TECHNICAL FIELD
This disclosure relates to temperature control appliances and more particularly to an appliance for selectively providing radiant heat and evaporative cooling in, for example, a gathering area.
SUMMARY
Disclosed herein are implementations of an appliance structure adapted to be suspended over a gathering area such as an outdoor restaurant table and capable of selectively providing radiant heating in cool weather conditions and evaporative cooling in warm weather conditions, wherein means are provided for selecting the operating mode while ensuring that both heating and cooling cannot be put into effect at the same time. In addition, features are provided to enhance the radiant heating effect and to provide safety in operation with combustible fuels such as natural gas and propane.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to-scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity.
FIG. 1 is an end view in section of a housing for the appliance structure adapted to be suspended over a gathering area;
FIG. 2 is perspective view of the housing from below showing a burner compartment and smaller control compartment;
FIG. 3 is a system block diagram showing the infrared burner and the misting nozzle array as well as control components;
FIG. 4 is a cross-sectional view of a preferred burner assembly;
FIG. 5 is an exploded view of the burner assembly; and
FIG. 6 is an exploded view of the various components of the burner system including portions of the burner structure shown more completely in FIG. 5.
DETAILED DESCRIPTION
Referring first to FIGS. 1 and 2, there is shown a generally rectangular stainless-steel housing 50 having a gabled roof or canopy 52 which separates from the lower body of the housing 50 along the outside edges to provide venting for conductive heat generated by a porous foam metal radiator element 12 mounted within the housing as better shown in FIGS. 3 and 5. Misting nozzles 14 are also shown attached along both sides of the housing 50 as better illustrated in both FIGS. 2 and 3.
As shown in FIG. 2, the heat radiator element 12 is mounted to other elements of a generally cylindrical burner assembly within the larger compartment in the housing 50 which is open to the bottom to permit the radiant energy from the semi-cylindrical foam metal radiator element 12 to radiate heat downwardly and outwardly from the housing toward a gathering area over which the housing is mounted. The housing may have a glass cover 60 or a slatted grille on the bottom of the burner compartment, which cover is transparent to infrared radiation. The right-hand portion of the housing structure 50 shown in FIG. 2 is preferably provided with a lockable hinged door to prevent access by unauthorized persons and provides mounting space for valves and control elements which are best located in proximity to the burner for reasons that will be apparent to persons skilled in the art. An exception is the manual control device 18 shown in FIG. 6 with a manual switch element 19 for selecting between off, heat and misting modes of operation; i.e. that device is preferably located remotely from the housing 12 so as to be accessed only by authorized persons.
Referring now to FIGS. 3-6, the burner is of overall cylindrical configuration and comprises a semi cylindrical plenum 38 of stainless steel adapted to receive in connection therewith and partially therein a venturi tube 32 which receives air pumped in by a fan 26 which is activated by the control board 20 when the mode selector device 18 is switches to the heat mode. Fuel is also supplied to the burner by means of a gas valve combination 28 and a modulator 30 which is opened proportionally to the heat level selected to supply fuel such as natural gas and/or propane to the burner structure in the selected volumes.
Describing the burner in more detail, with reference to FIGS. 2, 3 and 4 the semi-cylindrical plenum element 38 adapted to receive partly therein a Venturi tube 32 through which an air-fuel mixture is introduced when heat mode is selected. How the Venturi tube fits into the plenum 38 is best shown in Applicants U.S. Pat. No. 11,047,569 the disclosure of which is incorporated herein by reference. That patent also illustrates an alternative burner configuration that can be used.
The assembly shown in the Figures further includes a semi cylindrical, perforated stainless steel distribution element 40 with perforations arranged in staggered rows over the entire body of the element to evenly distribute a fuel air mixture which enters the plenum 38 by means of the venturi tube 32 when a fan 26 is activated and the gas valve 28 and the regulator is set opened. The well distributed fuel air mixture then passes through the perforations in the element 40 to the semi-cylindrical foam metal radiator element 12 which when fully heated glows red and projects infrared radiant energy downwardly and outwardly toward the gathering area from the housing 50 suspended above the gathering area. The composition of the foam metal radiator is made of an alloy of nickel, chromium and aluminum with a pore size on the order of 1,000 microns plus or minus 5% uniformly distributed throughout the material of the medium. The pore or cells in the elements or open to one another to allow for flow of the fuel/air mixture through the device 12. It has been found that this pore size produces optimum performance measured in terms of pore loading.
The fuel air mixture is ignited by an ignitor assembly 37 placed over the outside surface of the radiator element 12 as shown in FIG. 3. An air flow proving switch 34 is provided to make sure that the fan 26 has been turned on and the air is flowing to and thru the venturi tube 32 and into the burner plenum 38 before the ignitor 37 is activated.
The ignitor 37 is shown two-ways and maybe structured in either of the two-ways; the preferred structure is shown to comprise a high voltage spark prong, a ground prong, and a flame sensor prong as illustrated and described in the patent publication document U.S. Publication No. US2022-0381431 published Dec. 1, 2022 the content of which is incorporated herein by reference. As shown in FIG. 6, however, the flame sensor electrode may be separated from the other two electrode and mounted alongside of them.
When the misting function is selected by the control device 18, the switch element 19 is moved to the misting position to activate output from switch block 21 to open a water valve 22 to supply water under pressure of approximately 600 PSI to the series of misting nozzles 14 which are aimed downwardly toward the gathering area from the bottom of the housing 50 as illustrated in FIGS. 1 and 3. In warm weather conditions, mist from the nozzles evaporates rapidly and cools the air beneath the housing 50. The particular arrangement of nozzles is illustrative only and different numbers and sizes of nozzles may be used. The misting function is one-level only and modulators are, therefore, not needed. An exemplary orifice size is 0.008 in. with a flow rate of 0.3 gal/mn at 60 psi. pressure can vary with humidity conditions. Working pressure can be much higher; e.g. as high as 800 psi in which case a pump is required. Preferred nozzles have an anti-drip feature.
When the heat mode is selected the system may be structured to provide either a single heat level or multiple heat levels. In the latter case the control device 18 includes a potentiometer 27 as shown in FIG. 3 to provide signals to the control boards 20 and 24 to provide the air and fuel flow to produce the heating level selected. As previously mentioned, the gas valve 28 and modulator element 30 are activated to provide the selected level of fuel and air flow into the plenum 38. The ignition control device 24 is a Fenwal control board 35-53 available from Kidde-Fenwal of Ashland, Mass. For safety purposes board 24 provided to activate all control elements with 12-volt DC power as opposed to 110-volt AC power to produce a lower likelihood of spark issues.
By way of review, the plenum element 38 is joined to the semi-circular perforate plate 40 and the pores foam metal radiator element 12 as shown in FIG. 4 and the ignitor 37 is located to the outside surface of the radiator element to ignite the fuel air mixture flowing uniformly through the radiator 12.
The air flow proof switch 34 is used to ensure that the fan 26 fully operational to provide air flow into the burner structure before ignitor 37 can be activated. The device is operable in only one of the two operational modes; i.e. either radiant heat or misting and the two functions cannot be selected for activation at the same time.
It will be understood that the particular configuration, size and arrangement of the housing is non-critical but is in any case set up to be suspended at a safe distance above a gathering area.
Patent Application
20250180230
