FR2733031A1 - Incinerator for household waste or other solid materials - Google Patents

Abstract

The incinerator consists of a first section (1) with a chamber (7A) in which the waste material is burned, fed by a primary air flow. The chamber (7A) contains a reverse-draught firebox (8) with a partition (10) with apertures (11) linking it via a duct (16) to a post-combustion chamber (17) in a second section (2). The second section (2) of the incinerator has at least one duct (18) for introducing a secondary air flow to promote the combustion of gases and to create a turbulence which increases the time the gases spend in the combustion chamber.

Description

HOUSEHOLD WASTE INCINATOR AND OTHER FUELS
SOLIDS.

 The subject of the present invention is an autocombustion incinerator of solid waste such as household waste or other solid waste such as agricultural by-products or industrial waste which can be incinerated with little production of gas or toxic waste. .

 One of the drawbacks of household waste incinerators known to date is the production of ultimate waste in relatively large quantities.

 The essential object of the invention is to greatly reduce the amount of ultimate waste by improving the combustion of waste and by optimizing the oxidation of volatile materials.

 To this end, the incinerator according to the invention, for the treatment of household waste and other solid combustible waste, is essentially characterized in that it comprises a first vertical enclosure in the upper part of which is formed a reserve of waste which s flow by gravity into a conical waste combustion chamber supplied with a flow of primary oxidizing air, disposed under the waste reserve and in communication with the latter, delimited by a tubular wall in a truncated cone, for confining the mass of waste in ignition around and against an inverted draft fireplace occupying a vertical, axial position in the combustion chamber of the waste, and formed by an envelope wall of refractory material pierced according to its thickness of through-holes ensuring communication between the combustion chamber waste and an internal chamber in the home, into which the gases released és by the combustion of the mass of waste and in which the combustion of these gases occurs which is also supplied and maintained by the flow of primary oxidizing air, said gas combustion chamber being in communication by an upper mouth which it comprises with a horizontal duct, radial to the first enclosure determining a gas passage channel and penetrating radially into a post-combustion chamber made in a second enclosure adjoining the first, provided with a flue gas evacuation chimney in communication with the post-combustion chamber, the said second enclosure being provided with at least one secondary air inlet in the post-combustion chamber in order to improve the combustion of the gases and to form in the said chamber, vortices to increase the residence time of the gases in the post-combustion chamber.

 Advantageously, the wall for confining the mass of waste around the hearth, along its entire surface, comprises a multitude of radial through-holes, through which a uniform flow is introduced into the thickness of the mass of waste in combustion, oxidizing air introduced into the enclosure, in the lower part of the latter and below said wall.

 According to another additional characteristic of the invention, part of the primary air introduced into the first enclosure can be diverted and introduced directly into the combustion chamber delimited by the envelope wall of the hearth and this by passing through an opening. , with adjustment and shutter flap, formed in a bottom wall of said chamber.

 The hearth, according to an additional characteristic of the invention occupies a position spaced from the walls of the enclosure and rests on a support structure with legs.

 Preferably, the hearth occupies a small volume in comparison with the volume of the enclosure which allows obtaining high temperatures of the order of 1000 to 1400 degrees celcius conducive to improving the combustion of gases further favored by heating the primary air as it passes through the mass of ignition waste in the waste combustion chamber. The combustion of the gases ends in the post-combustion chamber at a temperature of approximately 1100 celsius.

 The heat given off by the combustion of the gases in the post-combustion chamber, according to an additional characteristic of the invention, is partially transferred to a steam generator.

This steam generator feeds, by a suitable pipe, a ramp with nozzles, arranged in the first enclosure on the path of the primary combustion air flow and upstream of the waste combustion chamber, to inject into the flow of primary oxidizing air an appropriate quantity of water vapor in order to improve combustion. The injection of water vapor reduces the amount of primary air by providing additional oxygen.

 According to yet another characteristic of the invention, the steam generator forms a horizontal tube engaged radially in the post-combustion chamber. This tube, outside the enclosure, surrounds the horizontal duct and is in heat exchange relation with the latter.

