|20030085021||Energy optimizer||May, 2003||Dykes et al.|
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|20060225869||Air conditioner and antibacterial case||October, 2006||Hara et al.|
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 This Application is a continuation in part of U.S. patent application Ser. No. 09/180,322, filed Oct. 18, 1999, by Jens Otto Ravn Andersen et al., entitled Flue Gas Heat Exchanger and Fin Therefor.
 The present invention relates to a flue gas exchanger comprising plane fins that extend from a first end to a second end of a jacket along and inside the jacket and that are assembled into blocks.
 DE 888 255 describes a flue gas exchanger comprising a chamber with a ribbed tube that extends along the chamber. The ribbed tube comprises ribs extending perpendicularly in relation to a longitudinal axis of the chamber. The ribs are provided with inlets and outlets for the flue gas. The inlets and outlets are constituted by segments of a circle having a constantly decreasing or increasing height. A cooling medium extends through a central tubing of the ribbed tube.
 The flue gas exchanger described in the above publication possesses some disadvantages. It involves large costs to produce a ribbed tube and at the same time the production has to be made for a specific dimensioning of the flue gas exchanger. Besides, a flue gas exchanger with a ribbed tube of the above-mentioned type with inlets and outlets constituted by segments of a circle has a limited capacity. The flue gas will be conducted to a centre of the jacket and cooling the ribs must take place by means of the central tubing having a limited surface area. Furthermore, the degree of rib effect is poor in a tube with external ribs. Finally, a ribbed tube having ribs that are provided with segments of a circle has a certain flow resistance towards the flue gas.
 This heat exchanger has the disadvantage that the flow of flue gas through the heat exchanger is very restricted thereby reducing the capacity. Consequently, the area of inlets or outlets in the flow path members amounts to a very low multiple of the size of a cross section area of channels between adjacent flow path members. Furthermore the heat exchanger both has actual flow path members but also has annular disk fins without inlets or outlets. This further restricts the flow of flue gas through the heat exchanger and thereby the capacity of the heat exchanger and gives a different flow of flue gas compered to as example DE 888 255.
 Thus, it is the object of the present invention to provide a flue gas exchanger that does not possess the disadvantages discussed above and which consequently increases the possibility of cooling the flue gas and reduces the flow resistance in order to increase the capacity.
 This object is obtained by a flue gas exchanger where said fins being arranged at a mutual distance and forming channels between adjacent fins, each of said blocks comprising an initial fin with an opening forming an inlet and subsequent fins each being provided with a first opening forming an inlet, alternatively an outlet, and a second opening forming an outlet, alternatively an inlet, and of said blocks a last block also comprising a last fin with an opening forming an outlet, and said inlets, respectively outlets, being intended for admitting a flow of a flue gas from the first end of the jacket through the inlets and outlets of the fins to the second end of the jacket, and said inlets, respectively outlets, forming inlet chambers, respectively outlet chambers, which are interconnected by the channels, and a total open area of inlets and outlets in the fits which is identical for each fin amounting to a multiple of between 1.0 and 1.5, preferably 1.1, of the size of a cross section area of the channels between adjacent fins, and the open area of the inlets, alternativly the outlets, decreasing, and simultaneously the open area of the outlets, alternatively the inlets, increasing through each block in the intended direction of flow of the flue gas.
 In an exemplary embodiment the inlets and outlets in the fins are constituted by sectors of a circle extending from a central part to an outer periphery so that the flue gas is conducted towards the jacket.
 By constructing a flue gas exchanger with these characteristics, one obtains a flue gas exchanger having a very low flow resistance. This means that the capacity is exclusively determined by the physical dimensions of the flue gas exchanger and the cooling taking place in the flue gas exchanger and is not limited by unfavourable flow conditions in the flue gas exchanger. Also, the flue gas being conducted towards the inner jacket increases the heat exchange substantially.
 The fins may be produced as individual fins, which are positioned on a central guiding element. The number and dimensions of the fins may vary in order to provide the flue gas exchanger with different capacities and with different other physical and thermal characteristics. This means that the diameter and length of the flue gas exchanger may be altered by using fins of a different diameter or by using a different number of fins.
 EP 0 571 881 describes a heat exchanger formed by fins, which are assembled into a block. The fins comprises openings that constitute sectors of a circle. The fins are assembled in such a manner that two helical channels are formed in the block. The heat exchanger described may be used for both fluent and gaseous media. U.S. Pat. No. 3,731,733 describes a similar heat exchanger formed with fins, which are assembled in blocks each with two fins. These fins also are assembled in such a manner that two, alternatively three, helical channels are formed in tire block.
