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Ground warming heater and method and system relating theretoGround warming heater and method and system relating thereto description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070176011, Ground warming heater and method and system relating thereto. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO RELATED APPLICATION [0001]This application claims priority from Canadian Patent Application No. 2,534,488 filed Jan. 30, 2006 entitled System and Apparatus for Safely Coupling Multiple Ground Thawing Heaters. FIELD OF THE INVENTION [0002]The present invention relates to a ground warming heater and more particularly to a ground warming heater having an improved torch and which may be coupled together in a system comprising a plurality of such heaters fuelled from a minimum number of fuel supplies. BACKGROUND OF THE INVENTION [0003]It is known to thaw frozen ground so as to ease excavation such as for maintenance or repair access to buried utilities. A variety of patents discuss prior art heaters including U.S. Pat. No. 6,408,843 issued to Olson, U.S. Pat. No. 5,441,038 issued to Ohmann, and U.S. Pat. No. 5,033,452 issued to Carriere. [0004]These prior art apparatus and others typically use propane as fuel and generally use one propane tank for each heater. A multiplicity of fuel lines are required and are exposed to vandalism and general damage. [0005]There is a need for a safe and efficient system of ground warming heaters. [0006]As stated in U.S. Pat. No. 6,408,843 to Olson, a ground heater is used to thaw ground to depths in the order of three feet during the cold winter months which will allow individuals to excavate soil from previously hard frozen earth to gain access to utilities. [0007]Some of the disadvantages of the prior art heaters include convenience and safety factors. Some ground heaters utilize burners which are removably installed and which may be easily dislodged by accidental contact with the fuel lines. Multiple burners have multiple lines which add to clutter and risk of damage. Multiple burners enhance the risk of one blowing out and discharging unburned fuel while the other continues to act as an ignition source. Other heaters are poorly insulated resulting in hot surfaces. [0008]Further, for large areas requiring thawing, multiple heaters have been provided however each being supplied with their own fuel supply, or with a header distributing a plurality of flexible lines, further elevating the risk of damage, numbers of connections and access by vandals. SUMMARY OF THE INVENTION [0009]In summary the present invention may be characterized in one aspect as including a ground heater for thawing or otherwise warming the ground and a method of using the heater, wherein the heater includes an insulated housing enclosing a primary fuel line within the insulation, an ambiently aspirated hollow heating tube running the length of the housing and extending substantially entirely through a cavity defined by an inner surface of the housing and wherein the cavity defines an opening into the housing, a torch head mounted in a torch head housing and having a fuel line thereto branched from the primary fuel line and mounted in fluid communication with an upstream end of the heating tube, the opposite downstream end venting to atmosphere so that a flame from the torch head extends along the interior of the heating tube to radiantly heat the cavity and a ground surface in registry with the opening. [0010]The cavity may extend along substantially an entire length of the housing, and the opening may be in a bottom of the housing and also extend along substantially the entire length of the housing. The heating tube may extend through the cavity and along the entire length thereof so as to extend through opposite end walls of the housing. The torch head housing may be cylindrical or tubular so as to conveniently mount in registry with or to the upstream end of the heating tube in fluid communication therewith. [0011]The primary fuel line may be mounted so as to extend along a sidewall of the housing from an upstream end wall to a downstream end wall. The branch fuel line may extend from the primary fuel line across the upstream end wall to an upstream end of the torch head housing. [0012]The torch head may include a fuel metering orifice and a bore extending therethrough downstream of the orifice. At least one aspirating aperture may be provided in a sidewall of the torch head in fluid communication with the bore downstream of the metering orifice. The torch head may be mounted substantially concentrically in, so as to be supported by, the torch head housing. The torch head housing includes a perforated support at a downstream end thereof. A flame holder end of the torch head is mounted to the support and adjacent the downstream end of the torch head housing so as to dispose a flame seated in the flame holder end downstream along the heating tube towards the downstream end of the heating tube to thereby discharge exhaust gases of combustion therefrom and to draw an ambient airflow into the upstream end of the torch head housing, over the torch head and through the at least one aspirating aperture and through perforations or apertures in the perforated support so as to flow into the upstream end of the heating tube for improved combustion of the fuel/air mixture at the igniter immediately adjacent the flame holder end of the torch head. [0013]In a preferred embodiment the perforated support includes at least one rigid member on which the torch head is mounted within the torch head housing, wherein the rigid member defines at least one breathing aperture, herein to include perforations or other apertures, where the at least one breathing aperture extends substantially entirely around the downstream end, that is, the flame holder end of the torch head in a plane substantially orthogonal to a direction of flow of the ambient air through the torch head housing, and wherein the torch head housing and the torch head define a substantially annular breathing channel therebetween extending in the direction of flow and in registry with the at least one breathing aperture. [0014]In one preferred heater embodiment the at least one breathing aperture includes a pair of breathing apertures oppositely disposed on opposite sides of the downstream end of the torch head. The at least one breathing aperture may consist solely of a pair of breathing apertures. The at least one breathing aperture may include a pair of opposed facing substantially semi-circular slots disposed substantially symmetrically on the opposite sides of the downstream end of the torch head. [0015]In one embodiment an outside diameter of the breathing channel may be substantially equivalent to an inside diameter of the heating tube. Further, the torch head housing may be cylindrical, and may include a concentrically nested pair of cylinders, wherein the torch head is mounted concentrically within an inner cylinder of the pair of cylinders. The upstream end of the heating tube may be of greater diameter than a throat and a mid-section of the heating tube extending between the upstream and downstream ends of the heating tube, so that an outer cylinder of the pair of cylinders may mate telescopically into or register against the upstream end of the heating tube. [0016]In a preferred embodiment the at least one aspirating aperture includes a radially spaced apart array of apertures radially spaced around the longitudinal axis of the torch head for radially aspirating air radially into the bore to mix with fuel flowing under pressure through the metering orifice and into the bore. Advantageously a perforated flame holder plate is mounted across a downstream end of the bore in the flow of the mixture of fuel and air exiting the bore into the upstream end of the heating tube. The igniter may be mounted adjacent and downstream of the flame holder end of the torch head. [0017]A system of such ground heaters may advantageously include a plurality of the ground heaters mounted one to another in series along the primary fuel line so as to be spaced apart along the primary fuel line. Further, the plurality of heaters may include at least a first plurality of the heaters mounted in series along a first primary fuel line and a second plurality of heaters mounted in series along a second primary fuel line, wherein the first and second primary fuel lines are in parallel fluid communication for operating their respective heaters in parallel. BRIEF DESCRIPTION OF THE DRAWINGS [0018]With reference to the drawings wherein similar characters of reference denote corresponding parts in each view: [0019]FIG. 1 is an underside perspective view from the upstream end of a heater according to one embodiment of the present invention. Continue reading about Ground warming heater and method and system relating thereto... Full patent description for Ground warming heater and method and system relating thereto Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Ground warming heater and method and system relating thereto patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Ground warming heater and method and system relating thereto or other areas of interest. ### Previous Patent Application: Thermostatic valve Next Patent Application: System for heating liquids Industry Class: Heating systems ### FreshPatents.com Support Thank you for viewing the Ground warming heater and method and system relating thereto patent info. 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