US3800858A

US3800858A - Railway car thawing system

Info

Publication number: US3800858A
Application number: US00219307A
Authority: US
Inventors: E Placek
Original assignee: Van Dorn Co
Current assignee: Van Dorn Co
Priority date: 1972-01-20
Filing date: 1972-01-20
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02

Abstract

Apparatus and methods are disclosed for thawing frozen particulate material such as coal disposed in a railway car. Thawing is achieved by heating the sidewalls and bottom of the car and the exposed upper surface of the particulate material by means of a heat source such as infra-red generators and flowing water downwardly through the particulate matter. The water functions to cool the heated surfaces of the car, the exposed surface of the particulate material and areas of the particulate material inwardly adjacent these surfaces and to transfer heat from these areas to inner regions of the mass of particulate material in the car to enhance thawing of the material. The bottom of the car is heated by directing heat downwardly and inwardly beneath the car and reflecting or reradiating the heat upwardly towards the bottom of the car by means of suitable reflective material, or a bed of heat radiating particulate material.

Description

United States Patent 1191 1111 3,800,858

Placek Apr. 2, 1974 RAILWAY CAR THAWING SYSTEM Primary Examiner-Granville Y. Custer, Jr. [75] Inventor: Eugene W. Placek, Parma, Ohio Attorney Agent or Firm-Meyer T'lberry & Body [73] Assignee: VanDorn Company, Cleveland,

Ohio 7] ABSTRACT [22] Filed: Jan. 20, 1972 Apparatus and methods are disclosed for thawing frozen particulate material such as coal disposed in a rail- [211 Appl' 219,307 way car. Thawing is achieved by heating the sidewalls and bottom of the car and the exposed upper surface Cl of the particulate material by means of a heat source 05/451 such as infra-red generators and flowing water down- [51] Int. Cl. F28c 3/00 wardly through the particulate matter. The water Field 0f Search functions to cool the heated surfaces of the car, the exposed surface of the particulate material and areas 126/2711; /1 of the particulate material inwardly adjacent these surfaces and to transfer heat from these areas to inner re- [56] References Cited gions of the mass of particulate material in the car to UNITED STATES PATENTS enhance thawing of the material. The bottom of the 752 59s 2/1904 Schwend 291 21 x Car is heated by directing heat downwardly 1,3021533 5 1919 Foote.......... 52.. 105/451 wardly beneath the Car and reflecting 0r refadialing 2,598,293 5 1952 Parker et al. 104 1 the heat p y towards the bottom of the car y 2,507,775 5/1950 Forsylhe et al.... 105/451 X means of suitable reflective material, or a bed of heat l,357,3()5 l 1/1920 Alvord l()5/45l radiating particulate material. 3,5l3,779 5/l970 Aitkcn lO4/I 32 Claims, 5 Drawing Figures PMENTH] APR 2 I974 sum 1 or z RAILWAY CAR THAWING SYSTEM This invention relates to the art of thawing frozen or partially frozen particulate material and, more particularly, to the thawing of a mass of particulate material disposed in or on support means therefor.

The invention is particularly applicable to the thawing of a mass of particulate material disposed in an open top railway car and will be described in detail in conjunction therewith. It will be readily appreciated, however, that the invention may be employed in conjunction with the thawing of a mass of particulate material disposed in or on support means other than such a railway car and which might be defined, for example, by a hopper, storage container, an underlying support surface such as the ground, or various types of conveyor means.

Particulate material such as coal, coke, iron ore, sand, gravel and many others are transported in large quantities by means of open top railway cars. The moisture content of the particulate materials and/or moisture added thereto as a result of inclement weather conditions causes the particulate material in a given car to freeze when transportation of the car carries it into a region where the ambient temperatures are freezing. Often, such freezing temperatures are well below F. The depth of freeze inwardly of the mass of material will vary depending on factors such as time of exposure to freezing temperatures. If the frozen material can not be readily and economically thawed, removal of the particulate material from the car when it reaches its destination can not be achieved, whereby the particulate material is not available to the purchaser or receiver for use, and further use of the car in which the material is disposed is delayed. Further, such detention of a car often results in a monetary penalty being imposed on the receiving party in the form of a demurrage charge. As an example of the complexity and magnitude of the problem, a user of coal was compelled, during a single period of freezing weather conditions, to hold 8,000 loaded coal cars which could not be dumped due to the freeze condition. The frozen conditions lasted for a period of over 100 days during which time the receiver was compelled to pay a demurrage charge of $3.00 per day per car. The demurrage charge alone amounted to $2,400,000. In addition to the demurrage charge, the receiver experienced production loss as a result of the unavailability of the coal. In this respect, each car contained approximately 70 tons of coal, whereby a total of approximately 560,000 tons was lodged with the receiver but unavailable for his use. Such production loss together with demurrage charges necessarily reduces the users profits or is reflected by an increase in the cost of his products.