 As a variant, the tube formed by the steam generator, outside the enclosure extends axially the horizontal duct and forms with the latter, gas passage channel towards the post-combustion chamber.

 According to another characteristic of the invention, the section of the post-combustion chamber is much larger than the section of the gas passage channel so that the gases when they arrive in said chamber lose their speed. This arrangement is conducive to promoting the deposition by gravity of the unburnt particles transported by the gases, on the bottom of the second enclosure.

 According to another characteristic of the invention, each secondary air inlet in the post-combustion chamber is formed at the end of a thermally conductive pipe extending horizontally in the post-combustion chamber, said pipe being provided at its other end with an air suction mouth disposed outside the second enclosure.

 Advantageously, the secondary air inlet occupies substantially a central position in the chamber, so that the pipe extends deeply into the latter.

Thus, the secondary air, before being injected into the post-combustion chamber undergoes a significant rise in temperature which is conducive to improving the combustion of the gases.

 Furthermore, the position of both the pipe and the secondary air inlet in the post-combustion chamber promotes the appearance of turbulence in the latter, which increases the residence time of the gases as well as their degree of combustion.

 Post-combustion can also be carried out in the horizontal duct and / or in the steam generator when the latter forms a passage channel for the gases.

 To this end, according to a characteristic of the invention, at least one other inlet of oxidizing secondary air is provided in the horizontal duct or in the channel delimited by the steam generator.

 Finally, according to another characteristic of the invention, above the post-combustion chamber, on the path of the burnt gases towards the exhaust chimney, is provided in the second enclosure, a calm chamber in which the flow gas tends to be or is laminar.

 In this quiet room can be arranged a heat exchanger, which can be arranged in series with the steam generator.

 As a variant, the calm chamber, of cylindrical shape, may be delimited by the heat recovery unit.

 Other advantages, aims and characteristics of the invention will appear on reading the description of a preferred embodiment, given by way of nonlimiting example with reference to the accompanying drawings in which - Figure 1 is a view schematic sectional view of an incinerator according to the invention, - Figure 2 is a sectional view on an enlarged scale of the lower part of the first enclosure.

 As shown schematically in Figure 1, the incinerator comprises a first enclosure 1 in which the combustion of waste occurs and a second enclosure 2 adjoining the first in which is completed the combustion of gases before their release into the atmosphere.

 The first enclosure 1, of generally cylindro-conical shape, comprises a lower chamber 3 or ashtray of cylindrical shape provided with at least one opening for introducing a primary oxidizing air flow for the maintenance of the combustion of waste taking place in a waste combustion chamber 7A arranged around a hearth 8 mounted in the enclosure 1 on a support structure. The lower chamber 3 is surmounted by an upper chamber 4 of frustoconical shape in which, by an upper opening 5 which it comprises, are introduced by a loading system 6, household waste and other solid waste to be incinerated in the chamber 7A. combustion of waste. The loading system 6 can be constituted by an endless belt conveyor or by any other means.

 This frustoconical chamber 4, of increasing cross section from the upper loading orifice to the lower chamber 3, constitutes a reserve of products to be burned and can receive in the upper part a level detector by means of which the loading system is activated. According to this arrangement, the quantity of product introduced into the incinerator corresponds to the quantity burned.

 The frustoconical chamber 4 through its lower zone is in relation to the waste combustion chamber 7A which is delimited by a frustoconical tubular wall 7, for confinement, against and around the hearth 8, of the mass of waste in combustion in the combustion 7A. This wall 7 forms a funnel around the hearth 8 with reverse draft, which brings the mass of waste to be incinerated against the latter. Preferably, this wall 7 along its entire surface has a multitude of through holes through which the flow of primary air is introduced into the waste combustion chamber and passes through the mass of waste substantially radially to maintain their combustion before reaching the hearth 8. During its passage through the mass of waste in ignition the primary air flow undergoes a significant rise in temperature which will then facilitate the combustion of gases as explained below.

The arrangement for distributing the bores along the entire extent of the wall 7 increases the area of penetration of the primary air into the mass of waste in ignition. Furthermore, the regular distribution of these holes allows a uniform distribution of the air flow in said mass.

