FR2800856A1 - VERTICAL TYPE BOILER - Google Patents

Abstract

The invention relates to a boiler for heating a heat transfer fluid comprising: - a hearth (5) closed by a hearth plate (3) and delimiting by its internal volume, a circuit for circulating the gases and fumes produced by a burner (39 ), - and a heat exchanger between the gas and fume circulation circuit and a heat transfer fluid circulation circuit (16). According to the invention, the hearth plate (3):. comprises a passage (45) for a pipe (43) for supplying a fuel ,. has a socket (31) for the combustion air,. internally delimits a circulation circuit (32) for the combustion air communicating with the air intake (31) and opening into a housing for a turbine (35) whose outlet (37) communicates with the burner (39), . and comprises an exhaust passage (52) for the gases and fumes, connected to a chamber (7) for collecting the gases and fumes.

Description

The present invention relates to heating boilers operating

  from a given energy, such as gas or fuel oil, and intended to ensure the rise in temperature of a heat transfer fluid which can be used for various purposes and, more specifically, in a space heating installation and, possibly heating domestic hot water. The object of the invention relates, more particularly, to the field of

  vertical type heating boilers.

  To assume the heating function of a heat transfer fluid, a vertical type heating boiler generally comprises a hearth closed by a hearth plate and delimiting, by its internal volume, a circuit for the circulation of the gases and smoke produced by a burner , for example of the oil or gas type. The boiler also includes a heat exchanger between the gas circulation circuit and

  smoke and a circulation circuit of a heat transfer fluid, such as water.

  The heat exchanger consists, in general, of a series of exchange units each comprising, on the one hand, a gas and smoke tube extending vertically and communicating, in its lower part, with the hearth and , on the other hand, an exchange envelope delimiting with the gas and smoke tube, an exchange capacity for the

coolant.

  The burner ensures combustion in the hearth, so that the gases and fumes are forced to rise inside the exhaust pipes before being collected in a manifold. During the operation of the burner, it must be considered that the heat transfer fluid undergoes a rise in temperature and rises to be collected in a mixing chamber equipped with pipes connecting to at least one circuit.

  use of the heat transfer fluid.

  A heating boiler of the type described above has a major drawback due to the poor combustion efficiency and to an unsatisfactory heat exchange between the combustion hearth and the heat transfer fluid. Another drawback of this type of boiler is the relatively high noise level that it presents. The object of the invention is to remedy the drawbacks stated above by proposing a new heating boiler for a heat transfer fluid allowing

  obtaining a good transformation efficiency of the energy used.

  Another object of the invention is to provide a heating boiler

  relatively silent and designed to operate from gas or oil energy.

  A further object of the invention is to provide a heating boiler

  designed to have a limited size.

  To achieve such objectives, the heating boiler for a heat transfer fluid comprises: - a hearth closed by a hearth plate and delimiting by its internal volume, a circuit for the circulation of gases and fumes produced by a burner, - and a heat exchanger heat between the gas and smoke circulation circuit and a heat transfer fluid circulation circuit, the heat exchanger being constituted by n exchange units each comprising, on the one hand, a gas and smoke tube extending vertically by communicating, at its lower part, with the fireplace and, on the other hand, an exchange envelope

  delimiting with the tube, a lamellar fluid exchange capacity.

  According to the invention, the hearth plate: A has a passage for a fuel supply line to the burner, * has a socket for combustion air, ò internally delimits a circulation circuit for air combustion unit communicating with the air intake and opening into a housing for a turbine, the outlet of which communicates with the burner, * and has an evacuation passage for gases and fumes, connected to an outgoing gas and smoke collection chamber of the upper part of the gas and smoke tubes, this collection chamber being closed at least in part by the hearth plate, in order to preheat the combustion air. Another object of the invention is to provide a heating boiler designed

  to prevent the proliferation of bacteria in the circulation circuit of the heat transfer fluid.

  To this end, the heating boiler is equipped with a mixing chamber comprising a bottom near which the connection pipe or pipes for the return of the heat-transfer fluid are mounted, the bottom having, on the one hand, calibrated orifices for communicating with the heat transfer fluid coming from the perimeter strip and, on the other hand, an external face in contact with the heat transfer fluid coming from the perimeter strip.

  Various other characteristics emerge from the description given below in

  reference to the appended drawings which show, by way of nonlimiting examples, embodiments and implementation of the subject of the invention. Fig. 1 is a sectional elevation of an exemplary embodiment of a boiler

  according to the invention of the fuel oil type.