When it is considered that there are approximately 1,000,000 railway cars per year in this country carrying coal or other particulate material which is frozen therein to the extent that removal is not readily achievable, whereby detention of the cars at their destination is required, the total scope of the problem will be apparent. Moreover, in addition to the specific financial problems set forth in the foregoing example, it will be appreciated that further expense is involved in the provision and maintenance of adequate siding for storage of the detained cars, and that the detention of cars denies their availability for use during the detention pcriod. Such unavailability may adversely effect the production or other operations of other parties.

Attempts have been made heretofore to overcome these and other problems relating to thawing frozen particulate material. In this respect, for example, railway cars have been provided with steam lines disposed therein and connectable with a source of steam located at the car destination. When the steam lines and source are interconnected steam is introduced into the car to thaw the frozen particulate material. An arrangement of this nature is undesirable for many reasons including the fact that the steam lines are subjected to damage and clogging by the particulate material. Moreover, the provision and operation of steam producing equipment is expensive. Still further, the time required for the steam to effectively thaw the frozen mass is undesirably long.

Other schemes heretofore devised for thawing the contents of railway cars have included the use of heating devices for heating the outer surfaces of the car and the exposed surface of the particulate material. Such heating devices may include electric heaters, gas fired burners, and the like, positioned to direct heat toward the sides and/or bottom of the car. Prior arrangements of this nature are disadvantageous in that the heating of the car and material must be maintained below a predetermined temperature level in order to protect the car and material from the effects of heat. In this respect, if the temperature of the car or material exceeds a predetermined level the materials may catch on fire and/or the paint on the car may be adversely effected and/or components of the car such as hose connections may be adversely effected. Further, when heating of the car material is maintained at a safe level the thawing process is extremely slow whereby the expense thereof is increased. Slowness of thawing results in part from the fact that the thermal conductivity of coal and ice is very low, whereby the conduction of heat inwardly of the mass is very poor. Adding to the slowness of the thawing process is the fact that the layer of particulate material adjacent the walls of the car becomes dehydrated as a result of the heating and this dehydrated layer further blocks heat conduction inwardly of the mass of material. It will be appreciated too that dehydration further increases the possibility of ignition of the particulate materials.

The foregoing disadvantages and other of prior systems for thawing particulate material are advantageously overcome in accordance with the present invention. In this respect, the present invention in its broadest aspect provides a method of thawing particulate material and especially coal by heating at least a surface area of the particulate material and/or support means therefor and flowing a liquid over and through the particulate material to transfer heat from the surface area to inner regions of the material. Such heating of a surface area of the support means and/or particulate material causes a portion of the material inwardly adjacent the surface area to be heated. The liquid in flowing over and through the particulate material provides a heat transfer medium effective to transfer heat from the surface area and adjacent portions of the material in a manner whereby inner regions of the mass of particulate material are effectively heated to thaw the material in these regions. Moreover, by transferring heat to the inner regions in this manner, the time required to thaw the mass is advantageously reduced.

Further, the outer surfaces of the support means and particulate material and the inwardly adjacent areas of the material are cooled by the liquid to the extent that the temperatures thereof are maintained well below temperatures which would adversely effect the support means or cause ignition of the material.

In accordance with another aspect of the present invention, the heating of a surface area of the material and/or support means therefor is advantageously achieved by the use of heating means which are, preferably but not limited to, gas fired infra-red generator units. The generators are suitably positioned to radiate heat toward the desired areas of the material and/or support means and provide the most effective, efficient and economical means for achieving the desired thermal characteristics.

