Abstract: The invention relates to a method for drying pasty materials, in particular sludge from wastewater treatment plants, including a first indirect drying stage (1) supplied with a heat-transfer fluid, which outputs (1a, 1b) pre-dried sludge and water vapour; a step (6) of forming sludge at the outlet of the first stage, and a second stage of drying (7) pre-dried sludge that is heated by means of a heating gas, in particular air, said second stage producing (7b) dried sludge; at least one portion of the dried sludge produced by the second stage is incinerated (23) to produce thermal energy, and at least one portion of said thermal energy is used to heat the heat-transfer fluid of the first drying stage.

Abstract: An apparatus for combustion of biomass is provided. The apparatus generally includes opposingly paired sidewalls, a fixed panel traversing the opposingly paired sidewalls, an actuatable panel opposite the fixed panel, and a fuel platform supported by a panel of either of the panels. A portion of the fuel platform is reversibly receivable through a portion of a panel opposite the panel supporting the fuel platform in furtherance of fuel conditioning upon actuation of the actuatable panel.

Abstract: A feed mechanism in which a ram (2) fed from a hopper (1) compresses a fuel against a closed valve (11) which is then opened for the ram to push the fuel towards a rotary scroll (6) for delivery to a processing vessel.

Abstract: A process is described for obtaining energy from waste, comprising the following phases: a) bio-drying of municipal solid waste (MSW) to transform it into refuse-derived fuel (RDF), a dry, homogeneous material with piece size of around 20-30 cm, known by the name of RDF; h) compacting of the material obtained from phase a) into bales or BIOCUBr and storage of the BIOCUBI® in bioreactors; c) activation by wetting with water of the bioreactors to produce biogas by anaerobic digestion; d) combustion at the start of the material obtained from phase a) (RDF) and subsequently of the residue already digested in the bioreactors, and therefore not biodegradable, in a waste combustor provided with a system of purification of combustion gasses and production of superheated steam at approximately 400° C. and pressure of around 70 bar; e) combustion of the purified biogas in a conventional boiler provided with re-superheaters for raising the temperature of the steam produced by the waste combustor by approximately 100° C.

Abstract: An apparatus for conveying solid waste to a furnace includes an opening to an elongated channel into which waste material is received and an outlet open to the furnace. A reciprocating ram with a head plate located in the channel opposite the outlet forces the waste toward the outlet. The ram also has an upper shield dimensioned to be slightly greater in area than the opening such that the opening is blocked when the ram is extended. The channel also includes an actuator-impelled restrictor plate for compressing waste as it is forced through said channel into a narrower portion, and a isolation door operable to close off the channel.

Abstract: Disclosed herein is an apparatus for producing a refuse-derived solid fuel using combustible waste. The apparatus of the present invention includes a forming body (10) which has a hopper (10a) through which combustible waste is supplied into the forming body (10), with a drive unit (11) mounted to the forming body (10). The apparatus further includes a force-feed pipe (30) which is mounted to the forming body (10). Thermal oil flows through a space defined between layers constituting the force-feed pipe (30). A force-feed screw (50) is provided in the force-feed pipe (30). The apparatus further includes a siphon (70) which is provided in a space defined in the force-feed screw, so that thermal oil flows through the siphon (70), thus drying the combustible waste. The apparatus further includes a plurality of rod type heaters (90) which are disposed at the first end of the force-feed pipe (30), thus heating an outer surface of the compressed waste.

Abstract: Method of treatment of domestic waste. A reaction space is provided, into which the waste to be treated is fed at a controlled rate. The waste is concurrently compacted to form a stopper preventing leakage of gases from the reaction space. An oxygen-containing gas is fed to the reaction space, in order to affect the combustion of the waste and produce gases and solid material. The gas is filtered through the solid material, causing the gases to react with the solid material, whereby to produce fuel gases and ash.

