MXPA01002075A - Asphalt repair apparatus with dry, radiant heat source - Google Patents

Abstract

The apparatus (101) comprises:a body (103) adapted to be mounted on a portable base. The body (103) has a hopper (105) with a V-shaped bottom wall (107). A paddle shaft (131), a screw conveyor (127) and dry heat retort tubes (133, 135) mix and heat the asphalt mix materials to a workable state. Burner elements (137, 139) communicate with exhaust stacks (141, 143) via a U-shaped retort tube comprising legs (145, 147), and curved loop portion (149). An electric emersion heater (151) is included when utilizing a heat transfer fluid to heat the asphalt mix materials.

Description

APPARATUS FOR THE REPAIR OF THE ASPHALT WITH A SOURCE OF HEAT "*) DRY, RADIANT Description 5 Technical Field The present invention generally relates to portable devices mounted on trucks and / or trailers for distributing pavement repair materials, and specifically, with a portable device for distributing. repair materials for asphalt pavements.

Previous Art In the past, sometimes three vehicles were needed to repair openings and potholes in asphalt, concrete or other road surfaces. A vehicle provided an air compressor for use with various pneumatic repair tools that were used to fix the well, break or cavity to be filled. Another vehicle contained liquid asphalt binder material that was sprayed on the cavity arranged, and a third vehicle distributed the asphalt mixing material in the cavity. Then, the asphalt was covered, compacted and leveled by hand to complete the repair.

U.S. Patent No. 4,196,827, issued April 8, 1980, entitled "Portable Asphalt Products Transport Machine for Use in Repairing Asphalt Pavements" shows a portable machine that was designed to incorporate all the phases of pavement repair in a mobile unit. The machine has a tank to transport the asphalt mixture, and a tank under the tank that has a heat source. The tank contained liquid asphalt binder material. The heat source is used to heat the liquid binder material, and the binder material is used to heat the bitumen mixture in the tank by heat transfer. The asphalt binder material is also distributed from the binder material tank by means of a spray equipment connected to a dump valve on the back of the truck. Instead of being less expensive to operate from the point of view of material and work, the previously described device had several disadvantages. For example, the liquid asphalt tank in the unit was suitable for oil and road return cuts but was not suitable for use with asphalt cements. In addition, in the case of the device described in the '827 patent, the liquid asphalt tank was not suitable for use with asphalt emulsions, because the volatile contents of the emulsions would go and dry the materials. U.S. Patent No. 4,944,632, issued July 31, 1990 and assigned to the assignee of the present invention, showed a portable unit with a separate binder oil reservoir that was supplied with its own heat source and that was designed to prevent phase separation of binder petroleum materials to overcome some of the deficiencies of prior art devices. This tank could be used successfully with both the emulsions and the asphalt return cut oils. Both prior art devices used a liquid heat transfer medium to heat the asphalt tank of the device and keep the asphalt mixing materials therein in a workable condition. While a liquid heat transfer medium has been used satisfactorily for many years to heat the asphalt tank, there are disadvantages associated with the use of a liquid medium. Many of these disadvantages are related to the release of volatile components from the medium while they are heated repeatedly during use. The liquid medium should also be maintained and / or replaced at regular maintenance intervals.

Accordingly, it is an object of the present invention to replace the liquid heat transfer medium used in the prior art to heat the tank compartment of an asphalt repair apparatus with a dry, radiant heat source that does not require filling and that does not emit volatile organic emissions into the atmosphere. Another object of the invention is to provide said source of dry, radiant heat for an asphalt repair apparatus whose heat source safely and effectively heat the unhardened asphalt repair materials, burn or carbonize said materials. Another object of the invention is to provide an apparatus that is simple in design and economical for processing.