In accordance with yet another aspect of the present invention the support means for the particulate material is a railway car having bottom wall means and the latter is effectively heated by directing heat downwardly and inwardly of the car beneath the bottom wall means and then upwardly toward the bottom wall means. This arrangement advantageously provides for heating the bottom wall means by the use of heater means which are positioned laterally outwardly of the car and above the underlying support surface therefor. Thus, the heaters are advantageously disposed in positions in which they are protected from dirt, liquid, and other foreign substances which might effect their operation. The infra-red radiation output from these generators may be reflected and/or reradiated by suitable means disposed or placed beneath the car and in the position required to achieve the desired reflection and- /or reradiation. A bed of particulate material disposed beneath the car provides a desirable surface for this purpose. Any suitable particulate material can be used such as, for example, glass, calcite, feldspar, quartz, Obsidian, or mica. It is believed that these materials as well as others which might be used such as ballast type materials direct heat toward the bottom wall primarily by radiation. At the same time, however, it is believed that the materials reflect heat to some extent. Thus, heat is direct by reflection and/or radiation toward the bottom of the car. Selection of the particulate material for the reflecting and/or radiating means will depend, in part, on the availability thereof and cost. Obsidian provides the best material, but is difficult to obtain. Calcite (white marble chips) feldspar (washed gravel) and quartz provide very good relfection and/or radiation and, of these, calcite is preferred. It has been further found that the effectiveness of reflection and/or radiation of the latter material is increased by spreading mica scrap therewith. In addition to being easy to maintain and providing for good heat reflection and/or radiation, a surface comprised of particulate material provides the additional advantage of having good permeation convection characteristics. Although particulate material is preferred, it will be understood that other surfaces such as metallic sheet material, for example, may be employed.

In accordance with the foregoing, an outstanding object of the present invention is the provision of a system whereby thawing of a mass of particulate material can be achieved more rapidly, more efficiently and at a lower cost than heretofore possible.

Another object is the provision of a thawing system of the foregoing character which provides for better and more uniform heat penetration of the particulate material than heretofore possible.

A further object of the present invention is the provision of a thawing system of the above character in which separate sources of heat and liquid are employed together to achieve thawing.

yet another object of the present invention is the provision of a thawing system of the foregoing character wherein liquid is employed to transfer heat from outer areas of the particulate matter to inner regions thereof to effect thawing.

Still a further object of the present invention is the provision of a system for more effectively, efficiently and economically thawing particulate matter disposed in a railway car than heretofore possible.

Yet a further object of the present invention is the provision of a railway car thawing system in which thawing is achieved in a manner whereby the car and particulate material are protected from damage resulting from heat employed in the thawing process.

Another object of the present invention is the provision of a system for thawing a railway car wherein surface areas of the car and/or material are heated by external means and liquid is flowed through the particulate material to transfer heat away from the surface areas whereby the surface areas are cooled and thawing of interior regions of the material is enhanced.

Still another object of the present invention is the provision of a railway car thawing system of the above character wherein heating of the car and/or particulate material is achieved by means of infra-red generators positioned to direct radiated heat toward the car and/or material.

Still a further object of the present invention is the provision of a railway car thawing system wherein heating of the bottom means of the car is achieved by directing heat downwardly and inwardly beneath the car and reflecting and/or radiating heat upwardly toward the bottom means of the car.

Yet another object of the present invention is the provision of a method of thawing particulate material by heating at least a surface area thereof and flowing liquid through the particulate material to transfer heat from the surface area.

Still a further object of the present invention is the provision of a method of thawing particulate material which provides for thawing to be achieved in a minimum amount of time and more economically than heretofore possible.

yet another object is the provision of a method of thawing particulate material disposed in or on support means therefor by heating at least a surface area of the support means and/or material and flowing liquid through the particulate material to transfer heat from the surface area.

A further object of the present invention is the provision of a method of thawing particulate material disposed in a railway car by heating at least a surface area of the car and/or material and flowing liquid through the particulate material to transfer heat from the surface area.

A further object of the present invention is the provision of a method of thawing flammable particulate material by heating the material in a manner whereby thawing is readily achieved and ignition or combustion of the material is prevented.

Still another object of the present invention is the provision of a method of thawing particulate matter disposed in a railway car in a manner whereby the car is protected against detrimental effects of heat employed to thaw the material and the temperature of the particulate material, if flammable, is maintained below the ignition or combustion temperature thereof.

Yet another object of the present invention is the provision of a method of thawing particulate material in a railway car which provides for a more rapid and uniform penetration of heat to interior regions of the material than heretofore possible, thus providing for the particulate material in a given car to be thawed in a minimum amount of time and at a minimum cost.

The foregoing and other objects of the present inven- 1 tion will in part be obvious and in part more fully pointed out hereinafter in conjunction with the description of the accompanying drawing. in which:

FIG. 1 is an end elevation, partially in section, of a railway car thawing arrangement made in accordance with the present invention;

FIG. 2 is a plan view, in. section of the arrangement illustrated in FIG. 1, the view being taken along line 22 in FIG. 1;

FIG. 3 is a side elevation, in section, of the arrangement illustrated in FIGS. 1 and 2, the view being taken along line 3-3 in FIG. 1;

FIG. 4 is an elevation view of a heater module of the arrangement illustrated in FIG. 1, the view being taken along line 44 in FIG. 1; and

FIG. 5 is a side elevation view of the heater module illustrated in FIG. 4.

