US 3291118 A
Description (OCR text may contain errors)
Dec. 1966 LA ROY A. WILSON 3,
SNOW MELTER Filed Oct. 9, 1964 3 Sheets-Sheet 1 BY ZUa/M, M, wfl 4M) ATTORNEYS Dec. 13, 1966 LA ROY A. WILSON 3,291,118
SNOW MELTER 5 Sheets-Sheet Filed 001;. 9, 1964 INVENTOR, [,4 Kay 4 lV/LSOA/ 1956 LA ROY A. WILSON 3,
SNOW MELTER 3 Sheets-Sheet 3 Filed Oct. 9, 1964 INVENTOR [A /0} /4; M150 BY ATTORNFY5 United States Patent 3,291,118 SNOW MELTER La Roy A. Wilson, 9641 Accord Drive, Potomac, Md. Filed Oct. 9, 1964, Ser. No. 402,814 14 Claims. (Cl. 126-2712) This invention relates to snow and ice removing devices or the like, and more particularly to ambulatory devices of this type which are adapted to apply heat to the snow or ice covered surface as they move along.
The general object of the invention is to provide a novel and improved device of this character which is selfcontained, and provided with means to deliver a blast of heated air against the snow or ice accumulated on sidewalks, driveways, parking lots, roofs, and other areas; and not only serving to melt the snow or ice but also to blow the resultant slush and water away. The invention in its preferred embodiments contemplates the provision of a vehicle in the form of a wheeled cart, truck, or dolly, upon which are mounted a two-stage fan blower, a burner installation where the heat is generated and controlled, a nozzle for spreading and applying the blast to the surface to be treated, an engine (preferably an internal combustion engine fueled from the same source which supplies the burner) for driving the fan, and a tank for such fuel; the tank and attached conduits being disposed in proper relationship to the engine and the burner for eflicient operation and adequate safety.
Features of novelty include the guidance of the air flow with relation to the two-stage fan, the particular construction of the burner and nozzle for efficient burning of the fuel with protection of the nozzle and other parts of the device from scorching. Also, novel means for igniting the fuel to start the operation of the burner are provided.
Prior devices intended for similar purposes have been defective in applying the blast, possibly with adequate volume but with insufficient pressure; and their burners have been subject to coking and have required frequent cleaning. For example, snow melters using conventional squirrel cage blowers usually apply pressure of only about six inches of water, while the present device can develop pressures of approximately five pounds. The heat range is also quite wide, being or the order of from about 200 F. to as high as 1500 F., although the requirements for average use would be say between 400 F. and 700 F.
Another advantage lies in the ability to independently regulate the air flow effected by the blower, and the flow of fuel to the burner.
Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which certain embodiments of the invention are illustrated by way of example.
In the drawings:
FIGURE 1 is a view ifi side elevation of a snow melting device embodying the principles of the invention;
FIGURE 2 is a top plan view of the device;
FIGURE 3 is a vertical longitudinal sectional view taken on line 33 of FIGURE 2;
FIGURE 4 is a fragmentary view in section of the rearward portion of the blast generating means, including the burner and the fan, being shown on an enlarged scale and in a somewhat modified structural form;
FIGURE 5 is a transverse sectional view taken on line 55 of FIGURE 4;
FIGURE 6 is a fragmentary sectional view taken on line 6-6 of FIGURE 4;
FIGURE 7 is a fragmentary sectional view taken on line 77 of FIGURE 5 FIGURE 8 is a sectional view taken on line 8-8 of FIGURE 1;
FIGURE 9 is an enlarged sectional view showing an exemplary form of fuel nozzle and fan mounting;
FIGURE 10 is an end view of the fuel nozzle;
FIGURE 11 is a still further enlarged sectional view being a fragment of the burner and showing an igniting device therefor; and
FIGURE 12 is a diagrammatic view showing in outline a multiple burner device embodying the principles of the invention.