Abstract: This invention relates to a method and device for converting energy by combustion of solid fuel, especially incineration of bio-organic fuels and municipal solid waste to produce heat energy and which operates with very low levels of NOx, CO and fly ash, in which that the oxygen flow in the first and second combustion chambers in at least one separate zone and by sealing off the entire combustion chambers in order to eliminate penetration of false air into the chambers, the temperatures in the first and second combustion chamber are strictly controlled, in addition to the regulation of the oxygen flow, by admixing a regulated amount of recycled flue gas with the fresh air which is being led into each of the chambers in each of the at least one separate zones, and both the recycled flue gas and fresh combustion gases are filtered in unburned solid waste in the first combustion chamber by sending the unburned solid waste and the gases in a counter-flow before entering the gases into the second combustion chambe

Abstract: The present invention is a rubber tire recycling process that does not require the inefficient procedure of cutting and shredding the rubber tires. The entire rubber tire enters the recycling process without ever being cut thereby maintains the integrity of the steel wires within the steel belted rubber tires. The present invention allows virtually every component of the rubber tire to be recycled and results in high quality recycled end products that include, among others, full strands of steel wires and high grade rubber.

Abstract: The system for producing combustion ash of cellulose-containing wastes, provided with a kneading device 3 for kneading cellulose-containing wastes with a prescribed amount of liquid fuel oil, a molding device 5 for molding said kneaded mixture, and a combustion furnace 7 for burning said moldings, is characterized in that the humidity conditioning furnace 6 for adjusting the water content of said moldings is arranged between said molding device and said combustion furnace. Since the water content of said moldings is adjusted by the humidity conditioning furnace at the time of burning said moldings, the organic substances (cellulose or the like) are burned almost perfectly. Consequently, the present invention has the advantage of being able to produce combustion ash of good quality without generating such combustion residue as graphite and black smoke.

Abstract: An incineration process and an incinerator using heat generated from combustion to bake and sublimate waste to produce gas as for burning waste is designed to use heat generated from the gas as burning chamber in the baking process and to allow waste to emit inflammable gas to be used as fuel in the gas burning chamber without using any other kind of fuel. The baked waste will be burned until it becomes charcoal in the burning chamber while its ash will be continuously removed and more waste continuously fed into the burning chamber. With this process, high temperature, low pollution, and budget savings will result.

Abstract: A method of waste water treatment including mixing waste material with a binder, pelletizing the mixture and kiln incineration of the pellets to ceramify same, with processing of flue gases. In an embodiment, the pH of the mixture is maintained alkaline. In an embodiment, the pelletized mixture is coated with ball clay to 10-20% by weight, and then with china clay, prior to firing. The high temperature flue gases and entrained heavy metal or dust exhausting the kiln are directed through a multistage scrubbing system. In an embodiment, volatiles are adsorbed prior to the gas passing through an alkali wet scrubber to remove chlorine compounds and heavy metals, and sulphur compounds. The sludge from the acid scrubber is neutralized and further treated to remove mercury.

Abstract: A waste treatment system for solidifying and increasing the speed at which manure would dry. The waste treatment system includes support members; and also includes an elongate tubular member being mounted upon the support members and having an inlet end and an outlet end and having a bore being disposed therethrough; and further includes a waste holding/compressing assembly being mounted to the elongate tubular member; and also includes an incineration/discharge assembly being disposed in and about the elongate tubular member for incinerating waste material.

Abstract: A method and apparatus for crushing waste gas cans between a pair of rotating rollers installed in a treatment chamber and removing the residual gas and residual liquid from the waste gas cans. The atmosphere in each of a waste gas can loading chamber, which is adjacent to the treatment chamber, the treatment chamber and a discharge chamber is replaced with an inert gas, thereby maintaining the oxygen concentration in the treatment chamber within a low range in which the residual gas will not burn explosively. Crushing of the waste gas cans is carried out while the oxygen concentration in the treatment chamber is within the low range. The pair of rotating rollers have two rotating shafts disposed approximately parallel to each other and sprocket wheels disposed on each rotating shaft at regular spacings.

Abstract: A compression device for feeding a waste material to a reactor includes a waste material feed assembly having a hopper, a supply tube and a compression tube. Each of the supply and compression tubes includes feed-inlet and feed-outlet ends. A feed-discharge valve assembly is located between the feed-outlet end of the compression tube and the reactor. A feed auger-screw extends axially in the supply tube between the feed-inlet and feed-outlet ends thereof. A compression auger-screw extends axially in the compression tube between the feed-inlet and feed-outlet ends thereof. The compression tube is sloped downwardly towards the reactor to drain fluid from the waste material to the reactor and is oriented at generally right angle to the supply tube such that the feed-outlet end of the supply tube is adjacent to the feed-inlet end of the compression tube.