Disclosure of the Invention The portable apparatus of the invention is used to transport heated pavement repair materials for use in the repair of roads and other traffic surfaces. The device includes a body adapted to be mounted on a portable base to transport the body to a repair location. The body has a tank compartment with a V-shaped bottom wall for transporting the asphalt mixing material and a generally V-shaped heating chamber below the tank compartment. The lower V-shaped wall of the tank compartment defines an upper end of the heating chamber. An endless screw conveyor is mounted in the lower part of the tank compartment to distribute the asphalt mixing materials from there. An agitator, such as a paddle, is located under the worm conveyor in the tank compartment to agitate the tank materials. A dry heat medium is connected to the heating chamber to heat the chamber and to transfer the heat to the tank compartment through the bottom wall of the tank to maintain the asphalt mixing materials in a state in which they are heated. can work Preferably, the V-shaped bottom wall of the tank compartment forms an upper wall, not insulated with the heating chamber. The heating chamber also has insulated bottom wall proportions that extend in an opposite manner. In a preferred embodiment of the invention, the dry heat means comprises a pair of retort tubes arranged opposite each other located within the heating chamber on each side of the lower wall of the tub. The retort tubes are heated by a thermostatically controlled gas burner to supply dry, radiant heat to the bottom wall of the tub. Each retort tube forms a simple pass circuit having a lighter installed at one end thereof and communicating with an exhaust pipe at the opposite end thereof. In a preferred arrangement, each retort tube is provided in the shape of an inclined U in a plane that is generally parallel to one selected from the isolated bottom wall portions that extend in opposite manner from the heating chamber. Each retort tube has a pair of outputs to the outside of the tank, one of the outputs has the lighter mounted on it and the other is connected to the exhaust pipe. The additional objects, features and advantages will be apparent in the written description, below.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top view of a portable device of the prior art for transporting asphalt repair materials; Figure 2 is a side, partial, cross-sectional view of the device of Figure 1 taken along lines 2-2 in Figure 1; Figure 3 is a terminal view of one end of the asphalt distribution device of Figure 1; Figure 4 is a terminal view, showing the opposite end of the device of Figure 1; Figure 5 is a perspective view, partially separated, of the improved body used with the apparatus of Figure 1 showing the screw conveyor, the vane and the dry, radiant heat source thereof; and Figure 6 is a partial, cross-sectional terminal view of the improved device of Figure 5.

