Municipalities, communities, resort areas, airports, and maritime locations, etc. often need to melt snow after large snow storms. Such winter storms can disrupt travel, hinder commerce, and otherwise cause problems. Accordingly, such entities will often go to great lengths to remove the snow as soon as possible in order for transportation services to get back on track and moving.
One way to remove large amounts of snow is to use commercial snow melting devices. These devices are sometimes referred to as “snow melters.” There are currently known snow melters offered to the marketplace. Trecan, a Canadian company, offers snow melting products using a submersible combustion system. While efficient at melting snow, this process consists of firing a flame or series of flames through a diesel fired (in most cases) burner into a weir that is submerged in the melt tank or snow dump area. That flame and exhaust warm the in-tank water temperature to the pre-determined level, cause underwater turbulence which assists in melting the snow that has been dumped or blown into the melt tank. All of the exhaust particulates escape into the melt water exiting the snow melter and into the storm drains, settling ponds, etc. This snow-melting process is efficient but very dirty.
A second type of melt process available to the marketplace is a direct fired melter, which employs the use of a jet turbine engine fired directly at the snow as it is dumped into a holding tank or melt tank. This process is very efficient, but absolutely filthy, emitting volumes of exhaust carbons for long distances especially in a windy location, and covering autos, buildings, lawns in the surrounding areas of operation, etc. The operation of this type of melter has been banned in at least one large airport location, except in dire or emergency situations. This application requires enormous fuel consumption—roughly 700 gallons per hour (“GPH”).
Accordingly, there is a need in the art for a new type of snow melter that is efficient to use, clean, portable, and inexpensive to use. Such a device is disclosed herein.
The present system is a portable snow melter. This snow melter may be used in municipal, resort, maritime and airport environments where, after a normal to major winter snow storm, it is necessary for transportation services to get back on track and moving. The melter alternative is both efficient and less costly, based upon distances to haul snow to permanent dump sites and the relative comparative costs involved; fuel, labor, equipment, etc.
This snow melter comprises two tanks which may be adjacent to each other. These two tanks are the melt tank and the dump tank. Snow is dumped into the dump tank whereas water is heated via a heat exchanger in the heat exchanger tank. The main concept is to have a dumping tank where snow is dumped separated from a heat exchanger tank. This way debris in the snow is not dumped directly on top of the heat exchanger. The heat exchanger may be a fully enclosed fire tube, wet back heat exchanger. In the current embodiment, a 2-pass exchanger is employed. An oil fired flame travels down the length of a larger diameter Morrison tube and then an enclosed turnaround box distributes the hot air and gases back through hundreds of small tubes where they meet an exhaust box where these air and gases are collected and exhausted through a stack. These exchangers are normally designed to achieve approximately 85% efficiency. The in-tank water to be warmed comes in contact with all of the surface area of the large and small tubes and collection boxes.
There are two primary water flows in operation. First, there is pumped circulation between the dump tank and the melt tank, meaning that water is pumped from the dump tank into the melt tank. Water is then returned to the dump tank via an overflow weir. The water level in the melt tank is higher than the dump tank to allow the water to fall in a waterfall back into the dump tank via the overflow weir. There is another weir (sometimes called a lower weir) in the dump tank for the exit of the melt water. Additionally, there is a lower weir in the dump tank for the exit of melt water. As snow is added to the dump tank and melted, the water lever rises in the dump tank until it overflows out of the dump tank via this lower weir. This water may then be directed via hoses to the ground, storm drain system, or to another water collection feature. This lower weir may be located at one end of the dump tank. It could further be distributed via ducts around the sides of the dump tank for more even distribution. Alternatively, additional piping or troughs could distribute the water from the upper weir to cascade into the dump tank along several sides to expose more of the snow on the dump tank surface to water directly flowing on it.
However, while the water is in the melt tank (i.e., before returning to the dump tank), the water will be heated by a heat exchanger. In some embodiments, this heating will cause the water to heat to about 39 degrees Fahrenheit. Thus, it is heated water that is returned to the dump tank. Additionally, there is a lower weir in the dump tank for the exit of the melt water out of the dump tank to be disposed of into the storm drain system. In some embodiments, water that leaves the dump tank (via the hoses, etc.) is at a temperature, such as 39° F., that allows the water to be directly poured into drains, etc., without risk that the water will re-freeze.
The heat exchanger is a closed loop system which means that at no time does the burner flame come into contact with the melt water. This makes this system much cleaner than other systems as pollutants formed by the burner never gain access to the water. Rather, the flame and the combustion products are completely housed within tubes that will heat up. These tubes will, in turn, heat up and warm the melt water in the melt tank.
In order that the manner in which the above-recited and other features and advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments the present invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of presently preferred embodiments of the invention.
