Rotary kiln end sealing technologyDate: 2019-07-17 Views:
The sealing device is one of the important parts of rotary kiln.The sealing performance of the sealing device has a great influence on the process operation of rotary kiln.This is because the rotary kiln is operated under negative pressure. If the seal between the kiln end and the smoke chamber is not good, because the negative pressure here is higher than that of the kiln end, it is easy to breathe in a lot of cold air, and the gas in the kiln is not easy to discharge, so that the combustion of pulverized coal is not complete, thus increasing the coal consumption and increasing the load of the kiln end fan.
1. Requirements for sealing devices
The sealing device is required to have good sealing performance and reduce the air leakage to the minimum.To be specific:
(1) adapt to all aspects of the movement and deformation of the cylinder. Considering that the smoke chamber at the end of the kiln is stationary and the rotary kiln is in motion, during the movement, the kiln will experience thermal elongation and upward and downward movement, and at the same time, bending deformation and end surface deformation will occur in the overhanging section, and even damage the smoke chamber in serious cases.Therefore, the sealing device should adapt to the above situation.
(2) high temperature resistance, wear resistance, long service life in view of the contact and wear of moving parts and stationary parts in the sealing device, at the same time, dust, high temperature, difficult lubrication, so the sealing material is required to wear resistance, heat resistance.
(3) simple structure, easy to manufacture and maintenance.
2. Kiln end seal
(1) analysis of kiln tail sealing structure
Common sealing structures of kiln end include labyrinth type and end face contact type. Labyrinth type is rarely used because of the small gap between movable sealing groove and friction ring, and it is easy to get stuck when the end of kiln end swings, and the air leakage between sealing groove and flange ring cannot be eliminated.Currently, the end contact type is commonly used, with various specific forms, including cylinder pressure, compression spring pressure, weight hammer pressure, tension spring lever pressure, etc.Their common characteristic is through the end surface pressure makes the movement, the fixed surface in the kiln rotation and up and down movement always maintain contact, achieve the purpose of sealing.
(2) working principle of end face contact seal under pressure of heavy hammer
The end face contact kiln end seal with heavy hammer pressure includes axial seal and radial seal. The basic principle is that the radial seal ring is suspended on the smoke chamber at the kiln end by the hanger rod, which moves with the kiln but does not rotate. Asbestos packing is used to seal between it and the sleeve of the smoke chamber.Axial seal connection in the hopper on the activities of the friction ring and the connection between the radial support plate fixed friction ring end face seal, through setting in uniform radial seal on the pull force caused by a heavy hammer, makes the friction ring contact all the time, and have added grease lubrication system between the two friction ring to slow the abrasion and can enhance the sealing effect.