US3598090A

US3598090A - Vapor generator

Info

Publication number: US3598090A
Application number: US18650A
Authority: US
Inventors: Richard J Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-11
Filing date: 1970-03-11
Publication date: 1971-08-10
Anticipated expiration: 1988-08-10

Abstract

A lightweight highly efficient vapor generator having low thermal inertia and fast response to varying load demands, particularly for automotive use. A series of radially spaced concentric heat sleeves surrounds the combustion chambers with incoming air passing between these sleeves for preheating the air used for combustion, this air providing heat insulation for the outer shell. An air register at one end of the shell imparts a swirling circular motion to the incoming air creating a vortex flow in the primary combustion chamber which continues on into secondary and tertiary combustion chambers. The wall of the tertiary combustion chamber is lined with vapor superheat tubes which receive vapor from banks of vapor generating tubes near mid length position in the shell, and these tubes in turn receive liquid from preheater tubes at the opposite end of the shell. The combustion gases pass between these tubes and exhaust from said opposite end of the shell. All radiant energy from the combustion chambers is intercepted and utilized with a minimum of loss to the outer shell.

Description

United States Patent Richard J. Smith 8591 Pyle Way, Midway City, Calif. 92655 [21] App1.No. 18,650

[22] Filed Mar. 11, 1970 [45] Patented Aug. 10, 1971 [72] Inventor [54] VAPOR GENERATOR 2,787,256 4/1957 [lune .1:

122/DIG. 1

Primary Examiner-Kenneth W. Sprague Attorney-Lee R. Schermerhorn ABSTRACT: A lightweight highly efficient vapor generator having low thermal inertia and fast response to varying load demands, particularly for automotive use. A series of radially spaced concentric heat sleeves surrounds the combustion chambers with incoming air passing between these sleeves for preheating the air used for combustion, this air providing heat insulation for the outer shell. An air registerat one end of the shell imparts a swirling circular motion to the incoming air creating a vortex flow in the primary combustion chamber which continues on into secondary and tertiary combustion chambers. The wall of the tertiary combustion chamber is lined with vapor superheat tubes which receive vapor from banks of vapor generating tubes near mid length position in the shell, and these tubes in turn receive liquid from preheater tubes at the opposite end of the shell. The combustion gases pass between these tubes and exhaust from said opposite end of the shell. All radiant energy from the combustion chambers is intercepted and utilized with a minimum of loss to the outer shell.

PATENTED AUG! 0 ran SHEET 2 OF 2 VAPOR GENERATOR BACKGROUND OF THE-INVENTION This invention relates to a vapor generator and has particular reference to an oil fired vapor generator adapted for automotive use.

Many attempts have been made to develop a practical and suitable steam generator for operating a steam engine to drive an automobile. The requirements are vastly different, how ever, from those of conventional steam generators for other purposes and no vapor generator has yet been developed which is competitive with internal combustion engines. The conditions of road vibration, size, weight, quick startup, fast response to widely varying load demands, safety and a multitude of other exacting requirements peculiar to this field of use have thus far defeated all attempts to provide a truly successful vapor generator.

Objects of the present invention are, therefore, to provide a practical and efficient vapor generator for an automobile engine, to provide a relatively compact, lightweight and inexpensive vapor generator without refractory insulation, to provide a vapor generator having low thermal inertia and fast response to widely varying load demands, to" provide a relatively simple tube system for a vapor generator, and to provide a vapor generator in which there is efficient and clean combustion of fuel with a low level of harmful exhaust emissions to pollute the air.

SUMMARY OF THE INVENTION In the present construction heavy and bulky conventional refractory insulation is obviated by utilizing the incoming air as an insulator for the outer shell or casing. This is accomplished by a plurality of radially spaced concentric heat sleeves which intercept radiation from the combustion cham bers and utilize such heat to preheat the incoming air for greater combustion efficiency.

A novel form of air register at one end of the casing imparts a circular swirling motion to the incoming air, distributing the air in concentric layers within the combustion chambers so that the hottest air moves around the outside wall of the primary combustion chamber and the coolest air flows directly into the center of the secondary combustion chamber. This air register is also arranged to intercept radiant heat at one end of the casing and utilize this heat for further heating of the incoming air. A tangential burner nozzle adjacent the outer wall of the primary combustion chamber initiates combustion in the hottest layer of air, the flame moving inwardly toward the axis to enter the secondary combustion chamber and mix with the cooler air.

