CA1041079A - Heat transfer structure - Google Patents
Heat transfer structureInfo
- Publication number
- CA1041079A CA1041079A CA105,018A CA105018A CA1041079A CA 1041079 A CA1041079 A CA 1041079A CA 105018 A CA105018 A CA 105018A CA 1041079 A CA1041079 A CA 1041079A
- Authority
- CA
- Canada
- Prior art keywords
- passages
- heat exchange
- fluid
- conduit
- average
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
- F28D7/163—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation with conduit assemblies having a particular shape, e.g. square or annular; with assemblies of conduits having different geometrical features; with multiple groups of conduits connected in series or parallel and arranged inside common casing
- F28D7/1669—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation with conduit assemblies having a particular shape, e.g. square or annular; with assemblies of conduits having different geometrical features; with multiple groups of conduits connected in series or parallel and arranged inside common casing the conduit assemblies having an annular shape; the conduits being assembled around a central distribution tube
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B37/00—Component parts or details of steam boilers
- F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
- F22B37/04—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler and characterised by material, e.g. use of special steel alloy
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B37/00—Component parts or details of steam boilers
- F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
- F22B37/10—Water tubes; Accessories therefor
- F22B37/107—Protection of water tubes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
- F24H1/10—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium
- F24H1/12—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium
- F24H1/14—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form
- F24H1/145—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form using fluid fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
- F24H1/10—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium
- F24H1/12—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium
- F24H1/14—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form
- F24H1/16—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form helically or spirally coiled
- F24H1/165—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form helically or spirally coiled using fluid fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D7/02—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being helically coiled
- F28D7/024—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being helically coiled the conduits of only one medium being helically coiled tubes, the coils having a cylindrical configuration
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
- F28F13/003—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by using permeable mass, perforated or porous materials
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S165/00—Heat exchange
- Y10S165/355—Heat exchange having separate flow passage for two distinct fluids
- Y10S165/40—Shell enclosed conduit assembly
- Y10S165/401—Shell enclosed conduit assembly including tube support or shell-side flow director
Abstract
Abstract A heat transfer structure and system including a matrix of tubes and spheres bonded together to provide a conduit for a first fluid such as water and a plurality of interconnected paths for a second fluid such as hot flue gas. The paths are made up of the spaces between the spheres such that the walls of the paths are portioned of spherical surfaces. The total path length is made less than twenty times the average radius of curvature of the spherical surfaces and the spacing between adjacent tube elements is of the same order of magnitude as the average length of the paths. A water heater or boiler so constructed may be made to transfer substantially all the heat in a flue gas to water in an average path length of one inch or less.
Description
~04107~
This invention relates to heat exchange structures and systems and more particularly to structures and systems useful where large tempera-ture differentials exist between the heat source and the heat sink, such as steam generators or water heaters.
It is well known that many systems for transferring heat from one fluid medium to another have been devised which have a relatively high efficiency, that is a relatively large amount of thermal energy is transfer-red with a relatively low expenditure of power for blowers, pumps, or other similar devices. Some systems have elaborate thin fin structures which are difficult to fabricate. Such fin structures are also subject to melting when exposed directly to hot gases of combustion at velocities encountered ~ in conventional boiler designs.
i Conventional boiler designs which do not use fins or other `~ such extended surfaces, are relatively costly and bulky, and the average length of the hot gas passages is at least several feet. Because of the large surface area required for a given heat transfer in conventional boilers, a large number of header joints are generally required since the length of a ~~ water tube at elevated temperatures is limited by structural considerationsO
In accordance with the present invention, a heat exchanger and a heat exchange system are provided which are compact, rugged and highly efficient in the transfer of thermal energy from a gas having a temperature above 1000 F, such as boiler systems in which the fuel air combustion products impinge directly on the heat exchanger surface.
Thus, in accordance with one aspect of the present invention, there is provided a heat exchange system, comprising a thermally conductive ~ -structure in structural and heat exchange association with a conduit for a first fluid and a plurality of passages for directing the flow of a second and hotter fluid through the thermally conductive structure, thereby to heat said first fluid~ the thermally conductive structure surrounding a central plenum, the conduit comprising a plurality of elongated conduit portions spaced around the central plenum and the thermally conductive structure rigidly interconnecting at least some of the conduit portions, ., .
10~
- the length of said passages being less than twice the average spacing between said conduit portions, a burner disposed within the central plenum compris-ing an apertured elongated structure supported outside said plenum and extending into said plenum, and a blower connected to the burner and arranged for supplying a mixture of fuel and air thereto.
In accordance with another aspect of the invention there is pro-.:; vided the heat exchange structure comprising: a thermally conductive matrix providing a plurality of conduit portions for a first fluid and a plurality . of passages for directing the flow of a second fluid therethrough; the :~ 10 major portion of the total wall area of said passages comprising surface `
,;,, ;; areas of rigid members interconnecting said conduit portions and surrounding ` a central plenum; said surface areas being predominantly curved in all directions and the average length of said passages being less than twenty times the average radius of curvature of said surface areas; and the average :
.. ,, :
-. maximum transverse dimension of the average minimum cross-sectional area ~.~ of said passages being less than said average length of said passages.
.. According to another aspect of the invention there is provided the : heat exchange system comprising: a thermally conductive matrix formed of a .
- plurality of layers of thermally conductive bodies, whose surface areas are 20 predominantly convexly curved in all directions and which are regidly inter- -; . connected between hollow elements defining a conduit for a first fluid; said bodies together with said hollow elements comprising a structure surrounding a central plenum; the surface areas of said bodies defining a plurality of interconnected passages having an average length of between three and twenty ~ .
times the average radius of curvature of said surface areas; means for direct-ing a second fluid, comprising a gas at a temperature substantially higher -. than the temperature of said first fluid, from said central plenum through said passages at velocities which produce a transfer of thermal energy between said first and second fluids which is the major portion of the thermal ~ -la-' , . .
~041079 - energy in said second fluid represented by the temperature differential between said first and second fluids; and the shortest conductive paths through said matrix from the surface areas of said matrix on which said second fluid first impinges to the nearest wall of said conduit means being not greater than six times the average radius of curvature of said thermally conductive bodies.
According to another aspect of the invention there is provided a a heat exchange system, comprising a thermally conductive structure in structural and heat exchange association with a conduit for a first fluid and a plurality of passages for directing the flow of a second hotter fluid through the thermally conductive structure thereby to heat said first fluid, - with said conduit comprising a plurality of elongated conduit portions spaced around a central plenum and rigidly interconnected at least at the ends of said conduit portions, the length of said passages in the direction of flow of said second fluid being less than twice the average spacing between said : conduit portions, the major portions of the surfaces of said passages being formed of thermally conductive elements rigidly bonded to said conduits, a ` burner extending into said plenum and rigidly supported with respect to said . thermally conductive structure for producing combustion within said plenum, ~-the diameter of said burner being less than one-half of the diameter of said . plenum, a blower supplying a mixture of gaseous fuel and air to the interior of said burner and a pressure regulator for supplying said gaseous fuel to the input of said blower.
~- Specifically, the invention provides for a matrix having a plurality of interconnected passages formed by the spaces between a plurality of solid spheres which together with tubular elements are bonded into an integral matrix. The tubular elements provide a conduit through which a fluid such as water is directed. A hot gaseous medium is directed through the inter-connected passages between the spheres. Since the average length of the ~ ~ -lb-- , -- . .: .,~ , , . :" :. . : , :
: 1~410~5~
: . ~
; passages is less than twenty times the average radius of curvature of the ~ .
i; surfaces forming the walls of the passages, a heat exchanger may be : fabricated in which the average length of' the passages is less than two .`'' .
,,' :,, :
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. :
....
.. ~ ., .
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., "', ' .
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. ' --lc--' : 10~0'~9 inches long and as much as 90% of the heat generated by the complete combustion of a fuel air mixture will be transferred through the matrix into water in the conduit.
The transfer of substantially all of the heat of combustion from a gas to a matrix in passages having an average length of less than two inches results in a system where the velocity of the hot gas may be directed through the passages at radically increased velocities with pressure drops along the gas paths similar to those encountered in conventional boiler systems such as, for example, a pressure drop of one inch of water. Such radial velocity increases over those previously commercially feasible provide for a system in which the heat transfer very substantially exceeds that of any known commercial heat tran-sfer system. For example, in conventional small boiler designs heat transfer rates of less than 10,000 BTUts per hour per square foot of boiler tubing are usual and heat transfer rates as high as 100 watts per square inch or roughly 50,000 BTU7s per hour per square foot, are rarely if ever achieved. This inven-tion, however, provides for heat transfer rates in small residential heating units in excess of 200,000 BTUts per hour per square foot, and in large high pressure high temperature embodiments of the invention heat transfer rates or.
the order of 1,000,000 BTUts per square foot per hour are commercially feasible.