Referring now to
The melter 100 may include two separate and distinct tanks, namely a dump tank 112 (which is sometimes referred to as a dumping tank) and a melt tank 116 (which is sometimes referred to as a “heat exchange tank”). The heat exchanger tank 116 includes a heat exchanger (not shown in
Other types of large capacity snow melting systems must be towed using tractors that have a capacity for greater than 10,000 lbs of trailer tongue weight. This then requires that this specialized equipment be provided by the user to move the equipment because most standard dump trucks are not equipped to tow this type of load. However, embodiments of the melter 100 may be designed in which a conventional dump truck 104 may be used as the towing vehicle. Specifically, the melter 100 may be designed such that the melter would have a tongue weight to be less than 10,000 lbs. This may be done by centering the largest weight of the melt tank 116 and associated water over a three axle 110 set on the trailer. Then cantilevered or extending behind the axles is the weight of the other components of the melter 100 (which, as explained herein, may include the fuel, burner system, and generator). This largely offsets the weight of the empty dump tank 112 which is forward of the axles 110. Then, the tongue weight is primarily any existing water in the dump tank 112, which of course, could be tailored and managed to acceptable levels. Accordingly, in this manner, the weight may be distributed to allow a regular dump truck 104 to be used as the towing device. Of course, other embodiments may also be constructed differently and may require the use of specialized equipment to haul/tow the melter 100.
The dump tank 112 also may include one or more doors 120. These doors 120 are designed to facilitate cleaning out the dump tank 112 after use. Specifically, the snow, when loaded into the dump tank 112, may include debris, tree branches, etc. that may be gathered in the dump tank 112 after the snow has been melted. Accordingly, these doors 120 (although shown in the closed configuration in
The melter 100 may also include an enclosure 122 that encloses the burner system, the fuel, the controls, the “genset” (typically a diesel driven electric generator), and other components that will be described below. These controls may be used to adjust the melting parameters (such as the heat discharged, the fuel used, etc.). The enclosure 122 may be positioned rearward of the melt tank 116.
Referring now to
As can be seen in
In some embodiments, steel deflectors may be added around the top inside of the dump tank 112 that operate to help deflect the water back into the tank 112 when snow is dumped in for cleanliness and to preserve the heated water for melting. The dump tank may have a stepped front face, normally at a 9 foot height to make it easy for the front end loader 124 to dump while the rear face and sides may be raised to further contain the snow and water.
The cold water in the dump tank 112 is circulated to the melt tank 116 for warming. This water flows through piping 128 from the interior of the dump tank 112 into the melt tank 116. A pump 132 may be used to facilitate this water flow. In some embodiments, the pump 132 may be capable of pumping up to 1500 gallons per minute of water. In some embodiments, the water may be pumped from the dump tank 112 to a rear bottom portion of the melt tank 116. The water is that is pumped from the dump tank 112 into the melt tank 116 may be referred to as “return water.” This water may exit at the top and opposite end of the tank. This may cause the water to flow over all of the tubes of the heat exchanger for maximum heat exchange. In the preferred embodiment, the inlet for the cold water to the pump is downward facing and large in area. This encourages dirt and debris to settle to the bottom of the tank rather than be entrained into the water flow and transported to the melt tank. This inlet is often covered with a screen to prevent large and lightweight debris from going through the pump.
Once the water enters the melt tank 116, it will be heated by the heat exchanger (not shown in
Clearly a burner (not shown in
Referring now to
The burner is positioned to fire into the large Morrison tube 178 of the heat exchanger 162. The water in the melt tank 116 surrounds the Morrison tube 178 and gas return tubes 186. Water fills the heat exchanger tank 116 above heat exchanger tube rack 162, until it cascades over the weir 196. Generally, the heat exchanger 162 may consist of a large Morrison tube 178 (which is a fire tube or other similar structure) into which the flame produced by the burner 166 is sent. The flame and/or gaseous products produced by the burner 166 may extend along the entire length of the large Morrison tube 178 until it reaches the turnaround box 182. Once the hot gas hits the turnaround box 182 (or turnaround area), it is returned, via a large number of gas return tubes 186 back towards the burner and then gathered in a box 188 and exhausted through the exhaust tube 152. Thus, the hot gases will heat the gas return tubes 186 which make contact with the melt water in the melt tank 116 both while hot gases are in the Morrison tube 178 and the gas return tubes 186, thereby increasing the heating and surface area contact with the melt water. In some embodiments, there may be multiple tubes 186 (even hundreds of tubes) as desired to maximize heat transfer efficiency.