The wall of the tertiary combustion chamber area is lined with superheat tubes which intercept and utilize outwardly directed radiation. Radiation toward the opposite end of the casing is intercepted and utilized by banks of vapor generating tubes and liquid preheating tubes, around all of which tubes the flame and products of combustion must pass to reach the exhaust opening at said opposite end of the casing.

The invention will be better understood and additional ob jects and advantages will become apparent from the following description of the preferred embodiment illustrated in the accompanying drawings. Various changes may be made, however, in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view with parts in elevation, showing a vapor generator embodying the principles of the invention;

FIG. 2 is an enlarged view on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary perspective view showing the construction of the air register;

FIG. 4 is an enlarged fragmentary'view of a portion of FIG. 3; and

FIG. 5 is a view on the line 5-5 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The vapor generator is housed in a cylindrical outer shell or casing which contains therewithin a concentric cylindrical inner shell 11. A space 12 between the two shells provides an annular passageway for incoming air as indicated by arrows 13 in FIG. 1. The air is blown into the space 12 tangentially at the lower end of the casing by blower 15 in FIG. 5. Blower l5 discharges into a scroll casing 16 which communicates with an arcuate opening 17 in outer shell It) as shown in FIG. I. Thus, the air follows a spiral path around shell 11 which is in clockwise direction in bottom plan view as indicated in FIG. 5 and counterclockwise in top plan view as indicated in FIG. 2.

Shells l0 and 11 are secured to a bottom end wall 20 by screws 21 in a pair of flange rings 22. These rings are spotwelded at 23 to end wall 20. At intermediate height the concentric spacing of shell 11 within shell 10 is maintained by a plurality of resilient curled tongues 24. These tongues are spotwelded to shell 10 arid merely bear against shell 11 without any positive connection thereto. Tongues 24 are freely yieldable to permit expansion and contraction of shell 11 as a result of heating and cooling.

For convenience in assembly, the upper end of shell 10 is made as a separate section, the joint between the two shells being indicated at 25. Screws 26 secure the upper section to a ring 27 which is spotwelded to the lower section. For purposes of the present description, however, the two sections will be treated as a single continuous shell 10.

The spiral flow of incoming air 13 passes upward and enters three annular passageways separated by a pair of

heat sleeves

30 and 31 which are maintained in concentric spaced relation, as shown, by additional resilient curled tongues 24. Inner sleeve 30 has an inturned upper end 32 and outer sleeve 31 has an inturned upper end 33 having a greater radial extent than end 32. The spacing of these inturned ends is maintained by additional resilient curled tongues 24. Outer shell 10 is connected to a top end wall 35 by screws 21 in a flange ring 22 which is spotwelded to end wall 35 in the same manner as bottom end wall 20. Heat sleeves 30 and 31 thus form three concentric

annular passages

36, 37 and 38 for the incoming air 13. These heat sleeves surround a primary combustion chamber A and the upper portion of a tertiary combustion chamber area C.

The three layers of air rising through

passageways

36, 37 and 38 absorb heat from the combustion chambers and prevent outer shell 10 from becoming hot to the touch. Inner shell 11 forms the wall of the combustion chambers and radiates heat to sleeve 30, some of the heat in shell 11 and sleeve 30 being removed by air in passageway 36. Sleeve 30 radiates heat to sleeve 31 and heat is removed from both of these sleeves by air rising through

passageways

37 and 38. Heat is also removed from sleeve 31 by air in passageway 38. Thus, passageway 36 conveys the hottest layer of air, passageway 37 conveys a layer of air at intermediate temperature, and passageway 38 conveys a layer of relatively cool air.

lnturned ends 32 and 33, being of different radial extent, conduct the layers of air of different temperature to different regions under the top end wall 35, the hottest air being discharged immediately inside shell 11, the air of intermediate temperature being conveyed between inturned

ends

31 and 32 closer to the center of shell 11 and the relatively cool air from passageway 38 being directed by inturned end 33 to a central region of the shell. The space receiving these three layers of air is designated as plenum chamber 39. The three layers of air entering the plenum chamber 39 are directed into the combustion chambers in circular swirling flow by an air register 40 having a series of sector-shaped plates 41. Plates 41 are spotwelded together at their apexes and are held in spaced relation to each other by rigid spacer tongues 43 as shown in FIG. 3. Around the periphery of the register the plates are spaced apart by resilient, curled tongues 24. Air register 40 is held against the upper edge of shell 11 by the resilient curled tongues 24 on the plates 41 and on the

intumed ends

32 and 33 of the

heat sleeves

30 and 31 as shown. Peripheral tabs 44 and welds 42 hold the plate assemblage together as a unit.