In addition, the invention provides for the heat transfer to the matrix to be made more efficient, and hence the passages shorter, by providing for substantial variation in the cross sectional area of the passages along the length thereof. The resultant turbulence of a hot gaseous medium flowing through -~the passages materially reduces the stagnant layer of the medium adjacent the matrix surfaces forming the walls of the passages and increases the hot gas heat transfer.
This invention further discloses that for any given volume fill-ed with a plurality of spheres,~the total surface area of the spheres varies inversely with their average diameter.,Accordingly, a matrix structure formed of spheres and tubes provide a total surface area of the interconnected passages which, for a given tube diameter, will vary substantially inversely with the diameter of the spheres filling the space between the tubes. By the use of spheres having an average diameter substantially less than the average diameter
This invention relates to heat exchange structures and systems and more particularly to structures and systems useful where large tempera-ture differentials exist between the heat source and the heat sink, such as steam generators or water heaters.
It is well known that many systems for transferring heat from one fluid medium to another have been devised which have a relatively high efficiency, that is a relatively large amount of thermal energy is transfer-red with a relatively low expenditure of power for blowers, pumps, or other similar devices. Some systems have elaborate thin fin structures which are difficult to fabricate. Such fin structures are also subject to melting when exposed directly to hot gases of combustion at velocities encountered ~ in conventional boiler designs.
i Conventional boiler designs which do not use fins or other `~ such extended surfaces, are relatively costly and bulky, and the average length of the hot gas passages is at least several feet. Because of the large surface area required for a given heat transfer in conventional boilers, a large number of header joints are generally required since the length of a ~~ water tube at elevated temperatures is limited by structural considerationsO
In accordance with the present invention, a heat exchanger and a heat exchange system are provided which are compact, rugged and highly efficient in the transfer of thermal energy from a gas having a temperature above 1000 F, such as boiler systems in which the fuel air combustion products impinge directly on the heat exchanger surface.
Thus, in accordance with one aspect of the present invention, there is provided a heat exchange system, comprising a thermally conductive ~ -structure in structural and heat exchange association with a conduit for a first fluid and a plurality of passages for directing the flow of a second and hotter fluid through the thermally conductive structure, thereby to heat said first fluid~ the thermally conductive structure surrounding a central plenum, the conduit comprising a plurality of elongated conduit portions spaced around the central plenum and the thermally conductive structure rigidly interconnecting at least some of the conduit portions, ., .
10~
- the length of said passages being less than twice the average spacing between said conduit portions, a burner disposed within the central plenum compris-ing an apertured elongated structure supported outside said plenum and extending into said plenum, and a blower connected to the burner and arranged for supplying a mixture of fuel and air thereto.
In accordance with another aspect of the invention there is pro-.:; vided the heat exchange structure comprising: a thermally conductive matrix providing a plurality of conduit portions for a first fluid and a plurality . of passages for directing the flow of a second fluid therethrough; the :~ 10 major portion of the total wall area of said passages comprising surface `
,;,, ;; areas of rigid members interconnecting said conduit portions and surrounding ` a central plenum; said surface areas being predominantly curved in all directions and the average length of said passages being less than twenty times the average radius of curvature of said surface areas; and the average :
.. ,, :
-. maximum transverse dimension of the average minimum cross-sectional area ~.~ of said passages being less than said average length of said passages.
.. According to another aspect of the invention there is provided the : heat exchange system comprising: a thermally conductive matrix formed of a .
- plurality of layers of thermally conductive bodies, whose surface areas are 20 predominantly convexly curved in all directions and which are regidly inter- -; . connected between hollow elements defining a conduit for a first fluid; said bodies together with said hollow elements comprising a structure surrounding a central plenum; the surface areas of said bodies defining a plurality of interconnected passages having an average length of between three and twenty ~ .
times the average radius of curvature of said surface areas; means for direct-ing a second fluid, comprising a gas at a temperature substantially higher -. than the temperature of said first fluid, from said central plenum through said passages at velocities which produce a transfer of thermal energy between said first and second fluids which is the major portion of the thermal ~ -la-' , . .
~041079 - energy in said second fluid represented by the temperature differential between said first and second fluids; and the shortest conductive paths through said matrix from the surface areas of said matrix on which said second fluid first impinges to the nearest wall of said conduit means being not greater than six times the average radius of curvature of said thermally conductive bodies.
According to another aspect of the invention there is provided a a heat exchange system, comprising a thermally conductive structure in structural and heat exchange association with a conduit for a first fluid and a plurality of passages for directing the flow of a second hotter fluid through the thermally conductive structure thereby to heat said first fluid, - with said conduit comprising a plurality of elongated conduit portions spaced around a central plenum and rigidly interconnected at least at the ends of said conduit portions, the length of said passages in the direction of flow of said second fluid being less than twice the average spacing between said : conduit portions, the major portions of the surfaces of said passages being formed of thermally conductive elements rigidly bonded to said conduits, a ` burner extending into said plenum and rigidly supported with respect to said . thermally conductive structure for producing combustion within said plenum, ~-the diameter of said burner being less than one-half of the diameter of said . plenum, a blower supplying a mixture of gaseous fuel and air to the interior of said burner and a pressure regulator for supplying said gaseous fuel to the input of said blower.
~- Specifically, the invention provides for a matrix having a plurality of interconnected passages formed by the spaces between a plurality of solid spheres which together with tubular elements are bonded into an integral matrix. The tubular elements provide a conduit through which a fluid such as water is directed. A hot gaseous medium is directed through the inter-connected passages between the spheres. Since the average length of the ~ ~ -lb-- , -- . .: .,~ , , . :" :. . : , :
: 1~410~5~
: . ~
; passages is less than twenty times the average radius of curvature of the ~ .
i; surfaces forming the walls of the passages, a heat exchanger may be : fabricated in which the average length of' the passages is less than two .`'' .
,,' :,, :
~.
,,,.,,,~ ~
. :
....
.. ~ ., .
~' :
1 ". .
., "', ' .
~,. ':':, . ' ' .
.
':
. ' --lc--' : 10~0'~9 inches long and as much as 90% of the heat generated by the complete combustion of a fuel air mixture will be transferred through the matrix into water in the conduit.
The transfer of substantially all of the heat of combustion from a gas to a matrix in passages having an average length of less than two inches results in a system where the velocity of the hot gas may be directed through the passages at radically increased velocities with pressure drops along the gas paths similar to those encountered in conventional boiler systems such as, for example, a pressure drop of one inch of water. Such radial velocity increases over those previously commercially feasible provide for a system in which the heat transfer very substantially exceeds that of any known commercial heat tran-sfer system. For example, in conventional small boiler designs heat transfer rates of less than 10,000 BTUts per hour per square foot of boiler tubing are usual and heat transfer rates as high as 100 watts per square inch or roughly 50,000 BTU7s per hour per square foot, are rarely if ever achieved. This inven-tion, however, provides for heat transfer rates in small residential heating units in excess of 200,000 BTUts per hour per square foot, and in large high pressure high temperature embodiments of the invention heat transfer rates or.
the order of 1,000,000 BTUts per square foot per hour are commercially feasible.
In addition, the invention provides for the heat transfer to the matrix to be made more efficient, and hence the passages shorter, by providing for substantial variation in the cross sectional area of the passages along the length thereof. The resultant turbulence of a hot gaseous medium flowing through -~the passages materially reduces the stagnant layer of the medium adjacent the matrix surfaces forming the walls of the passages and increases the hot gas heat transfer.
This invention further discloses that for any given volume fill-ed with a plurality of spheres,~the total surface area of the spheres varies inversely with their average diameter.,Accordingly, a matrix structure formed of spheres and tubes provide a total surface area of the interconnected passages which, for a given tube diameter, will vary substantially inversely with the diameter of the spheres filling the space between the tubes. By the use of spheres having an average diameter substantially less than the average diameter
- 2 -.
:, :
:, .
`
~` 104~ 75 ;; of the tubes, a heat exchange structure is provided in which substantially all of the heat of the combustion gases is transferred in a path length not substan-tially greater than the spacing between adjacent tubes. This spacing is gen-erally not substantially greater than the diameter of the tubes and accordingly the average path length for the hot gas through the matrix should be less than twice the diameter of the tubes or twice the average spacing between the tubes, ; , whichever greater. Any additional path length provides substantially no addi-tional heat transfer between the hot gas and the matrix and increases total pressure drop along the passage thereby reducing the volume of hot gas passing through the passages for pressure drop acceptable in commercially feasible boiler designs. In commercially feasible boilers embodying the invention the , .-passage length is less than twenty times the average radius of the spheres.For bodies having surfaces curved in two directions, many other than spherical such as egg or pebble shapes, the average length of the passages is less than twenty times the average radius of curvature of those portions of the surfaces of the passage walls which are curved in two directions.
The largest transverse dimension of the region of the passage having the smallest cross-sectional area is made relatively small, that is smaller than the length of the passages so that dimensional stability and structural rigidity is maintained even under conditions of large temperature differential between the hot gas flowing through the passages and the matrix.
