US2295106A - Apparatus for heating bituminous materials - Google Patents

Description

Sept. 8, 1942. w. E. GRACE ETAL 229,106

APPARATUS FOR HEATING BITUMINOUS MATERIALS Filed Sept. 2, 1941 2 Sheets-Sheet 1 3 wf I 50 Patented Sept. 8, 1942 warren STTES erg- I raise APPARATUS FQR HEATING BITUMINOUS MATERIALS 1 Claim.

This invention relates to machines for heating asphalt or bituminous materials in tank cars or other containers so' that the material may be readily pumped therefrom.

In order that the advantages and objects of the invention may be readily understood, it may be explained that in the construction of asphalt roads it is necessary for the highway department or contractor to unload and heat tank cars of asphalt or bituminous material before applying it to the road surface. It is desirable to heat the tank cars as quickly as possible, yet the heating unit must be reasonably light in weight and readily portable to permit rapid changes of location. In heating bituminous material, if rapid, positive circulation is not maintained over the hot surfaces, the bitumen or asphalt cokes which might also be called burning or sticking. This is a breaking down of the heavy asphalt hydrocarbon molecule into a sticky carbon deposit resembling coke and some lighter hydrocarbon, which is undesirable from the construction standpoint, as desirable properties of the asphalt or bitumen are lost, and also from the standpoint of heat transfer in the heating unit, as the coke deposit acts almost as an insulator and causes over-heating and burning of the heater flues and inefficiency. In heating there is also a tendency of asphalts or bitumens to form small lumps unless the material is well agitated and all parts of it are forced against a hot surface. Also, as bituminous material does not expand and circulate upon being heated as rapidly as water and most other liquids do, this invention provides for positive and rapid circulation against parts of the heating unit transferring heat.

It is also pointed out that bituminous material has been heated heretofore in several different ways, one of which is as follows: when the material in the container is cold or in a solid state, it is necessary to force steam through coils therein to get the bitumen in a liquid state. Continued application of the steam may be made and the material brought up to the desired temperature with steam, the degree of temperature depending upon the grade of bitumen. This method has the disadvantage of requiring high pressure steam and being slow, as when the higher temperatures are reached the rate of heat transfer from the steam is not rapid enough. The steam boiler required is also rather cumbersome and heavy to transport, and requires some time to get steam up.

It is therefore the principal object of this invention to provide a material heater in a single light weight and portable machine, combining a steam generating unit anda fast-heating pumping unit. The arrangement and construction of these units thus enables the machine to be used to thaw out or heat bituminous material, such as asphalt in one tank car or other container while the pumping means or booster is being utilized to circulate the material in another container.

Another object of the invention is to provide a material heater wh'ose construction and arrangement is such that the bituminous material is thoroughly mixed, lumps broken up, scouring of any coke deposit from the hot flues and tubes insured, and in addition, there is obtained a rapid transfer of heat from the flues into the bituminous material.

A further object of the invention is that the machine embodies a flue construction with coacting parts which makes the unit easily accessible for repairs or cleaning.

The invention may be fully. understood from a perusal of the following detailed description, taken in connection with the accompanying drawings, wherein:

Figure 1 is a side elevational view of a machine embodying the invention, the view being partly in section and partly broken away.

Figure 2 is a horizontal sectional top .plan view of Figure 1, the section being taken on line 2-2 of said figure,

Figure 3 is a transverse cross-sectional view on line 33 on Figure 1.

Figure 4 is a diagrammatic View illustrating the manner of connection of the various parts of the machine; and I Figure 5 is an enlarged detail sectional view, taken on line 5-5 of Figure 2.

Continuing with a more detailed description of the drawings, wherein like parts of the invention will be designated by corresponding numerals, the machine consists of a framework I, supported upon the wheels 2. for transportation from place to place. Centrally of the machine is mounted a shell casing 3, one end-4 being closed and the front end 5 forming a removable cap, held in place by the bolts and nuts 6, so that the flues may be longitudinally slid out for repair or cleaning, when the cap is removed.

The fiues consist of the pipes or tubes 1 with the spiral flanges 8 welded to the flues as shown, each flue having a bend 9, whereby the flame from the burners is carried through the flues around the return bend and thence back into the shell casing, making three passes the length of the unit.