Abstract: The invention relates to a device, and a process for its charging, for carrying out high-temperature recycling for heterogeneously occurring waste in compact packages. The compact packages are introduced into a heated channel for evaporation of liquids and slightly fluid materials as well as to partly decompose them. The invention is characterized by a temperature insulating mouthpiece interconnecting the reactor and the channel for limiting the conduction of heat from the reactor to the channel. Accordingly, packages may be serially forced through the channel and into the reactor while maintaining the packages in sealing engagement with the channel to prevent reduction in the predetermined cross section in response to high temperatures transmitted from the reactor.

Abstract: A waste tire incinerating and post-treatment system in which waste tires are continuously and efficiently burned. The system includes a waste tire reservoir tank, a hoist, a conveyor system, a tire-size sensing system, an incinerating part, a waste oil purifying part, a waste gas purifying part, and an incineration residual material treating part. Waste tires are accumulated in a waste tire reservoir tank before their incineration. A hoist transfers the waste tires from the waste tank reservoir to a conveyor system. The conveyor system conveys waste tires to an incinerating part. A sensing system senses the size of individual tires on the conveyor system to create tire size data. This size data is used to control and optimize the rate of feeding the waste tires into the incinerating furnace. The incinerating part further includes a material removal mechanism for removing incineration residual materials.

Abstract: Municipal or other solid waste is delivered in loose form to a processing facility where it is compacted into a supply chute adjacent the upper portion of a reactor. The compaction serves to remove most of the air and some of the water from the waste as well as to seal the reactor against air infiltration. The supply chute is equipped with a number of pusher units which are capable of pushing a portion of the compacted waste in the form of a block into the reactor. The blocks of compacted waste are deposited in the top of the reactor in response to a signal related to the height of waste in the reactor. A pivotally and extendible mounted plasma arc torch is employed as a heat source to pyrolyze organic waste components to generate desired by-product gases. Air and steam are added in controlled quantities to improve the operational efficiency and the by-product gas composition. Residual materials which do not pyrolyze are melted and cooled into a substantially inert vitrified mass.

Abstract: A system is disclosed in which municipal mixed solid waste is delivered to a processing facility where it is compacted before being placed into a reactor. The compaction apparatus serves to remove most of the air and some of the water from the waste as well as to seal the reactor against air infiltration. A transfer apparatus, in response to a signal relating to the height of waste in the reactor, sequentially deposits blocks of compacted waste in the top of the reactor when the height is low. The reactor has a pivotally and extensively mounted plasma arc torch as a heat source which is effective to pyrolyze organic waste components to generate desired by-product gases. Air and steam are added in controlled quantities to improve the operational efficiency and the by-product gas composition. The residual materials which do not pyrolyze are melted and cooled into a substantially inert vitrified mass.

Abstract: An incinerator for carrying out incineration of general or specific waste dry distillation, which can improve wastes incineration efficiency and prevent secondary pollution, such as a gas smell, by performing complete combustion by facilitating feeding of waste and discharging of ash under a condition that the furnace maintained sealed like for a conventional dry distillation incineration furnace. The incinerator is provided to feed waste introduced into a waste placing tube to a dry distillation incineration furnace by repeatedly pressing the waste, to discharge ash heaped on the bottom of the dry distillation incineration furnace by dropping into an ash placing tube with a discharge blade and pressing the dropped ash with a pressing plate, and to incinerate specific waste with high moist contents and waste wire using an indirect dry distillation tank accommodated in a combustion tank.

Abstract: A method and apparatus for continuously feeding hazardous waste fuels having a relatively high solids content to a rotary cement kiln by delivering the fuel to a feed hopper with screw-conveyor which transfers the fuel to a filling zone where a piston pump capable of pumping a composition having a solids content of at least 40% with particle sizes up to a maidmum of 2 inches continuously charges the fuel through a conveyance tube into a feed tube which introduces the fuel into the kiln through the feed end housing.

Abstract: A method for treating waste involves (a) compressing the waste at a pressure of over 800 bars under conditions resulting in separation of the wet fermentable fraction and the solid combustible fraction; (b) exploiting each of these two fractions separately by means of, for the fermentable fraction, specific treatment to take advantage of its biomass nature and, for the combustible fraction, burning to produce energy. The method allows the waste to be exploited with high profitability. The invention also describes an improved press for compression in two successive phases: a precompression phase up to an intermediate pressure (200 to 300 bars) and final compression up to a final pressure of over 800 bars.

