Abstract: A continuous evaporation process for drying water-wet waste solids and sludges, using a paraffin oil solvent, until the waste is dried to a near-zero wastewater product, without experiencing sticky solids. The invention involves (1) mixing the input solids or sludges with a paraffin oil solvent, (2) feeding the mixture into two or more stages of evaporation in parallel to evaporate some of the water present in the input solids or sludges and to extract some of the indigenous solvent-soluble compounds from the solids, (3) feeding the slurry from the parallel stages of evaporation to one or more final evaporation stages in series, and (4) feeding the slurry from the final stages of evaporation to a centrifuge or other device for separating most of the solvent from the solids.

Abstract: A sludge powder and sealant are prepared from paint sludge. A sludge powder is generated from a paint sludge having a volatiles content of 0-50% by weight by adding a processing filler thereto. A sealant composition is prepared by thereafter or concurrently therewith adding sealant ingredients including polymer, plasticizer, curative, and other sealant ingredients such as an adhesion promoter and sealant filler materials to the sludge powder. Alternatively, a sealant composition may be prepared by adding a paint sludge having a volatiles content of 0-50% by weight to the sealant ingredients, which may include a processing filler.

Abstract: In a treatment or processing or sewage sludge in the sense of recycling, where the sewage sludge is to begin with dried (T), subsequently converted (K) under anaerobic conditions at approximately 250.degree. to 350.degree. C. and finally is sintered at at least 1250.degree. C. in successive steps, it is proposed to perform all process steps including the conveyance of the commodity to be processed between the individual processing steps successively in continuous passage in a closed system. Only the vapors are removed in this system in the drying stage (T) and the conversion gases in the conversion stage (K) and they are condensed; the heat quantity contained in the flue gas generated during the sintering process (S) is utilized for heating to begin with the conversion stage (K) and after that the drying stage (T).

Abstract: The present invention provides improved systems for plastic recycling. In a first embodiment for recycling HDPE milk jugs, a cold water wash step is used to remove bacteria-generated odor from milk jugs. In a second embodiment, a system for recovering PET and HDPE from soda bottles is disclosed. The separation stage utilizes a three-compartment sump to separate HDPE using water as the medium, and two further stages using heavier media for separation of PVC cap liners and aluminum from the PET.

Abstract: A method and apparatus for the removal of water, liquids and liquors from sludges and slurries, the sludges and slurries mixed with an electrolyte to improve conductivity and introduced into a conveyor chamber where an electrical path is established to permit electrical energy to pass through the conveyor chamber and the sludge, slurry and electrolyte to free bound water and remove it from the sludge or slurry, and to heat the sludge or slurry to drive off remaining water by vaporization.

Abstract: An apparatus and method for the efficient removal of hazardous and nonhazardous volatile and semi-volatile organic materials from contaminated materials includes an evaporation/vacuum heating chamber that communicates with a microwave generator, a vacuum pressure system, a contaminated material in-feed system, and a residue removal system. The evaporation/vacuum heating chamber is fed with successive batches or a continuous supply of contaminated material and subjects the contaminated material to microwave energy and vacuum pressure to draw off volatile and semi-volatile material from the contaminated material as vapor and reduce the contaminated material to a dry residue. The vapors are drawn from the chamber by the vacuum pressure system and are condensed and collected. The dried material residue is removed from the chamber by the residue removal system and is also collected for later disposal or reuse.

Abstract: A combination of a dehydration process for dehydrating sewage sludge by mixing a quicklime-containing material with the sludge, a cement conversion process for introducing the solids produced by the dehydration process into a cement kiln with other cement raw materials to yield cement, and a gas treatment process for introducing gases generated in the dehydration process into a cement burning process, thereby enabling conversion of the sewage sludge into cement without releasing wastes, with a reduction in fuel consumption for the cement burning, and a reduction in NOx content of the exhaust gas.