Q Best Mode for Carrying Out the Invention The advantages of the present invention can be better understood with reference to the prior art device of the Applicant which used a liquid medium for heat transfer. Accordingly, going back to Figure 1, the commercially available design of the Applicant designated generally as 11 is shown. The device 11 includes a body 13 which is generally rectangular in shape and which is adapted to be mounted on the base of a truck, or on a trailer that will be towed by a Q vehicle. The truck or trailer will serve as a portable base to transport the body 13 to the repair site to repair a pothole in the asphalt pavement. As best seen in Figure 2, the body has a tank compartment 15 with a bottom wall in the form of 5 V 17 (Figure 3) for transporting asphalt mixing materials. In this debate, "asphalt mixing" materials means a pre-mix or aggregate of hot or cold asphalt mix and asphalt aggregate. The term "binder oil" means asphaltic cements, liquid asphalts, and asphalt emulsions of the type transported in a separate binder oil reservoir, as will be described. The upper part of the tank compartment 15 is open, and is covered with material to protect and isolate during use. A heat transfer oil reservoir 19 (Figure 3), which is also V-shaped, is located immediately below the lower wall 17 of the tub compartment 15 in the prior art device. The heat transfer oil reservoir 19 includes an upper wall 21 of the tank compartment 15. The heat transfer oil tank 19 is heated by a propane tube retort lighter 23. The propane burner has a heat transfer system. electric ignition and preferably is controlled with a built-in safety valve that includes two heating elements 25, 27 to be used when the asphalt mixing materials are left in the tank overnight or during the weekend, as shown in Figure 2, an electric oil circulation pump for heat transfer 29 causes the oil for heat transfer to flow through a conduit opening 31 through the circulation conduit 33 at the bottom of the reservoir 19 and emptied into the upper part of the reservoir 19 through the opening of the conduit 35. When the transfer oil is heated In the tank with the lighter 23 or the heating elements 25, 27 and circulating the oil with the pump 29, the asphalt mixture in the tank compartment 15 can be heated uniformly by transferring heat through the tank. of the bottom wall 17. The mixture of asphalt in the tank compartment 15 is discharged with a worm conveyor 37 which is hydraulically operated, mounted on suitable bearings 39, 41, so as to extend into an opening (43 in FIG. Figure 1) inside the tank compartment 154. The screw conveyor 37 is driven by a motor 45 that can be driven by a power start mounted directly by the truck transmission. A stirring shaft of the asphalt 47 (Figure 2) having blades 49 is mounted within the tank compartment 15 by suitable bearings 51, 53 and by a support bracket 55. The agitating shaft 47 is driven by a hydraulic motor 57 which can be driven by the same pump that supplies power to the screw conveyor. The agitation shaft 47 extends over the total length of the tank compartment, and the movement of the shaft eliminates the binder property of the asphalt or bridge connection on the worm conveyor. A separate binder oil reservoir 59 is mounted on the portable base at one end of the tub compartment 15 to transport and distribute binding oils including road oils, return cuts, asphalt cements, liquid asphalts and emulsions. The binder oil tank 59 is surrounded by an insulating layer 61 which also separates the tank from the asphalt mixture in the tank compartment 15. The circulation medium, such as a duct 63 and an on-off valve 64, it communicates with the heat transfer oil tank 29 and the separate binder oil reservoir 59. The circulation medium also includes conduits for heat transfer, in this case the coils 65 which are located inside the separate tank 59 and which is communicated by means of a conduit 67 with the opening 35 of the duct that empties the heat transfer oil again in the upper region of the transfer oil tank Heat 19. The circulation medium is completely enclosed within the body of the portable device and for this reason is isolated from the atmosphere. The separate binder oil reservoir 59 has a propane gas retort tube 69, as well as an electric heating element 71 thermostatically controlled to maintain the heat of the binder oil reservoir 59 overnight. These two heating systems are separate from the heat transfer ducts 65 to circulate the heat transfer oil from the reservoir 19. As shown in Figure 4, the separate binder oil reservoir 59 is provided with a liquid asphalt pump 73 and a pump motor 75 for distributing binding oils through a manually held rod (77 in FIG. 3) that is connected to the pump 73 by intermediate lines 79. At the front end 81 of the portable device 11 (FIG. 4) there are 3 flasks of propane 83, 85, 87, which can be removed that are full of valves and a regulator to supply fuel for the propane lighters of the retort tube 23, 69. The distribution end (89 in the Figure 3) of the portable device 11 also has lines of hydraulic tools 91 for a hydraulic drilling hammer (not shown) for cutting the asphalt and matching the potholes. The lines of hydraulic tools 91 are turned on from the hydraulic pump that is driven by the transmission of the truck. A 15 gallon diesel fuel tank 93 is provided in the left corner of the distribution end 89. Tank 93 can be connected to a sprinkler by an electric pump for use in cleaning the asphalt tank, asphalt duct (95 in Figure 2) and other tools. The hydraulic system used to ignite the worm conveyor, the agitator, the binder oil pump and the drilling hammer is controlled by manual valves 97 located at the distribution end 89. In operation, the oil for heat transfer in the tank 19 is heated by the propane burner 23, which in turn heats the asphalt in the tank compartment 15. The heat transfer oil circulates inside the tank 19 by means of the conduit 33 and the opening 35 and the Heat transfer oil circulates within the separate binder oil reservoir 59 through conduit 63 to heat the binder oil reservoir. The heat transfer oil is not mixed with the binder oil but circulates through the transfer conduits 65 and again through conduit 67 to the heat transfer oil reservoir 19. In the workplace, the hydraulic tools Suitable ones are connected to lines 91 so that repairs can be accomplished quickly. Spray equipment such as the rod 77 can be connected to the discharge valve 99 to distribute liquid asphalts or emulsions to seal and bind the arranged cavity. The screw conveyor 37 is then driven to distribute the asphalt mixing materials from the tank compartment 15 through the conduit 95 within the cavity as required. The filled cavity is then compacted with a hydraulic piston to complete the job. The present invention is directed to improvements in the compartment 15, heat transfer compartment 19 and the mechanism for heat transfer to the lower wall 17 of the tank compartment to maintain the asphalt repair materials contained therein in a been in which they can work. Figures 5 and 6 illustrate the improved device of the invention generally designated 101. The device includes a body 103 that is adapted to be mounted on a portable base. The body has a compartment of the tank 105 (Figure 5) with a V-shaped bottom wall 107 for transporting asphalt mixing materials. As best seen in Figure 6, the V-shaped lower wall of the tank compartment forms a common, non-insulated upper wall 119 of a V-shaped heating chamber 121. The V-shaped heating chamber 121 it is thus placed below the tank compartment 115 with the V-shaped bottom wall of the tank compartment defining an upper end of the heating chamber 121. The heating chamber also has isolated portions of the lower wall that they extend in opposite manner, 123, 125, as shown in Figure 6. As shown in Figures 5 and 6, the body 103 of the portable device is also equipped with an endless screw conveyor 127 which is mounted on the lower region 129 of the tub forming a channel-like opening extending longitudinally along the lower wall thereof. As previously described, the screw conveyor 127 is used to distribute asphalt mixing materials contained within the tank. A stirring means, such as a vane shaft 131 is located on the worm conveyor 127 in the tank compartment 115 to agitate the tank materials contained therein. A dry heat medium is associated with the heating chamber 121 for heating the chamber and for transferring heat to the tank compartment 115 through the bottom wall of the tank 117 to keep the asphalt mixing materials contained therein in the tank. a state in which you can work. Preferably, the dry heat means comprises a pair of retort tubes arranged opposite each other. side of the V-shaped bottom wall of the tank. The retort tubes are each heated by a 150,000 btu retort tube propane burner. The lighters are thermostatically controlled and regulated at 10 psi. Commercially available ignition systems use a J.Q electronic ignition DC 12 volts. The gas burner is preferably provided with a safety valve due to flame loss or excessive temperature. The lighter, the ignition and safety valve system commercially available for the retort tubes can be obtained from H.