In the device illustrated in the drawings by way of example, and designated by the general reference numeral 10, the operative mechanisms are carried upon a truck, cart, or dolly 11. The truck may be provided with wheels 12 of any suitable type, and it carries upon its rear portion a framework which may comprise the uprights 14 and 15 and the inclined table 16 supported thereby. Extending rearwardly from this framework are suitable handle bars 18 which may be varied in structure, position, and inclination as desired. I
The principal elements of the operative mechanism of the melting device will now be broadly described. The burner and associated parts are designated at 20 and the external portions visible in FIGURES 1 and 2 are the tapered blast nozzle 21, the air manifold bell casing 22, and the hollow tubular shaft 50 extending upwardly and rearwardly from the blast device. The blast casings may be supported from the dolly 11 as by means of the brackets or braces 26 and 27. A gasoline engine is shown in rather diagrammatic form at 30 and a fuel tank for supplying fuel to both the engine and the blast burner is indicated at 31 and may be secured to the frame piece 14 as by the band 32 and to the base of the dolly 11 as by means of the upstanding bracket 33.
Now referring more particularly to FIGURES 3, 4 and 8, it will be seen that the blast nozzle is of a tapered configuration, being substantially cylindrical at its rear end 35 but being flattened in the vertical direction and spread in diverging fashion in the transverse direction to provide the broad and relatively thin discharge orifice 36, the lateral walls of the forward portion of the device adjacent the orifice 36 being shaped in parallel fashion as indicated at 37 in order to confine the blast to a straight forward pattern rather than permitting further divergence beyond the mouth of the blast nozzle.
Secured to the rearward peripheral cylindrical portion 35 of the blast nozzle 21 is the baffle or manifold 22 which serves to guide the air to the burner installation. The manifold or casing 22 is substantially semi-toroidal in shape, its forwardly directed cylindrical portion 40 being secured at intervals around the periphery of the device to flange 35 of the blast nozzle by means of the radial partitions 41. If desired, the annular intake opening for the air, designated 45, may be split by the cylindrical plates 46 which can serve as a protective screen to prevent foreign material from entering the manifold.
The in-turned central flange 48 of the baffie or manifold 22 surrounds the tubular fan and fuel nozzle shaft 50 and a bushing installation 51 serves to provide centering and sealing means for the shaft 50 and the manifold, a collar 52 being provided to prevent relative endwise movement. Upon an adjacent portion of the shaft, and separated from the bearing bushings 51 as by means of the disc or washer 54, is the hub 55 of the fan member 56. This fan member is a double-bladed instrumentality having blades 57 radiating from the hub 55 and fixed at their outer ends to the cylindrical member 58. Outwardly of the member 58 and secured thereto are the reversely angled fan blades 60. Preferably the cylindrical member 58 is extended axially in both directions to provide better guidance and interfitting with the enveloping parts of the air channels.
A nut 62 is threaded upon the outer end of the tubular shaft 50 and together with the collar 52, maintains the shaft, the manifold, and the hub 55 of the fan in proper association. A key 63 maintains the fan in driving relationship to the shaft 50.
Suitably connected to the end of the tubular shaft 50 is a tubular extension 64 upon which is mounted a fuel nozzle designate-d generally by the reference numeral 65. The nozzle may be constructed as suggested in FIGURES 9 and of the drawings in which a circular plate 66 has a hub or flange 67 fixed upon the end of the tubular extension 64 as by means of the set screw 68. Suitably secured around the periphery of the plate 66 is a hollow sheet metal nozzle enclosure 70 which is disc like and has a rather acute angled periphery as at 71. Drilled at intervals around the sharp peripheral edge 71 are fine openings 72 for the fuel which will be sprayed from the openings in the form of a mist during operation. The purpose in providing such a sharp edge to the periphery of the fuel nozzle 65 is to prevent carbonizing or coking of the fuel upon the periphery of the nozzle, as would be the case if the nozzle had a relatively broad or flat peripheral surface surrounding the nozzle openings.
As clearly indicated in FIGURES 3, 4, 8 and 11, the nozzle 65 is disposed within the body of the burner 75. This burner body is preferably made of a ceramic material and can be conveniently made in two halves which can be suitably joined along the junction line 76 as indicated.
