Apparatus and control system for heating asphalt
OwnerGeorge F. Thagard, Jr.inventor
Life of this patent
Estimating the term…
Abstract
An apparatus is disclosed for melting asphalt and for maintaining it in a molten condition without producing by-products harmful to the atmosphere. The asphalt is heated and maintained in a liquid state in an enclosed vessel by transferring heat from a heating means through inner wall portions of the vessel. Air polluting by-products are minimized due to the increased surface area heating the asphalt and the resulting reduced thermal gradient which prevents decomposition of the asphalt. A control system for selectively controlling the heating of the asphalt in a manner which reduces the production of air polluting products is also disclosed.
Claims38
An apparatus for heating and maintaining an asphalt material to temperatures within a preselected range which comprises an enclosed vessel configured to contain the material in at least one of a solid and liquid state, inlet means for introducing the material into the vessel in at least one of a solid and liquid state, means for heating at least one of the wall portions of the vessel to maintain the temperature of at least one of the inner wall portions which contact the material therein and the material in the vessel above the melting temperature and below the decomposition temperature of the asphalt material, the surface area of heated wall portions contacting the material being sufficient to transfer heat to the material at least sufficient to maintain the temperature of the material to within said preselected range in a manner to avoid causing substantial decomposition thereof, control means for selectively controlling the temperatures of the heating means to maintain at least one of the inner wall portions of the vessel contacting asphalt material thereon and the asphalt material in the vessel within said preselected temperature range, venting means communicating an upper portion of the vessel with an atmosphere outside of the vessel, filtering means capable of filtering vapors such as condensible hydrocarbon vapors communicating with said venting means, and outlet means for removing the material from said vessel.
An apparatus for heating and maintaining an asphalt material to temperatures within preselected ranges, comprising an enclosed vessel configured to contain the material in at least one of a solid and liquid state, inner surface portions of the vessel defining at least first and second upper and lower heating zones, each having boundaries generally parallel to a horizontal plane when the apparatus is in a horizontal rest position;
- inlet means for introducing the material in at least one of a solid and liquid state;
- means for heating the heating zones of the vessel to maintain the temperature of the heating zones and the material in the vessel, within preselected temperature ranges, the surface area of the heating zones contacting the material being sufficient to transfer heat to the material to at least maintain the temperature of the material to within said preselected ranges while maintaining substantially all portions of the material below the decomposition temperature of the asphalt material;
- control means associated with each heating zone for independently controlling the temperatures of the separate heating zones to maintain the asphalt material in the vessel within said preselected temperature ranges;
- venting means communicating an upper portion of the vessel with an atmosphere outside of the vessel;
- outlet means for removing the material from said vessel;
- and means for transporting the vessel.
An apparatus for heating and maintaining asphalt in a molten condition and below its decomposition temperatures which comprises:
- a. an enclosed vessel configured to contain the asphalt in its liquid state, said vessel being comprised of an inner vessel and an outer vessel enclosing the inner vessel in spaced relation therewith to define a peripheral chamber therebetween, said vessel further being divided in upper, middle, and lower heating zones;
- b. independent electrical heating elements associated with each heating zone and secured to outer surface portions of said inner vessel adjacent each respective zone and in thermal conductive relation therewith;
- c. an electrical generator adapted for producing and transmitting electrical power to said heating elements so as to produce heat for heating the wall portions of the inner vessel;
- d. an internal combustion engine adapted to produce and supply motive power to said electrical generator;
- e. at least one venting means communicating between an upper portion of the inner vessel and the input end of a canister type filtering means, said filtering means having a filtering material therein capable of removing volatile hydrocarbon vapors from gases exiting from the inner vessel;
- f. means for connecting the output of the filtering means with the air/fuel inlet of said internal combustion engine such that atmospheric polluting hydrocarbon vapors which pass through the filtering means are burned with fuel in said engine;
- g. independent sensing means for detecting the temperature of the inner walls of said vessel at each of said heating zones and producing a signal in accordance therewith;
- h. means for preselecting the temperature desired in each heating zone;
- i. electrical control means associated with each heating zone adapted for independently controlling the temperature developed in each heating zone in accordance with the signal produced by the sensing means associated with the respective heating zone and for deactivating the heat supplied to each heating zone;
- j. an input means for introducing asphalt material into said vessel;
- k. means for sealing the input means in a manner to prevent air polluting vapors from exiting therefrom;
- l. a pumping means for removing asphalt from the vessel in its liquid state;
- m. a power source for operating the pumping means;
- n. means for directing the liquid asphalt removed from said vessel onto surfaces requiring the application of asphalt;
- o. wall members laterally positioned within said inner vessel in a manner to prevent excessive splashing of the molten asphalt during transit;
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- p. a movable trailer supporting the vessel and associated equipment, said trailer having means for attaching it to a motor vehicle for transporting the apparatus from place to place.
