The products fired in roller kilns have the advantages of small color difference and uniform size. Therefore, it has become the main equipment for quickly firing wall and floor tiles. Improper control during use can easily cause product blockage, affect production, and reduce service life. But how to avoid blockage of the roller kiln during the production process? To solve this issue, we first need to know reasons for the blockage of the roller kiln and how to avoid these problems.
Porcelain roller contamination is mainly manifested by oil stains on the roller, forming uneven bumps on the roller. Due to improper control of glaze application on adobe bricks, many glaze droplets adhere to the bottom surface of the product. This can cause the glaze droplets to soften and adhere to the rollers during high-temperature calcination, resulting in uneven roller diameters and causing resistance to the products running on the ceramic rollers. The subsequent products cannot move forward normally, resulting in irregular arrangement and product overlap. When the overlapping products exceed the high-temperature load softening point of the ceramic rollers, the ceramic rollers break, causing blockage in the kiln.
The temperature adjustment of the roller kiln is to divide the firing nozzle into several groups in the preheating zone and firing zone, and control them separately according to the upper and lower rows of the ceramic rollers. The cooling zone is controlled by controlling the cooling air volume. During the process of adjusting the firing temperature, if the upper temperature of the ceramic roller is significantly higher than the lower temperature, the product will experience concave deformation; On the contrary, convex deformation occurs. The former is more likely to cause adhesion or overlap between the front and back of the product in production, while the latter is prone to embedding between the rollers, breaking them, and causing blockages. Improper control of the cooling belt can cause product cracking, and broken products embedded between rollers may also cause blockage. In addition, when the atmosphere system adjustment is unreasonable, it can cause deformation, foaming, stacking of products during the firing process, and cause blockage of the kiln.
The control system of the roller kiln adopts interlocking automatic control. In case of power outage or mechanical equipment failure, the motion state of all rollers will automatically change to a swinging state based on the power frequency, causing the products to move back and forth in the kiln. The products will deform due to prolonged calcination time, causing blockages in the roller kiln.
Roller kiln firing is continuous. If the brick feed is unstable and the feed is intermittent, it will cause the products in the kiln to form gaps under the cover of the ceramic rollers, resulting in unstable kiln pressure, large temperature fluctuations, and easy deformation of the products, leading to product blockage.
Improper adjustment of roller speed can cause asynchronous speed of each group of rollers, resulting in uneven running speed of front and rear products, overlapping and deformation of products, and causing blockage of the roller kiln.
Uneven arrangement of bricks entering the kiln head will cause collision between the products and the kiln body, resulting in deformation or overlap of the products, and serious blockage of the kiln.
Loose and protruding ceramic roller pads can cause the rollers to rotate in different planes, causing product stacking or insertion between rollers, resulting in furnace blockage.
Check and replace some porcelain rollers daily, with a cycle of three months. For the porcelain rollers that need to be replaced, a cleaning machine should be used for calibration and cleaning, and a coating with a fire resistance of 1600 ℃ or above should be evenly applied on its surface to prevent adhesion between the glaze and the rollers. And the alloy rollers after each washing should be placed vertically or in a single layer.
Ensure that the firing temperature distribution of the roller kiln is uniform, and avoid product deformation caused by high or low temperatures. At the same time, reasonable regulation of the atmosphere system can prevent deformation and foaming of products during the firing process, which helps to prevent kiln blockage.
Through the control system of the roller kiln, in the event of power outage or other equipment failure, adjust the motion state of all rollers to a swing state based on the power frequency. This can avoid deformation caused by long-term calcination of products and reduce the risk of kiln blockage. When stopping the kiln, the temperature inside the furnace must drop below 200 ℃ in order to stop the roller operation. Otherwise, the alloy roller will deform due to uneven temperature.
When replacing the porcelain roller, it is necessary to slowly remove the roller.The removed roller rod should not directly contact the ground and should be placed on a dedicated rack for slow rotation and uniform cooling. During normal production, to replace the porcelain roller, it is necessary to preheat the roller to above 80 ℃ and slowly put it into the kiln.
Maintain the continuity of the roller kiln firing to avoid gaps in the product inside the kiln due to unstable brick feeding. This is beneficial for maintaining stable kiln pressure and minimal temperature fluctuations, reducing the possibility of product deformation.
Ensure that the roller speed is adjusted properly, so that the speeds of each group of rollers are synchronized, avoiding inconsistent running speeds of front and rear products, thereby reducing product overlap and deformation, and reducing the risk of kiln blockage.
Ensure that the arrangement of kiln inlet bricks is neat and orderly, avoid collision between products and kiln body, reduce product deformation or overlap caused by collision, and prevent kiln blockage from the source.
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