Industry News

Kiln tail sealing is an important part in the construction of rotary kiln. Its main function is to isolate the environment inside and outside the kiln and prevent the loss of heat in the kiln. The sealing effect has a great impact on the thermal system and environment in the kiln.

The common seal structures of rotary kiln tail are labyrinth type and end contact type. The labyrinth type is rarely used because of the small gap between the movable sealing groove and the fixed sealing ring, which is easy to be stuck when the kiln tail swings, and can not eliminate the air leakage between the sealing groove and the flange ring.

At present, the end contact type is widely used, with various specific forms, which can be summarized as follows: cylinder pressure, compression spring pressure, weight hammer pressure, tension spring lever pressure, etc. Their common feature is that the movable and fixed surfaces always keep contact when the kiln rotates and moves up and down by applying pressure on the end face, so as to achieve the purpose of sealing. Each of these forms has its own advantages and disadvantages. The compression mode of the cylinder is beneficial to the arrangement. 8 ~ 16 cylinders can be evenly arranged along the circumference, so the circumferential force is uniform, but more complicated gas path is required. The air can not be cut off during operation, and the cylinder may fail at ~ 100C temperature. Special measures are needed to solve the problem. Although the compression spring is simple in structure, it is easy to lose elasticity for a long time at ~ 100C temperature. Moreover, it is necessary to design long and soft springs, which makes the arrangement difficult. The advantage of the heavy hammer is that it is easy to adjust (increase or decrease the weight), but it is not easy to arrange at multiple points, and the layout space is large. The tension spring lever type overcomes the defect that the compression spring is too long to be arranged, but it also has the problem of failure after long-term use.

According to the current use situation, it is not found that there is no problem with any kind of sealing device, because the rotary kiln is in complex and harsh working conditions: the kiln body rotates and moves up and down, sometimes there is bending, kiln body end swing, serious dust and high temperature. But by contrast, as long as strict design and effective measures are taken, the cylinder pressure end contact type is still an ideal kiln tail sealing form.

The sealing of rotary kiln tail has an important impact on the production of kiln. Therefore, in the design and construction, we must strictly control every link, design reasonably, take active measures, do a good job in sealing work, and improve the working efficiency of the kiln.