Automotive unit for the collection and incineration of household or industrial refuse

Abstract

An automotive unit for the collection and incineration of refuse, comprising a fluid-tight incineration assembly formed by a rotary furnace, an outer casing turning jointly with said furnace and forming an ash storage receptacle, a fluid-tight device for the introduction of the refuse into the furnace, a fume discharge sheath connected in a fluid-tight manner to one end of said furnace and leading to means for after-burning and cleaning fumes and combustion gases.

Description

The present invention relates essentially to an automotive unit for the simultaneous collection and incineration of refuse, for example household or industrial refuse.

Indeed, the disposal of household refuse gives rise to problems of collection, handling, treatment and then of use of the products resulting from the treatment.

During the collection of the refuse, the usually known gathering dump-trucks must proceed to a discharge site and then return to the gathering location, thus leading to considerable loss of time. In some cases, the discharge site may be a treating plant and in other cases it may be a wagon or some other transportation means, or it may also be a controlled discharge. The latter, even under the best conditions, always gives rise to problems of ground surface and of distance with respect to the collection site, as well as problems of environment pollution.

The treating plants may be of three main types: composting, which requires marketing of the product, compacting and conditioning, in which the products are used for ground filling, and incineration, wherein the refuse is destroyed and the ashes are used in public works or agriculture.

However, the treating plants, whatever their type, give rise to a problem of distance with respect to the collection site.

The purpose of the invention is to provide a particularly efficient solution to household refuse disposal problems as regards environment pollution, which at the same time obviates the drawbacks of undesired transportation, by means of an automotive unit for the simultaneous collection and incineration of refuse just charged into the unit. To this end, the automotive unit according to the invention is provided with a rotary doublewall furnace which is substantially in the shape of a truncated cone and one end of which forms a refuse charging hole and whose other end forms an ash and incineration residue discharge hole, means for charging the refuse into the furnace, burners arranged in the furnace for the incineration of the refuse, and fume and combustion gas discharge means, and is characterized in that it comprises a substantially fluid-tight incineration assembly formed by:

- THE SAID ROTARY FURNACE,

- AN EXTERNAL CASING COAXIAL WITH THE SAID FURNACE AND ROTATING JOINTLY THEREWITH, CLOSED AT BOTH ITS ENDS AND EXTENDING BEYOND THE FURNACE DISCHARGE HOLE SO AS TO FORM AN ASH STORAGE RECEPTACLE,

- A SUBSTANTIALLY FLUID-TIGHT DEVICE FOR THE INTRODUCTION OF THE REFUSE INTO THE CHARGING END OF THE FURNACE, COMPRISING AN ENDLESS SCREW PLACED AT THE INLET OF A CHARGING CONDUIT SUBSTANTIALLY IN THE SHAPE OF A TRUNCATED CONE AND OPENING INTO THE FURNACE,

- AND A FUME DISCHARGE SHEATH SUBSTANTIALLY SEALINGLY CONNECTED TO ONE END OF THE FURNACE AND LEADING TO FUME AND COMBUSION-GAS AFTER-BURNING AND CLEANING MEANS.

Thus, the automotive unit according to the invention is provided essentially with a rotary furnace of a type known per se, but designed for sealed combustion operation without interfering air or gas admission, thus involving the use of strict control of air ingress into the furnace, refuse charging means of a particular type and ash storage and discharge means also designed to meet this requirement.

The charging device is constituted by an endless screw arranged in the lower portion of a receptacle into which the refuse is poured during its collection, the said screw pushing the refuse into a charging truncated-cone conduit opening by its larger base at the inlet of the furnace. This arrangement eliminates the risk of jamming of the refuse in the charging conduit. Moreover, the refuse pushed by the endless screw push those located in the charging conduit and which, at its end, fall into the furnace; a refuse plug always remains in the charging conduit and on the screw, thus ensuring the fluid-tightness of the device.

Furthermore, the said casing arranged in coaxial relationship to an outward of the bottom enables the ash discharge problem to be solved by forming about the furnace an ash receptacle in which the ashes fall freely through the discharge end of the furnace. According to another feature of the invention, a helical blade or screw is provided in the internal face of the casing over at least a portion of its length, between the latter and the outer wall of the furance, so as to drive and guide the ashes and incineration residues from the spot where they are discharged into the said ash receptacle to the opposite end of the said ash receptacle under the action of the rotation of the furnace and casing. In order to empty the ash receptacle it is sufficient to rotate the furnace in the opposite direction to allow the said helical blade or screw to move the ashes back to the furnace discharge hole, from which they can be discharged outside by means of, for example, a door provided in the said casing.

