Microwave drying of honeycomb foam ceramic filter plate

Honeycomb foam ceramic filter is widely used in casting industry, its function is to make the honeycomb hole of turbulent and turbulent metal liquid gold foam ceramic become smooth and even and clean, so as to greatly reduce the rejection rate of casting caused by non-metallic inclusions and save production cost.

Honeycomb Ceramic foam filter (CFF, namely Ceramic FoamFilter) polyurethane (pu) foam as the carrier, is immersed in the Ceramic powder, binder, sintering agent, suspending agent made of pulp, squeeze out the excess paste. The ceramic slurry is uniformly coated on the carrier skeleton to form the embryo body, which is then dried and sintered at high temperature. This process, also known as organic foam impregnation method, is a mature production process in the current domestic.

The problems of low strength and hard drying after extrusion of honeycomb foam ceramics seriously restrict the wide application of foam ceramics. In recent years, microwave drying technology has been applied to foam ceramics, which can solve the problems of low strength and difficult drying. Honeycomb foam ceramics due to the formation of more water, more pores, and the body of the blank pore wall is very thin.Therefore, the use of traditional methods will lead to uneven heating, extremely difficult to dry. Due to the poor thermal conductivity of honeycomb ceramics, its drying process requirements are particularly strict (such as the honeycomb foam ceramics used in environmental protection, automotive, heat storage, infrared radiation combustion board and so on). If the drying process is not well controlled, it will easily lead to deformation and affect porosity and specific surface area.

In order to improve the production efficiency and product quality, improve the factory image, solve the problems of slow drying and bad shaping of honeycomb foam ceramics after impregnation, a new material factory in ningjin, dezhou brought samples to our factory for inspection and experiment.

The water content of the soaked sample is 15% ~ 20%. The customer intends to use microwave equipment to remove 10% of the water, so as to finalize the ceramic body, facilitate the movement to the next process, and improve the yield.

The experiment was conducted with 20kw tunnel-type microwave equipment. The power was 100%, the temperature was set at 80 degrees, and the transmission was 50HZ. The impregnated ceramic foam filter was put in to conduct microwave drying.

The results show that microwave drying can reduce the moisture content of honeycomb ceramic body by about 10%.Ceramic filters set well.

At present, the drying methods of honeycomb foam ceramics include natural drying method, far-infrared drying method, steam drying method, microwave drying method and so on. The microwave drying method can overcome the problem that the surface drying speed is inconsistent with the internal drying speed.At the same time, the problems such as low strength before drying, difficult handling and easy cracking after drying are solved.

The drying process has a great influence on the yield of honeycomb foam ceramics. Most honeycomb foam ceramics are formed by wet extrusion, and the raw materials are usually added with 15% ~ 20% water. The interior of honeycomb ceramics is divided by many lattice-like partitions. No handling and subsequent processing after extrusion.Without rapid drying, the original shape will deform.

According to customer requirements, we provide customers with two 30kw air-cooled microwave equipment, and each equipment can process more than 4000 ceramic filter pieces per hour, meeting customer requirements of large output.

By analyzing the drying process of honeycomb ceramics, hot air drying and microwave drying can also be combined. Combine the advantages of the two to achieve the purpose of optimizing energy conservation.