In large high pressure water tube boilers, when the tubes are exposed directly to the hot combustion products, high gas velocity can result in substantial vibrations of the tubes and the production noise which can exceed ambient levels by over 100 decibels. Due to the structural rigidity of this invention such high velocities at elevated temperatures, and hence high performance can be achieved without such undesirable vibrations or noise.
An additional feature of this invention is the discovery that this structure is extremely stable when subjected to high thermal shock, that is rapid warm-up and cool-down cycles are possible since the multiple conductive connections through the matrix rapidly equalize temperature gradients in the solid~and thereby reduce the uneven stresses which could otherwise cause fail-ure in high temperature high pressure boilers.
~ ~04~LO ~9 -n ~
The heat exchange structure further provides, by reason of the - bonded matrix of spheres surrounding tubes, a structure in which for boiler designs the tube diameter may be made smaller for a given length and hence : the tube walls thinner while still retaining the same or greater rigidity along the length of the tube structure. With thinner tube walls which, for a given pressure, can result from smaller diameter tubes, a greater heat transfer rate may be achieved for a given interior wall temperature, which is determin-ed essentially by the water steam mixture passing through the tube, before the outer surface of the tube reaches a temperature at which it loses substantial strength. As a result, heat transfer rates in excess of one million BTU~s per hour per square foot of water area are possible with commercially available ~- boiler tube steels at pressures in excess of 500 psi and temperatures in excess of 500 F, whereas commercial high pressure boiler designs are currently limited to between two and three hundred thousand BTU~s per hour per square -~
foot of surface area.
A further advantage of this invention results from the discovery that the matrix will remain substantially free of deposits of combustion products in the hot gas passages even when the size of passages is reduced to that between spheres one-sixth of an inch in diameter, whereas in conventional ; 20 boiler designs substantially greater dimensions for the hot gas passages are required. The generally turbulent nature of the flow through the matrix which results from the spherical wall surfaces of the gas passages reduces or pre-vents the formation of such deposits even at low velocities corresponding to idling rates of burner design. This feature is particularly advantageous in those commercial boiler applications where a varying load requires a wide range of firing rates.
Brief description of the drawings.
- The invention as well as specific embodiments thereof will now be described, reference being directed to the accompanying drawings in which:
Figure 1 is a vertical cross sectional view taken along line l-l of Figure 2 of the preferred embodiment of the invention for heating a fluid with hot gas;
~ 4 ~
.
.
10410~ 9 .' Figure 2 is a transverse cross sectional view of the embodiment , .
shown in Figure 1 taken along line 2-2 of Figure l;
Figure 3 is a schematic representation of a closed cycle heat exchange system utilizing the heat ~ransfer structure illustrated in Figures 1 and 2;
Figure 4 is a schematic representation of a heat transfer system ` for heating water utilizing the heat transfer structure illustrated in Figures 1 and 2;
- Figure 5 is a schematic representation of a heat transfer system utilizing the heat transfer structure illustrated in Figures 1 and 2 for heating oil or other organic media;
Figure 6 is a vertical cross sectional view taken along line - 6-60f Figure 7 of a heat transfer structure illustrating a further embodiment ; of the invention;
Figure 7 is a transverse cross sectional view taken along line 7-7 of Figure 6 of the embodiment of the invention illustrated in Figure 6.
Figure 8 is a vertical cross sectional view taken along line 8-8 of Figure 10 of a heat transfer structure illustrating a further embodi-ment of the invention.
Figure 9 is an enlarged fragmentary view of a portion of the matrix included within the line 9-9 of Figure 8; and Figure 10 is a transverse cross sectional view of the matrix structure illustrated in Figure 8 taken along line 10-10 of Figure 8.
Referring now to Figures 1, 2 and 3, there is shown a preferred .
embodiment of the invention. A matrix 10 is formed of a plurality of tubes 11 which are, for example, of steel, approximately one half inch in diameter and six inches long, surrounding a central plenum region 12. A plurality of spheres 13 are positioned in the spaces between the tubes 11, and, as shown in this embodiment, are approximately one-sixth of an inch in diameter.
Matrix 10 extends in a direction radial to the axis of the plenum for a distance of approximately four rows of spheres such that the inner row of spheres is approximately tangent to the inner most portions of tubes 11 while - 5_ ~ 10410~79 the outer row of spheres is positioned beyond a circle tangent to the outer most portions of the tubes 11.
The tubes 11 and spheres 13, which may be of any desired therm-ally conductive material, are, as shown herein, commercial grade steel coated - with a bonding material such as copper or a copper alloy. The tubes and spheres have been bonded together by heating the elements above the melting temperature of the copper or copper alloy coating in an inert atmosphere to form the unified heat conductive matrix 10. The area of contact of the spheres to each other and to the tubes are enlarged due to capillary action of the molten brazing coating.
In practice, a copper coating approximately .001 inch thick will produce between two spheres approximately one-sixth of an inch in diameter, a contact surface having a diameter of around .070 inch so that the conductive heat path between the spheres and between the spheres and the tubes is maintained at a low value of impedance to heat flow, both because of the enlarged contact areas and because the copper used at the contact areas has high thermal conductivity.
The tubes 11 constitute a conduit for the flow of water or other fluid to be heated through the matrix. For this purpose an upper header member 14 is provided constituting a plate having holes through which the upper ends of tubes 11 extend and to which tubes 11 are connected by any desired ` means such as brazing. Plate 14 also acts to close the upper end of the plenum 12 and a cover dish 15 is sealed to header 14 in the region outside the tubes 11, for example, by brazing. A lower header member 16 consists of an annular plate through which the lower ends of tubes 11 extend and to which .. :
they are sealed in a manner similar to the attachment to upper header 14.
Two semiannular covers 17 each cover half of the portions of lower header 16 through which the tubes 11 extend, one of the covers having an input pipe 18 - and the other cover having an output pipe 19 attached thereto.
Extending centrally upwardly from lower header plate 16 into plenum 12 is a burner assembly 22 made up of a cylindrical screen 23 attached, for example, by welding to a lower annular support plate 24 which is removably .
.- :
' ~ ' ' .
104~0~-~9 ched to lower header plate 16, for example by bolts 25. The details of the burner assembly are more specifically described in Canadian application 95,184 filed October 8, 1970, by W.H. Hapgood and D.G. Protopapas and assign-ed to the assignee of this application.
In order to increase the combustion capability of the plenum 12 above that normally possible for its size, a screen 26 of refractory material such as kanthol is positinned around the burner screen 23. In the particular embodiment of the invention disclosed herein, the diameter of the burner screen is slightly less than one-third of the diameter of the plenum and the diameter of the refractory screen 26 is slightly greater than one-half the diameter of the plenum 12. The screen 26 is attached by rods 27 to the upper header mem-ber 13 and the upper end of the screen 26 is closed by a block of refractory material 28 while the lower end of the screen 26 contacts and is pressed against a lower block of refractory material 29.
The screen 26, during operation, becomes incandescent and radiates heat outwardly toward the matrix 10 and inwardly toward the burning flame adjacent the screen 23, thereby accelerating the combustion process and per-mitting complete combustion of the fuel gas mix~ure. In the particular , ` design illustrated having a plenum volume between the screen 23 and the tubes 11 of thirty to forty cubic inches, efficient and complete combustion may be achieved at rates of over 180,000 BTU's per hour, which represents a combus-tion rate of about ten million BTU's per hour per cubic foot of combustion volume.
The air fuel mixture is supplied by a blower illustrated in .` Figure 3 and removably connected by a tapered flange 47 to the annular burner support plate 24, for example, by bolts. An ignition device such as a spark plug 40 is screwed into plate 24 and extends into the plenum 12 in the region between screen 26 and matrix 10. The size of screen 26 is sufficiently coarse, for example, six spaces to the inch, that the gas fuel mixture passing through burner screen 2~ and refractory screen 26 will ignite and ~he flame path will travel back through refractory screen 26 to the burner screen 23. The hole diameter and spacing, for example, .027 inch in diameter spaced in an ortho-,~, ........................................................................ .
` la4l0~,~
gonal pattern with twenty holes per inch, prevent the flame surface from travel-ing through the burner screen 23.
In Figure 3, the embodiment of the invention shown in Figures 1 and 2 is collectively referred to as a heat transfer structure indicated at 50.
A blower 51 is connected through the fitting 47 to feed the air and gas mix-ture into the heat exchanger where, upon ignition, it burns to provide a com-bustion gas having a temperature of several thousand degrees.
A gas from a source 53, which may be a public gas main having a pressure of several inches of water or a bottled gas supply having a pressure `
of several pounds per square inch, is fed through a solenoid control valve 54 and regulator 55 to the inlet 52 of the blower 51. The size of blower 51 is such that it will provide a pressure in the combustion chamber of heat exchang-er 50 on the order of one inch of water. The hot burned gas passes through the heat exchanger matrix 10 and out through a flue 42.