Such an arrangement enables the supply with combustion air necessary for the incineration of the refuse to be readily controlled.

According to another feature of the invention, the rotary furnace is made from thin sheet-metal and its inner wall is provided with pulsed-air blowing perforations or orifices which are so arranged as to ensure a tridirectional blowing. According to still another feature of the invention, the air blown through the orifices of the inner wall of the furnace is conveyed by a stationary annular sheath provided with a rotary joint, arranged between two annular cheeks secured to the rotary furnace and connected to a blown-air intake nozzle.

The invention will be better understood and other objects, characteristics and advantages thereof will appear as the following description proceeds, with reference to the appended drawings given solely by way of example illustrating one form of embodiment of the invention and wherein:

- FIG. 1 is a general diagrammatic view of the refuse collection and incineration unit according to the invention;

- FIG. 2 is a longitudinal sectional view of the rotary furnace according to the invention;

- FIG. 3 is a partial perspective view of the inner wall of the furnace;

- FIGS. 4, 5 and 6 are enlarged views of the portions IV, V and VI encircled in FIG. 2;

- FIG. 7 is a perspective view of the pot mounted on the charging end of the furnace;

- FIG. 8 is a partial sectional view of the annular pulsed-air supply sheath mounted about the furnace;

- FIGS. 9 and 10 are front and side views of the sheetmetal band forming the annular sheath; and

- FIG. 11 is a diagrammatic view illustrating the operation of the unit according to the invention.

The household or industrial refuse collection and incineration unit therefore comprises a truncated-cone furnace 1 which is mounted on the frame of an automotive vehicle and the axis of which is slightly inclined to the horizontal line, so that the lower generating line of the truncated cone is substantially horizontal. A pot 2 is mounted on the larger end of the furnace and connected, on the one hand, to a charging conduit 3 and, on the other hand, to a fume escape sheath 4. The charging conduit 3 opens at its rear portion into a container 5 into which is poured the refuse and which comprises an endless screw 6 arranged at the inlet of the truncated-cone conduit 3. The screw 6 is driven by a hydraulic motor-reducer set 7.

The sheath 4 leads to a fume cleaning plant 8 which comprises a cyclone whose turbine 9 and drive set 10 are mounted within a flue 11 through which the fumes are discharged to the atmosphere. The latter is arranged above a constant-level tank 12, within a fume admission volute member 13 whose lower portion is immersed in the water in the tank 12. The volute member 13 is connected at its upper portion to the end of the aforesaid after-burning sheaths.

The truncated-cone double-wall furnace 1 is surrounded by a coaxial outer casing 15, also in the shape of a truncated cone, which is closed at both its ends and extends beyond the furnace discharge end 16 so as to form about the latter a storage space for the ashes and incineration residues. Advantageously, a helical blade or partition wall 17 is provided on the inner wall of the casing 16 over at least a portion of the length of the said casing, between the latter and the outer wall of the furnace 1. The casing 15 is also provided with doors 18 allowing the ashes to be discharged after a given operation.

The furnace 1 is also equipped with two burners 19 and 20 supplied from reservoirs 21. The burner 19 has a reducing flame, whereas the burner 20 has an oxidizing flame.

The power necessary for the operation of the whole plant is provided by a Diesel engine 32 mounted above a water reservoir 23 feeding part of the fume cleaning plant 8.

The truncated-cone furnace 1 which is shown more in detail in FIGS. 2 to 6 is double walled and comprises a metal bracing formed of beams 25 arranged about the longitudinal axis of the furnace so as to form a truncated cone. The said beams are interconnected at the rear end of the furnace by a circular channel bar 26 on which they are welded, and at their opposite end by an annular circular plate 27 to which they are also welded. At about two thirds of their length from the furnace charging end the beams 25 are connected by a circular angle bar 28 which is also intended to support the outer wall 29 of the furnace.

The inner wall 30 of the furnace is arranged within the bracing formed by the beams 25 and is formed by alternating omegasection plates 31 and substantially plane section plates 32 mounted between the section plates 31. This enables the inner wall 30 of the furnace to be given the shape of a truncated cone, by means of the plates 32 the edges of which are slightly raised inwardly as shown in FIG. 3. The plates 32 are mounted freely sliding in slots 33 formed by the outer side edge of a section plate 31 and an additional angle bar 34 secured under the said side edge. This arrangement allows free expansion of the element constituting the inner wall of the furnace, since the said elements are free to play tangentially and longitudinally with respect to the truncated cone formed by the beams 25.