During their incineration the waste flows slowly towards the wall 7 and / or towards the bottom of the funnel formed and the waste combustion chamber 7A is constantly supplied with waste to be incinerated, the latter flowing in the said chamber by gravity and this from the reserve formed in the upper part of the enclosure.

 Advantageously, at least one vibrator, not shown, may be provided, fixed to the wall 7 to vibrate the latter and facilitate the descent of the waste into the funnel that it forms and this during their incineration.

 Preferably, the wall 7 by its widest section is suspended from hooks fixed to the wall of the enclosure 1 which allows it to be vibrated.

The wall 7, at its base, determines a circular opening developing around the focal point with spacing of the latter.

According to this embodiment around the hearth, under the wall 7 and at a distance from the latter, a bottom wall 9 is arranged, preferably in the form of a grid, on which the mass of waste in ignition around the hearth 8 is supported. This wall bottom 9 develops transversely to the median vertical axis of the enclosure 1. The annular interval between the lower opening of the wall 7 and the hearth 8 on the one hand and between the wall 7 and the wall of bottom 9 on the other hand is sufficient to allow the evacuation of non-combustible waste such as cans and the like. The vibration of the wall 7 also aims to facilitate this evacuation. The non-combustible waste, flowing by gravity through the annular gap, is received by the bottom wall 9. Preferably, this wall 9, of frustoconical shape, is sloping from the hearth 8 towards the cylindrical face of the lower chamber 3.

This wall 9 by its border of larger diameter is spaced from the cylindrical face of the chamber 3 so as to release a sufficient annular gap through which the unburned waste can flow towards the bottom of said chamber 3. On the bottom from this chamber, also settle the unburned formed by the combustion of waste.

Opposite this wall 9, at least one inspection hole may be provided in the wall of the enclosure 1.

 The hearth 8 is coaxial with the enclosure 1 and is arranged at a spacing from the walls of the latter on a suitable metal support mounted for fixing in the lower chamber 3. In addition, this hearth 8 is installed in the waste combustion chamber 7A and is coaxial with the latter. Preferably the height of the hearth 8 is less than the height of said chamber 7A.

The hearth 8 essentially consists of an envelope wall 10 made of refractory material, coaxial with the enclosure 1 delimiting a chamber 12 for combustion of the gases substantially of cylindrical shape. The envelope wall 10 is pierced along its rectangular opening thickness 11 extending vertically along its height. These openings 11 ensure the passage of gases from the waste combustion chamber 7A formed around the hearth 8, to the gas combustion chamber 12.

 According to the preferred embodiment, the envelope wall 10 of the hearth 8 is formed by briquettes of refractory material arranged vertically at constant spacing from one another on the framework of the hearth which may be constituted by a circular lower strapping 13 on which takes support the briquettes, by a circular upper strapping 14 covering the upper end of the briquettes and by vertical uprights 15 fixed to one and the other straps. The distance between two successive briquettes determines a radial opening 11.

 The gas combustion chamber 12, through its upper mouth, is in communication via an elbow with a horizontal pipe 16 extending radially in the upper chamber 4. This horizontal pipe 16 passes through the wall of the upper chamber 4 by passing through an orifice made in the latter to engage radially in the second enclosure 2.

The gas combustion chamber 12 is closed in the lower part by a funnel-shaped bottom 29, plunging into the lower chamber 3, extended axially by a tubular part 29A provided at the lower end with an opening with shutter 23 actuated in the opening or closing direction by a suitable mechanism not shown, such as a rod coupled to the axis of the flap, mounted in a rotating guide bearing formed in the wall of the lower chamber 3 and receiving in coupling, externally to the lower chamber 3, a handwheel or a crank or alternatively the output shaft of a drive member. The bottom 29 is fixed to the lower strapping 13 by any means known to those skilled in the art.

 This arrangement with shutter 23 has the advantage of allowing the shutter 23 to be completely opened for the removal of unburnt material retained in the combustion chamber. The second advantage of this arrangement lies in the fact that by opening the shutter, during use of the incinerator, part of the primary oxidizing air is introduced into the combustion chamber and that by adjusting the degree of opening of this flap 23, it is possible to adjust the value of the air flow introduced into the combustion chamber 12.