Abstract: Dewatered municipal sludge is dried and simultaneously pelletized in an indirect dryer. A sweep air is introduced into the dryer to extract a water vapor and air mixture. The water vapor and air mixture is condensed and cleaned in a condensor and a scrubber to obtain a clean non-condensable gas. The non-condensable gas is heated and recycled to the dryer after heating for use as the sweep air. Since air leakage into the system is inevitable, an excess amount of air accumulates that does not need to be recycled to the dryer. The excess amount of air is diverted from the recycled sweep air and thermally treated to destroy any malodorous gaseous constituents contained therein. Preferably, the indirect dryer is a horizontal drum dryer that is heated by the hot flue gases from a combustion furnace.

Abstract: A process is provided for preparing preferred iron humate products. The preferred iron humate products provide iron and other nutrients and organic matter for vegetation. The preferred iron humate products are produced by using an iron salt coagulant that is relatively free of heavy metal contaminants and reacting the iron salt coagulant with naturally occurring humic substances such as those found in natural surface waters used in drinking water treatment facilities. According to the invention, iron is stoichiometrically reacted at a controlled pH with the humic and fulvic acid fractions in the water to precipitate an iron humate product precipitate. A preferred concentration of iron salt coagulants is used in order to minimize the formation of iron hydroxides which generally provide low iron availability to the plant. A more readily soluble iron humate complex is produced by the reacting and or blending of the iron humate residue with various nitrogen containing sources.

Abstract: A batch type process for purification of a polymer resin, in which a predetermined volume of acid is rapidly emptied and stirred into a fixed volume of polymer slurry for chemically treating impurities in the slurry, is converted to a continuous operation by supplying a substantially constant stream of polymer slurry and a controlled stream of acid to a mixing vessel. pH control of the polymer slurry required for effective purification of the polymer resin is achieved by manipulating the flow rate of the acid stream responsive to a feedforward control signal which operates in conjunction with a feedback signal. The feedforward signal is based on an upstream measurement of slurry flow rate to the mixing vessel and the feedback signal is based on a downstream pH measurement of slurry flowing from the mixing vessel.

Abstract: In a dewatering press having a number of rotors rotatable in a cylindrical press housing with an inlet channel defining an inlet for a humid mass into the housing, a mechanism for equalizing the amount of mass fed to the inlet channels. A screw feeder is associated with each inlet channel, and equalization is accomplished by providing opening communication between the screw feeders at their pressure ends, adjacent the inlet channels. A module having a conduit associated with each inlet channel, and a cross over tunnel at the portion of the module adjacent the press housing, is disposed between the feeder screw housing and the press housing.

Abstract: An apparatus for dewatering aqueous sludge is disclosed. A porous drum is partially immersed in a sludge pond. A porous belt is connected between the drum and a roller which moves the belt. As the belt moves, the sludge adheres to the belt. A vacuum is drawn on the interior of the drum, removing some of the water. Sludge which is conveyed on the belt is frozen as it approaches the roller. The frozen sludge is broken into smaller cakes as it leaves the roller. The frozen cakes are subsequently dethawed providing a solid residue which is disposed.

Abstract: A method of thermal disposal of sewage sludge. The sludge is dried and incinerated. The flue gases from the incineration are washed. The flue gas dust resulting from the incineration and the sludge resulting from washing of the flue gases are treated together with high temperature combustion which includes melting of solids.

Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge and low grade solid carbonaceous fuel and burning said slurry as fuel in a partial oxidation gas generator, furnace, or boiler. The aqueous slurry of sewage sludge is concentrated by removing water by means of a conventional belt filter press or presses. Prior to and/or immediately after said concentrating step particles of low grade solid carbonaceous fuel e.g. lignitic coal, peat, wood and cellulose-containing materials are mixed with the slurry of sewage sludge. The dewatered slurry of sewage sludge and low grade solid carbonaceous fuel is hydrothermally treated in three stages and excess water is separated by flash evaporization and/or centrifuging.

Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge and solid carbonaceous fuel e.g. coal, petroleum coke, rubber. The slurry is burned as a fuel in a partial oxidation gas generator, furnace, or boiler. In the process, an aqueous slurry of sewage sludge is concentrated by removing water by means of a conventional belt filter press or presses. The dewatered slurry of sewage sludge is hydrothermally treated and cooled and depressurized. The viscosity of the slurry of sewage sludge is reduced to less than about 2000 centipoise by shearing. The sheared sewage sludge is then ground together with a solid carbonaceous fuel to produce a pumpable slurry which is burned with a free-oxygen containing gas in a partial oxidation gasifier, furnace, boiler, or incinerator to produce a hot raw effluent gas stream. In a preferred embodiment, the effluent gas stream is cleaned and purified and non-contaminating ash and slag are separated.

Abstract: A process for treating sanitary sewage sludge to achieve increased solids, decreased viscosity, and a reduction of pathogens. The aqueous slurry of sewage sludge having a solids content in the range of about 3 to 35 wt. % is simultaneously conveyed and preheated, mascerated, heated in an heat exchanger, hydrothermally treated in a closed vessel under a blanket of nitrogen at about 500.degree. F. and a pressure of about 750 psig and above the vapor pressure of water at that temperature, dewatered and cooled in a first multi-step flash evaporation zone where the pressure is dropped in three steps from about 750 psig to about 50 psig and then in a second flash evaporation zone the pressure is dropped to about 25 psig, cooling and condensing the vapor from said first and second flash evaporation zones, and removing a dewatered pumpable slurry of sewage sludge product having a solids content in the range of about 5 to 50 wt. % and a reduced amount of pathogens.

Abstract: A method to improve dewatering of filter cakes in a filtration process. The method involves introducing a surfactant as a vapor or mist into a flow of steam and treating the filter cake with this gaseous mixture.

Abstract: A device for the removal of solids from slurries by continuous compaction in a screen chamber. Pressure of liquid in the chamber causes continuous extrusion of a dewatered solid from an open ended chamber. The walls of the chamber may be constructed from longitudinal wedge bars spaced apart to provide filtering spaces between them. A high pressure pumping arrangement, including a first slurry pump and an auxiliary piston pump, is provided to maintain a high-pressure throughout the chamber to facilitate the continuous extrusion.

Abstract: The invention relates to a method for dewatering particle collections with the aid of a filter press in a cyclic sequence comprising filling, dewatering and emptying stages. The various stages within each cycle and between consecutive cycles are followed-up and determined by measuring continuously a magnitude which varies with the mass of the press and its contents, preferably the pressure exerted by the press and its contents on the surface supporting the press.

Abstract: Procedure for dewatering sewage sludge comprising the steps of subjecting pumpable sludge to chemical pretreatment with addition of a flocculation agent, pre-dewatering the chemically pretreated sludge by gravity filtration and conveying the pre-dewatered sludge by gravity, dewatering the pre-dewatered sludge by pressure filtration to form a sludge cake, crumbling the sludge cake to obtain sludge cake pieces, and drying the sludge cake pieces. After the dewatering step, so hard sludge cake is formed that after crumbling the sludge cake pieces are obtained which maintain their shape in accumulated consistency. A plant for the execution of the procedure is disclosed.

Abstract: A method for making a filler from automotive paint sludge is provided. Paint sludge containing water, solvent and uncured polymer resin is treated by removing a first portion of the water by mechanically drying the sludge to produce a concentrated sludge, and a second portion of the water is removed by treating the sludge with a chemical drying agent to produce a dried powder. Alternatively, the second portion of the water may be removed by agitating the concentrated sludge under a vacuum to produce a dehydrated putty. The resulting dried powder or putty can then be used as a filler in sealants and other products.

