FR2547026A1 - HOT WATER GENERATOR, ESPECIALLY CENTRAL HEATING BOILER, WITH SOLID FUEL, PARTICULARLY FOR THE COMBUSTION OF WOOD LOGS - Google Patents

Abstract

1. Hot-water generator, in particular central heating boiler, for solid fuels especially for burning wood and, if required, also for liquid and gaseous fuels, comprising a firebox/heat-exchanger surrounded by a housing at a distance and surrounding a large-volume chamber substantially in the form of a cylinder with horizontal axis provided for accepting the solid fuel and delimited on its sides and on its rear end by double walls between which the water to be heated is circulated, and on its front end by a door, said double walls being interrupte at their lowermost part by at least one opening which is lined with a combustion nozzle, characterized in that the heating body (1) is composed of a plurality of identical annular hollow intermediate elements (11) each of which forms a closed annular chamber (14) around a central passage opening, each of said intermediate elements at one of its front faces having a local axial offset (20) which defines a recess part, two opposite holes (21, 22) being present in each of its two front faces ; of an annular front end element (10) which forms likewise a central opening, which provided with substantially opposite holes in at least one of its front faces and which is closed with a door (15, 17) in the plane of its other front face ; and of a hollow rear end element (12) without central opening which forms a double bottom and its provided with two substantially opposite holes in at least one of its front faces, said elements (10, 11, 12) lying end-to-end and being assembled so that the front faces with the said recess and the front faces without said recess of the successive intermediate elements (11) are disposed alternately in face-to-face and opposite relationship so that said recesses complete one one another in pairs defining thus a radial opening, and that the said holes (21, 22) of the successive elements (10, 11, 12) coincide, the firebox/heat-exchanger thus formed being set up with the said radial openings directed downwardly and each of said openings is lined with a jacket-like inserted element (25) which forms the combustion nozzle.

Description

Hot water generator, in particular central heating boiler, with combustion

  solid target, in particular for the combustion of wood logs.

  The present invention relates to a hot water generator, in particular

  to a central heating boiler, solid fuel, in particular

  wood and, where appropriate, liquid or gaseous fuel,

  nant, surrounded at a distance by a carcass, a heat exchanger surrounding a large chamber, substantially in the shape of a cylinder with a horizontal axis intended to receive solid fuel and delimited laterally and at the rear end by double walls between which circulates the water to heat and, at the front end, by a door, the double walls being interrupted, in the lowest part of the room, by at least one

  opening lined with a combustion bowl.

  In such a generator of the reverse flame combustion type, once the inner wall and the outer wall of the double chamber are used as a heating surface. In fact, the inner wall is heated.

  the heat given off by the carbonization of the wood, which takes place inside

  laughter of the chamber, while the outer wall is heated by the flames and the hot gases of the combustion proper, with flames returned from the volatile materials contained in the wood and released by the carb nization, this combustion taking place when passing through the lower opening of the chamber and in the part located below the chamber, the flames and the combustion gases then running along the outer wall of the 2 chamber upwards and backwards before escaping into the chimney Such a generator is distinguished both by the complete combustion of wood, due to the combustion with reverse flames (absence of bistrage, minimal CO 2 and CO 2 content in the combustion gases) and by the high efficiency due to the use of the inner wall and the outer wall

  heating element as heat exchange surface -

  This known hot water generator has a one-piece hearth-exchanger and has several drawbacks. On the one hand, the manufacture of a one-piece steel hearth-exchanger involves significant welding work, resulting in considerable labor cost. , in the case of large boilers, the handling and transport of the hearth-exchanger assembled in the factory can pose problems. Furthermore, due to the manufacture of the furnace:

  exchanger in steel sheet, there are risks of corrosion.

  The present invention relates to a hot water generator of the type defined above which, while retaining the advantages of complete combustion and high efficiency, can be manufactured at a reduced cost price, allows transport and simple handling with regard to the heat exchanger and eliminates or at least considerably reduces the risk

  chemical corrosion (sulfuric acid, acetic acid).

  In the hot water generator according to the present invention, the hearth-

  double wall type exchanger, has several openings in its lower part and is divided along its length into several elements These elements include several identical hollow annular intermediate elements, each delimiting an annular chamber closed around a central passage opening Each of these intermediate elements comprises on a front side a local axial recess defining an axially recessed part Each of these intermediate elements also has two substantially opposite holes in each of these two front faces The elements of the heat exchanger also include an end element

  rear, hollow, constituting a double bottom and having two sensitive holes-

  opposite opposite in one of its front faces, as well as a connection leading towards the outside. The elements of the heat exchanger include, moreover, a hollow annular front end element delimiting, like the intermediate elements, an annular chamber. closed around a central passage opening This front end element which can be provided with or without the

  recess provided on the intermediate elements has two sensitive holes

  clearly opposite in one of its two front faces, as well as a fitting

  leading outwards The end elements and the intermediate elements

  diaries are placed end to end and assembled in such a way that the front faces with recess and the front faces without recess of the successive elements are alternately in opposition and facing each other so that the recesses complement each other two by two to form a radial opening and that the front holes of the successive elements coincide Each of said radial openings is furnished with an insert element in the form of a jacket,

  constituting a combustion bowl without circulation of water.

