FR2475187A1 - SMOKE DUCT BOILER AND PIPE FOR SUCH A BOILER - Google Patents

Abstract

THE INVENTION RELATES TO A FLUE PIPE BOILER INCLUDING AN ENCLOSURE CONTAINING A CHAMBER SURROUNDED BY A MASS OF WATER, AND A PLURALITY OF WATER DUCTS IN COMMUNICATION WITH THIS MASS OF WATER HAVING AN EXCHANGE RELATION OF HEAT WITH THE CHIMNEY, CHARACTERIZED IN THAT IT CONTAINS AT LEAST ONE SECOND CHIMNEY 6 NEXT TO THE FIRST CHIMNEY 3, THIS SECOND CHIMNEY 6 CONSISTING OF AT LEAST ONE LARGE PIPE CROSSED BY A PLURALITY OF SUCCESSIVE WATER DUCT GROUPS 11, 13 , OF A RELATIVELY SIGNIFICANT DIAMETER, ORIENTED TRANSVERSALLY IN RELATION TO THE LONGITUDINAL AXIS OF PIPE 6, AND OCCUPYING A CROSSED POSITION IN RELATION TO THE PREVIOUS AND NEXT NEIGHBORING GROUPS. THE INVENTION ALSO RELATES TO A PIPE CROSSING WATER DUCTS FOR SUCH A BOILER.

Description

24 75 18 7

  The present invention relates to a flue gas boiler for obtaining hot water or steam, comprising a

  crankcase provided with a flue surrounded by a body of water, and a

  water pipes communicating with this body of water and being in heat exchange relationship with the flue. Such a boiler has for example been described in Dutch Patent No. 57,935. In this prior boiler, the flue is constituted by a single wide pipe, through which a plurality of relatively small diameter water pipes cross-flow: this is a single-pass, low-efficiency boiler, that is, the flue gases leave the

  boiler at a very high temperature. In addition, the relative diameter

  tively weak water pipes and their location in the

  back of the flue are not very conducive to good circulation.

  water supply, which also does not contribute to ensuring a good

  Dement. In the past, in order to improve their efficiency, multi-pass boilers have been designed, in which the boiler or the first flue, made in the form of a wide pipe, extends practically over the whole length of the casing. outlet of this pipe being connected to a combustion chamber from which, again, extends a large number of pipes of smaller diameter

  practically the entire length of the housing and forms a second car-

  neau. This second flue can end in a smoke chamber equipped with a chimney, or in an inversion chamber, to which is connected a third similar flue and which ends in a room

of smoke.

  These dual or triple-pass boilers provide better efficiency, but water circulation is still not ideal, especially in hot water boilers or low pressure boilers where a short circuit can occur even when

  employs a separate circulation pump. In addition, in these boilers

  multi-pass, resistance to evacuation is relatively

- 2 -

  which makes the use of a large-capacity wind tunnel neces-

  sary. Moreover, the large number of parallel and very close pipes, housed in the corresponding orifices in ordinary tube plates makes the construction of the second and, possibly,

  relatively complicated third flue, which manifests itself

  particularly well when after a number of years of

  one or more tubes must be replaced.

  The present invention aims to overcome the disadvantages mentioned above. Therefore, the invention relates to a flue boiler of the type described above, characterized in that it comprises at least a second flue next to the boiler or first flue, the second flue comprising a single wide pipe through which extends transversely with respect to the meaning

  of the wide pipe, a plurality of water pipes of a diameter

  be relatively high, and which occupy alternating cross-positions.

  The definition of water pipes occupying alternately

  crossed constructions is also aimed at constructions in which several, preferably two, water pipes are oriented in the same way and

  are followed and preceded by a few water pipes, for example

  two, in a crossed position with respect to the previously named ducts. By way of non-limiting example, an embodiment of the invention

  will be described below with reference to the accompanying drawing.

  The figure represents a perspective view of an embodiment of a flue gas boiler according to the invention. The boiler shown is triple-pass, but the invention also applies to boilers having a different number of passages, for example

two.

  A frame 1 supports a cylindrical enclosure 2, whose contours

  are represented in broken lines, provided with end walls.

  In this chamber extends, in the drawing from the left side to the right, -3-

  a wide pipe 3, forming the boiler or first flue. One end

  The melt of this first flue is connected through an orifice in the end wall to a blower, not shown, which, during operation, blows hot gases into the flue. The blower is located at the end of the boiler 4.

  The other end of the boiler ends in a chamber of

  version 5, sometimes called the combustion chamber, located in the

  tremity of the enclosure remote from the wind tunnel. Through the combustion chamber, the hot gases can enter the second flue 6, which extends from the combustion chamber substantially parallel to the boiler to a second inversion chamber 7, called in FIG.

  this description also includes a smoke chamber or

  front end, located at the end of the blower. In the case of a

  boiler with double passage, the room 7 is connected to the chimney.

  In the embodiment shown, however, a third

  flue 8 which extends from the smoke chamber 7 essentially paral-

  first to the second flue, and ends in a smoke chamber 9

  located at the opposite end of the enclosure and connected to a chimney 10.

  Around the first, second and third flues, the enclosure is completely filled with water to heat, and provided with entrances and

  outlets for cooled and heated water, not shown.

  The boiler or first flue, is constituted by a wide pipe. In the embodiment shown, the second and third flues are smaller but still relatively large pipes, in which a plurality of cross ducts are mounted transversely to the longitudinal direction of the pipes.

  the main ones, each of these cross ducts being oriented essentially

  perpendicularly to the position of the previous conduit. Under the operating conditions the axes of the cross ducts form with the vertical an angle preferably equal to or less than 450. As indicated above, the cross ducts may be arranged in alternating groups each comprising a few ducts oriented in the same direction, each group being

  preceded and followed by a group of crossed-oriented conduits.