As can be seen in
However, at one end of the melt tank 116 is a weir 196, which is an opening or other feature that allows the water heated by the Morrison tube 178/return tubes 186 to flow from the melt tank 116 back into the dump tank 112. As can be seen in
Referring now to
In the present embodiment, when the heated water flows out of the melt tank 116 back into the dump tank 112, the water flows over an overflow weir 196 back on top of the snow. This process provides agitation to promote mixing of the hot water with the snow to accelerate melting. In the present embodiment, this weir 196 is located at one end of the dump tank 112. It could be further distributed via ducts around the sides of the dump tank 112 for more even distribution. Additionally, in other embodiments, a second pump could be used to return the water to the dump tank via a pressurized spray system. Although more expensive (and thus less preferred), this more forceful spray breaks up the snow and ice more quickly exposing more surface area to the hot water and promotes more rapid melting. This second pump could operate off of water leveling sensing in the heat exchanger tank, with on-off or proportional control to maintain the water level in the heat exchanger tank.
With respect to the pump 132 that initially moves the water from the dump tank 112 to the melt tank 116. When the water enters the melt tank 116, the water will be circulated. To maximize heat transfer, water is circulated to the bottom rear of the heat melt tank 116 (via the opening 200) and exits at the top and opposite end of the melt tank 116. This causes the water to flow over all of the tubes 186 (as well as the Morrison tube 178) of the heat exchanger 162 (shown in
As shown in
A control panel 230 may also be used to control the heat exchanger 162. Specifically, this control panel 230 allows the user to adjust the burner 166 (such as the temperature, the fuel consumption, etc.) as well as the pump 218, the pump 132 (not shown in
A diesel genset 234 may also be added to power all of the pump 132 (not shown) and the other systems used in this melter 100. Again the genset 234 allows a user to control all aspects of the melter 100 including the water flow via the pump 132. Those skilled in the art will appreciate how the genset 234 and/or the control panel 230 may be implemented, modified, and used to control the melter 100. The genset 234 may include a generator and an auxiliary power unit for the melter 100.
As can be seen in
The present embodiments also provide a simple and easy mechanism for cleaning out both of the tanks 112, 116 after use. Debris is settled out in the following way: when snow is dumped into the dump tank 112, the solids (rocks, sand, etc.) tend to fall to the bottom of the dump tank 112.
With respect to the pump 132 that initially moves the water from the dump tank 112 to the melt tank 116, the inlet 200 for the water circulation pump 132 may be screened to keep out large objects like sticks and bottles and may include provisions for easy clean-out, such as by hinging the top of the inlet duct. The pump inlet 201b may further be designed with a clean-out door that allows for easy removal of trapped debris. The inlet for the circulation pump is elevated off the bottom of the tank and redirects the water first vertically through a duct before going into the pump inlet. The design of the inlet duct size is such that solids will not be entrained into the water flow and will remain settled out at the bottom the dump tank. Only light weight fines will find their way into the bottom of the heat exchanger tank. The pump inlet may further be designed with a clean-out door. To maximize heat transfer, water is circulated to the bottom rear of the heat exchanger tank and exits at the top and opposite end of the tank. This causes the water to flow over all of the tubes of the heat exchanger for maximum heat transfer. The heat exchanger is elevated off the bottom of the tank to allow for some accumulation of fines and to allow for it to be easily hosed via gasketed doors.
It is known that it can be very difficult to clean out dump tanks 112 (after use). Some previously known snow melters expect the debris to be manually shoveled. In our system, the preferred embodiment is to slope to all sides of the dump tank 112 to funnel all debris to specific collection areas. These areas, at one or both ends, may have full width gasketed doors 120 that may be opened, after the melt water has been drained, to discharge the debris. In the simplest embodiment, the doors may be opened and then the debris shoveled out the door, but at least there are not difficult corners to deal with. Gasketed doors 120 are provided for cleaning debris from the bottom of the dump tank 112. Similar doors may also be added to the melt tank 116, as desired. For safety and ease of use, some embodiments may have hydraulic cylinders 245 that can be used to raise the doors out of the way for cleaning. Pressurized sprays of water may also be used to push the debris out of the tanks.
In our preferred embodiment of
It should be noted that the hydraulic pump 218 (shown in
After cleaning, the system is now in a state where the dump tank 112 has no water and must be refilled typically via water truck or fire hydrant. In an alternate embodiment, the overflow weir 196 of the melt tank 116 is fitted with a door to allow it to be closed to store additional water. At the time of cleaning, the door is closed and water in the dump tank 112 is pumped to the heat exchanger tank 116 and stored on top of the normal water level. After cleaning, valves in the face of this door can be opened to return water to the dump tank. After the water pressure has been relieved via the valves in the face of the door, the door may be opened or removed exposing the normal overflow (heat exchanger) weir 196. So operation may resume after cleaning without the need to supply additional water.
As shown in
Obviously, those skilled in the art will appreciate that assorted fasteners, fuel and hydraulic lines, and other components known to those skilled in the art may be used to assemble and/or facilitate operation of the melter 100.
The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application claims the benefit of U.S. Provisional Patent Application No. 60/928,245, filed May 7, 2007. This provisional application is expressly incorporated herein by reference.
Number | Date | Country | |
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60928245 | May 2007 | US |