Abstract: Method of retrofitting catalyst coolers onto FCC regenerators and a cooler configuration specially suited for FCC regenerators uses a large manway or accessway commonly provided on the FCC regenerator to overcome the problems usually associated with finding a suitable space and clearance for the incorporation of a catalyst cooler. The catalyst cooler is added to the regenerator by removing the end cover from an existing manway on an FCC regenerator, extending the nozzle to provide a horizontal nozzle extension, attaching a vertical tube section of a catalyst cooler from the lower side of the nozzle extension and providing a new end closure at an opposite end of the nozzle extension. This method and the cooler apparatus minimizes the amount of welding and design work that must be done on the vessel and its associated piping when adding a catalyst cooler.

Abstract: An apparatus for particulate solids (e.g. FCC catalyst) regeneration comprising a regenerator housing containing fluidization means arranged below spent-solids inlet means and regenerated-solids outlet means and having fluid in- and outlet means, and further comprising at least one external heat exchanger housing containing heat exchanger means and communicating with the regenerator housing via solids in- and outlet means in which apparatus at least one solids outlet means directly connect a lower section of the heat exchanger housing(s) with a section of the regeneration housing above the fluidization means.

Abstract: A method and apparatus are disclosed for transferring heat to a reaction zone in which hot flue gas is passed through a heat exchanger positioned inside the reaction zone. The flue gas may be generated in a catalyst regenerator, a combustion chamber, or both. The combustion chamber may be external or internal to the heat exchanger. The invention is particularly useful for transferring heat to an endothermic fluid-bed catalytic reaction such as dehydrogenation or aromatization.

Abstract: A fluidized bed gas-solids contact reactor, which utilizes at least one capped concentric dual-sided riser-downcomer unit having a central inner riser passageway and a concentric outer downcomer passageway. The riser-downcomer unit is usually located above the fluidized bed, and is adapted for directing the downflowing solids back into the fluidized bed for recycle. The reactor unit inner and outer passageway surfaces include a heat exchange panel having inner and outer channels each containing a circulating liquid. Particulate solids from the dense phase fluidized bed are continuously circulated in dilute phase through the riser-downcomer unit passageways by a reactant gas to exchange heat with the liquid. The particulate solids can be a catalyst or a fuel material. The invention also includes a combustion system and method for combusting a particulate fuel such as coal in air to generate pressurized saturated liquid for producing saturated steam.

Abstract: A succession of low profile catalyst chambers each housing a reservoir of catalyst are alternately connected in sequence by openings below the levels of the catalyst reservoirs and openings thereabove. The catalyst in all reservoirs is fluidized by a gas moving upwardly therethrough. Separate portions of the sequence of chambers are operated as reactor and regenerator sections according to the gas used to fluidize the catalyst in those sections. Other portions of the sequence of chambers are used to create inert atmospheric seals between the reactor and regenerator sections. The entire apparatus is configured as a low-profile catalytic cracker wherein the fluidized flow of the catalyst moves throughout the apparatus in an alternating lifting and dropping sequence.

Abstract: An improved fluidized bed reactor and a method for its use characterized by a variable thickness inert liner surrounding the fluidized bed reaction zone. Such liner generates heat that is transferred to the reaction zone. The heat is generated in the inert liner by passing an electrical current through the inert liner. The inert liner is thicker at the top than at the bottom and therefore more heat is generated at the bottom of the reaction zone than the top of the reaction zone due to the increased resistance of the thinner portions of the inert liner.

Abstract: An improved heated fluidized bed reactor and a method of heating such reactor wherein a means defining an annular heated fluidized bed reaction zone is heated by a first heat source supplying heat to the outer periphery of the fluidized bed reaction zone and a second heat source supplying heat to the inner boundary of the annular fluidized bed reaction zone. The present invention is useful for reactions carried out in a fluidized bed reactor, such as the pyrolysis of silane containing gas into silicon.

Abstract: An improved process and regenerator suited for the regeneration of coke contaminated catalysts. Such coke contaminated catalysts are formed during the fluidized bed cracking of crude oil derived feed stocks into motor fuels and other distillates. The improved regenerator is equipped with an upper combustion zone for oxidizing carbon present on the catalyst to carbon dioxide and water and a lower cooling zone wherein hot catalyst is transported from the upper combustion zone to the lower cooling zone through a substantially vertical conduit for indirect heat exchange contact with a coolant for reducing the temperature thereof. The cooled catalyst is returned to the upper combustion zone. Air is used to fluidize the cracking catalyst in the lower cooling zone and is vented to the upper combustion zone and used as a source of oxidizing gas.