  Fig. 2 is a cross-sectional view taken substantially along the lines II-

II of fig. 1.

  Fig. 3 is a view of a characteristic detail of the heating boiler

according to the invention.

  Figs. 4 and 5 are cross-sectional views taken respectively according to the

lines IV-IV and V-V of fig. 1.

  Fig. 6 is a sectional elevation of a heating boiler in accordance with

the invention, of the gas type.

  Figs. 1 and 2 illustrate a heating boiler according to the invention operating with energy of the fuel oil type. According to this exemplary embodiment, the heating boiler comprises an enclosure 1 retaining, in a conventional manner, a refractory or insulating coating, not shown. The enclosure 1 delimits, by its top, an access opening 2 which is closed by a hearth plate 3 intended to cooperate with a peripheral seal 4. The internal volume delimited by the enclosure 1 is partly occupied by a hearth 5 constituted by an envelope 6 having a circular cross section and closed by a slightly curved bottom 6a extending opposite the access opening 2. The envelope 6 delimits, between the hearth 5 and the 'access opening 2, a chamber 7 for collecting gases and fumes whose function will appear more precisely in

  the rest of the description. The envelope 6 thus internally delimits a volume VI

  accessible by the hearth plate 3. The lower part of the internal volume VI contains a heat exchanger constituted by at least one and, in general, several exchange units 10, for example eight in number, in the example illustrated, distributed regularly along a circumference situated on the periphery of the envelope 6, with a view to

  leave the central part Sa of the fireplace free.

  Each exchange unit 10 comprises a gas and smoke tube 12 extending vertically over substantially the entire height of the hearth 5, opening on one side to

  near the bottom 6a and, on the other side, in the chamber 7 for collecting gases and fumes.

  For example, each gas and smoke tube 12 has a circular cross section. Each exchange unit 10 also includes an exchange envelope 13 surrounding the tube 12 at a distance over most of it to delimit a lamellar capacity Ci for a heat transfer fluid. Each exchange envelope 13 is closed on the lower part of the associated tube 12 and is fixed to a transverse wall 14

connecting to the enclosure 6.

  The lamellar capacities Ci of the exchange units 10 are intended to form part of a circuit 16 for circulation of a heat transfer fluid. The lamellar capacities Ci emerge through communication passages 17 made at the upper part of the tubes 12, in a mixing chamber 18 delimited in part by the casing 6 and by a peripheral box 19 surrounding the hearth 5 at its upper part and the gas and smoke collection chamber 7 at its lower part. The box 19 which delimits an internal volume C2, is extended by an annular plate 21 on which the gas and smoke tubes are fixed 12. The annular plate 21 extends at a distance from the transverse wall 14 which is connected to the plate 21 at their edges

  extremes, so as to leave an opening 22 between the chamber 7 and the hearth 5.

  The box 19 is equipped with pipes connecting to at least one circuit for using the heat transfer fluid. In the example illustrated, the box 19 is equipped, at its upper part,

  an outlet pipe 23a and, at its lower part, a return pipe 23b.

  The mixing chamber 18 communicates, at its lower part, with a perimeter blade C3 delimited between the lower part of the envelope 6 and an external cap 24. This cap 24 extends at a distance from the envelope 6 to delimit with it a perimeter blade or a substantially constant width C3 capacity. It should be considered that the perimeter blade C3, the mixing chamber 18 of capacity C2 and the lamellar capacities Ci of the exchange units, thus represent the circuit 16 for circulation of a heat-transfer fluid which can be removed and brought back by tubing of

connection 23a, 23b.

  According to a preferred embodiment characteristic and as it appears more precisely in FIGS. 2 and 3, the mixing chamber 18 communicates with the perimeter blade C3 by means of a series of calibrated orifices 26 arranged regularly in a bottom 27 of the mixing chamber, formed for example by a return of the envelope 6. The number and the cross-section of the calibrated orifices 26 are chosen to allow the passage of the heat transfer fluid of the blade to be determined.

  perimeter C3 to the mixing chamber 18.

  The bottom 27 of the mixing chamber 18 thus has an external face 27a which is in contact with the heat transfer fluid coming from the perimeter blade C3. To this end, the cap 24 is extended by a flange 29 extending away from the bottom 27 to allow the entire outer face 27a of the bottom to be in contact with the heat transfer fluid coming from the perimeter strip C3. Such an arrangement offers the advantage that the bottom 27 of the mixing chamber 18 into which the return of the installation 23b opens, has a sufficient hot temperature, in order to avoid forming a cold zone or a stagnation of a fluid. coolant at a temperature favoring the

proliferation of bacteria.