Referring now to the drawing in greater detail wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting the same, FIGS. 1-3 illustra'te an arrangement by which the present invention can be employed to thaw particulate material in a railway car. In this respect, a pair of rails are depicted for supporting a railway car 12 illustrated by broken lines and which, for example, may be an open top railway car of the character employed for transporting particulate material such as coal. Such a car includes sidewall means 14, 16, 18 and 20. Further, the car includes bottom wall means 22 which, as is well known, is defined in part by releasable door means which provide for dumping the contents of the ar. For purposes of the description to follow, car 12 is presumed to be filled with coal 24 which is frozen. It will be appreciated that the coal particles will vary in size and together normally define a porous mass. When frozen, the spaces between particles in at least outer regions of the mass may be partially or completely filled with ice whereby these regions define a mass of ice and coal in which the coal particles are frozen together and the spaces therebetween at least partially filled with ice.

In accordance with the preferred embodiment of the present invention, infra-red generators are provided to direct heat toward a surface area of the support means for the particulate material and/or toward a surface area of the particulate material itself, and means is provided to flow a liquid such as water through the particulate material to transfer heat to inner regions of the material, whereby thawing is effectively achieved in a minimum of time. In the embodiment herein illustrated, heating of the material is achieved by providing infrared generating sources 26 generally parallel to and along opposite sides of rails 10, generating sources 28 on opposite sides of rails 10 at an angle to the track centerline and at longitudinally spaced locations relative thereto, and generator source 30 vertically above the track elements. Infra-red generating sources 26 direct heat against sidewalls l4 and 18 of car 12, and generating sources 28 direct heat against sidewalls l6 and 20 of the car. For this purpose, generating sources 28 preferably are disposed at an angle of about 30 to the track centerline. Generating source 30 is positioned to direct heat downwardly toward outer surface 32 of the coal in car 12. In addition to generating

sources

26 and 28, generating source 34 may be provided on opposite sides of track elements 10 to direct infra-red radiation downwardly and inwardly beneath car 12 in the direction of arrows A in FIG. 1. Reflecting and/or radiating means 35 is provided beneath car 12 to reflect and/or reradiate the energy from the generating source 34 up wardly towards bottom 22 of the car in the direction of arrows B.

Generating sources

26, 28, 30 and 34 may be defined by any suitable heat output means. Preferably, however, the generating sources are defined by infra-red generators of the gas-fired variety because such units have a high energy output and are the most economical heating means from the standpoint of production, installation, operation and maintenance which can be employed to achieve thawing of a railway car in a minimum amount of time in accordance with the present invention.

The number and physical arrangement of the generators relative to a car to be thawed can, of course, be widely varied, and the disclosed embodiment is merely illustrative of a preferred one of such arrangements. In this respect, each of the generating

sources

26, 28 and 34 is preferably defined by a plurality of infra-red generators, and the generators preferably are assembled so as to define modular units such as the modular unit 36 illustrated in FIGS. 4 and 5 of the drawing. Modular unit 36 is comprised of a plurality of upper infra-red generators 38 mounted in side by side relationship between a pair of vertical support posts 40, and a plurality of lower infra-red generators 42 similarly arranged in side by side relationship between posts 40. The infraa triple mesh inconel primary grid and a single mesh inconel reverberator grid. It will be appreciated that units having other metallic grid structures or grids of material other than metal such as ceramics, for example, could be employed. Ceramic materials in particular, however, are fragile and easily damaged, whereby particles of the material being thawed could break or otherwise damage a grid upon contact therewith. Further, water vapor or droplets contacting a hot ceramic grid will cause the ceramic material to spall. Such damage to the grid reduces the efficiency of the generator and increases maintenance and replacement expenses. Thus, while generators having ceramic grids can be employed, units with metal grids are preferred. The number of

generators

38 and 42 in a given module and the energy output of the individual generators can, of course, be varied to provide different size modules and to provide a given module with a desired total output capability. Moreover, it will be appreciated that upper generators 38 define generating

sources

26 and 28 and lower generators 42 define generating source 34, and that the number of sizes of upper and lower generators in a given module can be varied as desired. Preferably, upper generators 38 are inclined approximately from vertical and lower generators 42 are inclined approximately 30 from vertical for the lower generators to direct energy output downwardly and inwardly beneath car 12. It will be appreciated, of course, that the inclination of lower generators 42 will depend upon the vertical disposition thereof relative to the car and the angle at which the reflecting and/or radiating means 35 is inclined relative to the bottom of the car.