Plates 41 are inclined in the manner of fan blades and have considerable overlap to form sloping passages which enhance the circular swirling motion of the air passing downward through the air register. The overlap of plates 4! and inturned

ends

32 and 33 intercepts upward radiation from the combustion chambers, producing radiation from one plate to the next and heating the air between the plates as described in connection with the insulting and air heating action of

heat sleeves

30 and 31. Thus, there is no direct radiation from the combustion chambers against end wall 35 and the heat reaching end wall 35 by plate to plate radiation is largely removed by the relatively cool air from outer passageway 38 which flows inwardly in contact with end wall 35 and then contacts the center of the air register, cooling plates 41 and heating the air.

A depending circular skirt 50 is suspended from the under side of air register 40 by means of tabs 52 welded to pl ites 41.

The lower edge of skirt 50 is spaced above an innular ly to skirt 50 and inturned end 33 overhangs skirt 50.

As shown in FlG. 2, fuel nozzle 60 injects a fine spray of oil tangentially into primary combustion chamber A directly into the vortex ring of the hottest iayer of air from passageway 36 which flows around the inside surface of shell 11. in starting operation the oil spray is ignited by spark plug 61 Larger droplets of the oil spray which are not immediately vaporized or burned are deposited on the wall of shell 11, the skirt 50 and, to some extent, also on the undersides of plates 41. The immediate combustion of the finer droplets greatly i icreases the volume of gas and the velocity of circular flow, pioducing a strong scrubbing action on any droplets adhering to such surfaces causing all the droplets to vaporize and burn.

This swelling and accelerating vortex of burning g ises can only escape by moving downward and toward thr center under the lower edge of skirt 50 and around cone 51 and thence upward within skirt 50 and downward through the cone in a tight spiral as shown. This produces a folded vortex in secondary combustion chamber B. At the upper end of cone 51 the burning gases mix with the cooler flows of air from

passageways

37 and 38 which are introduced into the upper end of skirt 50 from plenum chamber 39. This increased supply of oxygen completes combustion of all the fuel in an expanding downward moving vortex diverging into tertiary combustion chamber C.

Y I Beginning a short distance below diaphragm 53 the wall 11 in layers extending from shell 11 inward to a central refractory core 7 2. The turns of the coils are spaced radially in each layer and are staggered in vertical direction to intercept all downward radiation from secondary combustion chamber B and provide tortuous passageways for the flow of hot combustion gases between the tubes as shown.

Below

vapor generating sections

70 and 71 is a liquid preheater section 73 which extends down to a steel wire support rack 75. Refractory core 72 merely fills the open center of these coils so that there will be no free path for radiation from tertiary combustion chamber C to impinge on bottom plate 20 and no free path for the passage of combustion gases without wiping the tubes in

tube sections

70, 71 and 73. The combustion gas is discharged through support rack 75 and outlet 76.

holes in shell 11 as shown in FIG. 5, thereby allowing free expansion and contraction of the parts in heating and cooling. The whole stack of coils is confined 'by an upper ring secured in shell 11 by means of screws 81. The tubes in

sections

70, 71 and 73 are maintained spaced apart vertically and horizontally as shown by radial spacer strips 77 having notches to seat the tubes.

This is a single pass system wherein the liquid is introduced into lower tube section 73 through an inlet connection 85, the liquid flow then passing through

tube sections

71 and 70 where the liquid is vaporized and the vapor then passing through tube section 65, where the vapor is superheated, to outlet 86. The liquid may be water containing a suitable volatile antifreeze solution such as alcohol, it may be a mixture of water and a manufactured chemical, or it may be entirely a manufactured chemical composition.

The present construction provides an appropriate environment for the efficient and clean combustion of fuel. There are no tubes in the primary or secondary combustion chambers presenting relatively cool surfaces upon which partially burned fuel may quench and condense giving rise to unburned hydrocarbons, aldehydes and other noxious compounds in the exhaust. On the other hand, the combustion temperatures are deliberately kept below 2800 F. to prevent the highly objectionable oxides of nitrogen from being generated in excessive amounts. The intake of air directly into the secondary combustion chamber insures complete oxidation of all the fuel, substantially eliminating carbon monoxide. The tertiary or post combustion chamber C provides for completion of combustion so that flames do not impinge on the banks of tube surfaces below chamber C. These factors reduce any harmful exhaust emission to a relatively low level.