A system for heating a material such as asphalt in at least one of a solid and liquid state in an enclosed vessel defining at least two heating zones, and for independently controlling the temperatures of each heating zone within preselected temperature ranges which comprises:
- a. at least one electrical heating element associated with each heating zone and positioned adjacent wall portions of the vessel in thermal conducting relation with the inner wall portions thereof;
- b. an electrical generator means adapted to produce and supply electrical current to said electrical heating elements;
- c. means for supplying power to said electrical generator means for producing said electrical current supplied to said heating elements;
- d. means for sensing the temperature attained in each heating zone;
- e. a temperature regulator associated with each heating zone, each regulator having means for preselecting the temperature desired to be attained in the associated heating zone;
- f. means for transmitting a signal from each temperature sensing means to the associated temperature regulator in accordance with the temperature attained in the associated heating zone;
- g. means in each temperature regulator for producing a signal in accordance with the difference between the preselected temperature and the temperature actually attained in the associated heating zone;
- and
- h. a control circuit adapted for receiving the signal produced by the associated temperature regulator and for transmitting electrical energy from said electrical generator means to said electrical heating elements in relation to the signal produced by said temperature regulator such that the electrical energy supplied to said heating elements and the heat transmitted to each heating zone by the associated heating elements is produced in accordance with the difference between the preselected temperature and the temperature actually attained in the associated heating zone.
An apparatus for heating and maintaining an asphalt material to temperatures within preselected ranges, comprising an enclosed vessel configured to contain the material in at least one of a solid and liquid state, inner surface portions of the vessel defining at least first and second upper and lower heating zones, each having boundaries generally parallel to a horizontal plane when the apparatus is in a horizontal rest position;
- inlet means for introducing the material in at least one of a solid and liquid state;
- means for heating the heating zones of the vessel to maintain the temperature of the heating zones and the material in the vessel, within preselected temperature ranges, the surface area of the heating zones contacting the material being sufficient to transfer heat to the material to at least maintain the temperature of the material to within said preselected ranges in a manner to avoid causing substantial decomposition thereof;
- control means associated with each heating zone for independently controlling the temperatures of the separate heating zones to maintain the asphalt material in the vessel within said preselected temperature ranges;
- venting means communicating an upper portion of the vessel with an atmosphere outside of the vessel;
- and outlet means for removing the material from said vessel.
A method of processing asphalt material for application to a surface in a molten state comprising the steps of:
- a. introducing the asphalt material into a portable container, the walls of the container being thermally insulated from inside the vessel to an atmosphere outside the vessel;
- b. directing heat to an inner wall portion of the container which contacts molten asphalt material having a combined surface area to maintain and control the temperature of the asphalt material above the melting temperature and below the decomposition temperature of the asphalt material;
- c. controlling the temperature of heated inner wall portions of the vessel which contact the asphalt material to within the temperature range above the melting temperature and below the decomposition temperature of the asphalt material, the surface area of the heated inner wall portions which contact the asphalt material being sufficient to transfer heat to the asphalt material at least sufficient to maintain the asphalt material in a molten condition in a manner to avoid causing substantial decomposition thereof;
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- d. discharging molten asphalt material from the container for application to the surface.
Dependencies are inferred from the claim text.