HOT AIR HEATER

摘要

PURPOSE:To provide the hot air heater which is capable of setting oxygen shortage cut positions in strong and weak combustion conditions simultaneously by a method wherein the velocity of an air stream induced by a blower is reduced by increasing the area of passage of the induced air stream so that the primary air sucking characteristic of the heater is controlled by an ejector effect rather than by the induced air current. CONSTITUTION:A lath-net-like pressure equalizing plate 3 made of a transition metal is provided substantially parallel to the exhaust combustion gas stream at a position opposing a wire net flame hole 2 of a full primary surface combustion burner 1. A combustion chamber 4 is made narrower along the downstream side of the exhaust combustion gas on both longitudinal side surfaces thereof and is provided with an exhaust port 6 of the side surface opposite a blowout port 5. Air intake ports 7 are provided above, in front of, and at the back of, the combustion chamber 4. Further, the blower 8 is provided right below the full primary surface combustion burner 1 and the blowout port 5 is provided below the body 9 of the hot air heater. Accordingly, the stream of air induced by the blower 8 enters the heater through the air intake ports 7 but since the velocity of the air stream is reduced because of the wideness of the entire area of air intake, the primary air sucking characteristic of the heater is controlled by the ejector effect so that the rate of surplus air in the strong combustion condition is made slightly higher than in the weak combustion condition and as a result, when an oxygen shortage cut control is performed, it is possible to make the oxyen shortage cut position in the weak combustion condition equal to that in the strong combustion condition or to set its position on the safety side.