The number and arrangement of modules 36 can be varied to suit a particular set of circumstances and to achieve desired heating results. In the embodiment illustrated, a plurality of the modules are disposed in side by side relationship adjacent opposite sides of rail 10 to provide for generating sources 26 and the corresponding generating sources 34 to have a longitudinal extent corresponding generally to that of the length of car 12. Generating sources 28 and the corresponding generating sources 34 associated therewith are defined in the embodiment illustrated by single modules 36. The modular concept is preferred in that it permits shop assembly of the infra-red generators into a unit which is more readily installed for use and which permits the longitudinal length of the generating sources along the sides of the track elements to be readily varied. In this respect, it will be appreciated that the number of modules employed along the sides of the track elements could be increased to define generating sources capable of simultaneously or progressively heating a plurality of cars. Similarly, the number of side modules can be decreased to define side generating sources having a length less than that of a given car.

Overhead generating source 30 preferably is defined by a plurality of modules 31 each comprised ofa plurality of infra-red generators. Modules 31 are positioned in longitudinal alignment and extend generally between opposite ends of car 12 and centrally of

side walls

14 and 18 thereof. Further, each module 31 preferably has reflector means 44 associated therewith for directing infra-red radiation downwardly toward surface 32 of the particulate material and across the width of surface 32 as defined by

sides

14 and 18 of car 12.

It will be appreciated that fuel supply lines, not illustrated, will be provided to the modular units and to the individual generators in the module and that control means may be provided to facilitate the control of the modules and/or individual generators. It will be further appreciated that either a portion or all of the generators, or the generators of some or all of the module units may be operated at one given time to achieve the desired heating. Controls may be provided to facilitate such selective employment of the generators or modules so that heating can be controlled in accordance with the requirements in a given situation.

As best be appreciated from the illustrations of FIGS. 1 and 2 of the drawing, each of the upper generators 38 is adapted to direct heat toward a sidewall of car 12, thus to heat a small surface area of the total surface area of the sidewalls of the car. Similarly, each of the lower generators 42 together with reflecting and/or radiating means 35 is operable to direct infra-red radiation toward a surface area of bottom 22 of car 12, and each of the generators of a module 31 of generating source operates to direct radiation against an area of exposed surface 32 of particulate material 24. Accordingly, generating

sources

26, 28, 30 and 34 are operable to heat at least a surface area of the car and/or particulate material depending on which of the generating sources is being employed at any given time.

With regard to generators 42 and reflecting and/or radiating means 35, heating of bottom wall 22 of a car is advantageously achieved thereby without subjecting the generators 42 to the adverse effects of water, dirt or other deliterious materials to which they would be exposed if positioned adjacent the railway bed or beneath the car. It will be appreciated that these materials effect both the life and efficiency of the generators and create additional maintenance problems. These disadvantages and others are avoided in accordance with the present invention by positioning the generators laterally of the car and well above the ground level, whereby they are both removed from undesirable locations relative to the car and are readily accessible for maintenance and other purposes. Effective heating of the bottom wall means of the car is achieved by positioning the generators for the radiation emission outputthereof to be directed downwardly and inwardly relative to the bottom wall and reflecting and/or reradiating the heat thereof upwardly toward the bottom wall by reflecting and/or radiating means 35. Reflecting and/or radiating means 35 may be defined by any suitable material. For example, polished metallic sheet material could be positioned beneath the car and inclined relative to the heaters to reflect the radiant emission upwardly. Preferably, however, the reflecting and/or radiating means is a bed of particulate material such as might be defined, for example, by ballast type material, glass, calcite, feldspar, quartz, Obsidian, mica and the like. Calcite or white marble chips have been found to provide an excellent reflecting and/or radiating means and, accordingly, are preferred. ln any event, the bed of material is disposed beneath the car and preferably laterally outwardly thereof to further enhance directing heat toward the car bottom. The bed of material is, of course, graded to provide the desired slope thereof relative to the generators. It will be appreciated that heating of the bottom wall can be achieved from one or both sides of a car and from the ends thereof if desired and that the reflecting and/or radiating bed will be positioned accordingly.