  The construction method according to the invention of the hearth-exchanger makes it possible to assemble the latter from several elements of reduced size which lend themselves without problem to a manufacture by casting in cast iron the works

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  are therefore superfluous, the assembly being summed up in simple assembly work This assembly can be carried out at the place of generator installation particularly for high powers, hence a simplification of transport and handling From '' a model of elements, it is possible to produce hot water generators of different then by the use of a more or less significant number of intermed elements: Finally, the realization of cast iron elements very largely reduces the ris

  corrosion compared to a sheet steel heat exchanger.

  According to one embodiment of the invention, the holes in the front beams of the elements of the hearth-exchanger are tapped and the elements assembled using threaded sleeves screwed into said holes. According to another embodiment, the elements are assembled to using biconical penguins press-fitted into the smooth holes of the elements of the authentic exchanger. These are two simple assembly methods which, moreover, make it possible to easily replace any element that may have failed. The arrival of combustion air in the chamber defined by the furnace: exchanger is carried out in the usual way at the front end of the cellar body In order, however, to ensure uniform combustion from the front to the rear of the hearth-exchanger, it is advantageous to provide shutters to reduce the cross section of part of the bowls of combustion reported in

  lower openings of the heat exchanger.

  Referring to the appended drawing, there will be described below in more detail: an illustrative and nonlimiting embodiment of a hot water generator according to the invention; in the drawing: FIG. 1 is a side elevation view, partially in vertical longitudinal section, of a heat exchanger according to the invention inst; in a boiler; FIG. 2 is a front elevation view of an intermediate element: 3 (of the heating body; FIGS. 3 and 4 are sections along III-III and IV-VI of FIG. The central heating boiler with combustion reverse flames illustrated in fig 1 includes a heat exchanger l which is presented sout

  shape of a circular, elliptical or similar cylinder, with horizontal axis.

  hearth-exchanger 1 is surrounded at a distance, at its upper half and at the

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  by a carcass 2 which may preferably be of welded sheet steel La

  carcass 2 comprises a side wall 3 which is substantially half-cylinder

  drique in its upper part and is extended vertically downwards to a base wall 4 The carcass 2 also comprises a rear wall 5 provided with a nozzle 6 intended for the connection of the boiler to a chimney flue The carcass 2 finally comprises a front wall 7 provided below the heating body 1, with a secondary air inlet 8 a and an off-center door 8 b The base wall 4 is lined on its upper face

  a layer 9 of refractory material.

  The carcass 2 is advantageously surrounded by an insulating jacket (not shown). The heating body 1 is composed of a succession of elements, namely a front end element 10, several intermediate elements 11 and a rear end element 12 which are connected to one another in accordance with vertical planes perpendicular to the horizontal longitudinal axis of the

hearth-exchanger 1.

  The front end element 10 and the intermediate elements 11 each consist of a hollow annular element delimiting a chamber

  annular 13, 14, respectively, of square or rectangular section.

  On the front end face of the front end element 10 is articulated

  door 15 having a central opening 16 of square shape or

  rectangular 16 capable of being closed by a change door 17.

  This door 17 has a primary air intake opening 18 controlled by a primary air flap 19 under the action of a draft regulator not shown which usually detects the temperature of the water at the start.

  to the radiators of the central heating installation.

  The annular chamber 13 of the front end element 10 has a

  constant section over the entire circumference.

  Each intermediate element 11 has on a front side, in the lower part, a local axial recess 20 defining a recessed part (see fig 2 to 4) This recess 20 causes a local reduction of the section

  otherwise constant of the annular chamber 14 -

  The rear end element 12 is a hollow element without central opening like the elements 10 and 11, constituting a double bottom for the

hearth-exchanger 1.

  The intermediate elements It are placed end to end so that (the front faces with recess and the front faces without detachment of successive elements are alternately opposite and in opl sition, the recesses 20 opposite complement each other in the form a radial opening having a section twice that of each recess 20. Each intermediate element It has two opposite holes 21, 22 sensiblem E, one at the top and the other at the bottom, in each of two front faces (see fig 2 to 4) The front end element 10 and the rear end element 12 each have two corresponding holes in its front face facing the intermediate elements 11 and, preferably but not necessarily, two holes correspondents in sc

other front face.

  The two flat front faces of the intermediate elements 11 are rectified, while the end elements 10 and 12 are rectified st

  their flat front face facing the intermediate elements 11.