Abstract: An apparatus and method is provided for disposing of infectious waste. A decontamination chamber decontaminates the waste by dry heat sterilization, and a compactor reduces the volume of the waste subsequent to decontamination in the decontamination chamber. A robot assembly is mounted between the decontamination chamber and the compactor for automatically retrieving the waste from the decontamination chamber upon being decontaminated, and for transporting the waste to the compactor for volume reduction prior to disposal.

Abstract: Waste is treated in a furnace (6) which is pressurized by injecting thereinto either air which is strongly enriched with oxygen (even up to 100%), so that the temperature of oxidation of said waste, after a starting step wherein external fuel and said combustion supported are used, reaches so high values as to cause a substantial sublimation of said waste and its complete molecular cracking. The vapors resulting from the hyperbaric sublimation process are then submitted to a rapid adiabatic expansion or semi-adiabatic expansion in a suitable volume (23) to cause a first strong cooling of said gases, down to values which may be then abated by usual heat-dissipating systems (25-26).

Abstract: Methods and suitable devices for the intermediate storage, transport and preparation as well as utilization of waste goods of all kinds are described, said waste goods being compacted down to a plurality of its original volume while maintaining their mixed and composite structure, are stored in intermediate storage and are transported in this form, if required, and are so compacted subjected to a pyrolysis. The totality of the pyrolysis products being under elevated pressure is subsequently subjected immediately to a high-temperature treatment. The compacted waste goods may be crammed into containers and are subjected to a low-temperature pressure pyrolysis. In case of ecological preparation of consumption goods such as motor vehicle wrecks or the like, a large-volume apportioning of the scrap goods is carried out by subdividing and/or crushing prior to the intermittent feeding into the pyrolysis chamber.

Abstract: A process for rendering usable disposal products is described, in which unsorted pollutant-containing industrial, domestic and/or special refuse undergoes a high temperature treatment. Accompanied by the entraining of existing liquid fractions and while maintaining its mixed and combined structure, the disposal product is compressed batchwise to compact packs. While maintaining the pressure action it is subsequently positively introduced into a channel heated to over 100.degree. C. and is kept in sliding, non-positive contact with the channel walls until the initially present liquids are evaporated and mechanical restoring forces of individual disposal product components are eliminated. The entrained organic constituents at least partly assume a binder function. The shape and structurally stable, lumpy solid conglomerate forced out of the channel in this state is introduced into a high temperature reactor maintained at at least 1000.degree. C. and forms therein a gas-permeable bed.

Abstract: A method of treatment of waste material includes the steps of mixing the waste material with binder and pelletizing the mixture. The pellets are then coated with a non-agglomerating material selected to permit firing of the mixture without pellet agglomeration at a temperature above 1300.degree. C. The coated pellets are fed to a kiln and fired at a temperature above 1300.degree. C. before being discharged from the kiln. At least some of the heat of firing the pellets is recovered and recycled to the kiln.

Abstract: A sludge drying apparatus (10) including a housing through which air is recirculated wherein makeup air forms an air curtain assuring recirculation of heated air. The housing (12) includes a receiving station (14) in which sludge (20) is deposited on a conveyor belt (18). The conveyor belt (18) moves the sludge (20) to a drying station (16) where infrared heaters (42) radiate infrared heat on the sludge. Air for drying the sludge circulates from a fan plenum (28) to an air supply plenum (24). Air from the air supply plenum (24) passes across the face of the infrared heaters (42), and is directed downwardly toward the sludge (20) in a belt passageway (30). Air is returned through a return air plenum (26) located below the belt passageway (30). Part of the air received by the return air plenum (26) is ported directly from the belt passageway (30) to the return air plenum (26).

Abstract: In construction of an apparatus for innoxious disposal of medical wastes, the medical wastes containing meltable components such as plastic resins, and unmeltable components such as syringe needles and residues are thrown into a compression hopper and compressed under application of heat by piston operation into a compact cake. Sharp unmeltable components such as syringe needles are totally embraced by the meltable components such that they are not exposed outside the obtained cake, thereby removing the danger in subsequent handling of the cake. Pathogenic germs in the residues are killed during application of heat and the residues are fully evaporated due to heating in an evaporation dish arranged below the compression hopper.