The plates 31 and 32 are provided with orifices, respectively 35 and 36, for radial blowing of combustion air. The parallel sides of the section plates 31 are provided with air-blowing orifices 37, the general direction of which is inclined at 45.degree. to the wall of the said section plates so as to produce a tangential blowing and an axial blowing of combustion air.

The inner wall 30 of the furnace is simply placed on the bracing formed by the beams 25 and the channel bar 26, and is retained against translation within the said bracing by removable locking means enabling this wall to be very simply and rapidly removed from or mounted in the bracing. According to one form of embodiment, the said locking means comprise plane plates 38 each of which is mounted tangentially to the truncated cone within the channels formed by the section plates 31. The plates 38 cooperate with lock members 39 in the shape of angle strips secured to the said channel bar 26. Such simple locking means enable the inner wall of the furnace to be retained against translation towards the furnace discharge end and against radial displacement with respect to the bracing.

Locking means of the said type are provided on the angle bar 28 and comprise flat angle strips 40 secured to the angle bar 28 through the medium of flat plates or bars 41. The angle strips 40 co-operate with plates 42 secured tangentially to the truncated cone within the omega-section plates 31. The inner wall of the furnace is thus retained against translation in the axial direction and in radial displacement by the plates 42 and the angle strips 40.

Furthermore, a connecting flange is removably mounted on the channel bar 26 by means of triangular brackets or supports 46 and bolts 47.

The outer casing 15 forming the outer wall of the ash receptacle is secured at its end located at the furnace discharge side by an annular plate 49 secured to the aforesaid annular section-plate (FIG. 6). At its opposite end (FIG. 4) the casing 15 is welded to annular plate 50, the cross-section of which is in the shape of an outwardly open U which is itself secured to the beams 25 forming the furnace bracing by means of supports 51. The outer wall 29 of the furnace is also welded at one of its ends to the supports 51 and at its opposite end to the outer diameter of a disk 52 secured to the aforesaid angle bar 28 (FIG. 5).

Annular cheeks 53 and 54 are secured respectively to the section bar 26 located at the end of the furnace bracing and to the section plate 50 and the supports 51 so as to form an annular sheath 55 surrounding the charging end of the furnace. This annular sheath communicates with the space comprised between the outer wall 29 and the inner wall 30 of the furnace and is used as a pulsed-air intake conduit. The said air proceeding from the sheath 55 passes between the inner and outer walls of the furnace and is blown through the orifices 35, 36 and 37 of the said inner wall. The periphery of the sheath is closed by a cylindrical plate 56 secured to the frame of the unit and cooperating with the outwardly radial edges of the cheeks 53 and 54 by means of a rotary joint device formed by angle strips 57 secured to the cylindrical plate 56.

A modified form of embodiment is diagrammatically shown in FIGS. 8 to 10 where the reference numbers 29' and 30' designate respectively the inner and outer walls of the furnace, whereas the reference numerals 53' and 54' designate the two annular cheeks secured at the end of the wall, the periphery of the annular sheath 55' being closed by means of a sheet-steel band 56' co-operating with sliding binders 57' and guiding binders 57" made from copper or brass or any other material with a low coefficient of friction and arranged on the radial edges of the cheeks 53' and 54'. The sheet-steel band 56' is adapted to be adjustably tightened on the binders 57' and 57" by means of a screw-and-spring device 58' shown in FIG. 9. One end of the sheet-steel band 56' is secured to a bracket 59' on the frame and carries a screwing member surrounded by a spring. The other end of the steel sheet is provided with a lug through which passes the screwing member, and a nut is provided which bears upon the said lug and enables the band 56' to be more or less tightened around the binders 57' and 57". Furthermore, the band 56' is connected to a combustion-air intake conduit 60. The conduit 60 is connected to a blower 51 supplying the annular sheath with pulsed air.

In FIG. 7 is shown a perspective view of the pot 2 which is intended to be mounted on the charging hole of the furnace, i.e. on the connecting flange 45 provided at the end of the furnace. The pot 2 comprises at its lower end the truncated-cone charging conduit 3 and at its upper portion a flange 4' for connection with the after-burning sheaths 4. The pot also comprises an inspection door provided with a shutter 14, the opening of which is adjustable in accordance with the temperature of the fumes and which permits the ingress of fresh air for cooling the said fumes.

