Abstract: For cleaning at least one of the sides of the essentially vertical heat-transmitting walls between two fluids in a heat exchanger, solid particles are introduced into a stream of fluid, which particles are smaller than the distance between opposite walls defining the flow of fluid, said fluid with particles being introduced into part of a collection or distribution space above said walls and said particles being collected below said vertical walls and discharged from the heat exchanger. The particles are so heavy that they move downwards in the fluid even if this has an upward direction of flow between the walls. The particles are introduced above only part of the transverse plane above the vertical walls and switch means allow switching of said introduction to other parts of said transverse plane periodically. Thereby, the normal operation of the heat exchanger can continue with hardly any pressure loss during cleaning.

Abstract: Installations for operating physical and/or chemical processes, for example heat exchangers, comprising a bundle of parallel vertical tubes which, via tube plates, are in open connection with a bottom header and a top header, are known to operate with a granular mass maintained in a steady or quasi-steady fluidized state, at least in the tubes, by means of a medium flowing upwards through the headers and tubes. At start-up and shut-down of such installations problems are encountered because the granular mass tends to settle to form a packed bed, in particular if the upwardly flowing medium may contain solid impurities or has a rather high viscosity. The invention solves such problems by using a storage vessel, to which the granular mass is flushed at shut-down of the installation, a partial stream of the flowing medium being first fed through the tubes at start-up, after which the granular mass is flushed from the storage vessel to the tubes and only thereafter the main stream of medium is fed to the tubes.

Abstract: Apparatus for carrying out physical and/or chemical processes has a lower chamber, an upper chamber, vertical riser tubes for the passage of a first fluid medium from the lower chamber to the upper chamber and an intermediate chamber through which the riser tubes exetend so that a second fluid medium can contact the riser tubes. A granular mass is fluidized in at least the riser tubes by the flow of the first medium. A vertical gravity tube for return passage of the granular mass from the upper to the lower chamber has an outlet below the inlets of the riser tubes. A distribution plate for the first medium is mounted in the lower chamber between the inlets of the riser tubes and the outlet of the gravity tube. To allow the granular mass to fall below the distribution plate for start-up of the apparatus the gravity tube has, at least one opening connecting to the lower chamber above the distribution plate.

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: A heat exchanger for liquid/liquid heat exchange has a plurality of parallel vertical tubes arranged for the upward transport within the tubes of a first heat-exchange liquid, supply and discharge tanks for the first liquid into which the lower and upper ends of the tubes respectively open. A granular mass is fluidized during operation by the flow of the first liquid so as to occupy at least the tubes. Supply and discharge means for a second heat exchange liquid bring the second liquid into contact with the outer surface of the tubes. In order to improve the heat flow between the second liquid and the tubes, the supply means for the second liquid causes the second liquid to contact the tubes in the form of a film flowing downwardly along the outer surface of each tube.

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: Concentration of a liquid by evaporation is performed in a heat exchanger having riser tubes for the liquid and a granular mass fluidized by the liquid to occupy the tubes. At their upper and lower ends the tubes open into upper and lower chambers. A hot medium contacts the tubes to transfer heat to the liquid. In order to render this heat exchanger effective for evaporation concentration, means are provided for vapor collection and discharge from the upper chamber, the riser tubes extend above the base of the upper chamber. A return conduit for recirculation of the liquid and granular mass connects the upper chamber to the lower chamber, opening in each case at a lower level than the riser tubes. Supply and discharge connections for the liquid are at levels lower than the upper ends of the riser tubes.

Abstract: A method is described of operating heat-exchanger apparatus comprising a plurality of heat exchanger units which are connected together in series for countercurrent flow of respectively a first heat exchanging medium which contains fluidizable particulate material and a second heat-exchanging medium. Each said unit comprises at least one vertical tubular duct in which said first heat-exchanging medium flows upwardly with said particulate material in a fluidized state and a compartment through which said second heat exchanging medium passes and through which said duct extends. The particulate material acting to remove deposits formed on the tube inside walls by the first medium. In order to achieve cleaning of the tubes in cases where a high rate of deposit occurs, flow of said second medium through each of the compartments is intermittently interrupted for a period of time, while flow through at least one other of said compartments is maintained.

Abstract: In apparatus for flow of a liquid medium e.g. a heat exchanger the liquid flows through a plurality of parallel vertical pipes 10 from a bottom chamber 4 to a top chamber 5. The apparatus contains a mass of particles which are fluidized in the pipes by the flow of liquid. In order to allow a higher speed of liquid flow, giving the apparatus greater capacity transfer means 11,12,13,14 are provided to convey the particles batchwise from the top chamber to the bottom chamber. This transfer corrects the tendency of the higher flow speed to carry the particles into the top chamber. Suitably the transfer means is a lock chamber 11 with linked inlet and outlet valves 12,13.

Abstract: Heat exchanger having a plurality of vertical pipes for upward passage of a first heat-exchanging medium, at least one compartment for passage of a second heat-exchanging medium through which compartment said pipes extend, a lower chamber through which said first medium passes and into which said pipes open for admission to the pipes of said first medium, and a flow distribution element adapted to distribute the flow of said first medium in said lower chamber to the pipes. A fluidizable particulate material is in operation, is maintained in a fluidized state in the pipes by the flow of the first medium. The pipes have inlet elements extending downwardly into said lower chamber with their lowermost ends open. Stabilization openings are provided into said inlet elements above said open lowermost ends thereof.

Abstract: Apparatus for physical and/or chemical processes e.g. a heat exchanger, has a plurality of vertical riser tubes for upward flow of a liquid under treatment from a lower chamber to an upper chamber. A granular mass is fluidized by the flow so as to occupy at least the tubes. A return tube conveys the granular mass from the upper chamber to the lower chamber and has valve means to hinder flow of liquid through the return tube. To provide improved control of the liquid flow in the return tube, the valve means is embodied as a single valve having a valve member adjacent and movable relative to the lower end of the return tube.

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: A vertical multistage expansion evaporator comprising contiguous vertically arranged evaporator compartments, passages permitting communication between contiguous compartments and flow control apparatus positioned at each passage which is adjustable simultaneously by a single adjusting operation from outside the compartments. The contiguous compartments have a common ceiling and floor defining a passage therebetween. Each compartment further comprises a vertical separating wall extending partially the distance from the floor to the ceiling to divide the compartment into liquid and vapor sections so that liquid in the bottom of one compartment flows into the vapor section of the compartment next below.

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.