 Preferably, the oxidizing primary air is introduced into the lower chamber 3 of the enclosure through openings with a flap that the wall of the latter has. The associated shutter & each of these openings is adjustable in position in its opening which makes it possible to adjust the flow rate of primary air introduced and therefore the draft.

This component will be actuated by a motor member activated by a temperature sensor housed in the second enclosure and sensitive to the temperature of the gases or else housed in one of the heat exchangers that the latter comprises.

 The hot gases released by the combustion of the waste are forced, by suction, to enter the combustion chamber 12 by passing through the radial openings 11.

 The combustion of gases, favored by the significant rise in temperature experienced by the flow of primary oxidizing air during its passage through the mass of waste in combustion, occurs in the combustion chamber 12 at a high temperature and these gases during combustion are sucked into line 16 and brought into a post-combustion chamber 17 formed in the second enclosure 2. This enclosure 2 of cylindrical shape has under the post-combustion chamber, a recovery chamber for unburnt materials arranged in hopper provided with a lower orifice in connection with a worm extractor. The unburnt recuperated by this extractor are then introduced into enclosure 1 so as to undergo a second incineration.

 In the post-combustion chamber 17, by passing through an orifice in the wall of the enclosure, at least one horizontal pipe 18 radial to the enclosure penetrates. This horizontal pipe 18 introduces into the post-combustion chamber, a flow of oxidizing secondary air drawn externally from the enclosure.

This pipe 18, made of thermally conductive material, extends into the chamber 17 along a length corresponding substantially to the value of the radius of the chamber 17 so that the secondary oxidizing air is introduced substantially into the center of said chamber, into the flow of gases during combustion supplied by line 16. The secondary air, before reaching the post-combustion chamber 17, is strongly elevated in temperature and its introduction into the post-combustion chamber 17 promotes complete combustion gases by additional supply of oxygen on the one hand and by creation of turbulences which increase the residence time of the gases in the post-combustion chamber.

 Preferably, the pipe 18 is slidably mounted in an external radial sheath, fixed to the wall of the second enclosure. This arrangement makes it possible to adjust the degree of penetration of the pipe 18 into the post-combustion chamber 17.

 The post-combustion of the gases can also be carried out in line 16 and for this reason the latter can be equipped with one or more combustion air inlet each formed at the end of a radial pipe to the second enclosure and introduced into this last and in the post-combustion chamber 17 before entering the line 16 or more generally in the gas passage channel formed between the first enclosure and the second.

 This arrangement allows the formation of turbulence in this passage channel which further increases the residence time of the gases and improves their combustion.

 In the post-combustion chamber is arranged a steam generator 19 constituted by a heat exchanger receiving a flow of water transformed, under the effect of the heat supply, into a flow of steam. This exchanger has a water inlet and a steam outlet and supplies steam, via a pipe not shown, a ramp 20 with nozzles 21 mounted in the lower chamber 3 of the first enclosure 1 for injecting into the primary air flow combusting an appropriate quantity of water vapor in order to improve qualitatively the combustion of waste and produced gases.

 This steam generator 19 forms a tube and determines an internal gas passage channel in the axial extension of the channel determined by the horizontal conduit 16.

 As can be seen in Figure 1 this steam generator 19 extends diametrically in the enclosure 2 and forms in the latter the post-combustion chamber.

According to the vertical axis of the enclosure 2, the generator 19 comprises an upper opening for the passage of gases towards the chimney and a lower opening for the passage of unburnt. The post-combustion chamber 17 is located between the lower and upper openings.

 According to this embodiment, the steam generator 19 also extends externally to the enclosure 2 around the duct 16. The steam generator 19 can also determine part of the gas passage channel between the first and the second enclosure.

 As a variant, the steam generator 19 no longer extends diametrically in the enclosure 2 but radially, the chamber 17 for post-combustion of the gases in this case, considering the gas flow path , being formed downstream of the generator 19.

 The zone of the enclosure corresponding to the post-combustion chamber 17 has a much larger section than that of the gas passage channel so that the gases when they reach this zone decrease in speed which is conducive to facilitate the deposit of unburnt on the bottom of the enclosure 2.