D. Industries, Inc., of Jacksonville, Texas. The commercially available lighter has two stages, ignites in 10 ounces of pressure and operates at 10 psi. The retort tubes are used to supply dry, radiant heat to the lower wall of the tank compartment. 2Q As shown in Figures 5 and 6, each retort tube 133, 135 forms a single pass circuit having a lighter 137, 139 installed at one end thereof and communicating with an exhaust duct such as exhaust pipes 141, 143 at an opposite end thereof (Figure 5) . As best seen in Figure 5, each retort tube 133, 135 is provided in the shape of an inclined U that is disposed in a plane that is generally parallel to that selected from the isolated bottom wall portions extending from opposite way (123, 125 in Figure 6) of the heating chamber 121. Each retort tube 133, 135 thus has a pair of outlets to the outside of the tank. One of the outputs has the lighter mounted therein while the other communicates with the exhaust pipes 141, 143 as an exhaust duct. Each U-shaped retort tube includes a first member 145 (Figure 5) containing the lighter 139 and a second opposite extending member 147 leading to the exhaust pipe 143. The two members 145, 147 are connected by a curved circuit portion, 149. As shown in Figure 6, the heating chamber 121 can also be provided with an electric emersion type heater 151 as described with respect to the prior art apparatus. As best seen in Figure 6, the heating chamber 121 further includes a pair of heating baffles 153, 155 which are mounted next to the screw conveyor 127 of the tub. Each heat deflector is arranged to extend along a first member of a respective retort tube to partially protect the region of the worm conveyor from the dry heat source. The apparatus of the invention may also include a separate liquid asphalt tank mounted on the portable base for transporting and distributing liquid asphalt-type materials used to plug a pothole before distributing the asphalt mixing materials from the tub. The separate liquid asphalt tank can take the shape of the tank shown as 59 in Figure 2 of the drawings. The separate liquid asphalt tank may also take the form of the tank described in U.S. Patent No. 4,944,632, supra, assigned to the assignee of the present invention. The tank is provided with an internal circulation system to keep the liquid binding oils in an emulsified state. In the method of this invention, the portable base as previously described is used to transport asphalt mix type materials to a repair location. The V-shaped heating chamber located below the tank compartment is used to heat the asphalt mixing materials. The vane 131 is used to agitate the materials of the vat with the auger conveyor 127 which is used to distribute the materials therefrom. The lighters 137, 139 are used as a source of dry heat connected to the heating chamber to heat the chamber and to transfer heat to the tank compartment through the bottom wall of the tank to maintain the asphalt mixing materials in the tank. a state in which they can work. An invention with several advantages has been provided. The device is simpler and more economical to elaborate than prior art devices of the same general type. By using a dry, radiant heat source, the volatile constituents that have asphaltene or other components are not released into the atmosphere, thereby providing a more environmentally compatible operation. By eliminating the use of a liquid heat transfer medium, the tank compartment can be heated more economically without the need to refill the heat transfer medium or maintain said medium. Although the invention has been shown only in one of its forms, it is not limited in this way but is susceptible to several changes and modifications without departing from the spirit of the same.

