Patent ID: 7503842
Filing Date: 2009-03-17
Classification: F24C

Abstract:
1. An air-curtain-assisted exhaust method, using a receiving hood disposed above a worktable to suck and exhaust an air flow, comprising: disposing a plurality of air curtain generators on an outer edge of the worktable and vertically under the receiving hood to enclose an encircled area in the worktable; starting each of the air curtain generators to blow out the air curtain having an air blow speed, the air blow speed comprising an air blow direction and an air blow rate, the air blow rate gradually decreasing as the air curtain is far away from the air curtain generator; blowing each of the air curtain toward the opening of the receiving hood, the encircled area being smaller than the opening of the receiving hood, a vertical component of the air blow direction directing to the opening of the receiving hood; and starting the receiving hood to suck the exhaust air flow, the exhaust rate of the exhaust air flow gradually decreasing as the air flow is far away from the receiving hood, the exhaust rate at the opening of the receiving hood being larger than the air blow rate, the exhaust air flow and each of the air curtain defining a shielding space, wherein the lifting force of the air curtain blown out and the suction force of the receiving hood are in a balanced state in the shielding space to form a dividing height at a zone, such that a shearing stress generated by the air curtain under the dividing height forms an inward and downward vortex, so as to block large particles in a smoke to push the large particles towards the worktable by the inward and downward vortex and push the other smoke towards the air curtain to lift into the receiving hood, thereby improving the capture efficiency of the receiving hood in capturing and exhausting air flow, wherein the step of starting each of the air curtain generators further comprises a step of blowing out the air curtain having an angle from the air curtain generator, wherein the angle falls in 5 to 10 degrees, and is used to determine the air blow direction.