FR2503331A1 - SOLID FUEL BOILER - Google Patents

Abstract

SOLID FUEL BOILER WITH HIGH OPERATING TEMPERATURE TO AVOID TARPING. ACCORDING TO THE INVENTION, THE BOILER CONSISTS OF A LARGE COMBUSTION CHAMBER 11 BOUNDED BY A COMPOSITE WALL 19 INCLUDING A QUILTING OF REFRACTORY BRICKS 20, WHICH IS CONSOLIDATED BY A MAINTENANCE SYSTEM INCLUDING IN PARTICULAR AN EXTERNAL ENCLOSURE PREVIOUSLY 21A METALLIC . PART OF THE BOILER HEAT EXCHANGER IS INSERTED INSIDE THE COMPOSITE WALL.

Description

250333 1

SOLID FUEL BOILER

  The invention relates to a solid fuel boiler, in particular

  for wood, charcoal or coal, the design of which

  achieves a sufficiently high operating temperature

  in order for the combustion of this type of fuel to be

  as possible to avoid tarring or brewing

  boiler and chimney flues.

  As the price of petroleum products continues to rise, we

  interest, particularly in rural areas, for

  heating materials abandoned for many years, namely the solid fuels mentioned above. However, notions of comfort have changed significantly since the time when these fuels were commonly used, so that we have to develop boilers, especially for central heating, relatively high power, to ensure the heating of premises sometimes important. It is therefore necessary to provide a relatively large

  receive a significant amount of.combustible, to guarantee a self-

  sufficient energy and an efficient heat exchanger to guarantee

  a reasonable heat output of the entire installation.

  Recent trials have revealed the problem of relatively

  tars released by such fuels. The consequences

  these tar training on the proper functioning of the heat

  are: fouling and rapid filling of the pipes,

  lution and corrosion of flue pipes.

  The object of the invention is to solve all these drawbacks, mainly

  mainly by proposing a boiler structure to increase

  significantly reduce the temperature of the hearth to reduce the formation

  tar or greasy soot and to eliminate condensation.

  In this spirit, the invention relates primarily to a

  solid fuel, in particular for wood, charcoal and / or

  coal, of the type comprising a combustion chamber, an evaporation nozzle

  flue gas extraction and a heat exchanger in thermal contact with said combustion chamber and in which a coolant such as water is likely to circulate to be heated, characterized in that said combustion chamber is delimited essentially

  by a composite wall comprising a quilting of refractory bricks.

  simply stacked on top of each other and consolidated by a

  holding system including in particular an outer shell metal-

lique, preferably dismountable.

  According to another important characteristic of the invention, the heat exchanger comprises water circulation tubes, inserted

  in said composite wall, between the bricks, and welded to internal plates

  dermal of said holding system. This facilitates the exchange of heat between the hearth and this part of the exchanger, while avoiding the deformation of the internal sheets of the holding system, since these are

  continuously cooled by the flow of heat transfer fluid.

  The invention will be better understood and other advantages of this

  will appear better in the light of the following description of a

  presently preferred embodiment of a boiler according to the principle of the invention, given solely by way of example and with reference to the appended nonlimiting drawings, in which:

  - Figure I is a partial sectional elevation of the heat

  Dière; and - Figure 2 is a top view in partial section of this

same boiler.

  The boiler consists essentially of a combustion chamber

  It has, at the rear, a flue gas outlet nozzle 12 and, at the front, an upper door 13, for fuel loading, as well as a lower door 14, for the cleaning. These two doors each consist of two parallel sheet metal plates, assembled at their periphery, between which is inserted a thickness of glass wool. The lower door 14 further comprises a movable flap 15 regulating the flow of combustion air. A heat exchanger 16 is arranged

  around the combustion chamber to provide a thermal contact

  optimal health with the focus. This exchanger comprises a nozzle 17 for the departure of hot water, at its upper part, and a nozzle 18 for the return of water, at its lower part. According to a feature of the invention, the combustion chamber is essentially defined by a composite wall 19 comprising a brick quilting

  refractories 20, which bricks are stacked on top of each other

  very, mainly on both sides of the chamber

  bustion and on part of the height of the back side. In addition, this quilting is consolidated by a holding system 21 including an outer envelope 21a, sheet metal, removable. This system

  also includes internal plates 21b disposed vertically

  step by step between parts of the quilting of bricks.

  The sheets 21b are each welded to water circulation tubes 25

  of the exchanger 16. Thus, the function of these internal plates is double.

  They help maintain the quilting of bricks, and they promote

  heat exchange with the tubes 25 of the exchanger. In addition, their cooling is provided by the water circulating in these tubes, which prevents their deformation, even when the temperature of the hearth is

  the order of 500, which is the purpose of the invention.

  The outer envelope 21a is itself surrounded by an insulation barrier 26 having a certain thickness of glass wool or the like. On the other hand, the interstitial spaces 27 between the bricks

  and the tubes 25 inserted into the composite wall are filled with

corn.