In order to effectively thaw the mass of particulate material in car 12 in a minimum amount of time, it will be appreciated that the heat output of the generating sources must be extremely high. Accordingly, the surface areas of the car and/or particulate material become extremely hot during the thawing operation. If the surface areas are allowed to exceed a temperature of about 400F, the railway car may be adversely effected such as by burning or blistering of the paint thereon or damage to hoses, couplings and other components of the car. Moreover, if the particulate material in the car is flammable material such as coal, the high surface temperature may cause ignition and burning of the material. Still further, all of these undesirable results can occur while inner regions of the mass of particulate material in the car remain frozen. With regard to the latter, heating of a surface area of the car and/or particulate material results in dehydration of immediately adjacent inner portions of the material, whereby the latter portions not only become more readily combustible but also establish areas which block conduction of heat to the inner regions of the mass of particulate material. Thus, the internal regions remain frozen. By controlling the temperature to which the surface areas of the car and/or material are heated the above mentioned problems may be overcome. However, to merely reduce the surface temperatures increases the thawing time to such an extent that the thawing process is inefficient and is not economically feasible. Thus, in accordance with the present invention, means is provided to transmit heat from the surface areas of the car and/or material in a manner whereby the surface temperatures are maintained at a safe level and inner regions of the mass of particulate material are more readily heated and thawed than heretofore possible, thus to achieve effective thawing of the total mass of material in a minimum amount of time. Moreover, the transfer of heat provided for in accordance with the present invention permits the total heat input to be increased to further enhance thawing of the particulate material in a minimum amount of time, and the increased heat input can be achieved without elevating car and material temperatures beyond the critical temperatures thereof.

The foregoing heat transfer is achieved in accordance with the present invention by flowing a liquid, preferably water, downwardly through the particulate material during the heating thereof. More particularly, with reference to FIGS. 1 and 3 of the drawing, a pipe or header 46 is suitably supported above car 12 for delivering liquid downwardly onto an outer surface 32 of particulate material 24. Header 46 extends generally parallel to rails and, in the embodiment illustrated, is disposed laterally adjacent overhead generating source 30. It will be appreciated, however, that header 46 could be otherwise positioned and that a plurality of such headers could be employed as opposed to just one. Header 46 is provided along its length with a plurality of outlet means for directing liquid downwardly toward car 12. In this respect, header 46 is provided with a plurality of spray nozzles 46a spaced apart along the length thereof and directed downwardly toward car 12 in a manner whereby the spray output thereof effectively covers the entire outer surface 32 of material 24 between side walls l4, 16, 18 and 20 of car 12. It will be appreciated that control means not illustrated, such as valves, for example, may be provided so that header 46 and spray nozzles 4621 will deliver a controlled amount of liquid or water to the particulate material.

In the embodiment illustrated, spray nozzles 46 are so disposed that the water sprayed therefrom is partially heated initially by generating source 30. The

particulate material 24. In doing so the water flows through the particulate material in the areas thereof inwardly adjacent the car walls and outer surface 32, which areas as mentioned hereinabove are heated much more rapidly than the inner regions of the particulate mass as a result of their proximity to the car walls and outer surface of the material. These areas are thus advantageously cooled by the water flow as the water absorbs heat therefrom. Thus, as the water flows downwardly through the mass of particulate material it functions as a heat transfer medium transferring heat from the outer surfaces of the car and particulate material and the inwardly adjacent areas of the material to inner regions of the particulate material. Moreover, the water flow serves to maintain the portions of particulate material inwardly adjacent the outer surfaces of the car and material moist whereby these areas do not become dehydrated and thus subject to ignition or combustion. It will be further appreciated that by employing liquid in combination with external heating means, the amount of liquid added can be controlled in order that the moisture content of the particulate material can be maintained within prescribed limits which, particularly in the case of coal, is of particular importance. The car can, if desired, be provided with drain means to direct the water used away from the area beneath the car, or the water can be permitted to drain from the bottom of the car and then be removed by providing drainage means therefor beneath the car.

Thawing of a railway car or cars in accordance with the present invention preferably is further enhanced by disposing the generating source and liquid flow means within an enclosure such as that indicated generally by the numeral 48 in FIGS. 1, 2 and 3 of the drawing. Enclosure 48 is comprised of sidewall means 50 adjacent opposite sides of track elements 10 and roof means 52 extending between and interconnected with wall means 50. Enclosure 48 effectively traps the heat generated by the heating means to further enhance the thawing operation. The enclosure means may further include a shed portion 54 which might, for example, house the necessary control components for the combustion control and liquid supply and provide an observation room from which the thawing operation can be viewed. Enclosure 48 may be of any suitable structure and is of further advantage in that it provides means to support overhead generating source 30 and liquid header 46. Further, if desired, generator modules 36 can be interconnected with side wall means 50 to provide lateral support for the modular units. Enclosure 48 further advantageously facilitates providing the system with means for circulating heat and the products of combustion from the infra-red generator relative to car 12 to further enhance the thawing operation. In this respect, for example, roof means 52 may be provided with suitable blower and outlet duct means 56 operable to cause the products of combustion and heat within the enclosure to flow upwardly along the sides of car 12 for exhaustion or removal thereof from the enclsoure. Such circulation of the heat and products of combustion provide for a laminar flow thereof relative to car 12 to provide for a more uniform heat distribution relative to the outer surfaces of the car.