The burner, while provided with a rounded or some what spherical rear end portion 77 is flared and flattened in a somewhat similar manner to that of the blast nozzle 21, the divergent spread of the burner being clearly shown in FIGURE 8 and the vertical flattening in FIGURES 3 and 4. The burner 75 is centrally supported within the blast housing or nozzle 21 as by means of the spider braces 78, any number of which may be provided, these braces or supports being secured to the parts to which they are connected as by means of welding or in any other suitable manner.
The walls of the burner member 75 are formed with openings 81 for the admission of the portion of air which is to support combustion of the fuel, these openings preferably being provided with curved blade-like projections 80 directed inwardly from the margins thereof, which serve to increase the mixing and turbulent of the components of combustion. One way of providing such fireresistant structure would be to form the general configuration of the 'halves of the burner 75 of metal mesh and then punch burrs or flanges corresponding to the projections 80 in the metal, and finally coating the inside and outside surfaces of the metal core with several layers of firebrick composition.
Referring now more particularly to FIGURES 1, 2 and 8 of the drawings, it will be seen that the rotary shaft 50 is held in bearing installations 85 and 86 and fixed to the tubular shaft 50 is the driven pulley 87. Also, surrounding the shaft 50 is the rotary fluid coupling 88 which may be of any suitable construction and may be additionally supported by the bracket 89 from the table 16. The fuel is fed through a pipe 90 which leads from a pump 91 which is fed from the fuel tank 31 through the pipe 92. It is to be noted that the connection 93 of the pipe 92 with the tank 31 is slightly higher than the connection 94 through which the fuel is fed to the carburetor 95 of the engine 30. The purpose of this will be explained presently.
For the purpose of controlling the flow of fuel to the burner independently of the operation of the engine by means of its throttle, a manually operable valve 90a is installed in the line 90 and a by-pass or return conduit 92a leads from a point in the line 90 between the pump 91 and the control valve 90a, back to the tank 31. A safety relief valve 91a may be installed in the conduit 92a.
The driving pulley 96 on the engine 30 is connected with the driven pulley 87 by means of the endless belt 97. This belt is trained over a pair of pulleys 98, one of which may be provided with a smaller pulley 98a operatively connected by means of the belt 99 with the pump 91.
For the purpose of igniting the fuel of the burner 75, there is provided an electric sparking device indicated generally by the reference numeral 100 and seen best in FIGURES 8 and 11 of the drawings. The showing is somewhat diagrammatic but will be understood in its generic form and variations within the scope of the invention are to be embraced therein. For example, the casing 101 is secured within an opening in the wall of the blast nozzle 21 adjacent its rear cylindrical portion 35, and mounted for limited axial movement within the casing 101 is the insulated plunger 102, this plunger terminating upwardly in a head 103 and urged to its outer limit, indicated in solid lines in the figures of drawing, by means of the spring 105. A wire 106 leads from a suitable source of high voltage current and another wire 107 is grounded to the blast nozzle 21. The wire 106 terminates in a contact point 108 and the wire 107 terminates in a contact point 109. Cooperating contact points 110 and 111 are carried by the head 103 and these points are connected by insulated conductors down to the points of the spark gap at 112.
The operation of the novel snow and ice melter will now be described. When the engine 30 is started, the tubular shaft 50 begins to rotate and the fan 56 starts to turn and the fuel nozzle 65, controlled by the valve 90a, sprays the fuel outwardly through the orifices 71 to form a mist within the burner casing 75. The air to support combustion is drawn through the intake orifice 45 of the housing or manifold 22 by the fan blades 60 and is guided inwardly around the domed portion 22' of the manifold 22 back toward the inward portion of the fan where the blades 57 force the air into the rear portion of the blast nozzle 21. Part of the air supply of course enters the openings 81 throughout the area of the burner housing 75 and the mixture of fuel and air is ignited therein by the depression of the head 103 of the igniter 101. When contacts 110 and 111 touch the terminals 108 and 109 high voltage current bridges the spark gap 112 and ignites the fuel. Upon removal of pressure upon the head 103 the spring immediately restores the igniter points 112 to their idle position outside of the burner casing 75 and in the cooler surrounding air flow.
