Method for the production of a refractory filter
Method for the production of a closed edge refractory foam filter, by providing a reticulated foam substrate having at least one first surface for forming a side face of the filter and two opposed second surfaces for forming the through-flow faces of the filter, applying a liquid including an organic coating component to the first surface, solidifying the organic coating component to form a filter precursor having a continuous volatilizable coating on the first surface, and impregnating the filter precursor with a slurry containing particles of a refractory material, a binder and a liquid carrier. The impregnated filter precursor is dried and fired to form the filter having a closed edge.
1. A method for the production of a closed edge refractory foam filter, comprising:—
providing a reticulated foam substrate having at least one first surface for forming a side face of the filter and two opposed second surfaces for forming the through-flow faces of the filter;
applying a liquid comprising an organic coating component to the first surface;
solidifying the organic coating component to form a filter precursor having a continuous volatilisable coating on the first surface;
impregnating the filter precursor with a slurry comprising particles of a refractory material, a binder and a liquid carrier; and
drying and firing the impregnated filter precursor to form the filter having a closed edge.
2. The method of claim 1 , in which the reticulated foam substrate has a porosity of from 5 to 60 pores per linear inch (ppi).
3. The method of claim 1 , in which the liquid is applied to all of the first surfaces of the reticulated foam substrate.
4. The method of claim 1 , in which the liquid is applied by spraying.
5. The method of claim 1 , in which the volatilisable coating is flexible.
6. The method of claim 1 , in which the organic coating component is selected from the group consisting of polyurethane, polyvinyl chloride (PVC), polyester (PET), and polystyrene.