  According to an advantageous characteristic of the invention, the gas and smoke collection chamber 7 is closed by the stove plate 3 comprising a socket 31 for the air of

  combustion communicating with a circulation circuit 32 for combustion air.

  As illustrated in fig. 4 and 5, the air circulation circuit 32 is arranged in the hearth plate 3, so as to ensure the flow of air along a determined path represented by the arrows f. The combustion air enters through the air intake 31, inside the hearth plate 3 and is recovered by a passage 33 opening into a housing or a volute 34 arranged in the hearth plate 3. The volute 34 is intended to be occupied in part by a turbine 35 driven in rotation by means of a motor 36 fixed on the external face of the hearth plate 3. The volute 34 has an outlet 37 opening into a burner 39 mounted in the region central of chamber 7 for collecting gases and fumes. The burner 39, which is of the oil type in the example illustrated, is surrounded by a thermal insulation sleeve 40 mounted on the annular plate 21, thus allowing the burner 39 to open inside the hearth 5 , in its central part Sa, via

of the opening 22.

  In the illustrated embodiment, the burner 39 is associated with a

  line 43 for supplying the oil to a nozzle 44 located at the bottom of the burner 39.

  The supply line 43 passes through the hearth plate 3 via a passage 45 and is connected to a pump 48 fixed on the external face of said plate 3. Advantageously, the supply line 43 passes through at at least in part, the circuit 32 for circulation of combustion air, so as to allow the heating of the fuel oil by heat exchange between the fuel oil and the combustion air via the supply pipe 43. In the illustrated example, the supply pipe 43 crosses the combustion air circulation circuit 32 and comprises several turns shaped at the outlet 37 of the volute, so as to favor the temperature rise of the fuel oil. The hearth plate 3 has, on its internal face, a thermal insulation coating 50 intended to close the opening 2 for access to the hearth 5. The hearth plate 3 also has a passage 52 for evacuating communicating gases and fumes with the collection chamber 7 which collects the gases and fumes leaving the tubes 12. It should be noted that this collection chamber 7 also constitutes an expansion chamber for the gases and fumes leaving the tubes 12. It should be noted that the height from this collection chamber 7

  is adapted to reduce the expansion noise of gases and fumes.

  The discharge passage 52 is produced by a sleeve, for example bent, passing through the hearth plate 3. Preferably, such a sleeve 52 is mounted inside a bent sleeve forming the air intake 31. The mounting concentric of the air intake 31 and the gas and smoke evacuation sleeve 52 makes it possible to raise the temperature of the combustion air using the walls of the sleeve 52 constituting a capacity

  exchange with combustion air.

  In the same direction, the forced routing of the combustion air inside the hearth plate 3, also makes it possible to ensure the rise in the temperature of the combustion air due to the heat brought to the plate hearth 3 thanks to the collection chamber 7. In addition, the combustion air thus heated advantageously serves also to heat the fuel oil before its combustion. The rise in air temperature of

  combustion and fuel oil provides good combustion efficiency.

  The burner 39 ensures combustion in the hearth 5 and circulates the gases and fumes in the direction of the arrows fi. The gases and fumes are forced to descend into the central part of the hearth 5 by licking the exchange envelopes 13, then to rise inside the tubes 12 which also undergo a rise in temperature. These gases and fumes are then collected in the collection chamber 7, with a view to being evacuated

via the evacuation passage 52.

  The operation of the burner 39 leads to a sharp rise in temperature of the envelope 6 and the exchange envelopes 13, which is transmitted to the heat transfer fluid occupying the perimeter blade C3 and the lamellar capacities C2 of the exchange units. These fluid capacities very quickly rise in temperature and rise vertically to penetrate into the mixing chamber 7, at its lower part by the calibrated orifices 26 and, at its upper part, by the communication passages 17. Such a transfer of fluid causes a rapid rise in temperature of the heat transfer fluid contained in the mixing chamber 18. It appears that the heat exchanger consisting of the perimeter blade C3 and the lamellar capacities C2, uses a limited volume of fluid making it possible to

  reduce the temperature rise time of the fluid.

  It should be noted that the production of a stove plate 3 which by its nature enables the hearth 5 to be closed, offers the advantage of ensuring preheating of the combustion air, as well as of the fuel oil by means of the gases and smoke present in the collection chamber 7 and discharged through the passage 52. This stove plate 3 is mounted in any suitable manner on the upper end of the casing 6. Another advantage of the invention lies in the

  arrangement of the exchanger in the lower part of the fireplace and of the burner in the upper part.