The device will operate satisfactorily in any position. it is not necessary for it to be mounted in vertical position as shown in FIG. 1. Although the vapor generator is particularly adapted for automotive use, it is not limited to any specific field of use.

Having now described my invention and in what manner the same may be used, what 1 claim as new and desire to protect by Letters Patent is:

1. A vapor generator comprising concentric inner and outer shells, an annular primary combustion chamber in one end of said inner shell, a secondary combustion chamber in the center of said primary combustion chamber, concentric cylindrical heat sleeves surrounding said primary combustion chamber between said inner and outer shells forming concentric annular passageways between said shells, means for introducing air in circular flow between said shells at their opposite end producing spiral flows of air between said sleeves, means introducing said spiral flow from the innermost annular passageway into said primary combustion chamber, means introducing said spiral flow from the outermost annular passageway into said secondary combustion chamber, tubes for liquid in the opposite end of said inner shell, and an exhaust outlet in the opposite end of said shells for combustion gases.

2. A vapor generator as defined in claim i, said means in troducing said spiral flows of air into said combustion chambers comprising an air register extending across said one end of said inner shell in spaced relation to an endwall on said outer shell and inturned ends on said heat sleeves extending between said air register and said end wall.

Support rack 75 comprises crossed wires extending through 3. A vapor generator as defined in claim 2 including an annular diaphragm in said inner shell spaced from said air register, said primary combustion chamber extending between said air register and said diaphragm, said secondary combustion chamber. being contained within a circular skirt on said air register and a circular wall around the inner edge of said diaphragm extending into said skirt.

4. A vapor generator as defined in claim 2, said air register being arranged to intercept heat radiation toward said one end of said shells and said liquid tubes being arranged to intercept heat radiation toward said opposite end of said shells.

5. A vapor generator comprising concentric inner and outer cylindrical shells, end walls on said outer shell, an air register on one end of said inner shell forming a plenum chamber between said air register and one end wall of said outer shell, an exhaust'outlet in the opposite end wall of said outer shell, means for introducing air in circular flow between said shells adjacent said opposite end, a diaphragm across said inner shell forming a primary combustion chamber between said diaphragm and said air register, a secondary combustion chamber within said primary combustion chamber, and a tertiary or post combustion chamber on the opposite side of said diaphragm, concentric cylindrical heat sleeves surrounding 7 said primary combustion chamber between said inner and outer shells forming concentric annular passageways for conveying said circular flow of air to said plenum chamber, multilayered sloping passageways in said air register arranged to direct air from said plenum chamber into said primary combustion chamber in a circular vortex flow, a tangential fuel spray nozzle in said primary combustion chamber, said air register being arranged to intercept heat radiation directed toward said one end wall, a central opening in said diaphragm communicating with said secondary and tertiary combustion chambers, a superheat tube section in said tertiary combustion chamber, and vaporizing and liquid preheater tube sections between said superheat tube section and said opposite end wall of said outer shell, the tubes in said vaporizing and preheater tube sections being spaced apart to pass combustion gases to said exhaust outlet and arranged to intercept heat radiation from said secondary and tertiary combustion chambers directed toward said opposite end wall.

6. A vapor generator as defined in claim 5, said air register comprising a plurality of inclined, overlapping, spaced apart sector-shaped plates.

7. A vapor generator as defined in claim 5, said heat sleeves having inturned ends extending into said plenum chamber and overhanging said air register.

8. A vapor generator as defined in claim 5 including a circalar skirt on said air register forming an inner wall in said primary combustion chamber and a circular wall around said opening in said diaphragm extending into said skirt.

9. A vapor generator as defined in claim 5 including resilient spacers between said inner and outer shells and resilient spacers between said shells and said heat sleeves.

10. A vapor generator as defined in claim 5 including notched radially extending spacer strips holding said tubes in said vaporizing and preheater tube sections spaced apart in radial and axial directions relative to said shells.