Claims (1)

1. CLAIMS 1. A portable device for transporting asphalt repair materials for use in the repair of potholes in asphalt pavements, the device comprises: a body adapted to be mounted on a portable base to transport the body to the repair site, the body has a vat compartment with a V-shaped bottom wall for transporting the asphalt mixing materials and a generally V-shaped heating chamber located below the vat compartment, the V-shaped bottom wall of the vault compartment Cuba defines an upper end of the heating chamber: an endless screw conveyor in the lower part of the tank compartment for distributing asphalt mixing materials therefrom; a pallet located above the worm conveyor in the tank compartment to stir the tank materials; a dry heat medium connected to the heating chamber for heating the chamber and for transferring heat to the tank compartment through the bottom wall of the tank to maintain the mixing materials of the asphalt in a workable condition. The device of claim 1, characterized in that the lower V-shaped wall of the tank compartment forms a common, upper wall not insulated from the heating chamber, the heating chamber has isolated portions of the lower wall extending from opposite way. The device of claim 2, characterized in that the dry heat means comprises a pair of opposingly arranged retort tubes located inside the heating chamber on each side of the V-shaped bottom wall of the tub, the tubes of retort are heated by a thermostatically controlled gas burner to supply dry, radiant heat to the bottom wall of the tub. The device of claim 3, characterized in that each retort tube forms a single pass circuit having a lighter installed at one end thereof and communicating with an exhaust pipe at an opposite end thereof. The device of claim 4, characterized in that each retort tube is provided in the form of an inclined U disposed in a plane that is generally parallel to one selected from the isolated bottom wall portions that extend in opposite manner from the chamber of heating, each retort tube has a pair of exits to the outside of the tank, one of the outputs has the lighter mounted on it and the other is connected to the exhaust pipe. The device of claim 5, characterized in that the U-shaped retort tube includes a first member that contains the lighter and a second member that extends in an opposite manner that leads to the tube. - * -) exhaust and where the heating chamber further includes a stop of heat deflectors mounted therein in proximity to the worm conveyor of the tank, each heat deflector is arranged to extend along a length of first member of a tube of 20 retort to partially protect the conveyor region from the worm screw. 5 A portable device for transporting asphalt repair materials for use in repairing potholes in asphalt pavements, the device comprises: a body adapted to be mounted on a portable base to transport the body to the repair site, the body has a vat compartment with a V-shaped bottom wall for transporting asphalt mixing materials and a generally V-shaped heating chamber located below the vat compartment, the V-shaped bottom wall of the vault compartment the tub defines an upper end of the heating chamber; an endless screw conveyor in the lower part of the tank compartment to distribute asphalt mixing materials from there; a pallet located above the worm conveyor in the tank compartment to stir the tank materials; a dry heat medium connected to the heating chamber for heating the chamber and for transferring heat to the tank compartment through the bottom wall of the tank to maintain the mixing materials of the asphalt in a workable condition; wherein the dry heat means comprises a pair of retort tubes disposed opposite each other located within the heating chamber on each side of the bottom wall of the tub. The retort tubes are heated by a thermostatically controlled gas burner to supply dry, radiant heat to the lower wall of the tub; where each retort tube retort tube forms a simple pass circuit having a lighter installed at one end thereof and communicating with an exhaust pipe at the opposite end thereof, each retort tube is provided in the form of an inclined U in a plane that is generally parallel to one selected from the isolated lower wall portions that extend opposite from the heating chamber, each retort tube has a pair of outlets to the outside of the tank, one of the outputs has the lighter mounted on it and the other is connected to the exhaust pipe. The device of claim 7, further comprising: a liquid asphalt tank mounted on the portable base for transporting and distributing liquid asphalt-type materials used to fix the pothole before distributing the asphalt mixing materials. A method for repairing a pothole in an asphalt pavement, comprising the steps of: providing a body in a portable base for transporting the body to the repair site, the body having a tub compartment with a V-shaped bottom wall for transporting asphalt mixing materials and a generally V-shaped heating chamber located below the tank compartment, the V-shaped bottom wall of the tank compartment defines an upper end of the heating chamber; provide an endless screw conveyor mounted in the lower part of the tank compartment to distribute asphalt mixing materials therefrom; provide a pallet located above the worm conveyor in the tank compartment to agitate the tank materials; use a dry heat medium connected to the heating chamber to heat the chamber and to transfer heat to the tank compartment through the bottom wall of the tank to keep the mixing materials of the asphalt in a condition in which they can be worked; and distributing asphalt mixing materials from the tank compartment to fill and repair the pothole. 10. The method of claim 9, characterized in that the heat is supplied to the heating chamber by means of a pair of opposingly arranged retort tubes located within the heating chamber on each side of the V-shaped bottom wall of the tub, the retort tubes are heated by a thermostatically controlled gas burner to supply dry, radiant heat to the bottom wall of the tub. 11. The method of claim 10, further comprising the steps of: providing a liquid asphalt tank mounted on the portable base for transporting and distributing liquid asphalt type materials; distribute liquid asphalt material to fix the pothole to distribute asphalt mixing materials.