Surrounding each of the flues I is a tube or cylindrical hollow casing l0, these tubes following the bends or curved ends of the fiues by means of removable cap or head 5, in connection with the intermediate partition I I, as will be apparent from Figure 1. The inner ends of these casings or tubes are closed by the flanges l2 as shown in Figure 5, so that the asphalt, entering at the point A from the pump, will follow the path around the spiral flanges 8, and make its exit at the point B, as shown in Figure 4. A bypass pipe C connects the two inner ends of the tubes or casings II]. In view of this arrangement it will be apparent that the flues with the spiral flanges and the casings are stationary and the asphalt is forced around the fiues by the pump D through the pipe E and entering the lowermost casing I0 at the point A.

As shown in detail in Figure 5, and as carried.

out in the diagrammatic view, Figure 4, one end of each of the upper and lower casings I0 is provided with a firebox l3 and a burner l4, and from this point the hot gases or products of combustion from the burners [4 pass through the fiues 1, around the return bends 9 and back into the shell casing 3, through the flue ends 15. The burners are connected by a feed pipe line [6, which supplies fuel from the tank [8 to the burners and draft for the burners is provided by a blower of any preferred type indicated at H, the burners l4 and the blower being connected by an air pipe I9, see Figure 4. Each burner has a control valve l6-a. A fuel pump 20 is connected in the line Hi.

In connection with the preceding parts there are also provided a water tank 22 for supplying water to a heater coil 24, and a water pump 23 for pumping water from the tank through the pipe 25. The heater also includes a burner 26, which burner is also connected to the fuel line and the blower line l9, respectively.

The water tank 22 and the fuel tank 18 are mounted on one side of the machine and securely fastened to the framework I, while on the opposite side thereof are carried a motor 2'! and the water heater or coil 24. The motor thus provides a power source for driving through its shaft and the chain 28 the asphalt pump D, also the fuel pump 20, the blower I1 and the water pump 23. The blower and the water pump are driven through the same shaft such as shown at 29. The shell includes a smoke and fumes outlet 30.

In the diagrammatic view, Figure 4, is shown the manner in which the invention may be used for heating bituminous material in a tank car, the taller being indicated at 32, and ready to be unloaded of its asphalt or bituminous material; such cars being usually provided with a coil as shown at 33.

In accordance with the preceding explanation of the various parts of the invention, there is connected to the tank car coils a flexible hose connection 34, leading from the heater coils of the water heater 24. Also connected to the tank or other zone.

car or other zone to be heated, is a pipe line 35, connecting the tank car or zone with the asphalt pump D. The burners I4 and [6 of the water heater and the furnace respectively, are lighted, and the motor 21 started. As the steam generated in the water coils passes into the coils of the zone to be heated, the asphalt becomes liquid in form and the asphalt pump draws the asphalt through the pipe 35, forcing it through the casings or large tubes l I] in a spiral course made necessary by the flanges 8, thence out from these tubes into the pipe 31 back into the tank car 32 When the steam has melted or brought the asphalt into a condition where it will flow through the pump, and if there is another asphalt container which must be treated, the steam hose may be taken off the first and attached to the next zone, while the first zone is being prepared for unloading. It will be apparent from the foregoing that the bituminous material is forced around and around between the flues and large tubes [0, the heat meanwhile being applied to the bitumen from both sides. The spirals not only deflect the bitumen and insure scouring of any coke deposit away from the hot flues and tubes, but thoroughly mix the material and break up any lumps. The spirals also function as fins to facilitate the rapid transfer of heat from the flues into the bitumen itself. The flues with spirals attached may be slid outwardly from the machine for repairs or cleaning by removing the cap. 5.

While the disclosure presents a practical working embodiment of the invention, it is to be understood that the machine may be changed, altered and modified from the precise form shown, and in keeping with the intent and spirit of the invention, without departing from the meaning and scope of the appended claim.

What is claimed is:

A heater for bituminous materials comprising a casing having, its rear end sealed, a removable cap disposed over the opposite end of said casing, a material conduit horizontally disposed in said casing and shaped to define a convoluted passage from end to end of said casing, a partition in one end of said material conduit defining a chamber closed to said passage, a flue in concentric relationship and co-extensive with said conduit and communicating with the interior of said casing, a firebox in said closed chamber and communicating with one end of said flue, means for forcing the products of combustion from said firebox through the length of said flue and into said casing for intimate contact with the exterior of said material conduit and a spiral flange arranged in the space between said flue and conduit against the exterior surface of which the material is propelled for constraining said material to follow a tortuous path around said 'flue counter to the travel of said products of combustion and throughout the length of said convoluted passage.

WILLIAM E. GRACE. HUNTER STRAIN.

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