Construction of Refractory Castable

During the construction of refractory castable, special attention should be paid on pin welding, asphalt brushing, stirring of castable with water, making and fixing of mould, vibration and ramming of castable, demoulding, sizes’ and measuring points’ accuracy, etc. http://www.yilongrefractory.comDo construction strictly as material manufacturer and boiler works required.

1. Installation of Pin and Claw Nails

Reinstall the pins missing for any reason and the pins in the area of heating surface composite melding junction before hydraulic pressure. Lengthen and reinstall the pins properly in coal mouth, material return mouth and upper inflection point of air duct furnace so that meets the required density of pins. Brush all the pre-buried metal parts and claw nails with asphalt paint (thickness > 1mm) or cover them with combustibles before casting.

2. Dosing and Stirring of Castable & Water

The dosing of castable and water should be done strictly as the instructions of material manufacturer. The water should be clean, such as drinking water, ph 6-8. The mixer should be clean forced action mixer, and clean it for the next time using. Pay attention on the adding order of castable and water and its stirring time, adding water freely and prolonging of stirring time are forbidden. The water and castable should be mixed evenly and stirred till smooth. Carry away the mixed casatble immediately after stirring, the castable poured out from stirring tank is disallowed to be poured into the tank and stirred again. Clean the tank after every construction for the next using, record the amount of water and castable, and the stirring time.

3. Checking Before Making Template

Check carefully whether the pin, hook nail and strutting part conform to the drawing, whether all the re-welding and is done and firm, whether the temporary metal parts have been cut off. Check whether the metal parts which should be brushed with asphalt paint meet the requirement, whether the casting place is clean, any other unrelated materials are forbidden to appear. For easy demoulding, a thin tier of partition (such as used oil) can be brushed in the mould. There can not be gaps between each two templates to avoid castable leaking out, so that also convenient for mould releasing. The refractory castable should be used up in 30 minutes after stirring, and should be casted to the required thickness in 1 time. Ram the castable till tight. For the too thick parts, cast tier by tier, while casting the upper tier, vibration bar can not touch the lower casted tier.