4. Factors affecting the spraying of alumina foam ceramic filter plate
Alumina foam ceramics are classified into three categories of foam ceramic filter plate (alumina, carbonization
Silicon, zirconia) is an important branch and also the earliest one used
Similar foam ceramics are widely used in aluminum and its alloy casting industry. order
Previously, with the continuous improvement of performance requirements for aluminum and aluminum alloy products
Filtration also constantly puts forward new requirements, requiring high purity and impurity
The casting characteristics such as less aluminum liquid flow and gentle flow rate can achieve the cast aluminum products
It has good physical and chemical properties and machining properties, so as to meet the more stringent requirements
Use conditions and achieve the purpose of extending the service life of aluminum products.
Each technological process of foam ceramic production affects the quality of foam ceramic filter plate products
The quantity has an impact, among which the key process ingredients, sponge processing and sintering have an impact on the product
The quality has the greatest impact [61. The spraying process mainly affects the product’s quality and appearance. At the same time,
It also has a certain effect on endoplasm.
4.1 Size of slurry
The size of the slurry determines the dispersion of the sprayed slurry
Fine, the better the dispersion of the sprayed slurry, the more uniform the slurry sprayed on the green body
Uniform. At the same time, the finer the size of the slurry, the smaller the nozzle wear. The large size of slurry
It also determines the sintering condition of the product surface. 400 is generally used in production
The slurry with mesh residue of less than 0.5% shall be used as the spraying material for the porous ceramic filter plate
The sintering temperature of the formula is lower than that of the green body.
4.2 Water content of the slurry
The water content of the slurry is the direct factor that determines the consistency of the slurry. Consistency
The size directly affects the shotcreting effect. For the spraying process after sizing
In general, the water content of the slurry should not be too low, otherwise, there will be blind holes after spraying
The slurry effect is also poor, and its water content is generally controlled at 35%. 40%. For the spray process after drying, the surface of the green body is dry and hard, and it has a great adsorption effect on the spray material with large consistency. Therefore, the water content of shotcrete shall be controlled low
The effect of coating on the surface is better, and its water content is generally controlled at 25%~
35％。 When the water content of the shotcrete is low, it is necessary to select the air pressure with higher pressure
Machines and nozzles with a larger diameters can achieve the good spraying effects.