Abstract: A method and apparatus for treating soil contaminated with hydrocarbons by breaking up the soil into discrete particles and passing the particles through an open flame to cause the volatile substances in them to vaporize and burn. The apparatus is preferably portable and provides for continuous processing of the contaminated soil on-site so that it can be immediately returned to the ground free from contamination.

Abstract: A ram feed waste incinerator apparatus includes a vertical waste storage cylinder positioned above a combustion chamber and contains a movable ram to force the waste to be incinerated downwardly against a transversely extending, rotatably driven bar at the top of the combustion chamber. Combustion temperature control is provided by feeding air into the combustion chamber and by rotating the bar to abrade char from the waste supported by the bar. A bed of ash is maintained within optimum levels for thermal protection of bottom of the combustion chamber.

Abstract: The described refuse-treating unit (1) comprises a treatment chamber (2) adapted to hold a predetermined amount of refuse (6), a sterilization apparatus acting on the treatment chamber and adapted to administer heat to the refuse amount (6) until said amount is at least partly converted to a sterilized mass in a pasty state, and a compacting device (7, 8, 9) adapted to press the refuse amount (6) at least partly in a pasty state together, and convert it to a compact block (10).

Abstract: A melting disposal method of sludge. The method of the invention having the steps of collecting a plurality of cakes of dehydrated sludge generated at a plurality of sewage disposal plants at one melting disposal plant; incinerating or drying a substantially fixed amount or proportion of the dehydrated sludge cakes; mixing the resultant substance; and heat-melting the resultant mixture with addition of basicity conditioning agent.

Abstract: A garbage burning and melting apparatus is provided and consists of a modified blast furnace to burn coal and garbage therein so that molten slag and lava by products can be extracted therefrom into a conveyor while the exhaust can be filtered to remove powdered ash therefrom.

Abstract: A method for incinerating contaminated soil or other material utilizing an incinerator, such as a CBC, which is operated below atmospheric pressure and apparatus for carrying out such decontamination by delivering the soil to be processed in desired particulate size to the incineration unit, e.g., to a recirculation loop through which separated solids are being returned from a cyclone to a CBC. The system for supplying the contaminated soil is isolated from the chute leading to the incineration unit by a feeder that forms an agglomerated plug which serves as a pressure seal and prevents any gas flow therepast. Illustrated are a pair of twin counterrotating screws which include shafts that extend past the ends of the screw flights to locations where rotary cutters having multiple blades are mounted.

Abstract: A method and apparatus for extracting heat from a combustible material are disclosed which include the formation of a solid material strip of the combustible material, the formation of a series of spaced holes in the material strip, and the combustion of the material strip. The method and apparatus are particularly useful when a mixture of coal, clay, and lime is used as the combustible material, and the products of the combustion then include a structurally intact, solid residual strip composed substantially only of dehydrated clay and calcium sulfate, and a fluegas substantially free of carbon monoxide, nitrogen oxides, sulfur oxides, and micro fly-ash. Because of the stable and uniform combustion characteristic, it is also suitable for the co-combustion and reduction of most toxic and solid wastes into safe, recyclable residues.

Abstract: Initially moist metal hydroxide sludge is formed into a suitable mass, such as sludge cakes (2) which are fed downwardly in a hopper (1) and pressed into the cells (7) of a multi-cellular moving metal belt (5) in a two-stage process. The first stage deposits the sludge roughly into the cells, while the second stage compresses and compacts the deposited sludge tightly into the cells so that the sludge is in intimate contact with the cell walls throughout each cell. The sludge-filled belt is passed through a dryer (3) whereby the belt is subject to indirect, rather than direct, heating. More particularly, the belt passes through an enclosed muffle (21) and is caused to be in direct heat-exchanging contact with the bottom muffle wall (23). The latter wall is heated from beneath and outside the muffle chamber, as by heated air jets.

Abstract: A method and apparatus for treating sludge from a paint spray booth operation. The sludge from the spray booth is deposited onto a porous belt of a conveyor system to allow the water to pass through the belt where it is collected for discharge from the apparatus. The remaining residue is passed over a vacuum device positioned beneath the belt and is then carried by the belt through an oven comprising a series of infrared thermal reactors arranged in serial fashion over the belt. The sludge is passed continuously beneath the infrared reactors and is dried thereby so that the sludge leaving the apparatus is in a dried particulate form which may be readily disposed of and/or solid. Convection air is recirculated through the apparatus to preheat the incoming sludge, remove smoke and other contaminants from the oven, and provide the desired pressure condition within the oven to optimize the efficiency of the thermal reactors.

