Method for producing composite filter tube and filter element made of multilayer metal mesh and metal powders

A method for producing a composite filter tube and filter element made of multilayer metal mesh and metal powders, comprising:

• weaving wires to form a metal mesh of different mesh numbers, and then stacking up the metal mesh of different mesh numbers to obtain a layered structure on a principle that the mesh number increases from one side to the other, and number of layers of the layered structure is 1˜5;
• putting the layered structure in a vacuum furnace for 10˜30 hrs uninterruptedly sintering at 900˜1500° C. to obtain a multilayer metal mesh;
• after cooling down, taking the multilayer metal mesh out, making a metal composite layer made of metal powders with a mesh number of 100˜600 on a side with a higher mesh number of the multilayer metal mesh through electrostatic spraying or common spraying and casting method with a thickness of the metal composite layer controlled within 0.1˜0.5 mm;
• sintering the metal composite layer together with the multilayer metal mesh at 900˜1500° C., and after cooling down, a composite filter sheet and tube made of a multilayer metal mesh and metal powders with the multilayer metal mesh as a supporting layer and sintered metal powders as a filtering layer is obtained;
• taking the composite filter sheet or tube out and rolling it the composite filter sheet or tube into a tubular filter element with a forming machine;
• and
• welding a middle seam of the tubular filter element with one of an argon arc welding machine or plasma welding machine to obtain the composite filter tube and filter element made of multilayer metal mesh and metal powders.