Variable input radiant heater

Abstract

A variable demand radiant heating system applies variable burner control technology to singular or mulit-burner radiant heating systems. A radiant heater consists of a burner connected to an elongated heat exchanger tube. The combustion air is supplied to the burner via blower or draft inducer. Fuel is supplied to the burner via fuel regulator. Fuel and air are mixed in burner and communicated to the inlet end of the heat exchanger tube. Spent products of combustion are expelled from the heat exchanger at the outlet end. The burner controls continuously vary gas supply pressure (volume), via a modulating gas regulator, and combustion air pressure (volume), via a variable speed blower, communicated to the burner mixing chamber, which in turn, varies the burner input on a continuous curve (not stepped or staged) within a pre-determined input range as heat demand varies.

Description

FIELD OF THE INVENTION [0001] The present invention relates to controlling the thermal energy generated by a heating system. BACKGROUND OF THE INVENTION [0002] Presently, radiant heaters and radiant heating systems most commonly operate at a single preset input; and space temperature is controlled by a thermostat by turning the heater or heating system on or off. In the early to mid 1990's, radiant heaters have been developed to operate at either of two distinct preset inputs by varying the fuel pressure communicated to the burner via a two-stage fuel regulator. One radiant burner with a two-stage operation is described in U.S. Pat. No. 5,353,986 titled “Demand Radiant Heating System” by Joseph B. Wortman. In the '986 patent, Wortman describes a radiant heater with a single fuel control capable of dual regulation. The dual regulation is limited to only providing a high or low input rate to respond to a high or low heat demand. [0003] Further advances in radiant burner input control ...

AI Technical Summary

Problems solved by technology

The dual regulation is limited to only providing a high or low input rate to respond to a high or low heat demand.

Such two-stage burners are limited to only two distinct operating inputs, offering only coarse control of varying demands and do not match the heat demand for the majority of the time.

In both patents mentioned above, there are disadvantages to varying gas volume (or pressure) to the burner mixing apparatus without also varying combustion air volume (or pressure) to the burner's mixing apparatus.

Seel does not disclose, teach or suggest any ability to control a single “unitary” style infrared heater with associated burner modulating controls and blower mounted internal to the burner housing.

Fractional horsepower DC motors are readily available in the market and can easily be controlled to vary their speed, but a DC motor is more expensive than a shaded pole motor of similar size.

In addition to the DC motor costing more, a controller is needed to send a control signal to the DC motor to vary its speed; a controller would also need to send a separate control signal to vary the gas valve, adding more cost.

That capability is not possible in current modulating or two-stage infrared heater design with single speed blowers.

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