  The particular structure will now be described in more detail.

  This heat exchanger is in the form of a cage and comprises, in particular, a lower horizontal part forming a grid 28 fuel support. This grid is composed of a tubular frame 28a, rectangular, composed of relatively strong section tubes and a plurality of parallel tubes 28b, of smaller section, connected to the frame 28a. The tubes 25 inserted into the composite wall 19

  are arranged vertically and connected between the frame 28a and a reservoir

  see horizontal 29, upper, overcoming the combustion chamber 11.

  In addition, a rear laminar passage 30 extends along substantially the entire rear face of the combustion chamber 11. It establishes a connection between the frame 28a and the horizontal reservoir 29. This passage

  back is protected up to a certain height by some of the mate-

brick lassage.

  In addition, a means of drying the fumes is disposed in the combustion chamber, in the vicinity of the discharge nozzle 12.

  is a system of baffles 34 in tees, protruding into the

  of the combustion chamber and extending in the extension of

  the internal orifice 12a of the discharge nozzle 12. In the example shown in FIG.

  The baffle system is comprised of a stack of flat, parallel plates extending the full width of the combustion chamber 11, in front of the inner orifice 12a. In this way,

  fumes are forced to circulate in this system of superheated baffles.

  before being removed from the firebox.

  Finally, note the presence of an anti-tamper

  boiling, mainly consisting of a water circulation coil

  36, immersed in the upper reservoir 29. A temperature sensor

  erature (not shown) in thermal contact with the control exchanger

  the circulation of cold water in the coil when the water of the sample

  The temperature is threatening to boil.

  The advantages mentioned above of the boiler which has just been described result obviously from its structure. The matelassa-e refractory bricks allows to reach a temperature of function-

  much higher than those usual in boilers.

  used so far. The combustion is almost complete, which avoids the formation of tars. In addition, the drying of the fumes before their evacuation beyond the nozzle 12 avoids fouling

and corrosion of pipes.

  Of course, the invention is not limited to the embodiment of

  described above, but it includes all the technical equivalents of the means involved if they are in the context of the

following claims.

Claims (10)

  1. Solid fuel boiler, especially for wood, charcoal and / or charcoal, of the type comprising a combustion chamber (11), a flue gas discharge nozzle (12) and a heat exchanger (16) in contact with said combustion chamber and in which a coolant such as water is likely to circulate to be   heated, characterized in that said combustion chamber is deli-   formed essentially by a composite wall (19) comprising a matte   leaching refractory bricks (20) simply stacked on each   others, consolidated by a maintenance system (21)   also an outer shell (21a), metallic, preferably disassembled   corn. 2. Boiler according to claim 1, characterized in that said heat exchanger (16) comprises tubes (25) inserted into said composite wall between the bricks and welded to internal tales (21b) of said holding system, to facilitate the heat exchange and   avoid deformation of said tales.   3. Boiler according to claim 1 or 2, characterized in that said outer casing is itself surrounded by an insulation barrier (26) having a certain thickness of glass wool or similar.   4. Boiler according to one of claims 2 or 3, characterized   in that the interstitial spaces (27) between said bricks and   the tubes inserted in said composite wall are filled with sand.   5. Boiler according to one of claims 2 to 4, characterized   characterized in that said heat exchanger has a cage-like structure and in particular comprises a lower horizontal portion forming a fuel support grid (28), composed of a tubular frame (28a) of relatively large section and a plurality of parallel tubes (28b) of smaller section, connected to said frame, said tubes (25) inserted in said composite wall being arranged vertically and connected between said frame and an upper horizontal tank (29)   overcoming said combustion chamber.   Boiler according to claim 5, characterized in that   said tubes (25) inserted into said composite wall extend substantially   along two parallel side faces of said combustion chamber and a rear laminar passage (30) of said heat exchanger, extending along substantially the entire rear face of said 250333 1   combustion chamber, establishes a connection between said frame (28a) and said horizontal tank (29), this rear passage being protected   up to a certain height by a part of said quilting of bricks.   7. Boiler according to one of the preceding claims,   characterized in that it comprises a means for drying the fumes,   arranged in the vicinity of the aforementioned discharge nozzle (12).   8. Boiler according to claim 7, characterized in that said dewatering means is constituted by a system of baffles (34) made of sheet metal, projecting inside said combustion chamber, extending in the proldogement of the internal orifice (12a) of said discharge nozzle (12), so that the fumes must circulate in said superheated baffle system before being removed from the combustion chamber.   9. Boiler according to claim 8, characterized in that said baffle system consists of a stack of flat plates, parallel, extending over the entire width of the combustion chamber.   in front of said internal orifice (12a) of said nozzle.   Boiler according to one of the preceding claims,   characterized in that said exchanger is equipped with an anti-boiling safety system, comprising a coil (36) for circulating cold water, immersed in said exchanger, and a temperature probe in thermal contact therewith , to control the circulation of cold water in said coil.