 The steam generator 19 according to this embodiment may also extend outside the enclosure 2 around the duct 16 or else, always outside the enclosure 2, form part of the passage channel of the gas to post-combustion chamber 17.

 According to the preferred embodiment, the steam generator 19 is formed of a cylindrical outer casing in which is mounted coaxially a cylindrical inner casing. The two envelopes determine an annular interval and are kept apart from each other by a front partition shutter in a circular crown and a rear partition shutter in a circular crown.

 Above the post-combustion chamber and downstream of the latter, considering the path of the gases towards the chimney 2A, there is a calm chamber 24 in which the hot gases flow in a laminar regime.

 In order to force the gases to flow in a laminar manner in the still chamber 24, a screen 25 is arranged at the inlet of the latter and above the post-combustion chamber 17, transverse to the flow of the gases. , separated by its periphery from the internal face of the quiet chamber 24 to determine with said face an annular passage of gases. The purpose of this screen is to slow the flow of gases and to prevent the vortices formed in the post-combustion chamber 17 from propagating in the still chamber 24. In addition, this screen 25 forces the gases to remain more a long time in the post-combustion chamber 17 which further improves their degree of combustion. The screen 25, as can be seen in fig. 1 develops centrally with respect to the vertical median axis of the chamber 24 and is fixed at the lower end of a vertical element 26 fixed in the chamber 24. vertical element, elongated, door remote from the screen 25, a second screen 27 of smaller size.

The laminar flow of gases in the chamber 24 promotes the fallout of the unburnt carried by the gases.

 Advantageously in the chamber 24, of cylindrical shape, is arranged a heat recovery unit 28 of the air water type for example. The heat recovery unit 28 has a cold water inlet and a hot water outlet.

By its input and by its output, this generator can also be connected via pipes, respectively to the input and to the output of the steam generator 19.

Advantageously, the output of the steam generator 19 may be coupled to the input of a bypass connected on the one hand to the supply line of the ramp 20 and on the other hand, by a line, to the recovery of the recuperator 28.

 As a variant, the chamber 24 could be delimited by the recuperator 28, the latter taking on a tubular shape.

 In order to allow the cleaning of the radial openings 11 of the hearth 8 and this from outside the enclosure 1, the said hearth 8 is rotatably mounted on its support structure and can be actuated in rotation by an actuation mechanism. There is further provided a radial sheath 22 extending in the upper chamber 4 of the enclosure 1 and in the combustion chamber 7A, an opening made in the wall of the said enclosure 1. Next to this sheath are brought in turn the various openings 11 of the hearth 8, the cleaning taking place by passing an appropriate instrument through the sheath 22. To the lower strapping 13 of the hearth 8 is fixed a support 30, for example tubular, equipped in the lower part with organs bearing bearing on a circular running track imparted on a horizontal plate 31 which comprises the support structure. The conical bottom 29 in the form of a funnel, according to this embodiment, is dissociated from the tubular part 29A which is fixed to the support structure. Between the conical bottom 29 and the part 29A will be provided a seal allowing their relative rotation. Rolling members may be arranged between the bottom 29 and the part 29A.

 The actuating mechanism of the hearth 8 in rotation can be actuated from the outside and comprises for example a toothed ring 32 in engagement with the support 30 and a bevel gear pinion 34 mounted at the end of an actuating shaft guided in rotation along its axis in bearings mounted as fixings in chamber 3.

Outside the enclosure, this shaft is coupled to a manual or motorized operating device.

 It should be noted that the hearth can be rotated during the incineration of the waste to facilitate the descent of the waste into the funnel formed by the waste combustion chamber 7A.

 Finally, the incinerator as described is equipped with a forced drawing means.

This means consists of an accelerator 35 comprising on the one hand a suction mouth connected via a pipe 36 to the chimney 2A carried by the second enclosure, and on the other hand a discharge mouth preferably connected to a second chimney 40 via a gas filtration device 37 capable of retaining the dust that the latter conveys. This filtration device by its outlet is connected by a pipe 38 to the chimney 40. The chimney 2A upstream of the mouth of the pipe 36 has a shutter 39 placed in the shutter position when the accelerator is activated. . Preferably, the chimney 40 is installed on the floor.

