Maintenance of kiln mouth refractory
Date：2019-07-23 15:12 Source：未知Views:
The kiln mouth protection plate protects the kiln mouth from burning loss, wear and deformation. The effectiveness of the kiln mouth protection plate will cause damage to the kiln mouth cylinder and affect the service life of the kiln mouth firebrick or refractory castable.
No matter what measures are taken, the service life of the kiln mouth cannot be synchronized with that of other parts.Therefore, proper structure should be used to reduce the maintenance cost and improve the operation rate of kiln.
(1) reasonable type of kiln mouth cylinder
Personal use becomes a serious honk within a year and must be replaced.When replacing, first cut off the old kiln cylinder.It is very difficult to ensure the verticality of the end face of cutting seam, and it is not easy to ensure the concentricity and straightness when rewelding.Therefore, in foreign countries, the kiln mouth tube system into a single section, the flange and kiln body cantilever short tube with bolts together, not only easy to replace, and easy to find, but also reduce the deformation of the kiln mouth, improve the service life.It is advantageous that the end of the kiln tube extending into the kiln head cover should be suitable for the shapes of different kiln masks, but special reinforcement measures should be taken to avoid premature deformation.If the end is made of heat resisting steel, it can increase the service life, but it is too troublesome.In short, the use of flange kiln cylinder is a kind of structure worth popularizing, which should be popularized in the future design.
(2) reasonable shape of kiln mouth shield
Rotary kilns, kiln sheeting must be cast in expensive high quality heat resistant steel.Therefore, it is of great significance to use well-formed kiln mouth guard plate to protect refractory castable.
(3) improvement of connection mode of kiln mouth shield
The connection mode of kiln mouth cover also has a great influence on the service life of kiln mouth.At home and abroad, heat resistant steel bolts are often fixed, often loose, cut and other accidents, replacement is very inconvenient.Using reverse pin and fixing is a simple and easy structure. Heat resistant steel pin and fixing fork can be used many times as required.The service life of the guard plate fixed with this structure is much longer than that of the ordinary guard plate, and the installation and disassembly are simple and quick.
(4) give full play to the role of heat resistant castable
Refractory castable can fully protect the kiln mouth protection plate, the kiln mouth protection plate does not fail.Kiln tube is well protected.The rotary kiln cylinder does not deform, the kiln mouth guard plate fixed base is stable, not easy to deform, this will prolong the service life of refractory castable.
(5) control of adjacent radial clearance of kiln mouth shield
Starting from the end face of the kiln head, the kiln mouth guard plate is composed of several fan-shaped sections, forming a ring.After heating must expand, the temperature of the inner port is much higher than that of the outer flange.Therefore, when designing, manufacturing and installing, a radial expansion gap must be left between the adjacent two pieces.Otherwise, it is easy to cut off the coupling fixing bolt in the working process, which makes the kiln barrel become trumpet shape quickly.Kiln mouth protection plate is cast, the size is difficult to control.Therefore, after installation, the gap is too large, no gap, gap size, small inside and outside, local contact dead.In the past, due to the lack of harm to this phenomenon, this situation was not treated, resulting in the kiln's very short life.In this case, it should be timely handled and polished to ensure that the minimum radial clearance formed between two adjacent kiln mouth protection plates can meet the requirements of design clearance.Large gaps can be filled with asbestos, rock wool, etc., to ensure that no leakage occurs during casting.
It is very important to control the radial clearance of kiln end hood, but it is often neglected in the process of installation and maintenance.This is one of the most important reasons for premature failure of kiln mouth protection plate and rapid formation of kiln tube.