US 3155089 A
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United States Patent M 3,155,089 PORTABLE SNQW NELTiNG AND SNG DESPOSAL UNIT William H. Hoyt, 193 Ivy St., Oyster Bay, N.Y. Filed Feb. 8, 1962, Ser. No. 171,983 6 Qiaims. (Cl. 126343.5)
My invention is directed towards apparatus for melting snow and disposing of the water so formed.
I have invented a new type of apparatus for quickly disposing of large accumulations of snow removed from congested city areas, airfields, main highways and the like by melting the snow and disposing of the water so formed by discharging it into a storm drain or sewer, thus eliminating the much more expensive and time consuming process of plowing the snow into large piles, transferring the snow thus piled into trucks, carting the loaded snow away, and disposing of the carted snow at low temperatures.
Accordingly, it is an object of my invention to provide new and improved snow melting and disposing apparatus of the type indicated above.
Another object of my invention is to provide a wheeled, self powered vehicle for melting snow and disposing of the water so formed wherein an electrically operated oil burner supplies the necessary heat to melt the snow, and an electrically operated water pump discharges the water formed from melted snow into a storm drain or sewer.
Another object of my invention is to provide a wheeled self powered vehicle for melting snow and disposing of the water so formed, wherein the oil burner and water pump are automatically started and stopped according to a set variation in temperature of the water entering the pump.
Still another object of my invention is to provide a wheeled self powered vehicle for melting snow wherein heat is ahtracted from the disposed of water whereby it is caused to melt snow before disposal and to be discharged to a storm drain or sewer at a reduced temperature, thus decreasing operating cost by saving fuel.
These and other objects of my invention will either be explained or become apparent hereinafter.
My invention contemplates a vertical tank having a hinged top cover. I further provide a hot water boiler positioned below the tank, the bottom of the tank serving as the top of the boiler.- The bottom of the tank is perforated above the water space of the boiler.
A rectangular cooling trough is provided near the top of the tank and extends around the inner periphery of the tank. The water to be disposed of passes through the discharge pipe, which is contained in the cooling trough.
An electrically operated oil burner unit heats the water in the boiler, the electricity being supplied from an auxiliary gasoline engine powered alternating current generator.
A water pump electrically operated is attached to the boiler, creates a suction at the bottom of the boiler and causes water from the tank to be drawn through the perforated tank bottom into the boiler wherein the temperature of the water is increased before the Water enters the water pump. A portion of the hot water discharged from the water pump is recirculated to the tank, and the remaining portion is discharged to a storm drain or sewer.
A set variation in temperature of water entering the pump actuates the switches of aquastats attached to the side of the boiler. These switches are in the electrical circuits of oil burner and water pump and cause them to start and stop automatically as required to maintain boiler water temperature between set limits.
When the apparatus is made operable by filling with fresh water to a level above the bottom of the tank, and
3,155,089 Patented Nov. 3, 1964 this water heated to operating temperature, snow is placed in the open top of the tank. A portion of the snow falls into the cooling trough, is melted by contact with the hot discharge water pipe, and overflows into the tank.
The remainder of the snow falls into the hot water in the bottom of the tank and is sprayed from above by hot water recirculated by the water pump, as the snow melts the water so formed accumulates in the bottom of the tank and is drawn through the perforated tank bottom into and through the boiler by the suction of the water pump, a portion of the hot water is discharged from the water pump is returned to the tank as spray water. The remainder of the hot water is disposed of and passes through the discharge water pipe contained in the cooling trough, transmits heat through the metal of the discharge water pipe to the snow in the trough causing the snow to melt, the heat given up by the disposed of water in melting snow in the trough causes the temperature of the water to be reduced before it is discharged to a storm drain or sewer.
The invention itself and the manner of its organization can be better understood by referring to the following description taken in connection with the accompanying drawings wherein:
FIGURE 1 is a plan view of apparatus in accordance with my invention.
FIGURE 2 is an elevation view of the apparatus of FIGURE 1.
FIGURE 3 is a cross sectional view of the apparatus taken along the line 3-3 of FIGURE 2.
FIGURE 4 is an electrical diagram showing the electrical interconnections of various elements in the apparatus of FIGURE 1.
Referring now to FIGURES 1, 2 and 3, a rectangular tank 10 is positioned on top of a rectangular horizontal return tubular boiler 12. The tank 10 is formed by extending the front, rear and side plates of the boiler, the tank bottom 14 serves as the top of the boiler, and is perforated above the water space of the boiler so that water from the tank can enter the boiler.
These perforations 16 expose the boiler water to the atmosphere, and limit boiler pressure and temperature to 14.7 pounds per square inch and 212 F. respectively. Because of this pressure limitation lighter material may be used in construction of boiler and tank with a corresponding reduction in weight.
The perforations 16 may take the form of slots to prevent debris such as sticks and stones from entering the boiler, but not interfering with the flow of water thereto.
A cooling trough 48 extends around the inner periphery of and near the top of the tank, this trough is rectangular in cross-section and there are overflow openings 49 on the inner sides of the trough.
The discharge water pipe 46 connects to control valve 47, enters the trough 48, extends around the interior of trough 48 in the form of a coil, and its discharge end 5%) projects from the side of the tank.
