초록 ▼

Sintered fiber filters are provided that can afford high particle capture efficiency and/or low pressure drop during operation, and are useful in applications such as semiconductor processing. The shape of at least a portion of the individual fibers (e.g., metal fibers) used to make the filter have

Sintered fiber filters are provided that can afford high particle capture efficiency and/or low pressure drop during operation, and are useful in applications such as semiconductor processing. The shape of at least a portion of the individual fibers (e.g., metal fibers) used to make the filter have a three-dimensional aspect, which allows for a low packing density and high porosity filtration media. Certain filters have a cylindrical or tube-like shape with tapered ends of higher density. Methods of making such filters, for example, using axial pressing, are also described.

대표청구항 ▼

1. A method of making a sintered fiber filter element, the method comprising: (a) providing a mold having a cylindrical cavity with an end closure at one end of the cylindrical cavity, and a fill cap at another end of the cylindrical cavity, wherein the fill cap is removable to provide an open end,

1. A method of making a sintered fiber filter element, the method comprising: (a) providing a mold having a cylindrical cavity with an end closure at one end of the cylindrical cavity, and a fill cap at another end of the cylindrical cavity, wherein the fill cap is removable to provide an open end, and a core rod movably sealed in said end closure and extending coaxially within said cavity;(b) orienting said mold vertically with said open end disposed upwardly;(c) introducing fiber and liquid into said cavity through said open end substantially radially evenly about said core rod;(d) creating a pressure differential in the mold to expel liquid from the mold;(e) applying pressure to said mold and thereby to said fiber in said cavity, whereby said fiber coheres to form a substantially tube-shaped structure;(f) removing said substantially tube-shaped structure from said mold;(g) sintering said substantially tube-shaped structure to obtain a porous tube-shaped sintered filter element having a first end and a second end; and(h) densifying the ends of said porous tube-shaped sintered filter element. 2. The method of claim 1, wherein densifying the ends of said porous tube-shaped sintered filter element includes rotating said porous tube-shaped sintered filter element while applying a roller burnisher tool to the ends of said porous tube-shaped sintered filter element. 3. The method of claim 1, wherein densifying the ends of said porous tube-shaped sintered filter element includes rotating said porous tube-shaped sintered filter element while applying a tool to at least one end of said porous tube-shaped sintered filter element, and wherein the tool is designed to provide a gradual transition from a center portion of the filter element to an end of the porous tube-shaped sintered filter element. 4. The method of claim 1, wherein the fiber includes metal fiber. 5. The method of claim 4, wherein the metal includes stainless steel. 6. The method of claim 1, wherein the liquid includes water. 7. The method of claim 1, wherein the end closure is removable. 8. The method of claim 1, further comprising attaching a vacuum line to the mold, and opening the vacuum line while introducing fiber and liquid to the cavity. 9. The method of claim 1, further comprising drying said tube-shaped structure before sintering said tube-shaped structure. 10. The method of claim 1, further comprising welding an end of said porous tube-shaped sintered filter element to an end cap. 11. The method of claim 1, further comprising welding an end of said porous tube-shaped sintered filter element to a filter end fitting or housing. 12. The method of claim 1, further comprising applying pressure to the porous tube-shaped sintered filter element to control the density, shape, or length of the structure. 13. The method of claim 1, further comprising vibrating the mold. 14. The method of claim 1, wherein creating a pressure differential in the mold to expel liquid from the mold comprises applying a vacuum to the mold. 15. The method of claim 1, wherein creating a pressure differential in the mold to expel liquid from the mold comprises supplying pressurized gas to the open end of the cavity.