The present invention relates generally to vehicle heaters. More particularly, the present invention relates to a heater arrangement for thawing bulk materials frozen into a bulk load container of a vehicle.
The freeze and thaw cycles common during the winter months in the Northern United States and in Canada provide a number of challenges to bulk commodity haulers. Trucks and trailers used for the transportation of loose and moist materials such as sand or soil etc. in countries where the temperature drops below the freezing point, encounter unloading problems when the moist materials freeze on the walls and floor of the trailer and become hard to unload.
The transport of bulk goods during freeze/thaw cycles in commodity haulers such as walking floor trailers, belt clean-out trailers and the like is associated with weather related challenges. When the materials transported in the trailer freeze onto the moving slats, the moving slats may break and/or jam, leading to damage of the driving mechanism that operates them. The common solution to this problem is to drive the trailers into warm buildings and to wait for the frozen materials to thaw. In addition to the provision of a complete building being an expensive solution, it is just not possible to install a heated building at each unloading site. Moreover, this solution is very slow, since the heat supplied is absorbed not only by the bulk goods container, the only structure which needs to be heated, but many other structures, such as the trailer chassis and the whole truck and, of course, the whole building. Only a fraction of the supplied heat energy reaches the walls and floor of the bulk goods container. Also, a substantive amount of heat is lost to the atmosphere while the trailer is driven in and out of the building.
In dump trucks or dump trailers, if wet material is loaded and the ambient temperature is below the freezing point, the material will turn cold and freeze to the bed or bulk load container. In particular, the material will first freeze to the front and sidewalls and then to the floor, due to cooling by the slipstream while the truck is moved. Of course, not all the material will freeze at the same rate and normally the material will not freeze into a block before the destination is reached. The material will freeze to the side walls and the floor at different rates and to different degrees, so that when the dump is raised, bulk material stays stuck to the walls and floor. The freezing starts high on the side walls. The frozen material remains after dumping of the container, making the truck unstable. Also, the bulk material may end up being frozen more to one side of the trailer so that one side of the load will stay while the other side of the load will slip out during dumping. If the situation is not addressed or not detected, the vehicle may actually tip over in a turn, due to the high, unbalanced load. There have been many fatalities over the years because of unevenly loaded trailers tipping over. Sometimes only the trailer tips, but often both trailer and engine tip over, with possibly disastrous results. This problem is sufficiently well known and has a recognized effect on insurance premiums for bulk commodity haulers.
Truck dumpers and dump trailer bodies are known which include arrangements for heating the walls or floor of the truck bed, such as channels for hot exhaust gases from the engine or heated air from integrated or external heating arrangements. Although those arrangements assist in preventing the bulk goods from freezing to the walls and floor of the dumper, they are only effective at temperatures close to freezing and the same problems and dangers as discussed above are encountered at temperatures significantly below freezing.
It is, therefore, desirable to provide a more efficient and effective method for thawing frozen materials transported in a bulk goods container prior to unloading.
It is an object of the present invention to obviate or mitigate at least one disadvantage of previous arrangements for heating a truck.
In a first aspect, the present invention provides a heating apparatus for a trailer having a chassis and a bulk load container mounted on the chassis, the apparatus comprising a heating chamber for receiving the chassis, a heat source connected to the heating chamber for supplying heated gas to the chamber, and a seal mounted to the heating chamber for substantially sealing the heating chamber about the chassis and/or the container. The seal is preferably in the form of a plurality of flip-up seal panels rotatably attached to a top edge of the heating chamber walls. Alternatively, the seal is stationary on the walls and the walls are moveable to and from the chassis or the container to achieve sealing engagement of the seal with the chassis or the container.
In a further embodiment of the heating apparatus, the heating chamber is a drive-in chamber for permitting backing of the trailer into the chamber. Preferably, the drive-in heating chamber includes a floor, an end wall connected to an end of the floor and a pair of opposite side walls connected to opposite ends of the back wall and opposite sides of the floor, one of the walls being connected to the heat source for permitting passage of the heated gas across the wall and into the chamber, the end of the chamber which is opposite the end wall being open to allow entry of the trailer chassis into the chamber.
In another preferred embodiment, the heating chamber is a flip-up chamber erectable about the chassis, wherein the side walls are rotatably hinged to the floor. A heating apparatus with flip-up side walls allow the heating chamber to be used in space constrained areas where insufficient space is available for the trailer to be completely aligned with the chamber floor before entering the chamber. Having the side walls flipped down will allow the trailer to be directed into the chamber at an angle and only aligned with the floor once fully backed up against the end wall.
In another preferred arrangement, either in erect or flip-up configuration, the end wall is rotatalbly hinged to one of the side walls or to a stationary corner post mounted in a corner of the floor to allow swiveling of the end wall to a side. This allows the vehicle to be driven into the chamber in reverse when the end wall is in place, or in forward direction when the end wall is swiveled to the side. In the flip up configuration, this arrangement can also include 4 corner posts mounted to the corners of the floor and side walls which are either hinged to the floor or hinged to one of the corner posts. The side walls can also be divided into two or more sections individually hinged to the floor or the corner posts.