Reference is now made to FIG. 11 for the description of the operation of the incineration device according to the invention.

The refuse to be incinerated is poured into the receptacle 5 located at the rear of the unit an falls onto the endless screw 6 which pushes it into the truncated-cone charging conduit 3. The refuse pushed by the endless screw push in their turn those which are already in the conduit 3 so that a refuse plug remains all the time in the conduit, thus forming a tight lock-chamber through which the air cannot enter the furnace. At the outlet of the conduit 3 the refuse fall into the furnace on the inner wall of the latter and is exposed to the flame of the burner 19. The furnace is driven in rotation, for example by means of a hydraulic motor-reducer driving set comprising a pinion engaging an endless chain arranged in the U-section plate encircling the furnace.

As the furnace rotates the refuse is displaced towards the opposite end of the furnace and is exposed to the flame of the burner 20. The ashes and incineration residues then fall into the ash receptacle at its front end, wherefrom they are conveyed towards the rear of the ash receptacle by means of the helical partition wall 17. The discharge from the ash receptacle is performed by reversing the direction of rotation of the furnace, thus causing the refuse and incineration residues to be returned to the front of the ash receptacle, at the level of the doors 18. These doors are then opened and the ashes are discharged from the doors 18 onto any suitable conveying means which take them to a storage or treatment area.

The air necessary for the combustion is blown by the blower 61 into the annular sheath 55 and then passes through the inner and outer walls of the furnace and is blown into the furnace through the orifices of the inner wall.

The fumes and combustion gases are sucked axially in the furnace in the direction opposite to the translation of the refuse and leave the furnace through its larger base. Therefrom they pass into the pot 2 and reach the after-burning sheaths 4 where they are exposed to the flame of the burner 62 arranged at the inlet of the sheaths. The operation of this burner may be controlled by the temperature of the gases and fumes passing through the after-burning sheaths. A grating 63 of stainless steel is also arranged at the inlet of the after-burning sheaths for retaining the residues which may happen to be entrained by the sucking of the gases, such as pieces of paper or the like. These residues then burn rapidly at this point and the ashes fall onto the refuse entering the furnace.

At the outlet of the after-burning sheaths 4 the fumes and combustion gases pass through a fog of cold water produced by a spraying distributor 64 supplied from a clean cold water reservoir 23 by means of a pump 65. Thereater, the fumes enter the volute member 13 of a cyclone which comprises a distributor 66 producing a stream of water on the internal face of the walls of the volute member. The denser particles contained in the fumes and adhering to the outer wall of the cyclone volute member as a result of centrifugation are driven into the constant-level tank 12 by the water stream and settle at the bottom of the tank. The fumes and combustion gases may or may not bubble in the water in the tank, depending upon the position in height of the overflow pipe 67, and then penetrate into the sucking port of the turbine 9 before being discharged clean to the atmosphere at the outlet of the flue 11. The gases rotating in the flue 11 acquire a rising divergent helical motion which favours their dispersion and accelerates their cooling and dilution in the atmosphere. Thus, the turbine 9, by producing a vacuum in the fume cleaning assembly, the after-burning sheath, the pot 2 and furnace 1, drives the fumes and combustion gases from the moment they are formed in the furnace until they are discharged to the atmosphere.

The distributor 66 producing the water streams is supplied, on the one hand, by means of a pump 69 and a make-up reservoir 68 and, on the other hand, by a recirculation of the water contained in the tank 12.

The power necessary for the operation of the plant as a whole is provided by a Diesel engine 22 mounted above the water reservoir 23 supplying the spraying distributor 64. The Diesel engine 22 drives at a constant output speed a hydraulic pump 70 which itself drives the water pumps 65 and 69. The hydraulic pump 70 with its complete equipment supplies the hydraulic motor 10 driving the turbine 9, the hydraulic motor-reducer set 7 driving the endless screw 6, the hydraulic motor driving the blower 61 and the hydraulic motor-reducer set driving the furnace. In order to facilitate the maintenance of the unit, the latter is formed of two readily separable parts, i.e. the automotive vehicle frame carrying the furnace, the water reservoirs, the Diesel engine, the hydraulic set, the blower, the burner control members and the water pumps, and a rear part which comprises the pot, the endless-screw charging device, the fume cleaning set and the after-burning sheaths. This rear part is mounted on the frame by means of a system of disconnectable hinges 71 and a device 72 for locking its framework on a beam 73 secured to the unit frame. The front end of the after-burning sheaths 4 is locked on the superstructure of the unit frame by means which are not shown. The separation of the rear part is performed by keeping the same on rack props 74 provided under the rear part, after disconnecting the various connecting hoses.