Abstract: A process and apparatus for cooling FCC catalyst that provides two modes of operation for a remote heat exchanger type cooler. In the first mode the exchanger is operated in a backmix fashion where catalyst is circulated between the cooler and a disengagement zone. Regenerated catalyst is withdrawn from an outlet located close to the heat exchanger inlet so that essentially all of the heat removed by the cooler serves to reduce the temperature of catalyst entering the reaction zone. This mode of operation is particularly useful in obtaining a benefit from the cooler when processing light to moderate FCC feeds. In the second mode, the exchanger is operated in a flow through mode where hot catalyst is withdrawn from the disengaging zone cooled in the exchanger and passed into the combustion zone. The second mode of operation is used to withdraw heat from the overall regeneration process in the case of heavy FC feedstock conversion.

Abstract: A method of converting a stacked FCC reactor-regenerator arrangement into a two-stage regenerator. In this method, a stacked FCC unit having a bottom regeneration vessel, a superadjacent reactor vessel, and a stripping vessel laterally offset from and in open communication with the reactor vessel are used to make a two-stage regenerator having a lower first stage of regeneration, an upper second stage regeneration vessel, and a catalyst cooler for moving heat from the catalyst. This method makes complete use of the three existing vessels in the stacked reactor regenerator arrangement by converting the upper reactor vessel into the second stage regeneration vessel and the stripping vessel into the catalyst cooler. Therefore, apart from the addition of a new reactor only relatively minor modifications are nesessary to convert the stacked reactor-regenerator arrangement into a two-stage regenerator.

Abstract: A fluid bed combustor comprising a generally rectangular housing defining a freeboard space. A plurality of vertically spaced and horizontally staggered beds are provided in the housing and extend inwardly into the space from a rear wall and from a front wall of the housing. A serpentine flue gas path is defined between the staggered beds. Each bed is supplied with combustion air and fluidizable fuel with the freeboard space of each bed including gases from that bed plus gases from all previous beds in the flue gas path. In this way an increased residence time is established without substantially increasing the dimensions of the combustor. A simplified recycle system can also be provided since materials from each bed cascade down into a lower bed so that all materials are eventually accumulated in the lowest beds from which they can be removed.

Abstract: A fluidized-bed reactor for the pyrolytic treatment of wastes containing hydrocarbons and a high content of polymeric organic substances includes a circumferential wall having an inner surface and an interior with a conical lower section and an expanded cylindrical upper section. Fluidizing-gas feed pipes have ends with lower circumferential sections protruding directly from the inner surface of the circumferential wall into the conical lower section. Covering walls covering the ends of the fluidizing-gas feed pipes and extend obliquely downwardly and inwardly. Blow orifices are each disposed at a respective one of the lower circumferential sections and have an obliquely downward and inward blow direction for blowing fluidizing-gas into a fluidized-bed material in the interior. Heating pipes for heating with heating gas dip vertically from above through the expanded cylindrical upper section of the interior. The heating pipes have connections for heating gas, combustion air and exhaust gas.

Abstract: A process for producing non-oxide compounds such as silicon nitride and silicon carbide by using a multi-stage apparatus constructed of a raw material drier section, a reactor section including a multiplicity of reaction vessels, and a non-oxidizing gas feeder section, is disclosed. The sections are arranged serially in the vertical direction. Raw materials are reacted with one another while fluidizing or bubbling by a hot non-oxidizing gas (argon or nitrogen) occurs in the raw material drier section and reaction vessels.

Abstract: An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon.

Abstract: A multistage process and apparatus for regenerating fluid catalytic cracking catalyst is disclosed. Each stage preferably has a successively higher temperature, and flue gas is removed after each stage. The process may regenerate a single phase catalyst or, preferably, a dual phase catalyst system, wherein an intermediate pore zeolite catalyst contained within a less elutriatable catalyst particle and a larger pore zeolite catalyst contained within a more elutriatable catalyst particle, thereby separating the intermediate pore zeolite catalysts from the larger pore zeolite catalysts prior to a final regeneration step.

Abstract: A fluid bed reactor for treatment of refractory materials with a hot fluidizing gas and a method to use same. Both the refractory materials and the fluidizing gas are introduced from the top of the reactor. Unusually high reaction temperatures of up to 2000.degree. C. are maintained in the reaction chamber due to the presence of heating elements within the reactor and due to countercurrent heat transfer.