The exhaust temperature is dependent primarily upon the length of the passages through the matrix 10 and the quantity and temperature of hot gas passed therethrough. In general, the path length is made short enough to provide for an exhaust temperature above the condensation temperature of the exhaust products, for example 300 - 400 F.
A pump 59 pumps waterinto the heat exchange structure 50 and the outlet which may be water or steam at any desired temperature and pressure, depending on the rate at which pump 59 pumps the water into the heat exchange structure 50 and the rate at which fuel lS burned, flows to a load 57 which ; may be a hot water or steam radiator for commercial or residential heating purposes. Alternatively, the load 57 may be a power generation system such as a steam turbine, and condenser.
The heat exchanger illustrated in Figures 1 and 2 may be operat-ed at convective heat exchange rates exceeding one million BTUts per hour per square foot of the liquid surface. While additional blower power is needed to - 30 achieve these heat transfer rates, it is comparable to that required in con-ventional convective boiler designs in which heat exchange rates of 10,000 -20,000 BTU~s per square foot of liquid surface are typical.
: 104~()'79 Heat transfer rates over one million BTU's per square foot of liquid surface is possible in practical designs of high pressure boiler for ~` power generators since tube size may be made relatively small, for example, .
one inch diameter or less and several feet long with the necessary stiffness achieved by adjacent tubes being interconnected with spheres to form an integral matrix in accordance with the invention. In such a matrix, tubes made of inexpensive carbon steel or steel alloys with a wall thickness of one to two tenths of an inch will provide for heat transfer rates on the order of one million BTUts per square foot of liquid surface with the liquid - 10 under a pressure in excess of 500 psi and at a temperature in excess of 500 F.
Referring now to Figure 4, there is shown a heat exchange system with a heat exchange structure 50 embodying the elements of the invention illustrated in Figure 1 and 2 in which heat is supplied by a blower 51 blow-ing a mixture of air and gas from a supply 53 through a control valve 54 and .. . .
regulator 55 similar to that discussed in connection with Figure 3. Water from a main 56 is supplied through suitable metering, control and check valves :-not shown through an inlet tube 45 to the heat exchange structure 50 and after passing therethrough flows through a hot water pipe 46 to a hot water . . , - spigot 58 for instant usage. A temperature and pressure relief valve 59 may ,, .
be disposed in the line 46.
Referring now to Figure 5, there is shown a heat exchange system using a heat exchange structure 50 embodying the elements of the invention illustrated in Figures 1 and 2in which heat is supplied by a blower 51 blowing a mixture of air and gas from a supply 53 through a control valve .. . .
54 and regulator 55 similar to that discussed in connection with Figure 3.
Oil from a vat 61 is circulated through the heat exchange structure 50 by means of a circulating pump 59. Such a device will heat the oil or other organic liquid relatively unifor~ly without hot spots which would carbonize or decompose the oil. The oil in the vat may be used, for example for cook-ing, in which case a screen 60 is provided over the intake pipe leading to the pump 59 to prevent material other than oil fr~m entering the heat exchange structure 50. Alternatively, the oil could be heavy oil which requires heat-:, ,, ` 104~0~9 ,;
- ing prior to combustion or for use in industrial processes.
Referring now to Figures 6 and 7, there is shown a further embodiment of a heat exchange structure illustrating the invention. A plural-ity of tubes 11 approximately one-half inch in diameter and several inches long are arranged in a circle several inches in diameter surrounding a plenum 12. There are, for example, 24 such tubes and the spacing between the tubes is approximately one-half the diameter of the tubes. A plurality of spheres, 13, approximately one-sixth of an inch in diameter fill the spaces between - the tubes. The tubesand spheres are made, for example, of steel with a coat-ing of copper or copper alloy and the entire assembly bonded together as dis-closed in connection with Figures 1 and 2 to produce a matrix 10. The ends of the tubes 11 extend through upper and lower header plates 14 and 16 respec-tively, and the tubes are connected together in two series by upper header cover members 15 and lower header cover members 17 respectively. The unconnec-ted ends of the tubes 11 form entrance and outlet connections 18 and 19 respectively for the liquid.
~; Burner assembly 22 consists of a burner screen 23 extending into -the interior of the space defined by the matrix and supported by plate 24 attached to the lower header plate ~4 by bolts 25, screen 23 being attached `-; 20 by welding or otherwise to the plate 24. The diameter of the screen 23, as shown in this embodiment, is slightly greater than one-third of the interior diameter of the space formed by the ~atrix and is supplied with an air fuel .: :
mixture, for example through the blower Sl illustrated in Figure 3. Refractory material blocks 28 and 29 are attached to the upper header plate 14 and the burner supported plate 24 respectivelyO
It should be noted that in the particular embodiment illustrated herein, three laye~s of spheres 13 are shown, however, a greater or lesser number of spheres could be used dependent upon the total heat transfer desiredO
The spheres 13 do not extend beyond the inner or outer circles defined by the walls of the tubes 11 and therefore this structure is particularly adapted for mass production of residential heating structures where heat transfer rates on the order of 100,000 BTU's per square foot of liquid surface are desired and ;-. .
: .
1(~410 79 the temperature of the combustion gases after passing through the heat exchanger still remain above the condensation temperature of corrosive con-stituents of the flue gas, for example in the range of 300-400 F.
Referring now to Figures 8, 9 and 10, there is illustrated a further embodiment of the invention. A helical tube 11 is embedded in, surrounded by a plurality of solid metallic spheres 13 bonded together and - to tube 11, for example by brazing, to form an integral thermally conductive matrix 10.
The thermal conductivity of the materials used, the pressure drop across the foraminous matrix structure, and the thermal flux desired determine the spacing between adjacent elements of tube 11 which make up the :, fluid conduit. Good performance has been achieved when the distance between adjacent elements of the tube 11 is approximately equal to the diameter of the tube 11 and substantially all the heat is transferred to the matrix when the -:.
radial thickness of the matrix 10 is less than twice the spacing between adjacent conduit elements.
An inlet 18 and outlet 19 are respectively provided at the ends of the tube 11 through which the fluid to be heated passes. The matrix sur-rounds a central plenum 12 which acts as a combustion chamber at the lower end of which a burner plate 34 is provided having~a plurality of holes 35 for the . .
admittance of an air gas mixture under a pressure of, for example, on theorder of one inch of water, from a source coupled to inlet duct 36 and feed-ing through conical section 37 into the combustion chamber 38. Extending into one side of burner plate 34 is an ignition means 40 of any well known construction such as a spark plug to provide the necessary ignition of the gaseous fuel mixture.
An outer wall member 41 surrounds the heat transfer structure and a flue 42 provides for passage of the exhaust gases out of the heat transfer structure. A top plate member 43 is secured to the heat transfer structure by a stud embedded in the matrix and extending through plate 43 tog~ther with a nut 44 threaded on the stud and engaging the upper surface of plate 43.
:. :
, 10~ 9 In the embodiment shown in Figures 8 through 10, the number of spheres may be increased or decreased dependent on the total amount of heat to be transferred from the hot gas into the conduit. For example, if the total number of spheres one-sixth of an inch in diameter is formed into a matrix having a radial thickness of approximately eight rows, with a spheri-cal diameter of approximately one-sixth of an inch so that the total matrix thickness is approximately an inch and a quarter, a heat transfer rate in excess of one half million BTU's per hour per square foot of tubing surface can be achieved. If desired, combustion may occur outside of the plenum 12 and be directed into the plenum 12 to increase the combustion volume to achieve heat transfer rates up to a million BTU's per hour per square foot of tubing surface while still retaining an exhaust temperature of around 700VF. With a half million BTU's per hour per square foot of heat transfer, the exhaust temperature would be around 400F. Such a structure is particu-larly useful in high pressure mobile boilers, for example, for use in steam motor vehicles.
While the embodiments of the invention described in Figures 8, :., ~
9 and 10, as well as the other embodiment of the invention disclosed herein are particularly useful with water as the fluid inside the conduit, it is often desirable to use fluids such as a water steam mixture of organic com-pounds having heat transfer co-efficient less than that of water. Under these conditions when it is desired to produ~e a gas from a liquid in the conduit and to simultaneously transfer the heat of vaporization to the fluid in what is called a two-phase condition, this invention provides for an extended surface comprising spheres inside the conduit as shown, for example, in Figure 9 as a variation of the embodiment of the invention shown in Figure 8 which does not have spheres inside the conduit. The spheres are bonded to the interior of tube 11 along a portion on the entire length thereof in a similar fashion to that used to bond the matrix 10. The spheres - . , , ~' .
: , , ' ' ' 10410'79 in the conduit have been found to enhance turbulent flow of the fluid in a manner particularly useful in heat transfer to two-phase fluids.
It is, of course, obvious from the drawings that the average diameter of the plenum is substantially greater than the average lengths of the passages between the spheres and that the total volume of the matrix is substantially less than the total volume of the plenum.
This completes the description of the embodiment and the invention illustrated herein, however, many modifications thereof will be apparent to persons skilled in the art without departing from the spirit and scope of this invention, for example, spheres of the matrix may be of sizes and ...
shapes other than spherical such as ovid and the matrix structure may be ' - formed with the spheres and tubes cast as one integral piece and for certain - high temperature application the spheres and other portion of the heat exchange , .
