US2637637A - Apparatus for vaporizing liquid hydrocarbons - Google Patents

Description

y 5, 1953 c. A. FRENCH 2,637,637 APPARATUS FOR VAPORIZING LIQUID HYDROCARBONS Filed March 24, 1950 5 Sheets-Sheet l INVENTOR.

May 5, 1953 c. A. FRENCH 2,537,637

APPARATUS FOR VAPORIZING LIQUID HYQROCARBONS Filed March 24, 1950 5 Sheets-Sheet 2 ys, 1953 c. A. FRENCH 2,637,637

APPARATUS FOR VAPORIZING LIQUID HYDROCARBONS Filed March 24, 1950 3 Sheets-Sheet 3 47 ||l ii Patented May 5, 1,- 1,15%

UNITED 'sTA ss PATENT OFFICE new APPARATUS FOR VAPORIZIN G LIQUID Charles A. French, Cuernava'c'a, Mexico, assignor to Lenore C. Bates, Winnetka, Ill.

Application March 24, 1950, Serial No. 151,695

hydrocarbon fuel are disclosed, in whichan excess of the liquid hydrocarbon is maintained in a vaporizing chamber, in which a pilot burner delivers its products of combustion into contact with the excess of liquid hydrocarbon to vaporize a portion of the same and produce a vapor comprising a mixture of hot combustion products and vaporized hydrocarbon, in which air is delivered through a forcing nozzle discharging in a Venturi opening communicating with the top of the vaporizing chamber in such a manner as to premix the air and vapor in combustible ratio and deliver the same to a manifold, and in which the combustible mixture burned at the pilot burner is withdrawn from such manifold. The French method and apparatushave several distinct advantages as contrasted with vaporizing methods and apparatus of the prior art,,including the fact that within limits dictated by. a particular design, the quality of the combustible mixture is maintained uniformly automatically over a relatively wide range. By suitable controls such as shown in Faverty Patent No. 2,122,683, apparatus constructed in accordance with the French patents is capable of successful operation over a very wide demand range. I

By means of the French inventions as discussed hereinabove, itis possible to produce a clear blue flame and substantially perfect com bustion even with a relatively very heavy hydrocarbons. In starting a vaporizing device of the character identified, the common practice has been to hold a torch at the opening in which the pilot flame normally discharges and to operate the blower to pull hot products of combustion through the vaporizing chamber until heat enough is developed to vaporize the oil at which time oil was introduced and vaporization was initiated. When commercial gas is available, such vaporizing devices can be started on gas in one of two ways. If agas connection is made to the pilot burner, then the pilot burner is operated until the vaporizing chamber is hot enough to initiate vaporization, at whichtime the oil is introduced, and as soon as vaporization commences, the gas connection to the pilot burner is discontinued and the pilot burner then operated on a mixture of air and hydrocarbon or oil vapor. Such vaporizing equipment; however, can .also be started with gas by's'o connecting a'gas line into the system thatgas will be delivered to 1 Claim. (01. 48-101).

the mixing, chamber in place of the hydrocarbon vapor. In such instances, the entire system in: cluding .the main or power burners and the pilot burner can first be operated on a premixture of commercial gas and air and gradually changed ,-over to oil vapor operation. When employing this method to initiate operation, oil is introduced 1 to the vaporization chamber when it has been "heated by the pilot burner, and the gas is cut off as oil vaporization begins so as to maintain uniform quality during the change-over from ,gas to oil operation.

Regardless of the advantages described hereinabove, there are at times certain disadvantages in the use of an open pilot burner. Heretofore it has been impossible to enclose the pilot burner because the automatic response to demands for .fuel discussed hereinabove is in part made possible by the open pilot burner. When the demandis relatively very low, for example, the hot products of combustion fromv the open pilot burner merely spill out into the atmosphere instead of being delivered into the vaporizing chamber, Another problem which is solved by the utilization of an open pilot burner has to do with the starting of the vaporizing apparatus, par- -ticularly-when no commercial gas is available.

In any installation in which fumesfrom partially burned hydrocarbons can cause trouble with the product being processed as, for example, in the baking industry where ovens are not fully muiiled', it is, of course, exceedingly important that a starting-procedure be available which will prevent any possibility of inadequate vaporization, deviationfrom predetermined quality, or other 1 related occurrences.