Abstract: An apparatus for preparing high-purity polycrystalline silicon is constructed with a heating applicator, a vertical fluidized bed quartz reactor within the applicator, a microwave generator, microwave guide tubes for conveying microwaves from the microwave generator to the applicator, a reacting gas inlet and outlet, a gas distribution device for distributing reacting gas within the reactor, a silicon seed inlet for introducing silicon seed into the reactor, and an outlet for withdrawing polycrystalline silicon from the reactor. The microwaves provide the heat for the fluidized bed reaction.

Abstract: An improved fluidized bed process for upgrading olefinic hydrocarbon feedstock by contacting the feedstock with acidic siliceous zeolite conversion catalyst particles at elevated temperature under exothermic conditions to produce heavier hydrocarbons including gasoline range hydrocarbons. The improvement comprises maintaining a turbulent fluidized bed of catalyst particles by flowing hydrocarbon-containing vapor upwardly through said bed at less than transport velocity; and introducing liquid olefinic feedstock comprising at least one C.sub.4 -C.sub.6 diene component into the fluidized catalyst bed in a lower portion thereof by rapidly atomizing and vaporizing the liquid feedstock, thus converting feedstock to heavier hydrocarbon without substantial thermal diene degradation thereof prior to contacting conversion catalyst particles in the fluidized bed.

Abstract: A process for circulating solid particles within a fluidization chamber, in which is formed a circulating fluidized bed comprising a dense lower zone (A) with a high concentration of particles, above which is located a dilute zone (B) containing particles carried along by the rising stream of a gas towards the upper part of the chamber (1), the latter opening into a circuit (4) for discharging the gases and particles, incorporating a device (41) for recovering the particles carried along, which is connected to the chamber (1) by means of a circuit (45) for recycling the recovered particles. In the upper part (12) of the fluidization chamber, the circulation speed of the cases is reduced before their discharge, so as to produce above the dilute zone (B) an upper zone (C) with a higher concentration of particles, in which some (35) of the particles escape from the stream of gas and fall in a shower along the side wall of the chamber, at the same time forming a descending annular film (34).

Abstract: An apparatus for purifying exhaust flue gases includes a reaction vessel having a lower crude flue gas inlet and an upper purified flue gas outlet. A reaction chamber, disposed inbetween the inlet and outlet is fillable with solid bodies capable of carrying a desulfurizing agent. A screw conveyor passes through the reaction chamber and has a top inlet end for introducing the solid bodies into the reaction chamber. A bottom vessel outlet end is provided for discharging reacted desulfurizing agent from the vessel. A process for purifying exhaust gas includes passing a migrating layer of solid bodies carrying a desulfurizing agent countercurrently to a flow of exhaust gas in a cleaning vessel.

Abstract: In a fluidized bed there is immersed an internal heat-exchanger connected to a heat-transfer fluid discharge line which feeds an external heat-exchanger fitted in a fluidizing gas delivery line with a by-pass line connected to a flow-control valve so that the heat withdrawn from the fluidized bed and not used is reintroduced therein by means of the fluidizing gas.

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: A multiple hearth apparatus and process for the thermal treatment of organic carbonaceous materials under controlled pressure and temperature comprising a pressure vessel containing a plurality of superimposed annular hearths including hearths in a reaction zone of the apparatus which are formed with a foraminous upper surface disposed in communication with a plenum for injecting a heated fluid into heat exchange contact with the feed material disposed thereon. The injected heating fluid or gas in further combination with the volatile gases evolved during the thermal restructuring reaction pass countercurrently relative to the travel of the feed material to effect a preheating thereof to a moderate temperature in a preheating zone of the apparatus. Preferably, at least a portion of the volatile gases from the apparatus are treated to remove condensible portions thereof and are reheated and pressurized for recycle to the apparatus.

Abstract: Apparatus for catalytic cracking of a selected portion of a hydrocarbon feedstock comprising a riser reactor and a catalyst regenerator, a regenerated catalyst cooler, and an absorber. Regenerated catalyst from the catalyst regenerator is conducted through the catalyst cooler into the absorber where it adsorbs hydrocarbon cracking feedstock and then returned to the riser reactor. A duct carries part of the hot regenerated catalyst from the catalyst regenerator directly to the riser reactor to supply heat for cracking the hydrocarbon feedstock.