Of course, the invention is by no means limited to the form of embodiment described and illustrated, which has been given by way of example only. In particular, it comprises all the means constituting technical equivalents to the means described as well as their combinations, should the latter be carried out according to the spirit of the invention and used within the scope of the following claims.

Claims

What is claimed is:

1. An automotive unit for the collection and incineration of refuse, for instance household or industrial refuse, comprising a substantially fluid-tight incineration assembly in turn comprising a double walled rotary furnace substantially in the shape of a truncated cone and having one end forming a refuse charging hole and an other end forming an ash and incineration residue discharge hole, burners arranged in the furnace for the incineration of the refuse, an outer casing extending in coaxial relationship to the said furnace and turning jointly with the latter, said outer casing being closed at both its ends and extending beyond the furnace refuse charging hole so as to form an ash storage receptacle, means for charging refuse into the furnace and comprising a substantially fluid-tight device including an endless screw, a charging conduit substantially in the shape of a truncated cone between said endless screw and the charging end of the furnace for leading refuse advanced by said screw into the charging end of the furnace, a fume discharge sheath connected in a substantially fluid-tight manner to one end of the furnace, and means in operative communication with said sheath for the after-burning and cleaning of the fumes and combustion gases.

2. A unit according to claim 1, wherein the charging end of the furnace is closed by a pot connected with said charging conduit and said fume discharge sheath.

3. A unit according to claim 1, wherein a helical blade or screw is provided on the internal face of the said casing over at least a portion of its length, between the latter and the outer wall of the furnace, for driving and guiding the ashes and incineration residues from the point of discharge into said ash receptacle to the opposite end of the ash receptacle under rotative action of the furnace and the casing.

4. A unit according to claim 3, wherein said casing includes at least one door for discharging the ashes and residues outside the ash receptacle.

5. A unit according to claim 1, wherein the said rotary furnace is of thin sheet-metal, its inner wall being provided with pulsed-air blowing perforations for tridirectional blowing.

6. A unit according to claim 5, wherein the inner wall of the furnace comprises alternating substantially plane plates and omega-section plates whose concavity faces the outside of the furnace, the said plane plates being mounted in alternating and free axial and tangential sliding mutual relationship so as to allow expansion of the said inner wall of the furnace.

7. A unit according to claim 5, wherein the air blown through the orifices of the inner wall of the furnace is conveyed by a stationary angular sheath with a rotary joint, which is arranged between two annular cheeks secured to the rotary furnace and which is connected to a blown-air intake nozzle.

8. A unit according to claim 7, wherein said annular sheath is formed of a sheetsteel band wound on and between sliding and guiding binders secured to the said cheeks and being of a material having a low coefficient of friction, a tightening device being provided and including an adjustable tension spring for tightening said band on said binders.

9. A unit according to claim 1, wherein the said fume afterburning means comprise a burner placed at the outlet of the said volute member and the flame of which covers substantially the whole cross-section of the said sheath.

10. A unit according to claim 1 wherein the fume and combustion gas cleaning means comprise a cyclone whose sucking turbine is mounted in a flue for discharge to atmosphere, the lower portion of which penetrates in an adjustable waterlevel tank, a fume admission volute member surrounding the said flue and opening into said tank in predetermined relation to said water level, and a cold water spraying distributor mounted at the inlet of said volute member and a distributor producing water streaming on the wall of said volute member.

11. A unit according to claim 2, wherein the said pot comprises an inspection hole which can be closed by a shutter whose opening is adjustable in accordance with the temperature of the fumes.

12. A unit according to claim 2, wherein the said furnace is equipped with two burners, at least one of which is controlled by the temperature of the said furnace.

13. A unit according to claim 1, comprising a Diesel engine rotating at a constant speed to drive the hydraulic pump for the supply of hydraulic motors for operating the entire incineration plant.

14. A unit according to claim 1, having a rear portion including said device for charging refuse into the furnace and said means for the after-burning and cleaning of the fumes, said rear portion being movably mounted on the frame of the unit by means of disconnectable hinges and locking devices and including rack props enabling it to be supported when being dismounted.