 The unburnt particles retained by the filtration device 37 can be recovered by a worm extractor and be introduced by the latter or by any other means into the enclosure 1 to undergo an additional incineration.

 The present invention is not limited to the embodiments which have just been described and can receive any variant.

 Thus, the introduction of primary combustion air into the chamber 7A can be carried out by several lines of thermally conductive outside air intakes arranged convergently towards the hearth 8 in the funnel formed by said chamber.

 Similarly in the chamber 12 and more particularly in the part 29A, above the flap 23, a horizontal pipe, radial to the chamber 3 and having an external mouth for the entry into the chamber, may open. combustion chamber 12, oxidizing gas or water vapor. This mouth will be closable by a removable cap.

 It should be noted that due to the high temperature both of the waste combustion chamber 7A and of the hearth 8 and of the conduit 16 the heat released in the enclosure 1 participates in the drying of the waste ready to be introduced into the combustion chamber 7A, whereby very humid products can be incinerated.

 Due to the intense heat of both the combustion chamber 7A and the hearth 8, vapors resulting from the desiccation of the waste may diffuse through the mass of the materials to be burned and reflux to the top of the enclosure 1. The vapors could be recovered at this level by a collecting system coupled to a suction means and injected by this said means into the primary oxidizing air. The collector system can be constituted for example by a tubular ramp with suction nozzles. It should also be noted that the vapors given off by the products ready to be introduced into the combustion chamber are drawn into the latter by the effect of the reverse draft.

 Finally, it should be noted that the wall 7 keeps the wall of the enclosure 1 apart, the mass of waste in combustion. This has the advantage of avoiding subjecting this wall to too high a temperature.

 It goes without saying that the present invention can receive all arrangements and all variants in the field of technical equivalents without departing from the scope of this patent.

Claims (21)