Two angle members 44 are attached to the top of the tank and extend lengthwise across it. The angle members are arranged in the form of an inverted V. Their purpose is to distribute snow entering the tank, and to protect spray pipes 42 from impact damage.
Two spray pipes 42 extend lengthwise within the tank, beneath angle members 44. They are connected by header 36 to spray water valve it). The free end of each spray pipe is capped and that portion of each pipe extending within the tank from the side of the cooling trough to the capped end has numerous holes in its bottom part, so arranged that they are capable of directing a uniform and evenly distributed spray of water in a downward direction over the interior of the tank.
An electrically operated water pump 34 is attached to (.1! the boiler at the suction end by pipe 32, and on thedischarge end is attached to spray and discharge water pipes. A drain valve 35 is attached to the base of the pump.
An electrically operated oil burner unit 20 is attached to the fire box of the boiler, it is of the type suitable for automatic operation and is comprised of oil pump, fan, ignition set and nozzle. Tank 18 supplies oil to the burner unit.
A gasoline engine driven alternating current generator 56 supplies electrical power. The gasoline engine speed is governor controlled. Tank 58 supplies gasoline to the engine.
The whole arrangement is mounted on a truck frame 52 having wheels 54.
The electric circuit is shown diagramamticaily in FIG- URE 4. Switch 65) is a manually operated on-otl-switch. The switch 62 is a minimum water level contact switch, which opens when the level of water in the tank falls below a selected minimum level, and stops burner and pump motors. It is comprised of a float and bell crank lever located in the tank with a suitable screen covering to prevent contact with snow. The bell crank lever shaft protrudes through a gland in the side of the tank, to the end of which shaft is attached a water level indicator and the contact switch 62.
The switches 64 and 68 are temperature actuated aquastat switches which can be adjusted to operate at a set value of water temperature. Their sensing bulbs are immersed in the side of the boiler in the path of water entering the pump.
The switch 64 opens and stops pump 34 when the water temperature falls below a set value, and will close and start the pump when the water temperature rises above the set value.
The switch 68 will close and start the oil burner unit when the water temperature falls below a set value, and will open and stop the oil burner when the water temperature rises above the set value.
Switch 66 is a stack relay switch, essential to automatic operation of oil burner unit 20, with its temperature sensing element immersed in the flue 30. Switch 65 will open and shut oft oil burner unit 29 if ignition is delayed beyond a safe time limit.
When the apparatus is to be placed in operation, gasoline from tank 58 is used to operate gasoline engine driven alternating current generator 56.
With pump and tank valves closed, fresh water is added to tank to fill boiler 12 and bring the water level in tank 10 above the minimum level, as shown by the level indicator on the external shaft end of float operated switch 62, and cause switch 62 to close.
Aquastat switch 68 will be closed and aquastat switch 64 will be open because of the relatively low temperature of the added water, and when switch 60 is closed, an electric current from generator 56 will flow through switch 64), through switch 62, through a closed stack relay switch 66, through switch 63 and start oil burner unit 20, and cause oil from tank 18 to be pumped through the burner nozzle, mixed with air, and ignition to take place in the firebox of boiler 12. The products of combustion of the oil take the direction of the arrows through tubes 24 into flue 30 past damper 28 and exhaust to the atmosphere.
The oil burner flame radiates heat to the bottom plate 22 of the boiler, and the products of combustion supply heat by connection to the tubes 24, and to the front and rear tube sheets 26 to which the tubes are attached and to the unperforated portion of the tank bottom 14. This heat from the burner and products of combustion is transferred by conduction through the metal to the adjacent water in boiler and tank.
When the water temperature in the boiler has reached the set temperature of aquastat switch 64, switch 64 will close and start pump 34, and when valve 40 is opened the suction created by the pump will draw hot water from boiler and tank into the pump and recirculate it through spray pipes 42 into the tank. Oil burner unit 20 will continue to operate until the water temperature reaches the set temperature of aquastat switch 68, at which temperature switch 68 will open and stop oil burner unit 29.
When snow is loaded into the open top of the tank, a portion of the snow falls into the trough 48 and the remaining portion comes into contact with the angle members 44, is distributed over the tank and falls into the hot water at the bottom of the tank and is sprayed with hot water under pump pressure from overhead spray pipes 42.
As the snow melts the water so formed causes the temperature of the water entering the pump 34 to lower and when the water temperature falls below the set temperature of aquastat switch 68, switch 68 will close and start oil burner unit 29, and heat will be added to water in boiler and tank.
Similarly if the water temperature entering the pump falls below the set temperature of aquastat switch 64, switch 64 will open and stop pump 34, and when the water temperature has risen again above the set temperature or" aquastat switch 64, switch 64- will close and start pump 34.
In such fashion, according to the set temperature difference between aquastat switches 64 and 68 automatic operation or pump 34 and oil burner unit 20 will be pro-- vided to so pump and heat water in tank 10 and boiler 12 as to maintain the desired average temperature ofwater entering the pump 34.
