in the dryer and the cleaning of the bonded materials on the inner wall of the barrel:

1. Increase the inclination angle of the guide plate at the feed end of the dryer to quickly enter the enhanced drying stage of wet coal;
2. The front half of the dryer increases the length of the movable grate-type wing plate lifting plate to prevent materials from sticking;
3. The lifting plates are arranged at high and low levels along the radial direction of the circumference of the dryer barrel, so that when the material falls downward from the upper part of the cylinder, the number of times it collides with the lifting plates increases and is broken into small pieces by the lifting plates. , after being lifted and dropped hundreds of times, the coal clumps were finally broken down into spherical particles of about 10mm at the discharge end of the dryer.
4. Large-ring cleaning chains are all welded into the lifting plate hopper, which strengthens the cleaning and heat conduction effects of the chain on dispersed materials, and can effectively prevent materials from sticking to the inside and outside of the lifting plate and the inner wall of the drum.

3. Technical advantages of rotary dryer

Technical Parameters

1. The system technology is simple, the equipment layout is reasonable and compact, and the infrastructure investment is small.
2. The system is energy-saving and environmentally friendly, has reliable operation, requires little maintenance and has a long service life.
3. The dryer is a gas-solid two-phase direct heat exchanger with high drying thermal efficiency and good quality of dried products.
4. The drying system has low energy consumption. The coal consumption is about 150 kilograms of standard coal/ton of water, and the total power consumption of the system is about 500~600kw, about 4~5 kWh/ton.
5. Low drying cost. From drying with a moisture content of 30%~40% to 12~15%, the total drying cost is about 1~2$/t.
6. The coal grinding and dusting machine has the characteristics of easy operation, reliable operation, high combustion efficiency (combustion efficiency is greater than 98%), and low energy consumption, which reduces the physical labor of the operating workers.
7. The feeding amount can be adjusted in a wide range, the production adaptability is strong, the system material flow is smooth, and there is no shed or blockage.
8. The system adopts three dust removal methods: compound self-excited wet type (or bag dust collector), combined cyclone and gravity, to reduce fine dust in the exhaust. Secondary clean water can be used, which has the characteristics of high dust removal efficiency and good purification effect.
9. Use advanced computer control and multi-point monitoring methods to monitor and supervise multiple points such as combustion furnaces, dryers and induced draft fans to achieve intelligent measurement and control of the drying process system to ensure normal operation of the system and safe production.
10. Mature, advanced and economical smoke and dust removal and desulfurization devices can be used as needed. The desulfurization efficiency is high, and the exhaust gas emissions meet national environmental protection requirements.