Abstract: A dewatering system for use in the treatment of waste water is disclosed which includes a tank, an inclined filter bed having a plurality of filter elements and components for inducing a flow of air through the filter bed to accelerate drying of the removed solids. Also disclosed are components for adjusting the angle of inclination of the filter bed and mechanical components for removing solids from the filter elements. In one embodiment, the filter bed is disposed within an upper unit mounted for rotation on the tank floor to facilitate cleaning of the filters. Adjusting the angle of inclination of the filter bed provides access from the frame, below, for cleaning the underside of the filter.

Abstract: A device for treating human and animal dejecta with microwaves includes a duct for conveying dejecta material, a microwave applicator surrounding the duct in an irradiation zone, and a microwave generator coupled to the microwave applicator. A driven transporter screw, provided in the duct upstream of the microwave applicator, moves the dejecta material through the duct. An inlet, coupled to an upstream zone of the duct, feeds dejecta material to be treated into the duct adjacent the screw. A vapor extractor is coupled to duct immediately downstream of the irradiation zone to receive treated dejecta material immediately on leaving the irradiation zone. A condensation vat is connected to the extractor and vented through a chimney having a filter.

Abstract: A sludge volume of difficult to dewater sludge is subdivided in a sludge dewatering press into fractional volumes which are self-draining even at press pressures of 50 bar and more. The partitions are water-permeable and form water channels for conducting the expressed liquid away from the sludge volume.

Abstract: The invention discloses an apparatus and process for destroying pathogens and dehydrating streams of waste in one, continous process. More particularly, the invention contains an auger with specially modified, variably angled blades which agitates a stream of waste. Also, contained in tandem with the auger, a series of variably angled infrared radiate elements are positioned above the augar exposing the moving stream of waste to radiation. Thus, as the waste stream is transported along, the auger blades continually expose the waste stream to the radiation, thereby killing the entrapped pathogens and evaporating the insitu water. Further, the auger and infrared radiation heater elements are encased in a sealed trough, thus sealing in the heat being generated by this process. By sealing the trough, the heat provides excess energy to aid in destroying pathogens and evaporating the insitu water contained in the waste stream, until the water content is less than or equal to five per cent (5%) by unit volume.

Abstract: The invention concerns a filtering procedure by which the solid matter and the fluid contained in a sludge are separated in a box filter. The sludge is passed in the filter into a filtering space (2) between two opposite filter cloths (3), where the fluid is separated, whereupon the cake (13) of solid matter produced is dried by passing a stream of air through it. The essential feature of the invention is that the drying is performed by passing a stream of air into the cake (13) first from one side and then from the opposite side of the filtering space (2) in such manner that the air flows in opposite directions through the cake during these drying phases. Penetrating through the filter cloth (3) into the cake, the air causes the cake to be detached from the cloth. When the filtering space is opened, the cake thus detached and dried can be removed directly without specific detaching efforts.

Abstract: Slimy liquids, such as slimy manure, are passed through a press screw separator to separate the solids. Vibrations are introduced into the slimy liquid for reducing its viscosity to enable the liquid to more readily gravitate through a screen basket of the separator.

Abstract: In the process for the purification of diemthyl terephthalate (DMT) by recrystallization from methanolic solution, the mother liquor containing the impurities, substantially the isomers DMI, DMO and aldehydes, is separated off and passed to a workup tank. The moist crystals are dried by melting with the evaporation of methanol. The mother liquor is then separated off by filtration, and the moist crystals obtained from the separation are washed before melting. The washing liquid is recycled together with a portion of the separated mother liquor into the recrystallization tank.

Abstract: A simple, low cost continuous process for separating and purifying zirconium and hafnium which eliminates liquid waste and facilitates the management of RCRA and LLW wastes is provided. An aqueous zirconium and hafnium--containing feed solution is prepared and fed to a continuously rotating annular chromatograph containing a bed of acid exchange resin. An acid eluant, such as hydrochloric acid, nitric acid, phosphoric acid or the like, is fed through the acid exchange bed while chromatograph is rotating, which separates the feed into substantially pure zirconium and hafnium fractions and into RCRA and LLW waste fractions. The zirconium and hafnium are processed further into nuclear quality zirconium and hafnium metals. The acid eluant is recycled for reuse in the chromatograph, and the RCRA and LLW waste fractions are disposed of in solid form.