. .
structure may be made of nonmetallic substances such as graphite. Accordingly, `~1 it is intended that this invention not be limited to the particular embodi-; ments described herein except as defined by the appended claims.
:, " ' :~
-~ -13-.
:, :
:, .
`
~` 104~ 75 ;; of the tubes, a heat exchange structure is provided in which substantially all of the heat of the combustion gases is transferred in a path length not substan-tially greater than the spacing between adjacent tubes. This spacing is gen-erally not substantially greater than the diameter of the tubes and accordingly the average path length for the hot gas through the matrix should be less than twice the diameter of the tubes or twice the average spacing between the tubes, ; , whichever greater. Any additional path length provides substantially no addi-tional heat transfer between the hot gas and the matrix and increases total pressure drop along the passage thereby reducing the volume of hot gas passing through the passages for pressure drop acceptable in commercially feasible boiler designs. In commercially feasible boilers embodying the invention the , .-passage length is less than twenty times the average radius of the spheres.For bodies having surfaces curved in two directions, many other than spherical such as egg or pebble shapes, the average length of the passages is less than twenty times the average radius of curvature of those portions of the surfaces of the passage walls which are curved in two directions.
The largest transverse dimension of the region of the passage having the smallest cross-sectional area is made relatively small, that is smaller than the length of the passages so that dimensional stability and structural rigidity is maintained even under conditions of large temperature differential between the hot gas flowing through the passages and the matrix.
In large high pressure water tube boilers, when the tubes are exposed directly to the hot combustion products, high gas velocity can result in substantial vibrations of the tubes and the production noise which can exceed ambient levels by over 100 decibels. Due to the structural rigidity of this invention such high velocities at elevated temperatures, and hence high performance can be achieved without such undesirable vibrations or noise.
An additional feature of this invention is the discovery that this structure is extremely stable when subjected to high thermal shock, that is rapid warm-up and cool-down cycles are possible since the multiple conductive connections through the matrix rapidly equalize temperature gradients in the solid~and thereby reduce the uneven stresses which could otherwise cause fail-ure in high temperature high pressure boilers.
~ ~04~LO ~9 -n ~
The heat exchange structure further provides, by reason of the - bonded matrix of spheres surrounding tubes, a structure in which for boiler designs the tube diameter may be made smaller for a given length and hence : the tube walls thinner while still retaining the same or greater rigidity along the length of the tube structure. With thinner tube walls which, for a given pressure, can result from smaller diameter tubes, a greater heat transfer rate may be achieved for a given interior wall temperature, which is determin-ed essentially by the water steam mixture passing through the tube, before the outer surface of the tube reaches a temperature at which it loses substantial strength. As a result, heat transfer rates in excess of one million BTU~s per hour per square foot of water area are possible with commercially available ~- boiler tube steels at pressures in excess of 500 psi and temperatures in excess of 500 F, whereas commercial high pressure boiler designs are currently limited to between two and three hundred thousand BTU~s per hour per square -~
foot of surface area.
A further advantage of this invention results from the discovery that the matrix will remain substantially free of deposits of combustion products in the hot gas passages even when the size of passages is reduced to that between spheres one-sixth of an inch in diameter, whereas in conventional ; 20 boiler designs substantially greater dimensions for the hot gas passages are required. The generally turbulent nature of the flow through the matrix which results from the spherical wall surfaces of the gas passages reduces or pre-vents the formation of such deposits even at low velocities corresponding to idling rates of burner design. This feature is particularly advantageous in those commercial boiler applications where a varying load requires a wide range of firing rates.
Brief description of the drawings.
- The invention as well as specific embodiments thereof will now be described, reference being directed to the accompanying drawings in which:
Figure 1 is a vertical cross sectional view taken along line l-l of Figure 2 of the preferred embodiment of the invention for heating a fluid with hot gas;
~ 4 ~
.
.
10410~ 9 .' Figure 2 is a transverse cross sectional view of the embodiment , .
shown in Figure 1 taken along line 2-2 of Figure l;
Figure 3 is a schematic representation of a closed cycle heat exchange system utilizing the heat ~ransfer structure illustrated in Figures 1 and 2;
Figure 4 is a schematic representation of a heat transfer system ` for heating water utilizing the heat transfer structure illustrated in Figures 1 and 2;
- Figure 5 is a schematic representation of a heat transfer system utilizing the heat transfer structure illustrated in Figures 1 and 2 for heating oil or other organic media;
Figure 6 is a vertical cross sectional view taken along line - 6-60f Figure 7 of a heat transfer structure illustrating a further embodiment ; of the invention;
Figure 7 is a transverse cross sectional view taken along line 7-7 of Figure 6 of the embodiment of the invention illustrated in Figure 6.
Figure 8 is a vertical cross sectional view taken along line 8-8 of Figure 10 of a heat transfer structure illustrating a further embodi-ment of the invention.
Figure 9 is an enlarged fragmentary view of a portion of the matrix included within the line 9-9 of Figure 8; and Figure 10 is a transverse cross sectional view of the matrix structure illustrated in Figure 8 taken along line 10-10 of Figure 8.
Referring now to Figures 1, 2 and 3, there is shown a preferred .
embodiment of the invention. A matrix 10 is formed of a plurality of tubes 11 which are, for example, of steel, approximately one half inch in diameter and six inches long, surrounding a central plenum region 12. A plurality of spheres 13 are positioned in the spaces between the tubes 11, and, as shown in this embodiment, are approximately one-sixth of an inch in diameter.
Matrix 10 extends in a direction radial to the axis of the plenum for a distance of approximately four rows of spheres such that the inner row of spheres is approximately tangent to the inner most portions of tubes 11 while - 5_ ~ 10410~79 the outer row of spheres is positioned beyond a circle tangent to the outer most portions of the tubes 11.
The tubes 11 and spheres 13, which may be of any desired therm-ally conductive material, are, as shown herein, commercial grade steel coated - with a bonding material such as copper or a copper alloy. The tubes and spheres have been bonded together by heating the elements above the melting temperature of the copper or copper alloy coating in an inert atmosphere to form the unified heat conductive matrix 10. The area of contact of the spheres to each other and to the tubes are enlarged due to capillary action of the molten brazing coating.
In practice, a copper coating approximately .001 inch thick will produce between two spheres approximately one-sixth of an inch in diameter, a contact surface having a diameter of around .070 inch so that the conductive heat path between the spheres and between the spheres and the tubes is maintained at a low value of impedance to heat flow, both because of the enlarged contact areas and because the copper used at the contact areas has high thermal conductivity.
The tubes 11 constitute a conduit for the flow of water or other fluid to be heated through the matrix. For this purpose an upper header member 14 is provided constituting a plate having holes through which the upper ends of tubes 11 extend and to which tubes 11 are connected by any desired ` means such as brazing. Plate 14 also acts to close the upper end of the plenum 12 and a cover dish 15 is sealed to header 14 in the region outside the tubes 11, for example, by brazing. A lower header member 16 consists of an annular plate through which the lower ends of tubes 11 extend and to which .. :
they are sealed in a manner similar to the attachment to upper header 14.
Two semiannular covers 17 each cover half of the portions of lower header 16 through which the tubes 11 extend, one of the covers having an input pipe 18 - and the other cover having an output pipe 19 attached thereto.
Extending centrally upwardly from lower header plate 16 into plenum 12 is a burner assembly 22 made up of a cylindrical screen 23 attached, for example, by welding to a lower annular support plate 24 which is removably .
.- :
' ~ ' ' .
104~0~-~9 ched to lower header plate 16, for example by bolts 25. The details of the burner assembly are more specifically described in Canadian application 95,184 filed October 8, 1970, by W.H. Hapgood and D.G. Protopapas and assign-ed to the assignee of this application.
In order to increase the combustion capability of the plenum 12 above that normally possible for its size, a screen 26 of refractory material such as kanthol is positinned around the burner screen 23. In the particular embodiment of the invention disclosed herein, the diameter of the burner screen is slightly less than one-third of the diameter of the plenum and the diameter of the refractory screen 26 is slightly greater than one-half the diameter of the plenum 12. The screen 26 is attached by rods 27 to the upper header mem-ber 13 and the upper end of the screen 26 is closed by a block of refractory material 28 while the lower end of the screen 26 contacts and is pressed against a lower block of refractory material 29.
The screen 26, during operation, becomes incandescent and radiates heat outwardly toward the matrix 10 and inwardly toward the burning flame adjacent the screen 23, thereby accelerating the combustion process and per-mitting complete combustion of the fuel gas mix~ure. In the particular , ` design illustrated having a plenum volume between the screen 23 and the tubes 11 of thirty to forty cubic inches, efficient and complete combustion may be achieved at rates of over 180,000 BTU's per hour, which represents a combus-tion rate of about ten million BTU's per hour per cubic foot of combustion volume.