The principal object of the present invention is the provision of an improved method of and means for vaporizing relatively heavy liquid by .drocarbons. v a Another object is the provision of an improved yaporizingdevice which retains the advantages but obviates the disadvantages discussed here'- inabove.

Still another object is the provision of improved vaporizing apparatus in which the pilot burner is fully enclosed, in which quality is maintained ,over a relatively wide demand cycle, and in which .a foolproof, starting procedure is made possible; Other specific objects and features of the invention will become apparent from a considera :tion. of the following detailed description taken with the accompanying drawings, wherein: -'-.'-I.ig...1 is a perspective-view ofvaporizing apparatus embodying the features of the present invention;

Fig. 2 is an enlarged fragmentary sectional view partly in elevation showing a control feature;

Figs. 3 and 4 are transverse sectional views taken on the lines 3-3 and 4-4. respectively, of Fig. 2, looking in the direction of the arrows;

Fig. 5 is a transverse sectional view with some parts shown in the elevation, the view being taken along the line 55 of Fig. 1, looking in the direction of the arrows;

Fig. 6 is a sectional view with some parts in elevation, looking approximately at right angles to Fig. 5, the view being taken along the line 3-6 of Fig. 1;

Fig. 7 is a schematic circuit diagram showing a signal arrangement employed in starting; and

Fig. 8 is an enlarged fragmentary vertical sectional view taken through the enclosed pilot burner in the upper part of the vaporization chamber.

Referring now to the drawings, the vaporizing device there shown comprises a vaporizing chamber 10 in the form of acylinder with a top II and bottom l2. Within the vaporizing chamber is a central pipe [3 connected to the top H at one end and at the lower end projecting beneath a body of oil l4 maintained at a level indicated by the broken line A. The oil is delivered through pipe l6 and suitable leveling means, not shown, is employed. Hot products of combustion are delivered into the pipe [3 which thereby comprises a combustion tube from a pilot barrier, indicated generally by the reference character 11. The hot products of combustion delivered downwardly to the combustion tube of thepilot burner thereby pass beneath the oil M to vaporize a portion of the oil, and the vapor so produced is adapted to be delivered exteriorly of the vaporization chamber through an upper outlet II. The outlet I8 is above a baflie element ll carrying an annular member 2| spaced from the combustion tube [3, so that the vaporization products pass between the combustion tube l3 and the annular member 2! which thereby acts as a superheater to cause the vaporized products to be relatively dry. Such unvaporized oil particles as might have a tendency to be entrained with the vapor, accordingly either fall back into the pool of oil or if small enough to be retained, are vaporized in contact with the superheater.

As shown particularly in Figs. 5 and 6, the opening [8 is connected through suitable piping to a Venturi opening 22 forming part of a mixing chamber, a forcing nozzle 23 discharging into the Venturi opening 22 air under pressure and at relatively high velocity, which air is delivered to the mixing chamber from a suitable source through air inlet 24. Oil vapor is thus drawn into the mixing chamber for mixture with the air, and the mixture so formed is delivered to a manifold 26 connected to one side of the mixing chamber. Combustion apparatus, not shown, which may comprise a number of burners, a single large burner designed to burn at varying capacity or the like, is adapted to be supplied with the combustible vapor and air mixture from the manifold 26, and the vaporizing device of the present invention is adapted to respond to varying demands made by such combustion apparatus when associated with the said manifold. To control the amount of air delivered to the mixing chamber and hence the amount of combustible invention provides control mechanism of the general type disclosed in the same Faverty patent identified hereinabove. This comprises a tapered bar 21 projecting into the forcing nozzle 23 to vary the cross-sectional area thereof and hence to control the amount of air delivered there- .through. The position of the tapered bar 21 is controlled by a lever arm 28 mounted on a rocking shaft 29 (Fig. 1) and through suitable linkage adjustable by means of a diaphragm secured in a diaphragm housing 31, all as disclosed in the said Faverty patent. The diaphragm in diaphragm housing 3| is actually moved by air under pressure delivered to a pipe 32 and the amount of air so delivered is controlled by a control diaphragm device 33 which, in turn, is actuated through pressure in a pipe 34 connected at one end to the manifold 26. The manner of functioning is as described in the said Faverty patent. The pressure in the manifold 26, being slightly above ambient pressure, is responsive to demands for fuel. When more fuel is demanded as, for example, if a fresh burner is ignited, there is a slight drop in manifold pressure and this immediately affects the diaphragm device 33 which therebyfunctions to admit more air to the diaphragm contained in the diaphragm housing 3| and thereby rocks the shaft 29 in a counterclockwise direction, as seen in Fig. 1, and retracts the tapered bar 21. Retraction of the tapered bar 2! increases the air delivered to the mixing chamber and this, in turn, increases the amount of vapor withdrawn from the vaporization chamber. More combustible mixture, therefore, is available to the combustion system. Conversely, when the demand for fuel is less, pressure in the manifold is raised slightly and, through the mechanism described, the air delivered to the mixing chamber is reduced and the total amount of combustible mixture is reduced.