11. A single pass vapor generator comprising a circular tube bundle having a hot and cool end, an inner cylindrical shell closely surrounding saidbundle and having corresponding hot and cool ends, said hot end of said shell extending beyond said tube bundle to form a combustion chamber, an air register in said hot end of said shell forming one end of said combustion chamber, said air register comprising a multiplicity of sloping passages directed to give a swirl or vortex effect to combustion air pressured into said combustion chamber, coaxially spaced baffles within said combustion chamber, an outer shell coaxial to said inner shell spaced outwardly therefrom and including a solid dome end portion spaced away from said air register, a plurality of coaxial sleeves spaced between said inner and outer shells located at the hot ends thereof and extending inwardly on their hot end extremity into the spacebetween said air register and said dome, means for pressuring combustion air into the space between the inner and outer shells near their cool ends, a fuel spray means directed tangentially into a portion of the combustion chamber in a direction to correspond to the rotation of the vortex of combustion air, and a gas outlet connected to the cool end of the shells, to provide an integrated vapor generating unit in which the combustion air is heated prior to combustion for greater efficiency, said air fonning heat barrier to insulate said combustion chamber and in which the air entering the combustion chamber is divided and segregated according to temperature and these gradations of hot air are introduced into the combustion area selectively to enhance combustion efficiency, and wherein a vortex flow of combustion gases is formed to provide an extended path for said combustion gases prior to their being exposed to the tube bundle.

Claims

2. A vapor generator as defined in claim 1, said means introducing said spiral flows of air into said combustion chambers comprising an air register extending across said one end of said inner shell in spaced relation to an end wall on said outer shell and inturned ends on said heat sleeves extending between said air register and said end wall.

3. A vapor generator as defined in claim 2 including an annular diaphragm in said inner shell spaced from said air register, said primary combustion chamber extending between said air register and said diaphragm, said secondary combustion chamber being contained within a circular skirt on said air register and a circular wall around the inner edge of said diaphragm extending into said skirt.

5. A vapor generator comprising concentric inner and outer cylindrical shells, end walls on said outer shell, an air register on one end of said inner shell forming a plenum chamber between said air register and one end wall of said outer shell, an exhaust outlet in the opposite end wall of said outer shell, means for introducing air in circular flow between said shells adjacent said opposite end, a diaphragm across said inner shell forming a primary combustion chamber between said diaphragm and said air register, a secondary combustion chamber within said primary combustion chamber, and a tertiary or post combustion chamber on the opposite side of said diaphragm, concentric cylindrical heat sleeves surrounding said primary combustion chamber between said inner and outer shells forming concentric annular passageways for conveying said circular flow of air to said plenum chamber, multilayered sloping passageways in said air register arranged to direct air from said plenum chamber into said primary combustion chamber in a circular vortex flow, a tangential fuel spray nozzle in said primary combustion chamber, said air register being arranged to intercept heat radiation directed toward said one end wall, a central opening in said diaphragm communicating with said secondary and tertiary combustion chambers, a superheat tube section in said tertiary combustion chamber, and vaporizing and liquid preheater tube sections between said superheat tube section and said opposite end wall of said outer shell, the tubes in said vaporizing and preheater tube sections being spaced apart to pass combustion gases to said exhaust outlet and arranged to intercept heat radiation from said secondary anD tertiary combustion chambers directed toward said opposite end wall.

8. A vapor generator as defined in claim 5 including a circular skirt on said air register forming an inner wall in said primary combustion chamber and a circular wall around said opening in said diaphragm extending into said skirt.

11. A single pass vapor generator comprising a circular tube bundle having a hot and cool end, an inner cylindrical shell closely surrounding said bundle and having corresponding hot and cool ends, said hot end of said shell extending beyond said tube bundle to form a combustion chamber, an air register in said hot end of said shell forming one end of said combustion chamber, said air register comprising a multiplicity of sloping passages directed to give a swirl or vortex effect to combustion air pressured into said combustion chamber, coaxially spaced baffles within said combustion chamber, an outer shell coaxial to said inner shell spaced outwardly therefrom and including a solid dome end portion spaced away from said air register, a plurality of coaxial sleeves spaced between said inner and outer shells located at the hot ends thereof and extending inwardly on their hot end extremity into the space between said air register and said dome, means for pressuring combustion air into the space between the inner and outer shells near their cool ends, a fuel spray means directed tangentially into a portion of the combustion chamber in a direction to correspond to the rotation of the vortex of combustion air, and a gas outlet connected to the cool end of the shells, to provide an integrated vapor generating unit in which the combustion air is heated prior to combustion for greater efficiency, said air forming heat barrier to insulate said combustion chamber and in which the air entering the combustion chamber is divided and segregated according to temperature and these gradations of hot air are introduced into the combustion area selectively to enhance combustion efficiency, and wherein a vortex flow of combustion gases is formed to provide an extended path for said combustion gases prior to their being exposed to the tube bundle.