DES MOINES, Iowa (AP) -- A man has received a $500,000 federal grant to mass produce his invention, a machine that removes the odor from hog manure. The Tempest dryer, developed by Loran Balvanz, is designed to help solve water pollution, odor and noxious gas problems in the hog industry. Balvanz said that because his invention separates water from the solids in manure, it can solve air and water quality problems. The Tempest removes water from manure by spinning it at a high speed. The water is vented through the top of the dryer and vaporizes in the outside air....