Triple pass rotary drum dryer

sawsust rotary dryer

Table of Contents

Triple pass rotary drum dryer introduction

Adopt the new technology of high temperature fast downstream drying, new multi ring drum dryer, high efficiency and energy saving combustion hot air furnace. The original automatic control, system and a series of safety and explosion-proof devices, successfully solved the many difficulties of drying agricultural cash crops and agricultural by-products. Using coal as the drying heat source, with its low drying cost to meet the drying of low value-added products, while the market price is lower than the products in the same industry, the market share is leading in China.

Qingdao palet has been worked in the drying of wood chips, sawdust, wood shavings for more than 10 years. From then on, we have seen many different kinds of drying methods with varying degrees of success.

Triple pass rotary drum dryer process

The appearance of the rotary drum is no different from that of a normal rotary drum dryer, but the interior is a set of three straight drums of varying diameters, forming a three-ring drum, with a cross-plate on all surfaces where it comes into contact with the material. The three layers of rollers are radially fixed to each other and rotate at the same number of revolutions.
The direction of the material is: the wet material enters from the inner rotary drum cylinder, exits from the end and enters the middle cylinder, the middle cylinder exits and enters the outer cylinder, and finally exits from the end of the outer cylinder. (as shown in the figure below)

triple pass rotary drum dryer principle

Triple pass rotary drum dryer working principle

Why does the material not stick to the wall of the drying drum?

The reason is that the three-layer roller divides the cross-sectional area of the original single roller into three parts. Therefore, the cross-sectional wind speed inside the drum is 3 times faster than that of single layer drum, up to 5 meters per second. Under the action of high temperature (up to 800~850℃) and high speed hot air, the high temperature material (water content 70%~75%) will be evaporated quickly in an instant. The material and hot air form a spiral of fluid in the drum that moves at high speed. Drying is a completely different concept than the original rotary drum dryer.

triple pass rotary drum dryer process

Triple pass rotary drum dryer advantage

1. Compared with single-layer rollers, the length has been reduced by two-thirds and the plant area is small.

2. The small installed capacity of the mainframe reduces electricity consumption.

3、The cross-sectional area of the three-layered drum is scientifically and accurately calculated and designed according to the drying characteristics of the material, so that the speed and time of the movement of the material at different stages of precipitation are different, giving full play to the advantages of high temperature and speed, the drying strength is as high as 100~135kg(H2O)/M3h, which is 6.6~9 times higher than the current domestic machinery industry standard.

4、Three-layer drum set structure, the internal and external drums are equipped with a reading plate, which increases the filling rate of the material, ensures the contact area between the material and the hot air, and increases the drying strength and distribution speed.

5、Small heat loss: high-temperature hot air, first contact with wet materials in the inner tube, with the evaporation of water, the temperature of the hot air also reduces, through the middle tube, the original hot air of about 800 ℃, when it reaches the outer tube, it has been reduced to about 100 ℃ ~ 150 ℃, the heat transfer power has been reduced, the outer tube set up good heat preservation, so the heat loss is small.

6. The connection between the three layers of drums is non-steel, with a slipway at the connection to eliminate thermal stresses caused by different temperature expansions between the drums.

7、The drive of the drum adopts a special friction material friction drive, which is smooth running and low noise.

Triple pass rotary drum dryer specification and parameter

ModelSpecification (m)Capacity(kg/h)Rotate speed(r/min)Power(kw)Size(m)

Triple pass rotary drum dryer applications

Dregs, grass charcoal soil, alfalfa grass, marigold, ginkgo biloba, barley seedlings, chrysanthemum meal, beet dregs, corn kernels, vegetable stems and leaves, straw, Chinese herbs, wood chips and other materials.

Rotary drum dryer video

For detail and price of triple pass rotary drum dryer, please refer to:


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