Abstract: Apparatus for the treatment of domestic refuse to convert it into a solid odorless and non putrefiable residue of reduced weight and volume, comprises a sealable casing housing a process cylinder provided with means for compacting refuse introduced therein, and heater means for raising the temperature within the process cylinder to a level such as to vaporize any liquids contained in the refuse, the casing also housing extractor means for removing vapors, gases and fumes generated upon incineration of the refuse, and being provided with an upper door for the introduction of domestic refuse, and a lower door for the withdrawal of residues obtained after treatment.

Abstract: A waste product feeder in which when waste products are charged through a hopper into a trough are transported by a screw and then discharged, they are successively scraped by a scraper in a predetermined quantity or volume.

Abstract: A rubbish treating apparatus in which the rubbish is gathered, separated, and crushed, after that the crushed rubbish is transferred to a magnetic conveyor, such that ferro-metallic rubbish and non ferro-metallic rubbish are separated. The non ferro-metallic rubbish is then transferred to a pressing device in which the rubbish is pressed, and finally the rubbish is further crumbled and burned in a burner. The gas produced while burning is purified, therefore such procedure can be used to solve the problem of pollution due to rubbish.

Abstract: An automatic coal stoker is disclosed having at the base of its hopper an enclosed reciprocating pusher assembly rectangular box shaped which delivers compressingly a defined but variable quantity of coal into a restricted passageway. Successive quantities form a compressed strip of coal to be burned between side rails of an inclined fire grate situate over an air box fed with a forced air supply. As the strip works its way down the inclined grate it burns without forming clinkers and discharges ashes at the bottom of the incline.

Abstract: Slugs (4) of products dehydrated by compression are thrust into the tube (11) up to the hearth (15). The hot gases from the hearth passing round the tube (11) heat it up in order to release the gases and carbonize the solids which burn in the form of coke in the bottom (16) of the hearth. Household refuse may thus be eliminated not only without expense but with recovery of energy from it.

Abstract: A resource recovery utility is provided comprising a landfill having a continuous wall surrounding the perimeter thereof and a containment structure extending completely over the landfill affixed to the continuous wall. Refuse can be introduced into the landfill and compacted therein and at least a portion of the compacted refuse can be removed therefrom. Methane generated by anaerobic bacterial digestion of organic materials contained in the refuse can be removed and recovered.

Abstract: A combustion system to utilize particulate fuel where the fuel is compressed and extruded into a selected shape to be burned in a combustion chamber under conditions where particles of burning material are maintained in the combustion chamber until the weight of the particulate material decreases to the point where the particle is carried from the chamber through a heat exchanger by combustion gasses to a scrubber section for removal of impurities such as SO.sub.2 and NO.sub.x.

Abstract: Refuse derived fuel is produced by taking raw refuse, pulverizing it and n screening it to remove fines and oversize material, the screened residue being passed to an air classifier where the light fraction, rich in paper and plastics, is separated. This light combustible refuse fraction is then passed to a densifying machine, either directly or via a secondary shredder, to produce partially compacted material which is then dried in a rotary dryer. The dried material can be passed to a second densifying machine which produces pellets in the form of small dense cylinders or blocks having a calorific value equal to about half that of coal. Coal dust or other combustible particulate material can be added to and mixed with the combustible fraction between the two densifying machines.

Abstract: A furnace for burning a particulate fuel compacted into a plug which includes a force feed of particulate fuel through a compacting means and into a tubular furnace in which burning is expected within the compact fuel plug by injecting air through the furnace wall.

Abstract: A machine for charging a furnace with scrap to be incinerated comprising a hopper in which bulk scrap to be incinerated is fed and whose bottom opens into the interior of a rectilinear and horizontal tubular body connected at one extremity to the inlet of a furnace. Mounted at the other opposite extremity of the tubular body is a push member actuated by a first jack. The push member has a section corresponding to that of the interior passage in the tubular body. A first wall of the hopper is constituted by a trap door capable of being raised to uncover a crushing head articulated by a second jack of high power so that in lowered position it compresses the scrap against the bottom of the tubular body. A second wall of the hopper is disposed opposite the first wall and is pivotably connected to the base of the hopper for undergoing pivotal movement to a lowered position closing the top of the tubular body.