Abstract: In homogeneous substitution washing method and apparatus for a cake using a filter press which comprises pairs of opposed squeezed and squeezing filtering plate units, pairs of opposed squeezed and squeezing filtering cloths, each pair of filtering cloths being arranged between the pair of filtering plate units, and diaphragms. Each diaphragm is arranged on one side of one of the pair of filtering plate units. Stock solution is supplied into a space between the pair of filtering cloths, and is pressurized and dehydrated by the diaphragm to form the cake. The cake is processed in washing to obtain a clean raw material. In parallel with the pressurizing and dehydrating step of the stock solution, a washing liquid is poured into a space between the diaphragm and the squeezing filtering cloth abutted against the diaphragm, at a pressure at least a pressurizing and dehydrating pressure applied to the stock solution through the diaphragm, to wash the cake between the pair of filtering cloths.

Abstract: In the process for beneficiating a crude kaolin by the method which includes a wet classification step to provide a classified kaolin fraction having a PSD such that at least 50% by weight thereof are of less than 1/2.mu.m ESD and substantially 100% by weight are of less than 10 .mu.m ESD; and one or more steps wherein an aqueous slurry of the classified kaolin is at least partially dewatered by filtration; the improvement which comprises effecting at least one of said one or more filtration steps, by flowing said aqueous kaolin slurry through a ceramic filter plate which is characterized by a porous support layer and an overlying porous filtration layer, the ratio between the respective mean pore sizes of the filtration layer material and the base layer material being between about 2 and 50; the pore size in said filtration layer being in the range of from about 1 to 3 .mu.m, and the pore size in the base layer being in the range of from about 4 to 50 .mu.

Abstract: A pressurized liquid filter in which a series of spaced apart, vertically extending filter plates are mounted between the sides of housing, inflatable hose seals extending across each top entrance and bottom exit. Filter media strips are draped vertically into the spaces, each disposed over a perforated sheet forming the outer layer of either side of each filter plate. The space between each pair of filter plates is subdivided into two filtering chambers by a dual element dewatering diaphragm mounted in a frame disposed centrally in each space. Liquid slurry is introduced into each chamber under pressure, flow induced to pass through the filter media strips and passing into vertical passages in the filter plates and into collection troughs extending along each row of passages.

Abstract: The present invention is concerned with a process for enhancing the dewaterability of a waste sludge having a substantial content of water-retaining cellular structure arising from microbiological action and having a solids content of at least fifteen percent by weight. The pH of the sludge is adjusted to 4.0 or less, the sludge is subjected to heat treatment to significantly enhance its filterability, the pH is again adjusted to near neutral, the sludge is subjected to a second heat treatment step, and the sludge is filtered to a final solids content in excess of about fifty-five percent by weight.

Abstract: Residues which are obtained from the distillation of chlorosilanes prepared by reaction of raw silicon with chlorine or hydrogen chloride are processed by treatment in aqueous phase with an excess of at least 15% of calcium carbonate, and the liquid components are recycled into the process so that no liquid waste is formed.

Abstract: A method and apparatus for disposing of fecal matter from a toilet system in a fast moving vehicle during travel of the vehicle. The liquid components of the fecal matter are dehydrated to recover water. The water is disposed of by either discharging the water to the environment of the vehicle or by re-using the water in systems of the vehicle. The remainder of the fecal matter is introduced into a collection vessel of in the vehicle.

Abstract: Municipal sludge is dried in an indirect heating dryer to simultaneously dry and pelletize the sludge while preventing the escape of malodorous gases. The product exiting the dryer contains pelletized, undersized and oversized fractions. The dried product is classified to separate the undersized and oversized fractions from the pellets. The pellets are then cooled and stored for subsequent use as a fertilizer or fuel. The oversized fraction is crushed to obtain fines and mixed with the undersized fraction, which contains mostly fines. The fines are added to the liquid sludge before it is input to the dryer. The air that is used to cool the pellets, and that is used as sweep air in the dryer contains malodorous gases. In order to prevent the escape of these malodorous gases, the pellet cooling air and sweep air, which also includes the water vapor generated during the drying of the sludge, is deodorized by thermal treatment, preferably in a high temperature combustion zone.