  Thus, in the second flue, seen from the side of the blower, the first cross duct 11 is oriented from the bottom left to the top right at an angle of 450 to the vertical. The third

  led 13 is moving again from bottom left to top right etc ...

  The cross ducts are welded in corresponding orifices in the walls of the pipes 6 and 8, so that the water circulates in these ducts.

  The orientation of the cross ducts as described above

  above and shown in the accompanying drawing, creates a natural and advantageous circulation of water, counteracting the appearance of "shortcircuit" (a stream of cold water going directly from the inlet to the outlet) and, generally, a pump traffic is no longer

necessary.

  Experiments have shown that the diameter of the cross ducts is preferably at least 20% of the diameter of the wide pipe and is especially between 20 and 25% of the diameter.

wide pipe.

  In addition, respecting the shape of the flues as described,

  and shown in the drawing, the evacuation resistance is relative-

  low, so that the power consumption of the blower for the same or even higher efficiency of the heat exchange in the boiler is lower than that of the duct furnaces.

anterior smoke.

  Finally, the flue gas boiler according to the present invention

  tion is simpler from a constructive point of view than any existing boiler

  aunt, thanks to the fact that the flues according to the present invention make it possible

  save about 50% in construction material and labor. The flues according to the invention can be manufactured separately and be installed in one piece in the boiler. This is also important for repairs because downtime during

repair are thus reduced.

2477,187

  Many alternative embodiments are possible with respect to that described above. As stated above,

  the principle of the invention also applies to steam boilers

  passage. Experiments have furthermore shown that if, in a three-passage boiler in which the second and third flues are constituted by bundles of parallel flues, for example the second flue is replaced by a flue according to the teaching of the present invention. invention, a considerable improvement is achieved.

  The flues 6 and 8 do not necessarily have the same diameter.

  be. As shown in the drawing, the pipe 8 of the third flue can

  have a smaller diameter than the pipe 6 of the second flue.

  This is related to the lower temperature of the combustion gases.

  in the third flue compared to the second flue.

  Similarly, the cross ducts may have different diameters in each of the flues from the front towards

  the back, seen in the direction of flue gas flow.

  Moreover, it is also not strictly necessary that

  successive cross ducts intersect

  Perpendicularly, other positions are possible and

  ble. It should be noted again that a flue can also

  be formed by a plurality of parallel wide pipes provided with.

  water pipes in crossed positions, as described above.

475,187

-6-

Claims (9)

CLAIMS I - Flue gas boiler for obtaining hot water or steam comprising an enclosure containing a flue surrounded by a body of water, and a plurality of water conduits in communication with this body of water having a heat exchange relationship with the flue, characterized in that it contains at least a second flue next to the boiler or first flue, the second flue comprising at least one wide pipe traversed by a plurality of groups of ducts successive water of a relatively large diameter, oriented transversely to the longitudinal axis of the pipe, each group of ducts being composed of one or more successive water conduits having the same orientation and occupying a cross position by compared to previous and next neighbors.   2 - Boiler according to claim 1, characterized in that   that the water pipes intersect alternately.   3 - Boiler according to claim 1 or 2, characterized in that   water pipes have a diameter equal to at least 20% of the diameter be of the wide pipe.   4 - boiler according to claim 3, characterized in that the diameter of the water pipes is between 20 and 25% of the diameter wide pipe.   Boiler according to any one of claims 1 to 4,   characterized in that the boiler or first flue extends from a first end of the chamber to a combustion chamber located at the other, the second end of the chamber, the combustion chamber being in communication with the second flue that extends to the first end of the enclosure where it abuts in an inversion chamber, which in turn is in communication with a third flue returning to a smoke chamber, located at the other, second , end of the enclosure, and provided with a fireplace.   -7- 6 - Boiler according to claim 5 characterized in that the third flue comprises at least one wide pipe traversed by a plurality of successive groups of water pipes having a diameter   relatively large, and oriented transverse to the longitudinal axis.   dinal of the pipe, each group of water conduits being formed by one or more ducts. of water having the same orientation and occupying cross positions each time with respect to the groups of conduits previous and next.   7 - Boiler according to claim 6 characterized in that the successive water pipes of the third flue intersect alternately. Boiler according to Claim 6 or 7, characterized in that the water pipes have a diameter equal to at least 25% of the diameter of the wide pipe.   9 - Boiler according to claim 8 characterized in that the diameter of the water pipes of the third flue is between   and 25% of the diameter of the wide pipe.   Boiler according to any one of claims 1 to 9,   characterized in that the groups of water pipes in each pipe   wide, with water ducts intersecting essentially perpendicular   stretching and form, in operating position with the vertical   an angle equal to or less than 45 '.   Il - Boiler according to any one of claims 6 to   characterized in that the diameter of the wide pipe (s) of the third flue is smaller than the diameter of the wide pipe (s) the second flue.   12 - Boiler according to any one of claims 1 to   Characterized in that the diameter of the water conduits in the second and / or third flue varies in the direction of flue gas flow.   13 - Pipe for boiler with smoke pipes as defined   in any one of claims 1 to 12, characterized in that   that it includes a wide pipe equipped with successive groups of one or 2475,187   - 8 - several successive transverse conduits with open ends, these   groups alternately oriented crosswise.   14 - Pipe according to claim 13 characterized in that the   diameter of the cross ducts is equal to or less than 20% of the diameter   be of the wide pipe. Pipe according to Claim 14, characterized in that the diameter of the cross ducts is between 20 and 25% of the diameter of the wide pipe.   16 - Pipe according to any one of claims 13 to 15   characterized in that the diameter of the cross ducts varies all along the wide pipes.