Abstract: A porous ceramic gas burner constructed from ceramic blocks associated with each other to form a hollow chamber to receive naturally aspirated gas and air mixture from a venturi with the ceramic blocks including a plurality of small holes enabling passage of the gas and air mixture to the outer periphery of the burner for ignition and combustion with the structural characteristics of the small holes preventing flashback of the flames even though the velocity of the air and gas mixture is less than the flame propagation rate thereby reducing the noise level of the burner by reducing the velocity of the air mixture passing through the burner. The burner is associated with a forced air heater including a fan and a duct associated therewith to direct forced secondary air over the periphery of the burner with the periphery of the burner including a surface generally parallel to the flow path of the secondary air and the holes in the burner being perpendicular to the flow path of the secondary air.

Abstract: A compact forced air heater comprises a combustion chamber mounted in a housing, a burner module mounted across a back open end of the combustion chamber adjacent a back wall of the housing for producing heated air in the combustion chamber, an air intake in a front wall of the housing, and a high speed (3000 rpm) forced air blower mounted between the combustion chamber and the housing front end wall. The burner module includes a flameholder plate having a central primary air hole and circular rows of staggered secondary air holes surrounding the primary air hole. A flamespreader plate is mounted on the flameholder plate opposite the primary air hole, and an elongated right-angle burner tube, having a flattened locating-and-orienting end and at least one burner orifice in a sidewall of the tube, is located on an opposite side of the flameholder plate with the burner orifice aligned with the primary air hole and the flamespreader plate. An ignitor and a thermocouple are also mounted on the flameholder plate.

Abstract: A forced air heater (10) includes a removable burner module (26) in which all of the burner components are mounted on a common support plate (42) to facilitate mounting of the burner module in the heater and removal of the burner module from the heater for servicing. An elongated burner tube (46) has a closed flattened end (50) receivable in a location-and-orienting bracket (76) to locate a single burner orifice (52) in a sidewall of the tube in proper position with respect to a pancake flame-spreader plate (78). A gas valve (44) and ignition device (58) also form part of the burner module 26. A combustion chamber (24) is of essentially box-shaped construction, with one open end (36), and includes an inclined baffle plate (40) which enhances mixing of combustion products and intake air in the chamber. A forced air blower (28) is mounted adjacent a heated air discharge opening (36b) of the combustion chamber (24).

Abstract: A portable forced air heater having a flame holder positioned between a blower and a combustion chamber. The flame holder has a plurality of holes or openings formed therein to stabilize and control the combustion process within the combustion chamber. The holes or openings are arranged in such manner that the percentage of total flame holder area devoted to holes or openings increases at a general uniform rate as the distance from the center of the flame holder increases. The flame holder also has openings formed therein to support various components of the heater in order to provide a relatively small compact forced air heater.

Abstract: A heater having a water injection system for increasing the water vapor content of the atmosphere and reducing the temperature of the exhaust products of the heater. A nozzle assembly located in the stack of the heater injects a fine spray of water into the hot exhaust gases and onto the hot stack surface.

Abstract: A safety control system for use on a heater which shuts off the heater fuel supply if the heater flame is not present within a predetermined time after initial ignition is attempted or after re-ignition is attempted should the flame be extinguished. A flame sensor which makes use of the electrical conductivity of the flame is employed with a solid-state switch, silicon controlled rectifier, and time delay relay to provide a fast response control circuit for shutting off the fuel supply valve in the absence of flame after a predetermined delay.