The air fuel mixture is supplied by a blower illustrated in .` Figure 3 and removably connected by a tapered flange 47 to the annular burner support plate 24, for example, by bolts. An ignition device such as a spark plug 40 is screwed into plate 24 and extends into the plenum 12 in the region between screen 26 and matrix 10. The size of screen 26 is sufficiently coarse, for example, six spaces to the inch, that the gas fuel mixture passing through burner screen 2~ and refractory screen 26 will ignite and ~he flame path will travel back through refractory screen 26 to the burner screen 23. The hole diameter and spacing, for example, .027 inch in diameter spaced in an ortho-,~, ........................................................................ .
` la4l0~,~
gonal pattern with twenty holes per inch, prevent the flame surface from travel-ing through the burner screen 23.
In Figure 3, the embodiment of the invention shown in Figures 1 and 2 is collectively referred to as a heat transfer structure indicated at 50.
A blower 51 is connected through the fitting 47 to feed the air and gas mix-ture into the heat exchanger where, upon ignition, it burns to provide a com-bustion gas having a temperature of several thousand degrees.
A gas from a source 53, which may be a public gas main having a pressure of several inches of water or a bottled gas supply having a pressure `
of several pounds per square inch, is fed through a solenoid control valve 54 and regulator 55 to the inlet 52 of the blower 51. The size of blower 51 is such that it will provide a pressure in the combustion chamber of heat exchang-er 50 on the order of one inch of water. The hot burned gas passes through the heat exchanger matrix 10 and out through a flue 42.
The exhaust temperature is dependent primarily upon the length of the passages through the matrix 10 and the quantity and temperature of hot gas passed therethrough. In general, the path length is made short enough to provide for an exhaust temperature above the condensation temperature of the exhaust products, for example 300 - 400 F.
A pump 59 pumps waterinto the heat exchange structure 50 and the outlet which may be water or steam at any desired temperature and pressure, depending on the rate at which pump 59 pumps the water into the heat exchange structure 50 and the rate at which fuel lS burned, flows to a load 57 which ; may be a hot water or steam radiator for commercial or residential heating purposes. Alternatively, the load 57 may be a power generation system such as a steam turbine, and condenser.
The heat exchanger illustrated in Figures 1 and 2 may be operat-ed at convective heat exchange rates exceeding one million BTUts per hour per square foot of the liquid surface. While additional blower power is needed to - 30 achieve these heat transfer rates, it is comparable to that required in con-ventional convective boiler designs in which heat exchange rates of 10,000 -20,000 BTU~s per square foot of liquid surface are typical.
: 104~()'79 Heat transfer rates over one million BTU's per square foot of liquid surface is possible in practical designs of high pressure boiler for ~` power generators since tube size may be made relatively small, for example, .
one inch diameter or less and several feet long with the necessary stiffness achieved by adjacent tubes being interconnected with spheres to form an integral matrix in accordance with the invention. In such a matrix, tubes made of inexpensive carbon steel or steel alloys with a wall thickness of one to two tenths of an inch will provide for heat transfer rates on the order of one million BTUts per square foot of liquid surface with the liquid - 10 under a pressure in excess of 500 psi and at a temperature in excess of 500 F.
Referring now to Figure 4, there is shown a heat exchange system with a heat exchange structure 50 embodying the elements of the invention illustrated in Figure 1 and 2 in which heat is supplied by a blower 51 blow-ing a mixture of air and gas from a supply 53 through a control valve 54 and .. . .
regulator 55 similar to that discussed in connection with Figure 3. Water from a main 56 is supplied through suitable metering, control and check valves :-not shown through an inlet tube 45 to the heat exchange structure 50 and after passing therethrough flows through a hot water pipe 46 to a hot water . . , - spigot 58 for instant usage. A temperature and pressure relief valve 59 may ,, .
be disposed in the line 46.
Referring now to Figure 5, there is shown a heat exchange system using a heat exchange structure 50 embodying the elements of the invention illustrated in Figures 1 and 2in which heat is supplied by a blower 51 blowing a mixture of air and gas from a supply 53 through a control valve .. . .
54 and regulator 55 similar to that discussed in connection with Figure 3.
Oil from a vat 61 is circulated through the heat exchange structure 50 by means of a circulating pump 59. Such a device will heat the oil or other organic liquid relatively unifor~ly without hot spots which would carbonize or decompose the oil. The oil in the vat may be used, for example for cook-ing, in which case a screen 60 is provided over the intake pipe leading to the pump 59 to prevent material other than oil fr~m entering the heat exchange structure 50. Alternatively, the oil could be heavy oil which requires heat-:, ,, ` 104~0~9 ,;
- ing prior to combustion or for use in industrial processes.
Referring now to Figures 6 and 7, there is shown a further embodiment of a heat exchange structure illustrating the invention. A plural-ity of tubes 11 approximately one-half inch in diameter and several inches long are arranged in a circle several inches in diameter surrounding a plenum 12. There are, for example, 24 such tubes and the spacing between the tubes is approximately one-half the diameter of the tubes. A plurality of spheres, 13, approximately one-sixth of an inch in diameter fill the spaces between - the tubes. The tubesand spheres are made, for example, of steel with a coat-ing of copper or copper alloy and the entire assembly bonded together as dis-closed in connection with Figures 1 and 2 to produce a matrix 10. The ends of the tubes 11 extend through upper and lower header plates 14 and 16 respec-tively, and the tubes are connected together in two series by upper header cover members 15 and lower header cover members 17 respectively. The unconnec-ted ends of the tubes 11 form entrance and outlet connections 18 and 19 respectively for the liquid.
~; Burner assembly 22 consists of a burner screen 23 extending into -the interior of the space defined by the matrix and supported by plate 24 attached to the lower header plate ~4 by bolts 25, screen 23 being attached `-; 20 by welding or otherwise to the plate 24. The diameter of the screen 23, as shown in this embodiment, is slightly greater than one-third of the interior diameter of the space formed by the ~atrix and is supplied with an air fuel .: :
mixture, for example through the blower Sl illustrated in Figure 3. Refractory material blocks 28 and 29 are attached to the upper header plate 14 and the burner supported plate 24 respectivelyO
It should be noted that in the particular embodiment illustrated herein, three laye~s of spheres 13 are shown, however, a greater or lesser number of spheres could be used dependent upon the total heat transfer desiredO
The spheres 13 do not extend beyond the inner or outer circles defined by the walls of the tubes 11 and therefore this structure is particularly adapted for mass production of residential heating structures where heat transfer rates on the order of 100,000 BTU's per square foot of liquid surface are desired and ;-. .
: .
1(~410 79 the temperature of the combustion gases after passing through the heat exchanger still remain above the condensation temperature of corrosive con-stituents of the flue gas, for example in the range of 300-400 F.
Referring now to Figures 8, 9 and 10, there is illustrated a further embodiment of the invention. A helical tube 11 is embedded in, surrounded by a plurality of solid metallic spheres 13 bonded together and - to tube 11, for example by brazing, to form an integral thermally conductive matrix 10.
The thermal conductivity of the materials used, the pressure drop across the foraminous matrix structure, and the thermal flux desired determine the spacing between adjacent elements of tube 11 which make up the :, fluid conduit. Good performance has been achieved when the distance between adjacent elements of the tube 11 is approximately equal to the diameter of the tube 11 and substantially all the heat is transferred to the matrix when the -:.
radial thickness of the matrix 10 is less than twice the spacing between adjacent conduit elements.
An inlet 18 and outlet 19 are respectively provided at the ends of the tube 11 through which the fluid to be heated passes. The matrix sur-rounds a central plenum 12 which acts as a combustion chamber at the lower end of which a burner plate 34 is provided having~a plurality of holes 35 for the . .
admittance of an air gas mixture under a pressure of, for example, on theorder of one inch of water, from a source coupled to inlet duct 36 and feed-ing through conical section 37 into the combustion chamber 38. Extending into one side of burner plate 34 is an ignition means 40 of any well known construction such as a spark plug to provide the necessary ignition of the gaseous fuel mixture.
An outer wall member 41 surrounds the heat transfer structure and a flue 42 provides for passage of the exhaust gases out of the heat transfer structure. A top plate member 43 is secured to the heat transfer structure by a stud embedded in the matrix and extending through plate 43 tog~ther with a nut 44 threaded on the stud and engaging the upper surface of plate 43.
:. :
, 10~ 9 In the embodiment shown in Figures 8 through 10, the number of spheres may be increased or decreased dependent on the total amount of heat to be transferred from the hot gas into the conduit. For example, if the total number of spheres one-sixth of an inch in diameter is formed into a matrix having a radial thickness of approximately eight rows, with a spheri-cal diameter of approximately one-sixth of an inch so that the total matrix thickness is approximately an inch and a quarter, a heat transfer rate in excess of one half million BTU's per hour per square foot of tubing surface can be achieved. If desired, combustion may occur outside of the plenum 12 and be directed into the plenum 12 to increase the combustion volume to achieve heat transfer rates up to a million BTU's per hour per square foot of tubing surface while still retaining an exhaust temperature of around 700VF. With a half million BTU's per hour per square foot of heat transfer, the exhaust temperature would be around 400F. Such a structure is particu-larly useful in high pressure mobile boilers, for example, for use in steam motor vehicles.
