Abstract: A method of cleaning contaminated soil which achieves very low levels of residual impurities and does not produce contaminated residues is characterized by the steps of, (a) feeding the contaminated soil to a combustion space (6) of a fluidized bed furnace (4) having, at the underside of said combustion space, a structure (5) for air distribution, (b) forming a fluidized bed of the contaminated soil above said air distribution structure (5) in the combustion space by means of combustion air delivered under elevated pressure via the air distribution structure, and (c) mainly or completely burning the impurities from the soil in the combustion space (6), to provide cleaned soil. Preferably the air distribution structure (5) comprises a generally horizontal grid (7) of pipes having air distribution nozzles with gaps between the pipes, coarse soil particles passing through said gaps into a collection space (13) from the combustion space.

Abstract: The invention relates to apparatus for carrying out physical and/or chemical processes, more specifically a heat exchanger (10) of the continuous type, comprising a large number of vertical heat exchanger tubes (18) mounted between a lower chamber (17) and an upper chamber (16) within a jacket (15). Within the tubes (18) small solid particles are kept in a fluidized condition by the fluid medium passing up from the lower chamber (17) through the tubes (18), so as to achieve a good heat transfer, whereas also any deposit will be removed from the inner tube walls. For the downward flow of the granular mass at least one return tube (21) is provided. Downward circulation of the fluid medium through the return tube (21) should be minimal.

Abstract: This invention relates to apparatus for carrying out physical and/or chemical processes, more specifically a heat exchanger (10) of the continuous type, comprising a large number of vertical heat exchanger tubes (18) mounted between a lower chamber (17) and an upper chamber (16) within a jacket (15). Within the tubes (18) small solid particles are kept in a fluidized condition by the fluid medium passing up from the lower chamber (17) through the tubes (18), so as to achieve a good heat transfer, whereas also any deposit will be removed from the inner tube walls. For the downward flow of the granular mass at least one return tube (21) is provided.

Abstract: This invention relates to apparatus for carrying out physical and/or chemical processes, more specifically a heat exchanger (10) of the continuous type, comprising a large number of vertical heat exchanger tubes (18) mounted between a lower chamber (17) and an upper chamber (16) within a jacket (15). Within the tubes (18) small solid particles are kept in a fluidized condition by the fluid medium passing up from the lower chamber (17) through the tubes (18), so as to achieve a good heat transfer, whereas also any deposit will be removed from the inner tube walls. For the downward flow of the granular mass at least one return tube (21) is provided.

Abstract: In a method of operating a liquid-liquid heat exchanger the first heat exchanging medium is passed upwardly through a plurality of tubes in which a granular mass is kept fluidized by the flow of the first medium and the second heat-exchanging medium is passed downwardly through which said tubes extend spaced apart and whereby heat exchange takes place through the tube walls. To improve heat transfer between the tubes and the second medium, especially at low flow rates of the latter, said chamber contains, around and between the tubes, a loosely packed solid particulate filling material through which the second medium flows, and the longitudinal superficial velocity of the second medium between the tubes (U.sub.l,s) satisfies the relation 0.05<U.sub.l,s <0.25 m/sec.

Abstract: A ceramic article is made by shaping, drying and firing a body shaped from a mixture of clay and an organic fraction. The organic fraction is derived from domestic waste by separation of metal parts, coarse material and material in sheet form. The proportion of clay in the mixture is 40 to 65% by weight and the clay contains more than 10% by weight of particles of size greater than 2.mu..

Abstract: Sludge floating on the surface of liquid protrudes upwardly through a stabilization grid and is removed by scraping means into a gutter. In order to prevent the scraping means pushing the sludge back downwardly through the grid, the scraping means is provided with a knife which is driven in a forward movement towards the gutter and a return movement away from the gutter. In the forward movement the knife is tilted downwardly towards its free edge so as to cut the sludge and push it into the gutter. During the return movement, the free edge is raised above the grid.

Abstract: A process for reducing environmental pollution resulting from disposal of waste containing halogenated hydrocarbons by simultaneous treatment with used metal and/or metal scrap at elevated temperatures. The halogenated hydrocarbons are pyrolyzed and the resulting hydrogen halide containing gas is brought into contact with the used metal and/or metal scrap at elevated temperatures so as to form metal halogenides that are volatile under the conditions applied. The volatile metal halogenides are largely separated from the gaseous mixture formed, and at least part of the remaining gaseous mixture and/or hydrocarbon residue is used as fuel to maintain the required temperature. The waste feed compositions and process conditions can be chosen to effect separation between various metals by selective halogenation and condensation, and substantially all of the hydrogen halide can be tied up and recovered as metal halogenides.

Abstract: Apparatus for performing physical and/or chemical processes involving at least one liquid, e.g. a heat exchanger, has a plurality of vertical tubes opening at their top and bottom ends into top and bottom chambers respectively. Particulate material in the tubes and the chambers is fluidized by the upward flow of liquid in the tubes. To prevent inefficient circulatory flow of the particles caused by downward movement of the particles in one or more of the tubes, there is provided, in at least one of the top and bottom chambers, means for hindering the transverse movement of the particles in the chamber. Such means may be loose balls made of wire mesh of a size large enough to allow passage of particles through the ball under normal conditions.

Abstract: Vacuum filter belt apparatus has a continuous belt with an upper run at which suction filtering occurs, via passages which pass through a central thicker portion of the belt and open into a vacuum chamber. To avoid high frictional contact between the belt and the upper side of the vacuum chamber, the thick central portion of the belt passes right through the vacuum chamber from above to below and is supported below the chamber e.g. by rollers or a pressurized chamber.

Abstract: In a rotary drum vacuum filter, the drum sectors are connected by conduits to apertures in a rotary valve member on the drum which is opposed to a fixed valve member. The valve members thus control supply of vacuum (to cause suction filtering) and pressurized gas (to blow the cake of filtered material from the filter) to the drum sectors as the drum rotates. In order to eliminate the time delay between suction and blowing which is needed in order to allow the conduits to purge, another group of conduits is provided, having one-way valves adjacent their connection to the drum surface; this group is used only for blowing. The different groups of conduits are connected to apertures of the rotary valve member at different radial distances from the axis of rotation.

Abstract: A method of heat exchange in a heat exchanger which has a plurality of upwardly extending pipes for upward flow of a primary liquid medium and around which in operation a secondary medium flows, a lower chamber at the lower ends of the pipes from which the primary liquid enters the pipes and which contains a distribution system adapted to distribute flow across the cross-section of the lower chamber, and an upper chamber at the upper ends of the pipes into which the fluid passes from the pipes, the pipes and the upper and lower chambers containing fluidizable particulate material, in which method the flow-rate of the primary liquid medium is selected so that the particulate material is fluidized within the pipes and within the upper and lower chambers without mechanical stirring, the distribution system causes the primary liquid medium to be admitted to the pipes substantially uniformly across the transverse cross-section of the lower chamber and the pressure drop (.DELTA.P.sub.