Esmil, B.v.

Klarex Beheer B.v.

Other

Eskla B.v.

Bronswerk Heat Transfer B.v.

Dick G Klaren

Zacharias L Nunninga

An apparatus for carrying out a physical and/or chemical process, such as a heat exchanger, comprising a fluidized bed, through which a fluid flows, and a separator for separating fluidized bed particles from the medium for recirculation. According to the invention, the top box is provided with separated discharge means for discharging a main flow of medium with a partial flow of medium and for discharging granular material.

Apparatus for carrying out a physical and/or chemical process, such as heat exchanger

Heat exchanger, consisting of a reservoir, having upwardly directed tubes that are flowed through by a liquid to be heated and by fluidized bed particles for cleaning the tubes internally. Connected to the reservoir is an external downcomer (2) for receiving fluidized bed particles coming from the top box (21) of the reservoir and to be conveyed again to the bottom box (25) of the reservoir. Provided in the downcomer (2) is an inner tube (1) of smaller diameter, which is open at its bottom end (5) and provided, directly below the closed top end (9), with openings (8) for effecting a circulation flow in the downcomer (2).

Apparatus for carrying out a physical and/or chemical process, such as a

An apparatus for carrying out a physical and/or chemical process, such as a heat exchanger, including a reservoir in which a series of riser pipes (2) are arranged. Disposed in the reservoir (1) is a fluidized bed of granular material. The apparatus includes means for circulating the particles of the fluidized bed through the riser pipes (2), which means include a downcomer (15) arranged outside the reservoir (1), this downcomer being closed off at the bottom end by an inclined closing plate (16). Above the closing plate (16), via a bypass line (17), a part of the medium to be treated is fed to the particle bed resting on the plate (16).

Heat exchanger consisting of a reservoir with upwardly directed tubes through which flow a liquid to be heated and fluidized bed particles for internally cleaning the tubes. Connected to the reservoir is an external downcomer (5) for collecting fluidized bed particles coming from the top box of the reservoir and to be transported back to the bottom box (7) of the reservoir. The connecting line (4, 2, 1, 3, 6) between downcomer (5) and bottom box (7) is designed as two sections (2, 3) with an expansion bellows (1) arranged between them. The bottom section (3) is connected via two or more connecting stubs (6A, 6B) with the bottom box (7) for the uniform distribution of the flow of fluidized bed particles.

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.

Method for cleaning the walls of heat exchangers, and heat exchanger

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. At shut-down said main stream is first reduced and then the granular mass is flushed back to the storage vessel and thereafter the partial stream of the medium is shut off.

Method for the start-up and shut-down of an installation for operating

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.

Apparatus for carrying out physical and/or chemical processes, in

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. To stabilize the fluid bed in a riser tube the inflow pipe is provided with a lateral bore (23) and the top of the lower chamber above the level of the lateral bores (23) is fitted with an outlet 51 with a shutoff valve 52 to temporarily reduce pressure of the fluid medium at the top of the lower chamber should the lateral bores become clogged.

Apparatus for carrying out physical and/or chemical processes, more

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.

Heat exchanger for liquid/liquid heat exchanger

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. Downward circulation of the fluid medium through the return tube (21) should be minimal, however, which can be achieved by an increase of the pressure difference between the upper and lower chamber (16; 17), which increase of the pressure difference can be achieved by fitting several distribution plates (24; 42) at a level above the return tube (21) outlet into the lower chamber (17), preferably so that the apertures in the various distribution plates (24; 42) of the multiple design are not vertically in line. The second distribution plate (42) also serves to minimize excessive wear of the material of the jacket (15) due to the eddying motion of the granules.

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&lt;U.sub.l,s &lt;0.25 m/sec.

Method of operating a liquid-liquid heat exchanger

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.

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Hillegom, Netherlands

Dick G Klaren