While the embodiments of the invention described in Figures 8, :., ~
9 and 10, as well as the other embodiment of the invention disclosed herein are particularly useful with water as the fluid inside the conduit, it is often desirable to use fluids such as a water steam mixture of organic com-pounds having heat transfer co-efficient less than that of water. Under these conditions when it is desired to produ~e a gas from a liquid in the conduit and to simultaneously transfer the heat of vaporization to the fluid in what is called a two-phase condition, this invention provides for an extended surface comprising spheres inside the conduit as shown, for example, in Figure 9 as a variation of the embodiment of the invention shown in Figure 8 which does not have spheres inside the conduit. The spheres are bonded to the interior of tube 11 along a portion on the entire length thereof in a similar fashion to that used to bond the matrix 10. The spheres - . , , ~' .
: , , ' ' ' 10410'79 in the conduit have been found to enhance turbulent flow of the fluid in a manner particularly useful in heat transfer to two-phase fluids.
It is, of course, obvious from the drawings that the average diameter of the plenum is substantially greater than the average lengths of the passages between the spheres and that the total volume of the matrix is substantially less than the total volume of the plenum.
This completes the description of the embodiment and the invention illustrated herein, however, many modifications thereof will be apparent to persons skilled in the art without departing from the spirit and scope of this invention, for example, spheres of the matrix may be of sizes and ...
shapes other than spherical such as ovid and the matrix structure may be ' - formed with the spheres and tubes cast as one integral piece and for certain - high temperature application the spheres and other portion of the heat exchange , .
. .
structure may be made of nonmetallic substances such as graphite. Accordingly, `~1 it is intended that this invention not be limited to the particular embodi-; ments described herein except as defined by the appended claims.
:, " ' :~
-~ -13-.
Claims (32)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A heat exchange system, comprising a thermally conductive structure in structural and heat exchange association with a conduit for a first fluid and a plurality of passages for directing the flow of a second and hotter fluid through the thermally conductive structure, thereby to heat said first fluid, the thermally conductive structure surrounding a central plenum, the conduit comprising a plurality of elongated conduit portions spaced around the central plenum and the thermally conductive structure rigidly intercon-necting at least some of the conduit portions, the length of said passages being less than twice the average spacing between said conduit portions, a burner disposed within the central plenum comprising an apertured elongated structure supported outside said plenum and extending into said plenum, and a blower connected to the burner and arranged for supplying a mixture of fuel and air thereto.
2. A heat exchange system according to claim 1, wherein the thermally conductive structure comprises a plurality of thermally conductive elements which, together with the conduit portions, are rigidly bonded together to form a unitary heat conductive structure.
3. A heat exchange system according to claim 2, wherein the said ele-ments consist of a matrix of convexly curved bodies such that the major por-tion of the total wall area of the said passages is made up of surface areas which are convexly curved in all directions.
4. A heat exchange system according to claim 3, wherein the said sur-face areas are substantially spherical.
5. A heat exchange system according to claim 3 or 4, wherein the average length of the said passages is less than twenty times the average radius of curvature of the surface areas.
6. A heat exchange system according to claim 2, 3 or 4, wherein the average length of the said passages is less than twice the average distance between adjacent portions of the conduit.
7. A heat exchange system according to claim 3, wherein the matrix is formed substantially of a plurality of bodies of a first material coated with a second material which melts at a lower temperature than the first material.
8. A heat exchange system according to claim 7, wherein bonding bet-ween adjacent portions of the matrix is provided by the coating of the second material.
9. A heat exchange system according to claim 8, wherein the points of bonding form areas whose diameters are of the same order of magnitude as the radius of curvature of the curved surface areas.
10. A heat exchange system according to claim 2, 3 or 4 wherein the said conduit portions consist of parallel tubes extending through the thermal-ly conductive structure parallel to a central axis of the plenum and inter-connected by headers at the ends of the plenum.
11. A heat exchange system according to claim 4, wherein the matrix is formed substantially of a plurality of bodies of a first material coated with a second material which melts at a lower temperature than the first material.
12. A heat exchange system according to claim 11, wherein bonding bet-ween adjacent portions of the matrix is provided by the coating of the sec-ond material.
13. A heat exchange system according to claim 12, wherein the points of bonding form areas whose diameters are of the same order of magnitude as the radius of curvature of the curved surface areas.
14. A heat exchange system according to claim 7, 8 or 9 wherein the average length of the said passages is less than twenty times the average radius of curvature of the surface areas.
15. A heat exchange system according to claim 11, 12 or 13, wherein the average length of the said passages is less than twenty times the average radius of curvature of the surface areas.
16. The heat exchange structure comprising: a thermally conductive matrix providing a plurality of conduit portions for a first fluid and a plurality of passages for directing the flow of a second fluid therethrough;
the major portion of the total wall area of said passages comprising surface areas of rigid members interconnecting said conduit portions and surrounding a central plenum; said surface areas being predominantly curved in all direc-tions and the average length of said passages being less than twenty times the average radius of curvature of said surface areas; and the average maxi-mum transverse dimension of the average minimum cross-sectional area of said passages being less than said average length of said passages.
the major portion of the total wall area of said passages comprising surface areas of rigid members interconnecting said conduit portions and surrounding a central plenum; said surface areas being predominantly curved in all direc-tions and the average length of said passages being less than twenty times the average radius of curvature of said surface areas; and the average maxi-mum transverse dimension of the average minimum cross-sectional area of said passages being less than said average length of said passages.
17. A structure according to claim 16 wherein said surface areas are substantially spherical.
18. A structure according to claim 16 wherein said matrix is comprised of a plurality of layers of different metals.
19. A structure according to claim 16 wherein said conduit comprises tubing interconnected by a plurality of solid bodies bonded thereto and providing said passages.
20. A structure according to claim 16 wherein the average diameter of said plenum is substantially greater than the average length of said passages.
21. A structure according to claim 20 wherein the total volume of said matrix is substantially less than the total volume of said plenum.
22. A structure according to claim 16 wherein the average length of said passages is less than twice the average diameter of said tubing.
23. A structure according to claim 16 wherein the average length of said passages is less than twice the average distance between adjacent portions of said tubing.
24. The heat exchange system comprising: a thermally conductive matrix formed of a plurality of layers of thermally conductive bodies, whose surface areas are predominantly convexly curved in all directions and which are rigidly interconnected between hollow elements defining a conduit for a first fluid; said bodies together with said hollow elements comprising a structure surrounding a central plenum; the surface areas of said bodies defining a plurality of interconnected passages having an average length of between three and twenty times the average radius of curvature of said surface areas; means for directing a second fluid, comprising a gas at a temperature substantially higher than the temperature of said first fluid, from said central plenum through said passages at velocities which produce a transfer of thermal energy between said first and second fluids which is the major portion of the thermal energy in said second fluid represented by the temper-ature differential between said first and second fluids; and the shortest conductive paths through said matrix from the surface areas of said matrix on which said second fluid first impinges to the nearest wall of said conduit means being not greater than six times the average radius of curvature of said thermally conductive bodies.
25. A system according to claim 24 wherein said surface areas are substantially spherical.
26. A system according to claim 24 wherein said matrix is comprised of a plurality of bodies bonded together, said bodies having at least one subsurface layer and one surface layer, said layers being of different metals.
27. A system according to claim 24 wherein said matrix comprises a plurality of adjacent elements of tubing interconnected by a plurality of solid bodies bonded thereto and providing said passages, and at least some of said adjacent elements being connected for the sequential flow of said first fluid therethrough.
28. A system according to claim 24 wherein the average length of said passages is less than twice the average diameter of said tubing.
29. A system according to claim 24 wherein said conduit is formed into a non-rectilinear pattern.
30. A system according to claim 24 wherein said first fluid is the cooling fluid of a vehicle.
31. A system according to claim 24 wherein the means for directing said first fluid through said conduit are mechanically coupled to the same power source driving said means for directing said second fluid through said passages.