The water formed from melted snow will accumulate and cause the water level in tank 10 to increase. This change in water level will be shown by the water level indicating pointer mounted on the external shaft end of float and lever operated switch 62, said switch being attached to the side of tank 16. When the indicated water level has risen a selected distance above the minimum water level controlled by switch 62, to an operating water level, the water in excess of this level is disposed of by opening regulating valve 47 and causing the pump 34 to discharge a volume of hot water equivalent to the volume in excess of the tank operating level through discharge pipe 46 and to leave said pipe at its open end 59 under pressure and be discharged through suitable connecting piping to a storm drain or sewer.
This operating level is maintained through successive melting periods by adjusting regulating valve 47 to control the flow of water from pump 34 to discharge pipe 4-6.
This discharged water enters pipe 46 at water pump temperature and leaves pipe 46 at open end 50 at a reduced temperature because in traversing the length of pipe 46 to the trough 48, heat from the water is transferred through the pipe metal to the snow collected in trough 48 during successive snow loadings and melting takes place. The water so formed accumulates in trough 48, the Water level rises to the overflows 49 and passes into tank 10. Since snow is melted in trough 48 by heat abstracted from the discharged water, there is a saving of heat and an increase in operating economy.
It is to be noted that the melting of snow is accomplished in several ways; by contact with the hot discharge pipe 46 in trough 4-8, by falling into hot water at the base of tank 10. By being sprayed with hot water under pressure from overhead spray pipes 42, by contact with metal of tank, by contact with vapor rising from tank, and by the turbulence of water at the base of tank.
For the purposes of clarity in the drawings, the cover for the top of the tank, boiler casing, insulation for bottom and side of trough, means of draining trough, internal fire brick insulation in furnace, and the several electrical switching devices are not shown, although all are used.
While certain novel features of my invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions, and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing from the spirit of the invention.
Having thus described my invention, I claim as new and desire to secure by Letters Patent:
1. A mobile snow melting unit comprising a wheel supported frame, a boiler housing on said frame, including a hot-water boiler, a snow-receiving tank superposed over said boiler housing, the bottom of said tank constituting the top of said boiler housing, a continuous snow-receiving trough Within said tank extending at least the entire perimeter thereof, the bottom of said trough being vertically spaced above the bottom of said tank, a plurality of parallel angle bars each of inverted V-shape secured between a pair of opposed inside walls of said trough, a water spray pipe positioned within each angle bar, a heater pipe within said trough, a drain pipe connected to said heater pipe, openings in said tank bottom for the discharge of water directly into said boiler, overflow openings in the inside wall of said trough, a pump, a conduit connecting the bottom of said boiler to the inlet of said pump, a discharge conduit on said pump, and separate conduit means each including a control valve for connecting the discharge conduit to said spray pipes and to said heater pipe, whereby water heated by said boiler will be pumped through said spray pipes to be discharged into snow within said tank to melt the same, and at the same time, water heated by said boiler will be pumped through said heater pipe to melt the snow within said trough by heat transfer therewith, the water passing through said heater pipe being discharged through the drain pipe, the Water supplied to said boiler by the melted snow flowing from the trough over-flow openings into said tank and through the tank bottom openings into said boiler, being in part re-circulated to said tank and in part pumped through said heater pipe, for ultimate discharge through said drain pipe exteriorly of said snow melting unit.
2. The mobile snow melting unit of claim 1, wherein said boiler housing comprises a combustion chamber, a discharge stack, a burner, and flues within said hot-water boiler in heat transfer relation with the water therein and connecting said combustion chamber with said discharge stack for passing the products of combustion of said burner into said discharge stack.
3. The mobile snow melting unit of claim 2, wherein said pump is motor driven and said burner comprises a motor-driven oil burner, and an electric circuit connected to a source of electric supply and to the motors of said pump and burner for electrically operating the same; and switch means in said circuit operative to open said circuit when the water level in said tank falls below a selected minimum level to stop the motors of said pump and burner.
4. The mobile snow melting unit of claim 3, wherein said electric circuit includes a first thermostatically operated switch and a second thermostatically operated switch, both operative within pro-selected low and high temperature ranges of the hot water at the inlet of said pump for respectively starting and stopping the motors of said pump and burner.
5. The mobile snow melting unit of claim 4, wherein said electric circuit includes an on-oif switch to open and close the same and a stack relay switch for stopping the motor of said burner should ignition be delayed beyond a safe time limit.
6. The mobile snow melting unit of claim 1, wherein said openings in said tank bottom are of a shape and size to prevent the entry of debris into the boiler and further function to expose the boiler water to the atmosphere; and said trough overflow openings being located adjacent the top edge of the trough inner wall, the heater pipe located in said trough being positioned substantially at the bottom thereof.
References Cited in the file of this patent UNETED STATES PATENTS 281,500 Hannan July 17, 1883 553,401 Von Garnier Jan. 21, 1896 1,160,205 Smith Nov. 16, 1915 1,351,542 Ryan Aug. 31, 1920 1,821,292 Chase Sept. 1, 1931 1,841,245 Hogen Jan. 12, 1932 2,104,363 Devlin Jan. 4, 1938 2,977,955 Altenbury Apr. 4, 1961