US3503382A - Asphalt melting kettle - Google Patents

Description

P. WOLLNER March 31, 1970 ASPHALT MELTING KETTLE 2 Sheets-Sheet l Filed Feb. 27. 1968 INVENTOR PAUL WL /t/fQ,

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figg is ATTORNEY March 31, 1970 P. WOLLNER ASPHALT MELTING KETTLE 2 Sheets-Sheet 2 Filed Feb. 27. 1968 k., R Za Y mmf N w R En b o w .L w ...l Ill. B mrl r, a U 2 l).\// 6 3 6 F a o 3 a Elli/.11 L 0 /f/b 3 2 L m United States Patent O 3,503,382 ASPHALT MELTING KETTLE Paul Wollner, North Bergen, NJ., assignor to Aeroil Products Company, Inc., South Hackensack, NJ., a corporation of Delaware Filed Feb. 27, 1968, Ser. No. 708,708 Int. Cl. E01c 19/45 U.S. Cl. 126-343.5 6 Claims ABSTRACT OF THE DISCLOSURE The application discloses an asphalt melting kettle having a burner for introducing 'heated combustion products into tubing immersed in the melt. The tubing, herein designated the return tubing, which opens into the stacks, also communicates with fins which convey the products by an alternate route to the stacks through flow control openings. The fins are uniquely shaped to minimize the danger of flashing which commonly occurs at the surface of the melt. Also, the fins provide additional heat transfer area in contact with the melt thus affording an improved melting operation. In one embodiment of the invention the fins contain perforated baflie plates for flow control purposes.

This invention relates to heating equipment and, in particular, to apparatus for melting materials such as asphalt and the like where the temperature raising elements themselves are totally immersed in the material.

In melting materials contained in kettles, it is important that they be afforded a maximum heating surface for exposure to the material. It is the usual practice to provide tubular surfaces contacted by internal gasses to provide the necessary heat transfer to the material. When the heated surface is expanded to the extent that it presents surface area above he level of the material to be melted, it has been found that a flashing or sudden combustion can result when the material cornes into contact With the air. It is therefore important that the danger of such flashing be minimized while providing sucient surface area dimension for contact with the material to allow efficient 'heating and melting. The invention contemplates a melting kettle for bituminous material and the like which passes heated gasses through the material within uniquely shaped immersion tubing which allows for effective heating at an improved melting rate while substantially avoiding the danger of flashing. In general, this is achieved by controlling the return gas flow to the external stacks of the unit within chambers which are specially designed for that purpose.

Specifically, the resolution of the problem alluded to above requires additional heating surfaces Within a unit which provides outgoing and return tubing for asphalt melting. The additional surface area communicates with the return tubing and is exposed to gasses emanating from a manifold 'which directly receives the hot gas from the burner. The additional heat contacting surface area is especially important in the melting of the asphalt "which is nearly non-heat conductive. The additional surface area is effectively located atop the return tubing connected directly to the outgoing stack through a flow control opening surface and is provided by a tapered housing, an arrangement which minimizes the danger of flashing on the surface of the material in the kettle while providing maximum heating efficiency.

One object of the invention is to provide an improved melting kettle which minimizes the peril of flashing and yet provides an effective heating apparatus.

Another object of the invention is to provide an immersion type melting kettle having enfhanced surface area to effect heat transfer to materials which have inferior heat conducting characteristics.

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Other objects and advantages of the invention may be appreciated on reading the following detailed description of several embodiments thereof which are taken in conjunction with the accompanying drawings, in which FIG. 1 is a plan view of the improved melting kettle;

FIG. 2 is a section in elevation taken on line 2-2 of FIG. 1;

FIG. 3 is an end section taken on line 3-3 of FIG. l;

FIG. 4 is a plan view of a modified form of melting apparatus;

IIG. 5 is a section taken on the line 5-5 of FIG. 4; an

FIG. 6 is a section taken on the line 6 6 of FIG. 4.

Referring to FIG. 1 of the drawings, a burner unit 10 in kettle 11 is in communication with main pipe 12 which in turn communicates with manifold 14 having two outlets. One outlet communicates with enclosed stack 16 and return pipe 17 and the other outlet communicates with return pipe 18. Stacks 20 and 22 receive the heated gasses as source of the heat transferred to the material M from the return pipes 17 and 18 respectively. As shown in FIG. 2, the pipe 16 is provided with an additional heating surface or fin 24 having apertures 26 provided for passage of the heated gas therefrom to the fin. The lin 24 provides an additional opening 25 for the hot gas to pass to the stack 20 as a second route thereto. There is also provided a corresponding fin 27 serving as an additional heat transfer surface atop return tube 18. The fin 27 communicates with stack 22 through flow control opening 2.8. The fins 24 and 27 taper toward the top thus presenting minimum heat transfer area at their top which in operation may not be immersed in the melt, and where flashing ybeing most likely to occur at the surface thereof. The resulting diminished heat transfer surface at the top of the fins minimizes the danger of such occurrence. The openings 25 and 28 retards the flow of gas at the top of the fins causing a stagnant layer to form at that level serving to maintain this portion of the fins in a cooler state which also has the effect of preventing flash occurrences.

The modified embodiment of invention shown in FIGS. 4, 5 and 6, has a return tube 16a substantially identical to return tube 12a in communication with manifold 14. The return tubes are provided with baffles 30 apertured to permit and direct the passage of the hot gasses While importantly providing an additional heating surface Within the fins. The bales provide an effective flow control in the fins and serve to produce efficient heat transfer by the flue gasses thereWithin. The return tubing is in cornmunication with stacks 20a and 22a which are rectangular in cross section to provide greater exposure surface within the unit.

Various modifications of the invention may be effected by persons skilled in the art without departing from the scope and principle thereof as defined in the appended claims.

What is claimed is:

1. A melting kettle comprising a body adapted to receive material for melting by combustion products, a burner disposed in said body, an outgoing tube connected to said burner, at least one return tube communicating with said outgoing tube, and a stack in communication with said return tube by means of a first Opening, there being provided a separate channel communicating with said return tube and providing additional heat transfer surface area and a second gas flow control opening into said stack said channel comprising an enclosed fin open to said stack and attached to said tube and in communication therewith to permit the combustion products to pass to said stack by separate routes.

2. A kettle as defined in claim 1, wherein said iin is tapered from bottom to top whereby it presents a more diminished heat transfer area at the top than if said iin were not so tapered.

3. A kettle as deiined in claim 1, wherein there is provided an additional return tube, each tube having a communicating fin with a control opening into a corresponding stack and a manifold is provided to pass the ow from the outgoing tube to said return tubes.

4. A kettle as defined in claim 3, wherein each of said stacks are rectangular in cross section to provide optimum heat transfer surface area.

S. A melting kettle comprising a body adapted to receive material for melting by combustion products, a burner disposed in said body, an outgoing tube connected to said lburner, at least one return tube communicating with said outgoing tube, a stack in communication with said return tube, said return tube comprising a iin tapered from bottom to top whereby it presents a more dimin- 4 ished heat transfer area at the top than if said iin were not so tapered.

v6. A kettle as defined in claim 5, wherein there is provided an apertured baille in said fin for additional control of the return gas flow.

References Cited UNITED STATES PATENTS 2,290,784 7/1942 Turpin 126-3435 X 2,593,768 4/1952 Conn. 3,046,977 7/ 1962 Figge.

FOREIGN PATENTS 766,696 4/ 1934 France.

CHARLES J. MYHRE, Primary Examiner U.S. C1. X.R. 126--360

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