32. A heat exchange system, comprising a thermally conductive structure in structural and heat exchange association with a conduit for a first fluid and a plurality of passages for directing the flow of a second hotter fluid through the thermally conductive structure thereby to heat said first fluid, with said conduit comprising a plurality of elongated conduit portions spaced around a central plenum and rigidly interconnected at least at the ends of said conduit portions, the length of said passages in the direction of flow of said second fluid being less than twice the average spacing between said conduit portions; the major portions of the surfaces of said passages being formed of thermally conductive elements rigidly bonded to said conduits, a burner extending into said plenum and rigidly supported with respect to said thermally conductive structure for producing combustion within said plenum, the diameter of said burner being less than one-half of the diameter of said plenum, a blower supplying a mixture of gaseous fuel and air to the interior of said burner and a pressure regulator for supplying said gaseous fuel to the input of said blower.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA240,665A CA1041080A (en) | 1970-02-11 | 1975-11-27 | Heat transfer structure |
| CA256,576A CA1041081A (en) | 1970-02-11 | 1976-07-08 | Heat transfer structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US1033470A | 1970-02-11 | 1970-02-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1041079A true CA1041079A (en) | 1978-10-24 |
Family
ID=21745255
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA105,018A Expired CA1041079A (en) | 1970-02-11 | 1971-02-10 | Heat transfer structure |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US3704748A (en) |
| CA (1) | CA1041079A (en) |
| CH (1) | CH541790A (en) |
| ES (2) | ES383984A2 (en) |
| FR (1) | FR2079369B1 (en) |
| GB (2) | GB1314099A (en) |
| NL (1) | NL7015809A (en) |
| NO (1) | NO130606C (en) |
Families Citing this family (35)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3921712A (en) * | 1970-03-02 | 1975-11-25 | American Standard Inc | Heat exchanger structure for a compact boiler and the like |
| US3885529A (en) * | 1970-03-02 | 1975-05-27 | American Standard Inc | Heat exchanger structure for a compact boiler and the like |
| US3830221A (en) * | 1972-05-31 | 1974-08-20 | Raytheon Co | Oil heater protection system |
| DE2349294A1 (en) * | 1972-10-04 | 1974-04-11 | Brulfert | STEAM OR HOT WATER GENERATOR WITH CATALYTIC BURNING OF HYDROCARBONS |
| US4171772A (en) * | 1972-11-16 | 1979-10-23 | Amana Refrigeration, Inc. | Package heat exchanger system for heating and cooling |
| US3823704A (en) * | 1973-02-14 | 1974-07-16 | Rheem International | Power burner application to fin tube heat exchanger |
| US4274581A (en) * | 1973-12-06 | 1981-06-23 | Raytheon Company | Package heat exchanger system for heating and cooling |
| US3967590A (en) * | 1974-01-24 | 1976-07-06 | Amana Refrigeration, Inc. | Heat exchange control system |
| US4125151A (en) * | 1974-12-17 | 1978-11-14 | Raytheon Company | Package heat exchanger system for heating and cooling |
| US4135487A (en) * | 1975-08-29 | 1979-01-23 | Amana Refrigeration, Inc. | Heat exchange control system |
| DE2719958A1 (en) * | 1977-05-04 | 1978-11-09 | Sentras Ag | DEVICE FOR TRANSFERRING RADIANT HEAT TO A GAS OR LIQUID HEAT TRANSFER |
| US4222350A (en) * | 1978-06-26 | 1980-09-16 | Boston Gas Products, Inc. | Efficient heating and domestic hot water apparatus |
| US4593754A (en) * | 1980-06-24 | 1986-06-10 | Holl Richard A | Shell and tube heat transfer apparatus and process therefor |
| EP0042613A3 (en) * | 1980-06-24 | 1982-08-11 | Richard Adolf Holl | Apparatus and process for heat transfer |
| FR2493498A1 (en) * | 1980-11-03 | 1982-05-07 | Chavanelle Charlette | Unit for recovering energy from fluid - circulating into and out of container filled with numerous spheres |
| FR2514475A1 (en) * | 1981-10-08 | 1983-04-15 | Bonnet Claude | Heat exchanger heating boiler - has axial heating coil with heat exchange disc between coils |
| NL8202096A (en) * | 1982-05-21 | 1983-12-16 | Esmil Bv | HEAT EXCHANGER CONTAINING A GRANULAR CONTAINING VERTICAL TUBES. |
| US4708198A (en) * | 1982-11-01 | 1987-11-24 | Holl Richard A | Construction and method for improving heat transfer and mechanical life of tube-bundle heat exchangers |
| JPS61500132A (en) * | 1983-10-05 | 1986-01-23 | ベイパ− コ−ポレ−シヨン | Cylindrical and tubular heat transfer device and its method |
| US4723513A (en) * | 1986-01-30 | 1988-02-09 | Lochinvar Water Heater Corporation | Gas water heater/boiler |
| GB2199647B (en) * | 1987-01-07 | 1991-05-15 | Nicholas Julian Jan F Macphail | Improvements in heat exchangers |
| DE9215710U1 (en) * | 1992-11-19 | 1993-09-30 | Mundt Juergen | Luminous heat generator and convector |
| US6213757B1 (en) * | 1995-06-07 | 2001-04-10 | Quantum Group Inc. | Advanced emissive matrix combustion |
| US6250301B1 (en) * | 1997-08-28 | 2001-06-26 | Hortal Harm B.V. | Vaporizer for inhalation and method for extraction of active ingredients from a crude natural product or other matrix |
| DE10038523C1 (en) * | 2000-08-08 | 2002-06-27 | Xcellsis Gmbh | Combined component from heat exchanger and reactor |
| US7073567B2 (en) * | 2001-08-14 | 2006-07-11 | Global Cooling Bv | Condenser evaporator and cooling device |
| US7346210B2 (en) * | 2001-12-28 | 2008-03-18 | Nikon Corporation | Image processing device and image processing program for determining similarity factors of pixels |
| US7575043B2 (en) * | 2002-04-29 | 2009-08-18 | Kauppila Richard W | Cooling arrangement for conveyors and other applications |
| KR100481008B1 (en) * | 2002-06-03 | 2005-04-07 | 주성엔지니어링(주) | Gas heating apparatus for chemical vapor deposition process and semiconductor device fabrication method using the same |
| EP2083217B1 (en) | 2008-01-03 | 2013-05-01 | WORGAS BRUCIATORI S.r.l. | Gas burner for boiler |
| US20110300050A1 (en) * | 2010-06-08 | 2011-12-08 | Memc Electronic Materials, Inc. | Trichlorosilane Vaporization System |
| US20130341925A1 (en) * | 2011-01-07 | 2013-12-26 | Joao Soares | Device and method for producing green energy |
| US20130220301A1 (en) * | 2012-02-29 | 2013-08-29 | Atul Saksena | Gas burner system for gas-powered cooking devices |
| US11346611B2 (en) * | 2016-08-16 | 2022-05-31 | Hamilton Sundstrand Corporation | Heat exchangers with multiple flow channels |
| CN116952038B (en) * | 2023-09-14 | 2023-12-08 | 南京宜热纵联节能科技有限公司 | Indirect heat exchange device |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2893702A (en) * | 1947-12-12 | 1959-07-07 | Richardson Edward Adams | Heat exchange apparatus |
| FR1201074A (en) * | 1957-08-09 | 1959-12-28 | Apparatus for steam generation | |
| US3118430A (en) * | 1960-11-25 | 1964-01-21 | Ace Tank And Heater Company | Water heater |
| FR1313183A (en) * | 1961-11-13 | 1962-12-28 | Babcock & Wilcox France | Improvements to heat exchangers |
| US3289756A (en) * | 1964-10-15 | 1966-12-06 | Olin Mathieson | Heat exchanger |
| US3315646A (en) * | 1965-01-22 | 1967-04-25 | American Radiator & Standard | Boiler |
| US3513908A (en) * | 1967-08-18 | 1970-05-26 | Guru B Singh | Embedded tube heat exchanger |
| CA1040025A (en) * | 1968-01-24 | 1978-10-10 | Raytheon Company | Heat transfer structure |
-
1970
- 1970-02-11 US US10334A patent/US3704748A/en not_active Expired - Lifetime
- 1970-09-25 ES ES383984A patent/ES383984A2/en not_active Expired
- 1970-10-16 GB GB2508172A patent/GB1314099A/en not_active Expired
- 1970-10-16 GB GB4934570A patent/GB1314097A/en not_active Expired
- 1970-10-28 NL NL7015809A patent/NL7015809A/xx not_active Application Discontinuation
-
1971
- 1971-02-03 NO NO395/71A patent/NO130606C/no unknown
- 1971-02-10 CA CA105,018A patent/CA1041079A/en not_active Expired
- 1971-02-11 CH CH203271A patent/CH541790A/en not_active IP Right Cessation
- 1971-02-11 FR FR7104638A patent/FR2079369B1/fr not_active Expired
-
1973
- 1973-03-09 ES ES412497A patent/ES412497A2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1314099A (en) | 1973-04-18 |
| NO130606C (en) | 1975-01-08 |
| NL7015809A (en) | 1971-08-13 |
| DE2054692A1 (en) | 1973-02-22 |
| FR2079369A1 (en) | 1971-11-12 |
| DE2054692B2 (en) | 1977-04-14 |
| ES383984A2 (en) | 1973-03-01 |
| GB1314097A (en) | 1973-04-18 |
| FR2079369B1 (en) | 1975-04-18 |
| US3704748A (en) | 1972-12-05 |
| NO130606B (en) | 1974-09-30 |
| CH541790A (en) | 1973-09-15 |
| ES412497A2 (en) | 1976-03-01 |
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