 1 / Incinerator of household waste or other solid combustible waste characterized in that it comprises a first vertical enclosure (1) in the upper part of which is formed a reserve of waste which flows by gravity into a conical chamber (7A ) of combustion of waste supplied with a flow of primary oxidizing air, disposed under the waste reserve and in communication with the latter, delimited by a tubular wall (7) in truncated cone, for confining the mass of waste in ignition around and against an inverted draft hearth (8) occupying a vertical, axial position, in the waste combustion chamber (7A) and formed by an envelope wall (10) of refractory material pierced according to its thickness of through-holes (11) ensuring the communication between the ignition ignition chamber and a chamber (12) internal to the home, into which the gases released by the combustion of the mass of d and in which the combustion of these gases occurs which is also supplied and maintained by the flow of primary oxidizing air, said chamber (12) for combustion of gases being in communication by an upper mouth which it comprises with a horizontal duct (16), radial to the first enclosure (1) determining a gas passage channel and penetrating radially into an after-combustion chamber (17) formed in a second enclosure (2) adjoining the first, equipped with a chimney (2A) for evacuating the burnt gases in communication with the post-combustion chamber (17), the said second enclosure (2) being provided with at least one secondary air inlet in the post-combustion chamber (17 ) in order to improve the combustion of the gases and to form in said chamber (17) vortices to increase the residence time of the gases in the post-combustion chamber.  2 / Incinerator according to claim 1 characterized in that the wall (7) along its entire surface has a multitude of radial through holes, through which is introduced uniformly into the thickness of the mass of waste in combustion, the flow primary oxidizing air introduced into the enclosure (1), in the lower part of the latter and below said wall (7).  3 / Incinerator according to claim 1 or claim 2 characterized by several outside air intake pipes arranged convergently towards the hearth (8), in the chamber (7A) of combustion of the waste to introduce into the latter and into the mass of waste in ignition the primary oxidizing air flow.  4 / Incinerator according to claim 1 characterized in that in the post-combustion chamber (17) is disposed a steam generator (19) supplied by the heat released by the post-combustion of gases, said steam generator (19) supplying steam with a ramp (20) with nozzles (21), disposed in the first enclosure (1) on the path of the primary oxidant air flow and upstream of the combustion chamber (7A) of waste, to inject an appropriate quantity of water vapor into the primary combustion air stream in order to improve combustion.  5 / Incinerator according to claim 1 characterized in that the hearth (8) is spaced from the walls of the enclosure (1) and rests on a support structure with legs.  6 / Incinerator according to claim 1 characterized in that a part of the primary oxidizing air introduced into the first enclosure (1) is derived and introduced into the combustion chamber (12) of the hearth (8) and this by passing through the through an opening with shutter (23) for closing and adjusting, said opening being formed in a wall (29), (29A) constituting the bottom of the combustion chamber 12.  7 / incinerator according to claim 1 characterized by a calm chamber (24) formed in the second enclosure (2) in which the gas flow tends to be laminar, said chamber (24), considering the path of the gases to the chimney (2A) of said enclosure (2), being arranged downstream of the post-combustion chamber (17).  8 / Incinerator according to claim 4 characterized in that the steam generator (19) forms a horizontal tube and is engaged radially in the post-combustion chamber (17).  9 / Incinerator according to claim 8 characterized in that the generator (19) outside the enclosure (2) surrounds the duct (16) and is in heat exchange relationship with the latter.  10 Incinerator according to claim 8 characterized in that outside the enclosure (2) the generator (19) extends axially the conduit (16) and forms with the latter, gas passage channel to the post-combustion chamber ( 17).  11 / Incinerator according to claim 1 characterized in that each air inlet in the post-combustion chamber (17) is formed at the end of a pipe (18), thermally conductive extending horizontally in the post-combustion chamber combustion (17), said pipe (18) being provided at its other end with an air suction mouth disposed outside the second enclosure (2).  12 / Incinerator according to any one of claims 1, 8, 9 and 10 characterized in that in the gas passage channel defined by the generator (19) and / or by the conduit (16) is arranged at least one inlet combustion air.  13 / Incinerator according to claim 1 characterized in that the section of the post-combustion chamber (17) is larger than the section of the gas passage channel.  14 / Incinerator according to claim 7 characterized by a screen (25) transverse to the gas flow, disposed above the post-combustion chamber (17) at the entrance to the chamber (24), the said screen ( 25) by its periphery being arranged apart from the internal face of said chamber (24) to determine with said face an annular passage of gases.  15 / Incinerator according to claim 7 or claim 14 characterized by a heat recovery unit (28) disposed in the chamber (24).  16 / Incinerator according to claim 15 characterized in that the chamber (24) is delimited by the heat recovery unit (28).  17 / Incinerator according to claim 1 or claim 5 characterized in that the hearth (8) is rotatably mounted on its support structure and is actuatable in rotation by an actuating mechanism to bring in turn the openings (11) qu 'it comprises opposite a radial sheath (22) extending in the enclosure (1) and in the combustion chamber (7A), an opening made in the wall of said enclosure (1), so that by passing through the sheath (22) of an appropriate instrument. each opening (11) can be cleaned.  18 / Incinerator according to claim 1 characterized by a forced draft means constituted by an accelerator (35) comprising on the one hand a suction mouth connected by the intermediary of a pipe (36) to the chimney (2A) d gas evacuation carried by the enclosure (2) and on the other hand a discharge outlet connected to a second chimney (40) by a pipe (38) via a gas filtration device (37) capable of retaining dust that the latter convey, the chimney (2A) upstream of the mouth of the pipe (36) comprising a shutter (39) shutter placed in the shutter position when the accelerator is activated.  19 / Incinerator according to claim 1 characterized by a gas collecting system, mounted in the upper part of the enclosure 1 and coupled to a gas suction means, which means injects them into the primary combustion air.  20 / Incinerator according to claim 6 characterized by a horizontal pipe opening into the chamber (12) above the flap (23), said pipe having externally to the enclosure (1) an inlet mouth closable by a removable plug .  21 / Incinerator according to claim 1 characterized in that the frustoconical wall (7), by the circular opening which it determines at its base is spaced from the hearth (8) and that around the hearth, under the wall (7) and spaced from the latter is disposed a bottom wall (9) on which bears the mass of waste in ignition around the hearth (8).