Fire Grate for Enhanced Combustion

Abstract

An improved fire grate may provide fresh oxygen rich air to a secondary combustion zone, created by the improved fire grate, of a combustion chamber where a combustion gas stream is typically oxygen starved assisting in the burning process of incompletely burned particulates and reducing other harmful emissions. A baffle plate may be introduced in the secondary combustion zone to increase a combustion chamber temperature, encourage mixing of oxygen starved air with oxygen rich air and increase a residence time of the combustion gas within the combustion chamber. These aspects of the baffle plate promote more efficient burning of the biomass / fuel. Additionally, log lighter(s) may be disposed in the secondary combustion zone to increase a temperature of the combustion chamber for the purposes of reducing harmful emissions.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not ApplicableSTATEMENT RE: FEDERALLY SPONSORED RESEARCH / DEVELOPMENT[0002]Not ApplicableBACKGROUND[0003]The improved fire grate for enhanced combustion relates to an apparatus for improving efficiency of a fireplace in relation to reduction in harmful emissions and / or heating a room.[0004]A fireplace is a structure to contain a fire for heating. The fire is contained within a firebox which defines a combustion chamber. A chimney or other flue directs combustion gas to the environment. Studies have shown that fireplaces produce a significant amount of emissions (e.g., particulate, carbon monoxide, volatile organic compounds, etc.) that is harmful to humans and the environment. These harmful emissions rise up with the combustion gas and escape through the chimney to the environment.[0005]There are three time honored principles to good combustion. They relate to time, temperature and turbulence. Time is residence time or the amount of time c...

AI Technical Summary

Benefits of technology

[0011]In addition to supplying fresh oxygen to the secondary combustion zone of the combustion chamber, a baffle plate may be disposed over the biomass / fuel to be burned. The baffle plate interrupts the flame path rising up from the biomass / fuel being burnt in the sense of velocity, direction and turbulence. The interruption of the flame path encourages larger incompletely burned harmful particulate to fall out of the combustion gas stream and may be reentrained in the combustion gas stream at an earlier point and rise back up toward the baffle plate. This allows the harmful particulate to stay within the flame path for a longer period of time (i.e., longer residence time) and promotes more complete combustion thereby reducing harmful emissions. There are generally less harmful particulate, the more time the particulate stays within the combustion chamber. Also, a more complete combustion is promoted thereby reducing harmful emissions. The baffle plate may be fabricated from a refractory material or another material having good insulation characteristics. As such, the baffle plate increases the temperature at the secondary combustion zone as well as the primary combustion zone to promote complete burning of the harmful particulate matter. It is also contemplated that the baffle plate may have a lower surface formed with a plurality of channels or other groove shapes to interrupt the flow of gas flowing up from the fuel source to the chimney. The channels or grooves formed in the lower surface of the baffle plate may be configured to route the combustion gas stream toward the sides of the baffle plate. When the gas stream from the sides of the baffle plate and the gas stream from the front of the baffle plate recombines above the baffle plate, turbulence may occur which promotes mixing of oxygen rich air with the oxygen starved air.

[0012]The baffle plate may also be tilted in the forward direction. Provided that the baffle plate also has good emissivity characteristics, the forward tilt may redirect heat from the burning biomass / fuel into the room to be heated. This may also allow the improved fire grate with enhanced combustion to be utilized in a zero clearance fireplace as well as a masonry fireplace. The baffle plate may optionally be disposed slightly forward of the fuel source to allow flames from the fuel source to rise up behind the baffle plate. This further splits up the gas stream such that the recombined gas streams above the baffle plate may be more turbulent and promote mixing of oxygen starved and oxygen rich air.

[0013]Optionally, a log lighter may be disposed in the primary combustion zone and below the biomass / fuel to be burned. This log lighter aids in rapid ignition of the biomass / fuel. The log lighter may be turned off after the biomass / fuel starts its burning process. However, it is also contemplated that the log lighter may be left on to promote efficient burning of the fuel source. Other log lighters may be disposed at other areas within the combustion chamber. By way of example and not limitation, one or more log lighters may be disposed in the secondary combustion zone of the combustion chamber. As discussed above, the baffle plate redirects the combusted gas stream having harmful emissions therein. The log lighter disposed in the secondary combustion zone may increase temperature in the secondary combustion zone. The increased temperature aids in completing the burning process of the biomass / fuel and reducing harmful emissions.

Problems solved by technology

Studies have shown that fireplaces produce a significant amount of emissions (e.g., particulate, carbon monoxide, volatile organic compounds, etc.) that is harmful to humans and the environment.

These harmful emissions rise up with the combustion gas and escape through the chimney to the environment.

During operation of the fireplace, the biomass / fuel being burned consumes oxygen in the surrounding area.

The biomass / fuel being burned produces harmful emissions because the residence time of the combustion gas in the combustion chamber may be too short to allow the biomass / fuel to completely combust.

Additionally, the biomass / fuel being burned may not completely combust because the temperature within the combustion chamber may be too low.

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