FR2515315A2 - Heat recuperator for hearth - has finned plates on fireplace hearth and walls to form widenings and constrictions - Google Patents

Abstract

The heat exchanger fins are aligned sinusoidally or stepped to form channels in the direction of flow of heated air and their summits form a succession of restrictions and widenings, creating turbulence. The fins are perforated at core extraction, mould striking or by partial cutting and pressing through the metal, without detachment. The gills are on one or both sides of the fins, to create further turbulence by flow between channels giving a more intimate air mix in contact with the metal surfaces of the hearth.

Description

 The purpose of this addition is to improve the heat exchange in heat recuperators for open fireplaces and to extend the processes for heat exchange in closed fireplaces.

 Heat recuperators for fireplaces have been well known since the 19th century.

 Heat recovery in open fireplaces is generally done by air circulation in a duct more or less completely enveloping the fireplace, and / or the flue and the flue.

 The fresh air preferably taken outside is admitted in the lower part by a pipe, and discharged into the room in the upper part after reheating in contact with the plates surrounding the hearth, and / or the drain and the smoke duct. .

 The chimneys thus equipped have a better draft, because the room in which the chimney is located is well ventilated, their performance is improved because the air admitted into the room is heated when passing through the duct.

 In order to improve the heat exchange between the metal walls and the air admitted into the exchanger, it is useful to have fins fitted in steel or coming from a cast iron foundry on the back of the metal plates constituting the part of the sheath against the home.

 These have two functions: on the one hand to increase the exchange surface, on the other hand, to stir the air to better heat it.

 The shape and arrangement of the fins have a large influence on the performance of the recuperator.

 If the fins are longitudinal, the air circulation is insufficient for good heating.

 If the fins are transverse or oblique, they slow down the flow of heated air which limits recovery and impairs the proper draft of the chimney.

 The shapes and arrangements of the fins and "pins" which are the subject of the invention have the effect of perfecting the mixing of the air and therefore its heating in the recuperator while maintaining a sufficient flow rate.

 According to the embodiment which is the subject of the main patent, the heat exchange and stirring are carried out by fixing, under the hearth plate and the reluctant, continuous fins forming sinusoidal or broken lines arranged so that their vertices of waves are in opposition.

 The fins thus delimit channels in the direction of the normal flow of the heated air, the channels thus formed have throttles and bulges in which primary turbulence arises.

 These fins are perforated, which creates exchanges between channels giving rise to secondary turbulences which multiply the contacts with the exchange surfaces without opposing the general movement of the air in the sheath.

 According to the object of the additive E101, the perforated fins have been replaced by demolded teeth with the plates and arranged in opposite broken or sinuotic lines to obtain the same types of turbulence.

 The object of this addition is the improvement of the perforated fins and the extension of the provisions which are the subject of the main patent and of its first additive to all of the metal parts surrounding the hearth, and / or the flue and the smoke duct, whether it is an open hearth or a closed hearth.

 The perforated fins which are the subject of the main patent were obtained by punching the fins with a punch.

 The object of this additive is characterized by the replacement of punched perforations by a partial knockout producing gills.

 This new arrangement gives the fins more rigidity, more exchange surface and makes it possible to order the turbulence by arranging the vents so as to obtain a more intimate mixing of the air and thereby multiplied contacts with the surfaces. exchange plates and fins.

 On the other hand, the use of these fins or of the teeth which formed the additive N 1 is not limited to the hearth plate or to the reluctance of an open hearth fireplace, but can extend to all the metal walls surrounding the hearth, the drain and the smoke pipe as well as on the walls of closed hearths, whether they are stoves or chimney stoves. These are then hot air convectors that recycle the air inside a room or a house.

The characteristics and advantages of the invention will emerge more clearly from an examination of the accompanying drawings given by way of nonlimiting example where:
Figure 1 is a perspective view of a hearth wall fitted with perforated fins as described in the main patent.

 FIG. 2 is a perspective view of a hearth wall fitted with teeth as described in the additive N 1.

 Figure 3 is a perspective view of a hearth wall equipped with fins pierced with ears.

 FIGS. 4 5 and 6 are examples of the arrangement of the bottles in the fins.

Claims (6)

1- Plates with fins intended to equip the bottom and the walls of a chimney with recuperator of heat by circulation of air around the hearth, and, or of the gutter and the smoke pipe. Characterized by the arrangement of the fins in sinuosidal or broken lines delimiting channels in the direction of the circulation of the air to be heated and whose opposing peaks determine a succession of bottlenecks and bulges in which turbulence arises. 2- fins according to claim 1 characterized by their perforation with a punch or demolding which creates secondary turbulence by exchanges between channels. 3- Fin; according to claim 1 characterized by the perforation of hem obtained by partial cutting and stamping without detachment of metal. Said ears are perforated either all in the same direction, or alternately on either side of the dishes constituting them and make it possible to orient the turbulence and the exchanges between channels with a view to a more intimate and more orderly mixing of the air in contact with metal surfaces heated by the fireplace. 4- Cast iron plates intended to equip the bottom and the walls of a chimney with recuperator of heat by circulation of air around the hearth, and, or of the gutter and the smoke pipe characterized by the fact that they are bristling with protruding teeth molded with the plate in order to ensure the conduction of the heat captured by the plates and its transmission to the air circulating in the recuperator sheath. 5- projecting teeth according to claim 4 characterized by their arrangement in opposite sinuosidal lines from the release which allows maximum conduction, and which creates turbulence, increasing the exchange contacts without opposing the passage of air in sheath. 6- Use of fins plates or projecting teeth according to claims 1 to 5 to form the walls of heating appliances with closed hearths producing hot air by natural or pulsed convection.