Common Problems and Solutions for Push Plate Kiln

Saggar is commonly used in various kiln, and today let's talk about what to take heed when using push plate kiln equipment.

1. Problems caused by the structure of the kiln itself

In the heating process of the kiln, the insulation materials in the furnace will expand due to heat, so a safety gap should be reserved between each insulation material. It is important to keep enough clearance between each hearth bottom; Otherwise, the bottom plate of the furnace will bulge due to thermal expansion, directly triggering the top kiln.

2. Problems caused by kiln furnishings Kiln furnishings include push plates and saggers.

Saggar plays a bearing and protection role in the firing process of products. As long as its structure is reasonable, it has certain mechanical strength at high temperature and is not easy to break and will not trigger the top kiln. The push plate is different. It not only bears the weight of the product and sagger at high temperature, but also bears the huge pressure of the propeller in the direction of advance. The result is that after several cycles, the push plate becomes shorter in length, wider in width and even thicker in thickness. The deformation of the push plate will cause the saggar and products to burst the top of the furnace and trigger the top kiln. So high temperature resistance and low deformation rate of the push plate are very important.

3.Problems caused by temperature control element under heating element

For the high-temperature push kiln of sintered 95 porcelain, the silicon and molybdenum rods are easy to be broken; It is very difficult to clean the scrap rods and plug bricks from the high temperature kiln. Once they hook the push plate and sagger, they will trigger the top kiln. Therefore, high quality plug brick and silicon molybdenum rod are quite significant, and make sure that the silicon molybdenum rod in the corresponding temperature won’t work overload. Secondly, there should be a gap between the silicon and aluminum rod and the plug hole (do not plug it with insulation cotton) to facilitate the discharge of corrosive gas in the kiln; Furthermore, the cold end of continuous aluminum molybdenum rod is kept in good contact to avoid the formation of oxide film and burning off the cold end. The service life of the silicon molybdenum rod can be extended to the maximum extent. As for the top kiln caused by temperatures-controlled thermocouple, it was mainly caused by the corundum sand tube breaking off and sticking the saggar. As long as the operator pays attention, top kiln will not ensue.

4.Problems caused by sintering process

First of all, ensure that there is a gap (10-15mm) between the highest point of the loaded products and the lowest point of the top of the furnace. Because during propulsion, debris from the slide can get into the bottom of the push plate and push up the push plate and sagger. Second, making sure that no space is left between saggers in the forward direction. Traditionally, there should be a saggar between two push slabs, and the push plate is usually 5mm wider and longer than that of a saggar, which is actually a drawback. It seems that since the push plate keeps shrinking while the size of saggar keeps quite stable, so push plate wider and longer than saggar will be more reasonable and efficient.

In fact, it's advantageous that the push plate is wider than the sagger; However, if the push plate is longer than saggar, it will lead to the gap between saggars and once the waste silicon molybdenum rod or the wall of the kiln is rubbed against the saggar, it is easy to cause the saggar to displace, and top kiln will occur.

Corundum mullite brick is one of the refractory materials with strong friction resistance, impact resistance and abrasive resistance. The higher the abrasion resistance, the better its performance. Corundum mullite brick is commonly used in push plate kiln.