 The fins of these heat exchangers have the disadvantages that they are not to a sufficient extent able to create a forced flow, e.g. of a flue gas. The object of the heat exchanger described is to reduce tire flow resistance. However, a helical channel established with this known technique will not to a sufficient extent ensure proper cooling of the flue gas since the latter will be conducted through a short channel with a large flow cross-section resulting in a high ratio between the cross section area of the channels between the fins and the area of tire inlets and outlets of the fins. Furthermore the fins of EP 0 571 881 are not provided with an actual inlet and outlet but merely help to form the helical channels. Thus, two openings forth two channel systems. Besides, the material consumption is very large compared to the heat transmission area, and the surface in the channels is angular, which increases the flow resistance.
 Fins in which inlets and outlets consist of sectors of a circle have the advantage that the flue gas is conducted towards outer areas of the ribs. Thus, cooling of the ribs may take place at the jacket, which has a considerably larger surface area than any central tubing. The jacket and the ribs correspond to a tube with internal ribs as opposed to a tube with external ribs, in which cooling takes place at the internal tube having a small surface area. This increases the capacity of the flue gas exchanger and, also, the flue gas exchanger according to the invention with a given capacity has considerably smaller dimensions than known flue gas exchangers with the same capacity.
 The sectors of a circle help to obtain the low flow resistance. The sectors of a circle vary in size in such a manner that in a block of fins there is a constant reduction of the open area of the inlets while at the same time there is a constant widening of the open area of the outlets through the block. The total area of inlet and outlet is identical for each fin.
 A simple way of producing the sectors of a circle in each fin is using a punching tool having the shape of a sector of a circle and with an angle corresponding to the smallest sector to be made in a fin. Other sectors of a circle are produced as a multiple of the smallest sector by using the same punching tool and simply perform a number of adjacent punchings corresponding to the required multiple of the smallest sector. The fins of an exemplary embodiment are produced from aluminum.
 The flue gas exchanger according to the invention may be used in many contexts, e.g. as a heat exchanger from a fuel device in a central heating installation. It is also possible to use the flue gas exchanger according to the invention for different kinds of vessels.
 What are needed, and not taught or suggested in the art, are a method and an apparatus for Flue Gas Heat Exchanger And Fin Therefor.
 An embodiment of the invention is a heat exchanger including a plurality of fins, each having a first aperture and a second aperture. A first aperture of a downstream one of the plurality of fins decreases relative to a first aperture of an upstream one of the plurality of fins. A first fluid from the first aperture of the upstream one of the plurality of fins is received partially in the first aperture of the downstream one of the plurality of fins and the remainder of the first fluid is diverted along the downstream one of the plurality of fins and received in the second aperture of the downstream one of the plurality of fins. An inner jacket contacts each of the plurality of fins. An outer jacket surrounds the inner jacket defining a chamber for containing a second fluid therein. The first aperture and the second aperture each define sectors of a circle extending from a central part to an outer periphery for conducting the first fluid toward the inner jacket. The inner jacket is configured to transfer heat to the second fluid via said plurality of fins.
 Another embodiment of the invention is a heat exchanger including a plurality of fins, each having a first aperture and a second aperture that define an open area for receiving a first fluid. The open area is substantially constant among the plurality of fins. An inner jacket contacts each of the plurality of fins. An outer jacket surrounds the inner jacket defining a chamber for containing a second fluid therein. The first aperture and the second aperture each define sectors of a circle extending from a central part to an outer periphery for conducting the first fluid toward the inner jacket. The inner jacket is configured to transfer heat to the second fluid via said plurality of fins.
 A further embodiment of the invention is a heat exchanger including a plurality of fins, each having open area for receiving a first fluid. An inner jacket contacts each of the plurality of fins along a heat transfer area substantially constant for each of the plurality of fins. An outer jacket surrounds the inner jacket defining a chamber for containing a second fluid therein. The open area defines a sector of a circle extending from a central part to an outer periphery for conducting the first fluid toward the inner jacket. The inner jacket is configured to transfer heat to the second fluid via the plurality of fins.
 The invention provides improved elements and arrangements thereof, for the purposes described, which are inexpensive, dependable and effective in accomplishing intended purposes of the invention. Other features and advantages of the present invention will become apparent from the following description of the exemplary embodiments which refers to the accompanying drawings.
 The invention is described in detail below with reference to the following figures, throughout which similar reference characters denote corresponding features consistently, wherein:
 A flow gas, illustrated by means of flow lines
 The chamber
 A first fin shown in
 The openings in the fins
 As mentioned, the first fin is provided with a first opening
 Referring to
 Referring also to FIGS.
 Consequently, in operation, flue gas received from passage
 The diverting of streams of flue gas across fins
 In an exemplary embodiment, chamber
 The openings
 The invention has been described above with reference to a specific embodiment of a flue gas exchanger according to the invention and for specific embodiments of fins. It will be possible to use alternative embodiments of both flue gas exchanger and fins. Thus, the flue gas exchanger may contain a number of blocks of fins other than eight, and the number of fins in each block may be different.
 The invention is not limited to the particular embodiments described herein, rather only to the appended claims.