As illustrated in FIGS. 2 and 3 of the drawing, enclosure 48 preferably is longitudinally divided into a thawing area 58 and a soak area 60. This provides for a car to be disposed in thawing area 58 for the time required for effective thawing to be achieved and to then be moved into soaking area 60 in which final draining of the liquid from the car can be achieved while the car is maintained in a warm environment, thus to prevent refreezing of any portion of the particulate material prior to dumping thereof. In this respect, a certain amount of the heat generated in the thawing area will circulate into the soaking area and thus be available to maintain the car warm while it is in the latter area. It will be appreciated too that some thawing may be achieved in the soaking area during the final drainage flow of the liquid through the particulate material. Still further, while a thawed car is disposed in the soaking area, a succeeding car can be undergoing thawing in the thawing area.

While the enclosure of the illustrated embodiment has but a single thawing area, it will be appreciated that any number of thawing areas could be provided one after another along rails in separate enclosures or one continuous enclosure to facilitate the thawing of a plurality of cars at the same time. Moreover, a plurality of thawing areas could be provided side by side in a single enclosure through which a plurality of tracks extend. Many such variations will be readily apparent.

While the generating sources disclosed herein include means to heat the sidewalls of a car, the bottom wall means of the car and the exposed upper surface of the particulate material in a car, it will be clearly understood thatall of the generating sources do not have to be employed simultaneously during a given thawing operation. For example, in certain instances it may be necessary or desirable to employ only the overhead generating source 30 together with liquid flow and, in other instances, it may only be necessary or desirable to employ some or all of the generating sources for heating the sides and/or bottom means of a car together with liquid flow. Thus, during a given thawing operation generating sources may be employed to heat a surface area of the car and/or particulate material and the term surface area as herein employed is intended to mean either a small portion of or the total surface area of a car wall or the exposed surface of the particulate material. Moreover, it is to be understood that the heating of a surface area may be achieved by one or more of the modular units, or by one or more of the generators in a given modular unit. Still further, while the use of modular units has been illustrated it will be appreciated that other forms of infra-red generators may readily be employed and that forms of heaters other than infra-red generators may likewise be employed in accordance with the principles of the present invention.

As many possible embodiments of the present invention may be made and as many possible changes may be made in the embodiment herein described, it is to be distinctly understood that the foregoing description matter is to be interpreted merely as illustrative of the present invention and not as a limitation.

Having thus described my invention, 1 claim 1. A system for thawing particulate material, comprising means supporting the material, said support means and material having exposed external surfaces, means for radiantly heating at least a surface area of the exposed external surfaces of said support means and/or particulate material, and means for introducing liquid onto said exposed external surface of said particulate material for flow therethrough and transfer of heat from said heated surface area.

2. The system of claim 1, wherein said support means is a receptacle having sidewalls and bottom wall means and said means for heating includes one or more radiant heaters for heating at least an exposed exterior surface area of at least one of said side walls.

3. The system of claim 1, wherein said means for heating includes one or more radiant heaters for heating at least a portion of the exposed external surface of said material.

4. The system of claim 3, wherein said support means is a receptacle having side walls and bottom wall means and said means for heating further includes one or more radiant heaters for heating at least an exposed exterior surface area of at least one of said sidewalls.

5. The system of claim 4, wherein said radiant heaters are infra-red generators.

6. The system of claim 1, wherein said exposed external surface of said particulate material is an exposed upper surface and said means for introducing liquid includes means for delivering liquid downwardly onto the exposed surface of the material for gravity flow through the material.

7. The system of claim 6, wherein said liquid is water and said means for delivering includes spray means.

8. The system of claim 1, wherein said support means is a receptacle including bottom wall means, and wherein said means for heating includes one or more radiant heaters for directing heat downwardly toward an area beneath the receptacle, and means in the path of the directed heat for directing heat upwardly toward said bottom wall.

9. The system of claim 8, wherein said means for directing heat upwardly toward said bottom wall means is reflective material.