Abstract: Heat exchanger tubes which are immersed in a fluidized bed of a combustion fluidized bed installation are provided with flow deflectors which reduce erosion of the fluidized materials in the bed on the tubes. The flow deflectors are preferably fins or pins, which protrude from the surface of the tubes and which disturb the erosive flow against the outer walls of the tubes. The flow deflectors also increase the surface areas of the tubes and thereby improve heat transfer from the combustion in the fluidized bed to a fluid heat exchanging medium within the tubes.

Abstract: An apparatus for the cooling of hot fluidized solid particles such as catalyst of an FCC petroleum refining process includes a conduit in which particles flow downward from a first dense phase fluidized bed into a cooling chamber and contact the shell side of a vertically oriented shell and tube heat exchanger where cooling occurs via indirect heat exchange with a cooling medium circulating in the tubes. The extent of cooling is controlled by the varying of the heat transfer coefficient between the tubes and particles in the heat exchanger. The coefficient is varied by changing the quantity of fluidizing gas fed to the fluidized bed in the heat exchanger. The heat exchanger is located within a lower portion of the cooling chamber totally below the particle inlet and outlet conduits. The heat exchanger can therefore be removed from service and protected by being buried under unfluidized relatively cool catalyst. The fluidizing gas supports combustion within a lower combustion zone.

Abstract: In an apparatus for the regeneration of fluid cracking catalyst, the catalyst is cooled in a heat exchanger mounted to the lower side of the regenerator and cool catalyst is returned to the regenerator by means of a separate gas lift.

Abstract: An improved heat balanced hydrocarbon conversion process is disclosed of the type employing circulating solids between a riser reactor (contactor) and regenerator (combustor). The ratio of circulating solid to hydrocarbon feed (C/O or cat-oil ratio) is increased by: directly cooling a portion of hot freshly regenerated contact material; passing a portion of hot regenerated material into the steam stripper; cooling hot regenerated contact material and charging it to the riser downstream of charging uncooled hot regenerated material which charging hydrocarbon feed to the bese of the riser along with lift gas or steam; or lifting hot regenerated contact material by a carbonizable lift gas into the riser before contacting it with hydrocarbon feed which is injected higher in the riser.

Abstract: An apparatus and method are provided to remove the heat during the regeneration of catalyst particles. A regenerator comprises a regeneration zone and a cooling zone having disposed therein a steam coil. The two zones are separated by a vertical partition open at both ends. Colder catalysts from the cooling zone flows into the regeneration zone and visa versa due to differences in densities of the fluidized particles in each zone. The flow of aeration steam to the cooling zone is controlled by a valve.

Abstract: Fluidizing apparatus comprises a grid defining cavities and main fluidizing gas blower channels connected to these cavities. Complementary channels pass through openings in swellings at the intersections of the cavities. Their upper ends are above the level of the grid. They are adapted to blow a complementary gas into an active area disposed above each swelling. A heat exchanger is adapted to exchange heat with the fluidized bed. It comprises at least one tube shaped so as to extend over the grid and through a plurality of these active areas. The rate of heat exchange may be modified by altering the complementary gas flowrate, without modifying the fluidization velocity.

Abstract: A mounting assembly 4 is provided for a feed tube 12 of a high-temperature fluid-wall reactor of the type having a vertically oriented reactor tube heated to incandescence for emitting radiation radially inward to a reaction zone. The mounting assembly 4 comprises a tube support 34 having an opening 42 through which the feed tube 12 can pass, and a pivot seat member 30 secured to the reactor. The assembly 4 further comprises a retainer 52 for selectively fixing the orientation of the feed tube relative to the reactor, and a releasable attachment mechanism 70 for allowing the axial position of the feed tube to be adjusted relative to the assembly 4. According to the method of the invention, undesirable conditions within the reactor are detected, and the orientation of the feed tube is pivotably adjusted in response thereto for reducing undesirable reactor operating conditions.

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 hot support rack (46) for supporting an in-bed heat exchanger (44) of a fluidized bed furnace (22) is comprised of a plurality of support bars (54, 56) disposed diagonally between spaced vertical support posts (58). The support bars (54, 56) form a criss-cross array of quadrangular openings through which the tubes (44) of in-bed heat exchanger (44) pass with each tube (44) passing through a quadrangular opening being supported by the upper surface of the lower bars (54, 56) forming the quadrangular opening.