  Indeed, it results from this arrangement a more regular distribution on the exchange surfaces, of gases and fumes which follow an imposed movement making it possible to obtain a good return on the energy consumed. The arrangement of the burner in the upper part of the hearth, also makes it possible to eliminate the problems of absorption of dust, to favor

  its access and maintenance and to adapt another type of burner, for example of the gas type.

  Fig. 6 illustrates an exemplary embodiment of a gas-type heating boiler. The gas type heating boiler is constituted in the same way as the oil type heating boiler described in figs. 1 to 5. In this regard, the references used for the oil-type heating boiler are kept. The main modification concerns the burner 39 which is of the gas type and the gas supply pipe 43 which opens into the hearth plate at the outlet 37 of the volute 34. The gas is thus mixed with the air issuing of the volute 34 in a mixing enclosure 39 'forming part of the burner 39. This gas supply pipe 43 is connected to a control valve 48' fixed on the external face of the hearth plate 3 and making it possible to control the gas supply or shutdown. It should be noted that in this alternative embodiment, the expansion chamber 7 has a reduced height compared to the chamber 7 forming part of a heating boiler of the oil type. The invention is not limited to the examples described and shown, since various

  modifications can be made without departing from its scope.

Claims (7)

CLAIMS:   1 - Boiler for heating a heat transfer fluid comprising: - a hearth (5) closed by a hearth plate (3) and delimiting by its internal volume, a circuit for the circulation of gases and fumes produced by a burner (39), - and a heat exchanger between the circuit for circulation of gases and fumes and a circuit (16) for circulation of the heat-transfer fluid, the heat exchanger being constituted by n exchange units (10) each comprising, on the one hand, a gas and smoke tube (12) extending vertically, communicating, at its lower part, with the hearth (5) and, on the other hand, an exchange envelope (13) delimiting with the tube (12), a lamellar fluid exchange capacity (CI), characterized in that the hearth plate (3): has a passage (45) for a pipe (43) for supplying a fuel to the burner (39), * includes a socket (31) for combustion air, * internally defines a circulation circuit (32) for combustion air communicating with the air intake (31) and opening into a housing (34) for a turbine (35) whose outlet (37) communicates with the burner (39), and comprises an evacuation passage (52) for the gas and smoke, connected to a chamber (7) for collecting gases and smoke leaving the upper part of the gas and smoke tubes (12), this collection chamber (7) being closed at least in part, by the hearth plate (3), to ensure preheating of the combustion air.  2 - Boiler according to claim 1, characterized in that the fuel supply line (43) is mounted to pass, at least in part, the circulation circuit for the preheated combustion air, in order to heat the   fuel prior to combustion.   3 - Boiler according to claim 1, characterized in that the gas and smoke collection chamber (7) has a height suitable for ensuring the expansion of the gases and   smoke leaving the upper part of the gas and smoke tubes (12).   4 - Boiler according to claim I or 3, characterized in that the gas and smoke collection chamber (7) extends above the hearth (5) which delimits between an envelope (6) and a cap (24) , an interval of small width, substantially constant, to form a perimeter strip (C3) of heat transfer fluid forming part of the circuit   (16) circulation of the heat transfer fluid.   - Boiler according to claim 4, characterized in that the perimeter blade (C3) communicates, at its upper part, with a mixing chamber (18) equipped with connection pipes (23a, 23b) to at least one use circuit heat transfer fluid. 6 - Boiler according to claim 5, characterized in that the mixing chamber (18) comprises a bottom (27) near which the connection pipe or pipes for the return of the heat transfer fluid are mounted, the bottom (27) having, on the one hand, calibrated orifices (26) for communicating with the heat transfer fluid coming from the perimeter blade (C3) and, on the other hand, an external face in contact with the heat transfer fluid   from the perimeter blade (C3).   7 - Boiler according to claim 1, characterized in that the combustion air intake (31) concentrically surrounds the gas and smoke evacuation passage (52)   to allow heating of the combustion air.   8 - Boiler according to claim 1, characterized in that the gas and smoke collection chamber (7) comprises in its central part, the burner (39) surrounded by a thermal insulation sleeve (40).   9 - Boiler according to claim 8, characterized in that the burner (39) opens in the central part (Sa) of the hearth, whose exchange units (10) are distributed according to   a circumference located at the periphery of the hearth.   - Boiler according to claim 1, characterized in that the hearth plate (3) is   fitted on the fireplace side with a thermal insulation coating (50).