The present invention provides an enclosed pilot burner I'I so arranged that it is automatically responsive to the demands for combustible mixture and controls the flow of the hot prodv nets of combustion delivered to the vaporization chamber by controlling or regulating the flow of the vaporization products delivered to and burned at the pilot burner.

The portion of the manifold 26 connected to the mixing chamber, shown in the form of a casting in thed'rawings, has an offset portion 36 for delivering combustible mixture to a pipe 37 connected to an elbow 38 for delivery to an enclosed burner tip 39 secured within a housing 4| (Fig. 8). The burner tip 39 has a central main opening 42 and a number of downwardly inclined generally radial small side openings 43. A valve in the form of a tapered rod 44 is vertically reciprocable in a guide 46 set into the elbow 38. The tapered rod 44 has its upper projecting end connected to an arcuately shaped arm 41 which is pivoted at 48 and thereby adapted to be moved about the said pivot to raise or lower the tapered rod. When the tapered metering rod is moved downwardly, the total orifice area of the burner tip is reduced, and the rod is adapted to be moved down a sufficient distance to close substantially completely the main orifice 42 and permit burnfin'gpnly at the smaller orifices 43. The pilot burner discharges its hot products of combustion ,tl'ii'o'ugh an orifice in a heat resistant member 49,

' whence the hot products of combustion are delivered to the inside of the combustion tube 13. The pilot burner is adapted to be ignited by mixture delivered to the manifold, the present means of a spark plug H. The arrangement of r orifices and, ports in the pilot burner tip 39 is such as to, maintain operation of the pilot light. It is known that if a relatively slow burning, heavy liquid hydrocarbon. is burned in an orifice in which movement of combustible mixture is relatively rapid, the flame will be blown away from the burner orifice because the rate of flame propagation may notbe as fast as the movement of the combustible ,mixture' By the arrangement employed, the smaller'orifices will maintain themselves and they will also maintain the flameat the main burner orifice.

To control the position of the arm 47 and the tapered pilot burner regulating rod 44, an upright arm 52 is supported to move with the rock shaft 29' Figs. 1 to 4, inclusive). The upright arm 52 is connected to the arcuate control arm 1 by means of a link structure comprising a rod 53 pivoted to the arm ll, a rod 54 pivoted to the arm 52, and an adjusting member 56 which is pivotally connected to the rod 54 and threaded on the end of the rod 53. The rod 54 is adjustably connected to a block 51 by a thumbscrew 58 and the block 51 is pivotally connected to the arm 52. It will be noted that both the arm 4'! and arm 52 are provided with a series of holes to which opposite ends of the link structure defined may be pivoted. Thus, the extent to which a given movement of the arm 52 will pivotally move the arm 4'! can be established. The length of the link structure between the arms 52 and 41 will, of course, determine the relative position of the metering rod 44 and, of course, the amount of combustible mixture delivered to the pilot burner at any particular adjustment of the control mechanism which, of course, includes the air regulating rod 21. Since the proportion of vapor available for mixture with the air is a function of the proportion of combustible mixture delivered to the pilot burner and the proportion of hot products of combustion delivered to the vaporization chamber, the particular setting of the rod 44 with respect to the position of the air regulating rod 21 will determine the proportion of vapor available for mixture with the air. In other words, the adjustment of the linkage between the arms 52 and 41 comprises an adjustment for rich or lean combustible mixture, as these terms are sometimes employed. In general, it will be desirable to set the controls for as near perfect combustion as possible, and to do this, the adjustment is first made approximately correctly by adjusting the position of the rod 54 with respect to the block 51. The final adjustment is made by turning the adjustment member 55 to either the right or left, depending upon whether more or less vapor with respect to air is desired.