Abstract: A multiple hearth reactor apparatus and process for the thermal treatment of organic carbonaceous materials under controlled pressure and temperature comprising in accordance with one embodiment, a pressure vessel containing a plurality of superimposed annular hearths including a series of upper hearths defining a preheating zone and a series of lower hearths spaced therebelow defining a reaction zone. The reactor is provided with an inlet for introducing a moist carbonaceous feed material under pressure into the preheat zone and the feed material is transferred downwardly in a cascading manner through the preheat zone and reaction zone. The solid product is extracted from the lower portion of the apparatus while waste water and product gas are extracted from the preheat zone. The hot gases are passed in countercurrent fashion to effect a preheating of the feed material.

Abstract: A mounting assembly 4 is provided for a feed tube 12 of a high-temperature fluid-wall reactor of the type having a vertically oriented reactor tube heated to incandescence for emitting radiation radially inward to a reaction zone. The mounting assembly 4 comprises a tube support 34 having an opening 42 through which the feed tube 12 can pass, and a pivot seat member 30 secured to the reactor. The assembly 4 further comprises a retainer 52 for selectively fixing the orientation of the feed tube relative to the reactor, and a releasable attachment mechanism 70 for allowing the axial position of the feed tube to be adjusted relative to the assembly 4. According to the method of the invention, undesirable conditions within the reactor are detected, and the orientation of the feed tube is pivotably adjusted in response thereto for reducing undesirable reactor operating conditions.

Abstract: An apparatus is presented for burning carbonaceous deposits off of fluidized particles. The apparatus is preferably employed as the catalyst regeneration zone of a fluidized catalytic cracking process. Heat pipes are used to cool the particles and transfer heat to an external steam generation zone. Preferably, the heat pipes extend vertically upward from an external catalyst transfer conduit to the steam generation chamber. The water level in the steam generation chamber or the density of the fluidized particles in contact with the heat pipes can be used to control the rate of heat removal from the combustion zone.

Abstract: A feed input assembly 2 for a high-temperature chemical reactor 4 includes a feed tube 6 having a feed inlet opening 8 and a feed-discharge opening 12. A cooling jacket 14 surrounds a length of the feed tube 6 extending from the feed-discharge opening 12. The cooling jacket 14 has an inlet 22 and an outlet 24 for respectively receiving and discharging a coolant. A coolant channel 17 is formed by a space between the cooling jacket 14 and the feed tube 6. The input assembly also includes flow-directing conduit means 32 for directing a flow of coolant from the inlet 22 of the cooling jacket 14 against inner wall portions of the feed tube 6 and cooling jacket 14 adjacent the feed-discharge opening 12.

Abstract: The present invention is concerned with the cooling of the fluidizable particulate solids, either catalytic or inert, in the regenerator section of an FCC process, an RCC process or a metals removal systems or "ART" type process. It is directed to the use of a conduit means for charging fluidizing gaseous material to a vertical cylindrical vessel for cooling fluidizable particulate solids flowing through said vertical cylindrical vessel, which conduits means comprises a horizontal header means having suspended therefrom a plurality of vertical and horizontally spaced apart conduits, each conduit having near its open end a restriction orifice. The header means can be located near the top of the cylindrical cooling vessel. While the example of a specific embodiment discloses one portion of the vertical conduits with lower ends located in a lower cross-sectional area of the vessel other arrangements sufficient to ensure proper fluidization are also possible.

Abstract: A fluid catalytic cracking (FCC) process and apparatus containing a reactor riser zone and radially extending sidearms as the first catalyst-hydrocarbon product separation means. Hydrocarbon products separated in the sidearms are conducted through an enclosed passageway to a secondary separation means, such as a cyclone. The catalyst is also conducted through the enclosed passageway to a stripping apparatus, wherein entrained hydrocarbons are removed therefrom. The enclosed passageway contains a means for accommodating sudden surges of catalyst flow and increased pressure, e.g., a trickle valve.

Abstract: A fluid catalytic cracking (FCC) apparatus and process comprising a reactor riser zone, a primary and a secondary cyclones, connected in series to the riser zone, and a stripping zone. The riser zone, the primary and the secondary cyclones, and the stripping zone, are placed within a single reactor vessel. The primary cyclone is connected to the reactor riser zone by an enclosed conduit which prevents random post-riser thermal cracking of the hydrocarbons after they exit the reactor riser zone. The conduit contains a trickle valve, or other means, to accommodate sudden increased surges of flow of the hydrocarbons and catalyst mixture.