The air which does not enter the openings 81 to support combustion in the burner, passes around the burner housing 75 and hugs the inner wall of the blast nozzle 21 maintaining it somewhat cooler than the blast temperature itself and thus preventing scorching of the metal of the nozzle. The proportioning of combustion air and surrounding cooling air is regulated in accordance with the balance between the heat required for melting the snow and ice and the maintenance of the condition of the metal of the nozzle. This boundary layer cooling has been found to be quite effective, but for the further protection of the nozzle and of personnel, it is preferred to coat the nozzle shell with a material of low heat-transference properties such as certain plastics, for example, the epoxy resins; alternatively, the entire shell could be molded of one of these compositions.
The power takeoff from the pulleys 98 by means of the belt 99 drives the pump 91 which supplies fuel from the tank 31 to the rotary fluid coupling 88 and thence to the center of the hollow shaft 50. The throttle of the engine and the valving 90a are of course independently operable.
It is important to maintain the engine fuel connection 94 at a lower point in the tank 31 than the takeoff for the burner fuel pipe so that when the fuel gets low the first to cut off will be the burner fuel, whereby the engine 30 will keep on running and operating the fan 56 to cool down the blast assembly. If the construction were otherwise, the fan might stop before the burner, with deleterious results to the blast device.
For adapting the present invention to more flexible uses, especially in the treatment of wider or irregular areas which might be covered with snow or ice, multiple units of the burner and blast structure 20 may be mounted upon a larger wheeled vehicle or truck, possibly three of these units carried on a boom so that they could be maneuvered by swivelling up to 90 either to the right or to the left of the vehicle. This would give the operator the ability to melt ice and snow from sewer connections or diverging pathways in addition to the straightaway surfaces. Such a unit would be of considerable advantage for cleaning highways and airport runways as well as streets and pavements. One variation of this general character is suggested in FIGURE 12 of the drawings, wherein there is shown a wheeled base 11A having three burner units A, 10B, and 10C, the outer units 10A and 10C being provided with substantially vertical pivotal supports suggested diagrammatically at 27A, whereby the outer units may be swung outwardly at an angle to the path of travel of the device.
It is understood that various changes and modifications in the embodiments of the device illustrated and described herein may be made without departing from the scope of the invention; and possible other uses of the novel portable device would suggest themselves, for example, the drying out of roofs, burning of weeds, smoothing the surfaces of ice-skating rinks, and various other purposes.
Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:
1. A snow and ice melting and removing machine or the like, comprising a wheeled truck, a blast chamber mounted on said truck and having a nozzle adapted to be directed toward the material to be melted or removed, a liquid fuel burner within said chamber and comprising a perforated casing, a rotary fuel nozzle within said casing, a two-stage fan device carried by said truck and adapted to supply air to said burner, and means on said truck for powering said fuel nozzle and said fan.
2. The machine as set forth in claim 1 in which the power means comprises an internal combustion engine, a liquid fuel tank is carried by said truck, and means are provided for conducting fuel to the burner and the engine, whereby said tank comprises a common source of fuel for both instrumentalities.
3. The machine as set forth in claim 2 in which said conducting means comprises a conduit leading from said tank to said burner and a conduit leading from said tank to the engine, the first named conduit being connected with the tank at a somewhat higher elevation than the second named conduit.
4-. The machine as set forth in claim 2 in which separate means are provided for controlling the speeds ofthe engine and fan, and for controlling the flow of fuel to the burner.
5. The machine as set forth in claim 4 in which said first named controlling means is the throttle and carburetor of the engine, and said second named controlling means is a manually operated valve in the fuel conduit leading from the tank to the burner.
6. The machine as set forth in claim 5 in which there are provided a fuel pump disposed in the fuel conduit leading to the burner, means for driving said pump from said engine, the said manually operable valve disposed beyond said pump, and a return conduit leading to the tank and connected in said burner fuel conduit between the pump and said manually operable valve, and a relief valve in said return conduit.
7. The machine as set forth in claim 1 in which there is provided a common drive shaft for said fan and said rotary fuel nozzle, said shaft being tubular and having a rotary intake liquid coupling thereon and carrying said nozzle at one of its ends.
