Fuel ignition systems

Abstract

Disclosed is a furnace adapted for burning solid materials, including biomass fuels. The furnace comprises an igniter having a heating element carried by a ceramic core and disposed within a ceramic cover tube for directing air at fuel disposed within the furnace for the purpose of igniting the fuel. Also disclosed is an igniter having a heating element carried by a ceramic core and disposed within a ceramic cover tube for directing air at fuel disposed within the furnace for the purpose of igniting the fuel.

Description

FIELD OF THE INVENTION [0001] The present invention is related to furnaces, in particular furnaces for burning biomass and to igniters for such furnaces. BACKGROUND OF THE INVENTION [0002] Biomass is gaining popularity as a replacement fuel for fossil fuels such as coal, natural gas and petroleum-based products such as fuel oil. The energy stored in a biomass fuel ultimately comes from the same source as fossil fuels, solar energy. The process of photosynthesis captures the solar energy and stores it by creating carbon-carbon bonds. This stored energy can be released by burning or oxidation, breaking the bonds and generating gaseous carbon typically in the form of carbon dioxide. The burning of fossil fuels, therefore, releases carbon into the atmosphere that has otherwise been stored under the earth's surface for millions of years whereas burning of biomass such as wood, corn and other plant material releases gaseous carbon into the atmosphere that was removed only recently through...

AI Technical Summary

Benefits of technology

[0009] The present invention is directed toward an apparatus for burning solid fuel, wherein the apparatus has a burning chamber for receiving fuel in communication with a fuel inlet, an air inlet, an exhaust outlet and at least one igniter and the at least one igniter includes at least i) an inlet block defining a channel therethrough, the inlet block including structure defining first, second and third orifices in communication with the channel; ii) a seal disposed within the second orifice; iii) a ceramic cover tube having first and second ends, the first end of the ceramic cover tube operably secured in the first orifice to the inlet block and the second end in communication with the burning chamber; a ceramic core disposed within the ceramic cover tube, v) a heating element carried by the core, and vi) electrical leads in electrical communication with first and second ends of the heating element, the electrical leads passing through the seal. The apparatus further includes a control circuit connected to the electrical leads, a gas source in communication with the third orifice for forcing a gas through the channel, into the ceramic cover tube, and out through the second end of the ceramic cover tube into the burn pot assembly. The apparatus may also have a fuel feed mechanism in communication with the fuel inlet. The fuel to be burned in the apparatus may be a biomass fuel and may be dried, shelled corn. In another embodiment, the ceramic cover tube of the at least one igniter is constructed from a ceramic such as alumina, mullite or corderite. In yet another embodiment, the ceramic core of the at least one igniter is constructed from a ceramic such as alumina, mullite or corderite. In some embodiments, the ceramic cover tube has an outer diameter of about 0.5 inches. In other embodiments, the heating element of the at least one igniter is rated between 300 and 600 watts at 120 volts AC and may be rated at 500 watts at 120 volts AC. In yet another embodiment, the gas source delivers a gas flow of 25-30 SLPM at 2

Problems solved by technology

A number of hurdles exist to utilizing biomass fuels on a widespread basis.

For example, storage and conveyance of biomass fuels to the furnace can be a burden that may put off many potential users of biomass fuels.

Prior art igniters have used materials that do not provide for optimum durability and conveyance of heat to the fuel.

Images