Abstract: A mixture of an oil sludge and an oil-contained waste water is first separated into a first oil-contained water and an oily dust containing metal-contained dust, fine metal powder and small fragments. Secondly, the oily dust is washed and separated into a harmless oil-free dust and a second oil-contained water containing the metal. Finally, both the first and second oil-contained water are separated into oil, harmless water and metal hydroxide by electrolysis. Thus, the mixture of the oil sludge and the oil-contained waste water is separated into components, which are in turn recovered, recycled, or converted into new materials, and the purification of the waste water can be realized.

Abstract: The method of the invention is advantageously applicable to realize a multistage chemical process during which liquid clarifiers suitable for the purification of water and sewage, furthermore, fine-disperse pulverulent solid products utilizable as pait pigments and fillers may be recovered. Each final product of the multistage chemical processes is a useful material, so the whole technology is waste free.

Abstract: The present invention relates to a procedure and a device for dewatering slurry and similar substances, in which the slurry is fed into a completely enclosed slurry chamber (2) by a pump (7), and a hydrostatic pressure of adjustable magnitude is produced. The slurry chamber (2) is subsequently isolated from the pump (7), the volume of the slurry chamber (2) is reduced and a mechanical dewatering pressure is generated.

Abstract: The present invention relates to a process to pretreat aqueous biological sludge in order to provide combustibles solids to an autogenous combustion system used to thermally oxidize the sludge.

Abstract: A receptacle for use in compacting liquid-laden asbestos-containing material to separate the liquids therefrom, the receptacle being adapted to be compacted within a compactor, wherein the receptacle is liquid permeable and capable of retaining a substantial portion of the asbestos-containing material when compacted within the compactor so that a quantity of the liquids are separated from the asbestos-containing material and expelled from the receptacle when the receptacle is compacted within the compactor. A method for separating liquids from liquid-laden asbestos-containing material comprising collecting liquid-laden asbestos-containing material in a liquid permeable receptacle capable of retaining a substantial portion of the asbestos-containing material when the receptacle is compacted, and then compacting the receptacle so that a quantity of the liquids are separated from the asbestos-containing material and expelled from the receptacle.

Abstract: An apparatus and process for separating waste material requiring use of ground water for processing in a wet mill a drum separator in combination with purification and recycling, routing recycled water to a biomonitoring fish pond and use of a system wash water for washing for processing in a wet mill sanitizing of refuse collection vehicles. The groundwater is obtained from an aquifer underlying and containing leachate from a landfill, thereby solving environment problems.

Abstract: Apparatus and method for dewatering radioactive waste slurry solids. The apparatus includes a vacuum pump for applying a vacuum to a suitable flexible filter and collapsible membrane combination in which the slurry solids are contained so that the slurry solids are compressively dewatered when the vacuum is applied. The apparatus further includes a container for suitably storing the resulting dewatered slurry solids.

Abstract: An apparatus for extracting liquid from a sludge/conditioning agent mixture which comprises a first endless belt (10) of filter material; a second endless belt (12) of filter material; and rollers (20, 21, 22, 23, 24, 25, 26, 27, 13, 14, 15) for the belts (10, 12). That part of the belt (10) between the rollers (20, 23) is defined as a gravity de-watering zone; the part of the belts (10, 12) between the rollers (21, 13, 14, 15) is defined as a pressure de-watering zone. Filtrate is collected in a tray (17); liquid is collected in a tray (35). Monitoring means monitors a characteristic of the filtrate and the liquid to enable a rate of change in the characteristic of the filtrate/liquid to be determined. The apparatus functions at its optimum at a loading rate for the mixture which is just less than that which causes extrusion of the liquid in the pressure de-watering zone.