8. A hot blast device as for melting snow or ice from surfaces upon which it lies, said device comprising a blast chamber comprising a relatively fixed casing, a burner casing fixedly supported within the blast casing, a spray nozzle for liquid fuel disposed within said burner casing, and means for supplying said nozzle with fuel, multiple openings formed in the burner casing for the admission of combustion-supporting air, and a two-stage rotary fan supported adjacent the rear end of said blast casing and arranged to blow air toward the rear end of said burner casing, at least a portion of said air adapted to enter said openings to mix with the sprayed fuel to support combustion and create the hot blast, said two-stage fan comprising a unitary rotary member having a hub, an inner circular series of radially disposed blades angled to propel air toward said burner casing, and an outer circular series of radially disposed blades angled to draw atmospheric air into the ambit of said first named series of blades, and a curved manifold for guiding said air from the outer blades comprising the first stage to the inner blades comprising said second stage.
9. A hot blast device as for melting snow or ice from surfaces upon which it lies, said device comprising a blast chamber comprising a relatively fixed casing having a substantially cylindrical rear end and a widened and flattened forward nozzle end, a burner casing fixedly supported within the blast casing and having an approximately spherical-segmental rear end and a somewhat widened and flattened forward end; a rotary spray nozzle for liquid fuel disposed within said burner casing, and means for supplying said nozzle with fuel; multiple openings formed in the burner casing for the admission of combustionsupporting air, and a two-stage rotary fan supported adjacent the rear end of said blast casing and arranged to blow air toward the rear end of said burner casing, at least a portion of said air adapted to enter said openings to mix with the sprayed fuel to support combustion and create the hot blast.
10. The device as set forth in claim 9 in which said rotary nozzle comprises a hollow circular disc having an axial inlet opening and an extremely thin peripheral edge, and a plurality of circumferentially spaced small discharge openings around said thin edge; all whereby peripheral surfaces upon which coking might occur are substantially eliminated.
11. A hot blast device as for melting snow or ice from surfaces upon which it lies, said device comprising a blast chamber comprising a relatively fixed casing having a substantially cylindrical rear end and a widened and fiattened forward nozzle end; a burner casing fixedly supported within the blast casing and having an approximately spherical-segmental rear end and a somewhat widened and flattened forward end; a spray nozzle for liquid fuel disposed within said burner casing, and means for supplying said nozzle with fuel; multiple openings formed in the burner casing for the admission of combustion-supporting air, and a two-stage rotary fan supported adjacent the rear end of said blast casing and arranged to blow air toward the rear end of said burner casing, at least a portion of said air adapted to enter said openings to mix with the sprayed fuel to support combustion and create the hot blast; the walls of said burner casing and of said blast casing being spaced apart peripherally and said two-stage fan disposed so as to direct a portion of its air through the space between said walls.
12. A hot blast device as for melting snow or ice from surfaces upon which it lies, said device comprising a blast chamber comprising a relatively fixed casing having a substantially cylindrical rear end and a widened and flattened forward nozzle end; a burner casing fixedly supported within the blast casing and having an approximately spherical-segmental rear end and a somewhat widened and flattened forward end; a rotary spray nozzle for liquid fuel disposed within said burner casing, means for spinning said nozzle, and means for supplying said nozzle with fuel; multiple openings formed in the burner casing for the admission of combustion-supporting air, and a two-stage rotary fan supported adjacent the rear end of said blast casing and arranged to blow air toward the rear end of said burner casing, at least a portion of said air adapted to enter said openings to mix with the sprayed fuel to support combustion and create the hot blast; the walls of said burner casing and of said blast casing being spaced apart peripherally and said two-stage fan disposed so as to direct a portion of its air through the space between said Walls, the openings in the walls of the burner casing being marginally provided with fins projecting into the interior of said burner casing to provide baffies for increasing the agitation and turbulence of the fuel and air mixture for efiicient combustion and blasting.
13. The device as set forth in claim 10 in which the burner casing is at least partially made of heat-resistant ceramic material.
References Cited by the Examiner UNITED STATES PATENTS 1,855,339 4/1932 Cornelius.
2,602,292 7/ 1952 Buckland et a1.
3,174,477 3/1965 Wilson 126271.2 3,176,749 4/1965 Downs 1S876 X 3,228,125 1/ 1966 Wiebe.
15 CHARLES J. MYHRE, Primary Examiner.