The heating apparatus may be stationary or portable. The portable heating apparatus can be of a fully assembled unitary construction, or can be in the form of a kit. The kit preferably includes an end wall connectable with the heat source for permitting passage of the heated gas through the end wall and a pair of sidewalls connectable to opposite ends of the back wall. More preferably, the kit further includes a floor panel to which the side and end walls are connectable. Most preferably, the floor panel is made of inter-connectable panels in order to facilitate assembly and tear down of the arrangement and transport from location to location.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
Generally, the present invention provides a method and system for thawing bulk materials frozen to a truck bulk load container or a trailer bulk load container. More particularly, the invention provides a heating apparatus 100 for a vehicle 20 having a chassis 22 and a bulk load container 24 mounted on the chassis 22 (see
A heating apparatus 100 in accordance with the invention and as illustrated in the Figures, includes a heating chamber 110 for receiving the chassis 22, a heat source 200 connected to the heating chamber 110 for supplying warmed up heating gas to the chamber, and a seal 150 mounted to the heating chamber 110 for substantially sealing the heating chamber 110 around the chassis 22 and/or the container 24, when the vehicle 20 is in the chamber 110, while leaving an exhaust opening for spent heating gas, preferably at an end of the chamber opposite the location of the heat source.
In the basic embodiment, as illustrated in
In a preferred embodiment as illustrated in
In the embodiments illustrated in the Figures, the heat source 200 is a pair of conventional combustion heaters (oil, gas, etc.) attached to the end wall 130. An end 112 of the chamber 110 opposite the end wall 130 is open to allow entry of the vehicle chassis 22 into the chamber 110 (see
The seal 150 may also be mounted to the top end 144 by any other attachment structure, such as flexible or elastic structures or webs, such as a living hinge, which allow the seal panels to be swiveled about the top end 144 between the sealing and open positions. Moreover, any other seal structure which is movable between the open and sealing positions can be used, as long as the seal structure in the open position does not impede the positioning of the vehicle into the heating chamber and in the sealing position is in a sealing engagement with the chassis and/or the container to impede heating air from escaping therebetween. For example, the seal can be moved in between the open and sealing positions in a manner other than rotationally, such a linear, for example by way of sliding tracks mounted on the outside of the side walls (not shown).
The heating apparatus 100 can be portable as illustrated in
The heating apparatus 100 can also be constructed as a flip-up chamber 110 erectable about the chassis 22. In the flip-up embodiment, at least one of the side walls 140, 142 is rotatably hinged to the floor 120 (see
In another preferred arrangement, the heating apparatus 100 is in a drive-through configuration in which the end wall 130 is rotatalbly hinged to one of the side walls 140, 142 (see
The portable heating apparatus 100 can be of a fully assembled unitary construction as shown in
The side walls and the floor panel can be unitary panels or can be assembled from subpanels. Preferably the side walls 140, 142 are assembled from subpanels 146, more preferably extruded, hollow aluminum panels welded together along their edges. Preferably, the floor panel 121 is assembled from subpanels 127, more preferably extruded, hollow aluminum panels welded together along their edges. When the heating apparatus is in the form of a kit, the floor panel 121 and the side walls 140 and 142 are preferably made of individual sub panels which are interconnectable for assembly of the apparatus. This will facilitate assembly and tear down of the heating arrangement kit and transport from location to location.
The stationary seal 150 on the end wall is preferably a cushioned seal, more preferably a loading dock cushion 155 that is compressible to avoid damage to the seal when the vehicle is backed into the seal. The seal panels on the sidewalls are preferably divided into two or more sections for ease of handling. The panels preferably have a large rubber flap 158 (see
As is apparent from
During use of the heating apparatus, the vehicle is backed in between the chamber sidewalls until the vehicle back end hits the loading dock cushion mounted on the chamber end wall and seals the back end from hot air escaping. Then the sealing panels are flipped up and in and come to rest on the bulk load container sides to seal the hot air in.
Once the vehicle is in place and the apparatus sealed against the container, the heat source can now be started up. Any type of heater can be used, but construction heaters are preferred. Construction heaters are robust and suited well for high volume throughput, are easy to use, often have an automatic starter arrangement and an automated fan or blower. Direct fired or indirect heaters can be used, which means the heating flame can go right into the heating chamber with exhaust included (direct fired) or the exhaust can be separate from the heated air (indirect fired). Indirect fired heaters generally include heat exchangers.
The hot gas from the heater flows down through the heating chamber and directly heats the floor and lower sides of the bulk container. Seal panels of different height can be used to reach up higher on the sides of the container, if desired, to heat all of the container sidewalls. After flowing along the container, the spent heating gases are exhausted out the open end of the heating chamber.
Although it is generally only necessary to heat the floor and sidewalls of the bulk load container for the load to release, the chamber sidewalls and the sealing panels can be extended in height for the seal between the sealing panels and the container to occur at the top edge of the container sidewalls. This may be required for applications far north where it may be necessary to heat substantially the whole container.
In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention.
The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
This application claims the benefit of priority of U.S. Provisional Patent Application No. 61/441,479 filed Feb. 10, 2011, the contents of which is incorporated herein by reference.
Number | Date | Country | |
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61441479 | Feb 2011 | US |