10. The system of claim 8, wherein said means for directing heat upwardly toward said bottom wall means is reflecting and/or radiating means defined by a bed of particulate material.

11. The system of claim 8, wherein said receptacle further includes side walls and said means for heating further includes one or more radiant heaters for heating at least an exposed exterior surface area of at least one of said side walls.

12. The system of claim 11, wherein all of said heaters are infra-red generators.

13. A system for thawing particulate material disposed in an open top railway car having side walls and bottom wall means comprising, means for radiantly heating at least an exposed exterior surface area of said car and/or particulate material, and means for introducing liquid onto the exposed exterior surface of said particulate material for How through the particulate material and transfer of heat from said surface area.

14. The system of claim 13, wherein said heating means includes a plurality of heaters for directing heat toward at least one of said side walls and the exposed surface of said particulate material.

15. The system of claim 13, wherein said heating means includes a plurality of heaters for directing heat toward the exposed exterior surface of at least one of said side walls and a plurality of heaters for directing heat downwardly toward the exposed surface of said particulate material.

16. The system of claim 15, wherein said heating means further includes a plurality of heaters for directing heat downwardly and inwardly beneath said bottom wall means and means in the path of said downwardly and inwardly directed heat to direct heat upwardly toward said bottom wall means.

17. The system of claim 16, wherein said means to direct heat upwardly toward said bottom wall means is reflective material.

18. The system of claim 16, wherein said means to direct heat upwardly toward said bottom wall means is reflecting and/or radiating means defined by a bed of particulate material.

19. The system of claim 16, wherein said means for introducing the liquid includes header means positioned above the open top of said car and having outlet means for directing the liquid toward said material.

20. The system of claim 19, wherein all of said heaters are infra-red generators.

21. The system of claim 19, and enclosure means for said railway car including outlet means, said pluralities of heaters being disposed in said enclosure means and being gas fired infra-red generators, and means for circulating the heated products of combustion of said gas fired generators relative to a car in said enclosure means and out said outlet means.

22. A method of thawing a mass of particulate material having an outer surface comprising, radiantly heating at at least an area of said exposed outer surface of said material, and flowing liquid onto said outer surface of said material for at least a portion of the liquid to flow in heat transfer relationship relative to said surface area to transfer heat from said surface area.

23. The method of claim 22, wherein said heat is radiant heat.

24. The method of claim 23, wherein said liquid is water.

25 The method of thawing a mass of particulate material disposed in a receptacle comprising, radiantly heating at least an exposed external surface area of said receptacle and/or material, and flowing a liquid onto the exposed surface area of said material for flow through the material to transfer heat from said surface area.

26. The method of claim 25, said receptacle having side and bottom wall means, and heating an exposed exterior surface area of said receptacle by directing heat toward at least one of said side and bottom wall means, and flowing said liquid downwardly through said material.

27. The method of claim 26, and heating said exposed exterior surface area of said material by directing heat downwardly toward said material in said receptacle.

28. The method of claim 25, said receptacle having bottom wall means, and heating an exposed exterior surface area of said receptacle by directing heat toward said bottom wall means.

29. The method of claim 28, said receptacle having side wall means, and heating an exposed exterior surface area of said receptacle by directing heat toward said side wall means.

30. The method of claim 29, and heating said exposed exterior surface area of said material by directing heat downwardly toward said material in said receptacle.

31. The method of claim 27, and directing heat toward said one of said side and bottom wall means and toward said material by infra-red radiating means.

32. The method of claim 30, and directing heat toward said bottom wall means and side wall means and toward said material by infra-red radiating means.

Claims

1. A system for thawing particulate material, comprising means supporting the material, said support means and material having exposed eXternal surfaces, means for radiantly heating at least a surface area of the exposed external surfaces of said support means and/or particulate material, and means for introducing liquid onto said exposed external surface of said particulate material for flow therethrough and transfer of heat from said heated surface area.

13. A system for thawing particulate material disposed in an open top railway car having side walls and bottom wall means comprising, means for radiantly heating at least an exposed exterior surface area of said car and/or particulate material, and means for introducing liquid onto the exposed exterior surface of said particulate material for flow through the particulate material and transfer of heat from said surface area.

23. The method of claim 22, wherein said heat is radiant heat.

24. The method of claim 23, wherein said liquid is water.

25. The method of thawing a mass of particulate material disposed in a receptacle comprising, radiantly heating at least an exposed external surface area of said receptacle and/or material, and flowing a liquid onto the exposed surface area of said material for flow through the material to transfer heat from said surface area.