Residential fireplace insert system improvements
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This CIP titled “Residential Fireplace Insert System Improvements” involves an improvement in the efficiency of the slide-in “Residential Woodburning Fireplace Insert System”, formerly application Ser. No. 11/507,343 filed Aug. 21, 2006, (now Pat. No. 7,509,954) wherein the heat output and fuel consumption are improved by controllably shutting off free air flow into the the combustion chamber by using a framed panel of heat-tolerant plastic film (as an alternate to using the glass doors) at the surround door location, then controlling the generated heat and fuel combination by carefully injecting just the proper ratio of the oxygen-to-fuel necessary for controlling both the heat output rate and fuel consumption parameters which include soot and creosote control improvements.

Schreffler, Robert Zerby (Chester, VA, US)
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International Classes:
F24B1/189; F24B13/00
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Primary Examiner:
Attorney, Agent or Firm:
Robert Z. Schreffler (Chester, VA, US)
1. I claim an improvement in the art related to the parent application Ser. No. 11/507,343 filed Jun. 18, 2008 wherein a modification to the said parent application is so effective that radiated heat transfer is enhanced and controlled by the ability to shut off free normal oxygen combustion air intake into the combustion chamber by using a thin rigid metal frame with a taut, leakproof, stretched temperature-tolerant plastic film panel option in place of the usual glass closure doors, and using a plurality of air purge inlets located immediately behind and around the surround area to supply and control the necessary optimum fuel/air ratio combustion combination, the drilled said air purge inlets strategically arranged in the air pressure supply tubing constraint coming from the plenums which assist in the formation of a swirling turbulent inlet air action in near proximity to, directed generally parallel to, and to the rear of the film plane, additionally using one or more soot controls or similar smoke deflector means to prevent as much smoke deposit or similar accumulation as possible on the said temperature-tolerant plastic film panel and/or door closure, including a dome light centered over the said combustion area to render aid in observing and making possible fuel/air adjustments based on burning and flame pattern characteristics.



This Sub-Spec Contains No New Matter

This application is a Continuation-In-Part to: “Residential Fireplace Insert System”, (Pat. No. 7,509,954).


These improvements relate to the normal advancements, innovations and improvements discovered during the almost three-year period the parent application was wending its way through the examination process. In few words these discoveries center around a modification to the bifold glass door closure area, supplementary air controls within the heat combustion area, modification for soot and creosote control and a dome light mounted to the under-underside of the tubing air manifold for close observation of needed fine adjustments.


The “Continuation-In-Part” will be described with reference to the Parent application Ser. No. 11/507,343 filed Jun. 6, 2008, but persons skilled in the art will recognize the continuation in part where improvement in the art is effected.


(Not Applicable)

The applicant knows of no effort by any fireplace “surround” door manufacturer or heating insert manufacturer to try and consolidate their areas of expertise for their mutual benefit. There is little or no background work done or on record. The people who manufacture and market fireplace inserts do not, or have not, ventured into a “tie-in” effort related to the screen or glass door closure area where the two, but separate, products could have been integrated. In a similar manner fireplace screen or closure producers have not cared to venture into the fireplace insert area. Each group tended to develop and try to expand its own separate chosen field of expertise. Hence, no prior art record or knowledge is apparently known or available to the applicant or to the public.


The purpose of using a fireplace insert is to generate sufficient room heating by burning wood, coal, briquettes, etc. for fuel in an available standard fireplace. The end-goal is to get the longest consistant, sustained “fireheat” by controlling the flame intensity and heat duration using the minimum of fuel to do it. During the nearly three-year period of time the parent application was going through the examination period, testing and evaluations were constant challenges to obtain the optimum target conditions for fireplace efficiency. Early on, it became evident that the “standard” door closures of the industry were woefully inefficient. All models “leaked” air volumes into the combustion chamber with no real heat or fuel consumption controls. Conclusion; Shut off all air supply sources past the “surround” enclosure. This was done using a rigid, very close-fitting metal frame with a thin temperature-tolerant plastic film stretched tightly across it in order to effectively shut off the air supply past the door closure location. Next, restore the air flow necessary for combustion by injecting enough “metered air” into the combustion area thus permitting a suitable consistant oxygen burning ratio for consuming the fuel. These injectors “air purges” consist of a plurality of small holes drilled into the tubing-confined air passage system carrying air under pressure, and located at strategic peripheral locations to supply and direct pressured air in a swirling plane parallel to, and directed generally toward, the center of the door closures (or plastic film panel). The peripheral locations include the holes in the tubing air manifold located above in the dome area.


It is necessary to devote time and understanding to the simple subject of “soot” (including its cousin creosote) and how to modify or eliminate it. Now, into the area of physical chemistry (Phys/Chem). When a consumable fuel burns, the resultant soot (carbon) combines with the moisture generated by the heat of fusion (combustion) and forms a globule or “suspension” of carbon and water. This problem tends to be resolved with the careful placement of drilled holes called “air purges”. The planned peripheral air insertions were calculated to create a “swirling confluence” of air very close to the rear surface of the door closure (or film) plane in order to keep the smoke generated by the fire constantly churning. This effort tends to keep smoke away from the said door (or film) surface as long as possible and helps drive off the moisture in the soot globule. Therefore, the longer the churning of heated air, the better is the chance the moisture can be driven off and the dried-out carbon dust particle component might be exhausted up the chimney. If the globule hits a cooler, smoother surface (glass door) before the moisture is evaporated, the moisture globule will “wet-out” and spread. If this occurs and the water evaporation takes place, the result is a “baked-on” soot deposit which is quite difficult to remove. On the upper-rear portion of the surround a soot deflector of thin metal sheet is attached. The combined air flow volumes coming from all the air purges (front tubing portion plus air manifold above), assisted by the said soot deflector plate, establishes a swirling “air knife” barrier to help control soot deposit. Not to be neglected is a dome light, a valuable aid to “high-light” smoke patterns above the flames which can indicate needed draft control adjustment; the dome light is also a very welcome housekeeping aide as well.


FIG. 1 is a top plan view of the fireplace insert and the manifold 16 properly identified.

FIG. 2 is an exploded front quarter-view of the fireplace insert in perspective with important modifications added and identified.


FIG. 1 is a plan top view identifying manifold 16.

FIG. 2 is an exploded front quarter-view of the fireplace insert FIG. 1. The hinged door closures 10 are mounted onto the surround 11 in a customary way and can be completely opened wide as indicated. A thin rigid metal frame 12, on which a temperature-tolerant plastic film 13, is stretched and mounted has nearly the same overall dimensions as the said hinged door closures 10 and is able to be stored behind the closed said door closures 10. Attached to the back side of the said surround 11 is a soot deflector 18, a narrow, thin-gage panel of metal

attached to shield the top three or four inches of the said surround 11 opening from soot accumulation. The said soot deflector 18 and deflector 19 help generate a “swirling” air purging action with assistance from a plurality of small openings called air purges 17. These said air purge holes 17 are especially located in the tubular means 15 which contain moving columns of air under pressure originating from the plenum source 14. The especially planned and located said insertion holes 17 create a swirling confluence of air directed very closely to, and parallel with, the plane of the said door closures 10 (or the said film closure 13) to keep the smoke churning until the moisture in the soot has evaporated and the dried-out soot particles are dispersed up the chimney. On the underside of the said air manifold 16 is a lamp receptacle 20 with a protective cover 21.