  For the assembly of the hearth-exchanger 1 from the elements 10, 11 E 12, the said elements are placed end to end so that the holes 21, 22 different elements coincide, by interposing a refractory sealing material between the front faces opposite the elements 10, 11 and 12, the various elements are assembled by keeping them tight one against the other Thus, the chambers 13 and 14 of the elements 10 and 11 and the chamber of the element 12 communicate with each other through the holes 21 and 22 As a result, the heat exchanger 1 can be inserted in a heating circuit by means of a connector 23 provided on the front end element 10 and a rac

  24 provided on the rear end element 12.

  Each lower opening formed in the heat exchanger 1 by the recesses 20 of two intermediate elements 11 whose recesses <complement each other is provided with a jacket 25 attached from the top,

  the heat exchanger 1 down This jacket 25 serves as a "fuel bowl"

  It is recognized in FIG. 1 that the combustion bowl 25 closest to the primary air intake opening 18 comprises a shutter 26 reduces the passage section of the bowl 25 The next bowl 25 also includes a shutter 27 which reduces the passage section of the bowl 25 in a more fa: measure that the shutter 26 This progressive reduction of the passage section of the combustion bowls as we approach the intake opening d primary air 18 ensures a uniform distribution of the primary combustion air over the different lower openings of the hearth-exchanger 1, hence regular combustion through the different combustion bowls, despite the different distances of these bowls pdr compared to the primary air intake opening, and despite the use of elements

  intermediate 11 all identical and 25 identical combustion bowls.

  Different embodiments are possible for assembling the

  elements 10, 1 l and 12 in the form of a heat exchanger 1.

  A particularly advantageous embodiment consists in assembling said elements in the manner of elements of a cast iron radiator. For this purpose, the holes 21, 22 of the elements 10, 11, 12 can be tapped and the neighboring elements are then tightened together. against the others using threaded sleeves 28 screwed into the tapped holes provided in the front faces opposite the neighboring elements, each sleeve 28 having a left-hand thread and a right-hand thread Another possibility is to use biconical sleeves 28 smooth and fit these sleeves

  press in the smooth holes 21, 22 of the elements 10, 11 and 12.

  In both cases, at least one of the end elements 10 and 12 must have holes 21, 22 in its two front faces in order to allow such an assembly which is done from the inside The holes of the end elements , 12 not receiving sleeves 28 can be closed with plugs or used to connect the hearth-exchanger 1 to the heating circuit, as shown by the connector 23 of the front end element 10 according to the fig 1 It is also possible to use this opening to connect other accessories, for example a draft regulator acting on the

  flap 19 for primary air intake.

  When assembling using press-fitted sleeves, it is preferable to provide, outside the hearth-exchanger, several tie rods

  axial to tighten elements 10, 11 and 12.

  Although the boiler as described above and shown in the accompanying drawing, of the reverse flame combustion type, is designed more particularly for the use of wood and in particular of firewood logs: as fuel, it goes without saying that it can also be equipped as a complement with a liquid fuel burner mounted on the por

17, or a gas burner.

Claims (4)

  1 Hot water generator, in particular central heating boiler, with solid fuel, in particular with wood, and, if necessary, with fuel   liquid or gaseous, -comprising, surrounded at a distance by a carcass, a hearth-   exchanger surrounding a large chamber, substantially in the shape of a cylinder with a horizontal axis, intended to receive solid fuel and delimited laterally and at the rear end by double walls between which circulates the water to be heated and, at the end front, by a door, the double walls being interrupted, in the lowest part, by at least one opening furnished with a combustion bowl, characterized in that the heating body (1) is composed of several intermediate elements identical hollow annular (11) each delimiting a closed annular chamber (14) around a central passage opening, each of said intermediate elements comprising, on a front side, a local axial recess (20) defining a recessed part, and having two holes (21, 22) substantially opposite in each of its two front faces, of a hollow annular front end element (10) also delimiting a central opening, presents having two substantially opposite holes in at least one of its front faces and closed by a door (15, 17) in the plane of its other front face, and a hollow rear end element (12) without central opening , constituting a double bottom and having two substantially opposite holes in at least one of its front faces, said elements (10, 11 and 12) being placed end to end and assembled so that the front faces with recess and the front faces without recess of the successive intermediate elements (11) are alternately opposite and in opposition so that the recesses are completed two by two in the form of a radial opening and that said holes (21, 22) of the successive elements (10, 11, 12) coincide, the hearth-exchanger thus formed being installed so that said radial openings are facing downward, and that each of said openings is provided with an insert (25)   shirt-shaped constituting combustion bowl.   2 generator according to claim 1, characterized in that said holes (21, 22) in the end faces of the elements (10, 11, 12) are tapped and that said elements are assembled using sleeves   threaded (28) screwed into said holes. 9 2547026   3 Generator according to claim 1, characterized in that said elements (10, 11, 12) are assembled using biconical sleeves (28) fitted to the press in said smooth holes (21, 22) of the elements (10, 11, 12).   4 Generator according to any one of claims 1 to 3, cara   laughed at by the fact that the hearth-exchanger further comprises shutters (26, 27) to reduce the passage section of part of the liners (25)   reported in the lower openings of the heat exchanger.