Heating process of sludge drying equipment technology

The technology of sludge drying equipment makes use of the principle of heat and mass transfer between high humidity hot gas and wet materials to make wet sludge heated and evaporate water. Dried sludge plays an important role in building materials processing, cement manufacturing, combustion power generation and other industries. As the sludge drying equipment in the process of work, mainly rely on the continuous combustion of fuel to generate heat to achieve the drying of materials, so the heating process of sludge drying equipment technology is also very important.

Detailed explanation of heating process of sludge drying equipment technology:

1、 Direct heating technology

Direct heating technology refers to the direct contact heating between the hot air entering the cylinder and the wet material. The advantages of this technology are fast heat transfer speed, small heat loss, high heat utilization rate and fast drying speed. However, due to the direct contact between the hot air and the material, the material capacity is easy to be polluted and the operation burden of waste gas treatment equipment is increased. Direct heating technology can also be divided into counter flow type and forward flow type according to the running direction of material and air flow.

Downstream drying means that the material and hot air flow in the same direction, high feed temperature, low discharge temperature, due to the initial temperature difference between the two is too large, so it can evaporate a lot of water. Countercurrent drying means that the material and hot air flow are in the opposite direction, the disorder degree increases, the dust particles in the sludge are less, and the drying efficiency is high.

2、 Indirect heating technology

Indirect heating technology is also a common technology in sludge drying equipment. Different from direct heating, hot air and wet sludge do not directly contact in the cylinder, but indirectly transfer heat through the pipe wall. Such as paddle, disc and other sludge drying equipment. The heat energy generated by heat transfer oil and steam enters the equipment and flows in the hollow pipe to heat the sludge on the other side of the pipe wall and evaporate water. The advantages of this method are to avoid material pollution, high cleanliness, low waste gas treatment burden, simple structure and easy operation. However, the indirect heating method is more suitable for the drying of small and low moisture materials due to the large heat loss and more heat consumption. It has the advantages of cleanness and small floor area.

3、 Compound heat transfer technology

Direct heating and indirect heating are used in this sludge drying equipment. When the hot air is in direct contact with the wet sludge, the heat energy is transferred to the material indirectly through the hollow wall to accelerate the drying speed of the material.