My present invention may conveniently be utilized in conjunction with a special starting feature, as shown particularly in Fig. 8, although it is to be understood that I do not claim inventorship of said special starting feature. Oil under pressure is delivered through a tube 6| to a spray nozzle 62 contained Within a pipe 53 Set at an angle into the top of the vaporizer and firing into the combustion tube l3. Air under pressure is delivered to the inside of the pipe 53 near the spray nozzle 62 by a pipe 64, and a pair of electrodes 65 is provided for continuously maintaining a spark in the path of the sprayed fuel to burn the same within the pipe 53. A starting device of this type comprises, in essence, a relatively small oil burner which projects into the combustion tube I3, which normally receives hot products of combustion from the pilot burner,

tease and in this manner brings the vaporization chamber and all parts associated with it up to suitable starting temperature. It facilitates starting to operate the blower during the heating up period and since substantially complete combustion can be obtained by a starting burner of the type shown and described, it is possible to leave the main combustion burners open to bleed off excess products of combustion without introducing deleterious odors.

In a vaporizing device of the type disclosed, in which'the pilot burner and starting burner are completely enclosed, it is desirable that means be provided to insure satisfactory vaporization after the oil is introduced into the vaporization chamber in orde'rjthat undesirable odors of partially vaporized: oil 'b'e'a'voided. To this end a thermostatic switch H is provided in the general manner shown in Fig. 5, and in this instance, it is placed immediately above a T 12 to which a drain pipe 13 is connected. This is a pipe provided for draining the vaporization chamber at the end of a run and the opening so afiorded into the vaporization chamber is utilized to bring the thermostatic element of the switch ll into a position where the temperature has a direct relation to the temperature on the inside of the vaporization chamber. The thermostatic switch H is of any suitable type and is connected into a circuit including conductors 14 and 16 and a signal device 11, here shown in the form of a pilot light. The signal device thus is made to indicate a temperature on the inside of the vaporization chamber adequate to operate the vaporizing device. It is, therefore, at the same time an indication or guide as to when oil can be introduced into the vaporization chamber during starting and it is also a warning signal if for any reason (e. g., extinction of the pilot burner fiame) the vaporizing device is not operating satisfactorily to produce oil vapor.

The above description is adequate to enable those skilled in the art to understand the manner in which the present invention is practiced. In starting the equipment, the starting burner is first operated with no oil in the vaporization chamber and operation is continued until the signal device I! shows that the vaporization chamber has reached an adequately high temperature. Oil is thus permitted to flow into the vaporization chamber and at the same time the pilot burner is started and the starting burner stopped. vaporization of oil starts almost immediately and the main combustion burners can be lit. The mechanism responds automatically to deliver more or less combustible mixture to the pilot burner as the demands of combustion equipment are increased or decreased.

The embodiment shown in the drawings shows several features which function mutually to secure unusually desirable results in practice, but all of the features need not be used together, and the invention may take various forms within the scope of the claim.

I claim:

In that type of vaporizing apparatus for liquid hydrocarbon fuel which includes a vaporization chamber adapted to contain an excess of liquid fuel, a mixing chamber for combining air and vapors from said vaporization chamber to form a combustible mixture, a manifold receiving combustible mixture from the mixing chamber for delivery to a main burner wherein the manifold pressure varies in accordance with the demands of the main burner, an air supply valve for regulating the air supply to the mixing te m chamber, control means including a movable member and responsive to manifold pressure, a connection between the movable member of the control means and the air supply valve for regulating the air supply to the mixing chamber in accordance with main burner demands, an enclosed pilot burner discharging its combustion products into contact with the excess of liquid fuel in the vaporization chamber to vaporize the same. a connection between the manifold and pilot burner for delivering combustible mixture to the pilot burner and a pilot burner valve in the connection for controlling the amount or combustible mixture delivered to the pilot burner, the improvement which comprises, in combination, a connection between the movable member of the control means and the pilot burner valve for regulating the supply of combustible mixture to the pilot burner and hence the vapor delivered 8 to the mixing chamber in accordance with the demands of the main burner to maintain the richness of the combustible mixture substantially constant over wide demands of the main burner, said connection between the movable member of the control means and the pilot burner valve including adjusting means for varying the position of the pilot burner valve with respect to the air supply valve for predetermining the richness of the combustible mixture.

CHARLES A. FRENCH.

References Cited in the file of this patent UNITED STA'I'ES PATENTS Number Name Date v 2,122,683 Faverty July 3, 1938 2,123,885 Faverty July 19, 1938 2,174,663 Keller Oct. 3, 1939

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