Abstract: A method and apparatus provide for the effective centrifugal washing and/or thickening of paper pulp, using a perforated cylinder. A stock head box, located within the cylinder, applies a thin sheet of pulp on the interior the cylinder, at a high rate (e.g. about 20 meters per second), at a first arcuate position. The cylinder is rotated at high speed (e.g. 100 rpm, to provide an acceleration on the order of about 10 gs), whereby centrifugal force causes liquid in the pulp to move radially outwardly through the openings in the screen cylinder. The pulp is withdrawn from the interior of the cylinder by a vacuum roll or the like at a second arcuate position less than 360.degree. from the first position. The withdrawn pulp is moved by a screw conveyor or the like away from the cylinder in a dimension generally parallel to the axis of rotation, and the withdrawn liquid passes through channels in a drum surrounding the perforated cylinder, and is engaged by an impeller, and flows to a volute for removal.

Abstract: Solids contained in waste water are separated and dewatered by a separator comprising a cylindrical strainer basket and a rotary screw disposed in said basket. The screw terminates short of an outlet end of the basket. Waste water introduced into the separator is advanced by the screw until a solids slug is formed between a discharge end of the screw and a solids discharge formed by a cylindrical tube extending forwardly from the basket. About seventy to ninety-five percent of the slug is contained in the basket and is pressed laterally against a wall of the basket to promote the removal of water. The terminal portion of the screw tapers in order to maximize the compaction of the solids slug.

Abstract: An apparatus for dewatering and squeezing a water containing material comprises a drum with a sieve mantle defining two co-operating drum sections, each comprising a feed screw extending therein. The first section of the drum in the feed direction is formed for dewatering of the material mainly by self-drainage. The first drum section is rotatable and is provided with means for cleaning the sieve mantle holes. The second section is formed for increased compression of the material, and has a thread height for the feed screw smaller at the outlet of the second section than at the inlet to this section.

Abstract: Commercially valuable oil is recovered from refinery-produced, Resource Conservation and Recovery Act classified, hazardous waste oil sludges by a series of volatilizing and condensing steps (which may vary depending on the oil, water, and solids content of the sludge) resulting in the production of nonhazardous water and solid waste byproducts. A pumpable, low viscosity, high oil- and/or water-content sludge is first centrifuged to separate free oil and water, while the thick waste oil sludge, centrifuge solids, or other sludges low in oil and/or water content are heated to volatilize the contained water and oil. Dry, friable, deoiled solids are recycled with the oily sludge feed to prevent material agglomeration and heat exchanger fouling. Oil and water vapor from the high-temperature volatilization apparatus is recycled as an indirect heat source to the low-temperature volatilization apparatus.

Abstract: The present invention provides an improved biological sludge dewatering process. The process comprises the steps of: (a) heating biological sludge to a temperature of about 90.degree. to about 150.degree. C. which corresponds to a pressure of about 0 to about 55 psig and retaining the biological sludge at that temperature for less than about 15 minutes; (b) centrifuging the heated biological sludge to isolate the solids of the heated biological sludge from the liquid of the heated biological sludge; (c) chemically conditioning the isolated solids; and (d) dewatering the conditioned solids to produce a high solids biological sludge. The present process is used for dewatering any biological sludge to produce a high solids cake. The resulting high solids cake may be used as landfill, incinerated, or used as fertilizer by spreading on land and plowing said fertilizer into the soil.

Abstract: A completely integrated and automated apparatus by which liquid sewage sludge from any sewage or waste treatment plant may be processed into a completely dry, pelletized and sterilized product of an organic nature containing nutrients valuable for the support of plant life. The apparatus involves one completely integrated and automated unit together with a control center by means of which electric circuits program each component of the apparatus to automatically regulate the operation of each component, so that no labor or other manpower is required in the operation, except for observation, lubrication, maintenance and repair of the various motors and machineries involved.