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: For processing matter in a turbulent mass of particulate material, a substantially annular processing region (14; 104; 206) is provided and is preferably in the form of a substantially annular processing chamber having a radially inner wall which includes a waist (38; 122). A flow of fluid and matter to be processed are admitted to the processing region through one or more inlets (28, 46; 108, 124; 214, 220) with the flow of fluid being directed generally circumferentially into the processing region. In the processing region, matter to be processed is embedded in a compact turbulent band of particulate material for processing. Once processing is complete, the processed matter is withdrawn from the processing region, preferably by entrainment in an exhaust flow of the fluid.

Abstract: Integral apparatus is disclosed for fluidized bed reaction systems wherein one or more of the following system component elements are positioned in a unitary reactor body: cooler means, compressor means and fluid recycle conduit means. Such cooler means also serve as gas distributor means acting to support the fluidized bed.

Abstract: A fluidized bed heat exchanger having a plurality of tubes for passing a primary medium, a particulate matter bed, and side and base inlet conduits for passing the primary medium fluid into the heat exchanger with the base inlet conduit adapted to receive the primary medium and fluidizing the particulate matter bed. The primary medium passing through the inlet conduits is controllable to maintain a desired amount of fluidized particulate matter within the tubes when descaling is desired and reduced at the base inlet conduit to eliminate the fluidized particulate matter from flowing within the tubes when descaling is not desired while flow of the primary medium through the tubes is maintained.

Abstract: Method and a device for controlling the temperature of a reaction carried out within a vessel in a fluidized bed containing solid particles which can be entrained with the smoke and then recovered in a separating device and recycled into the fluidized bed after passage through a heat exchanger where they yield up their heat. The flow of particles separated from the smoke is divided into two parts, a hot part recycled directly into the fluidized bed and a cool part constituted by particles taken up at the outlet of the separating device and passed into the heat exchanger to constitute a reserve of cold material which can be mixed with the hot part before reinjection into the fluidized bed, the relative flow rates of the hot particles and of the cold particles being regulated so as to control the flow-rate and the average temperature of the flow of particles recycled into the fluidized bed for maintaining at the desired level the reaction temperature in the midst of the latter.

Abstract: A chamber for the treatment of particulate matter in a fluidized bed, e.g. at elevated temperatures, comprises an apertured bottom for the admission of carrier gas into the overlying space. The latter is divided by upstanding partitions into at least one medial compartment and at least two additional compartments adjoining the at least one medial compartment at the opposite sides of the latter. The apparatus further comprises a duct of substantially triangular cross-section with a horizontal base and an upwardly sloping side walls located in the at least one medial compartment, with the side walls of the duct extending in directions parallel to the partitions, and the base of the duct being imperforate and resting on the wall of the chamber and preventing the entry of the carrier gas into the at least one medial compartment from below; and a nozzle arrangement in each of the upwardly sloping side walls of the duct.

Abstract: Method and apparatus for regulating the heat transfer coefficient between a granular material and an exchange surface inside a heat exchanger in which a descending flow of a charge of material is arranged in the form of a mobile bed in contact with an elongated exchange member extending between lower and upper levels of the tank of the exchanger. The latter is provided with injection means for a gas into the charge of material. The flow conditions of the gas passing through the charge from below upwards are regulated so that the ascending flow speed is initially less than, at the base of the tank, the critical fluidization speed and then increases gradually to reach such critical speed at an adjustable level comprised between the lower and upper levels of the exchange member. The invention is especially applicable to heat exchangers used for cooling a granular material and/or for the heating of a heat transfer fluid.

Abstract: A fluidized bed reactor in which at least a portion of the walls of the reactor housing are formed by a plurality of water wall tubes. A fluidized bed is formed in the housing and a plurality of heat exchange tubes are provided, at least a portion of each of which extends into the bed. One or both ends of each heat exchange tube registers with a water wall tube and a water flow circuit is formed that includes the water wall tubes and heat exchange tubes for passing the water in a heat exchange relation with the bed.

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 heat exchanger including a serpentine heat transfer tube embedded in a fluidized bed contained in a vertical casing. The heat transfer pipe has a construction such that fluid undergoing heat exchange and particles of the fluidized bed do not move straightforwardly from an inlet port at the bottom of the casing toward an exit port at the top of the casing. The heat transfer tube includes a horizontal portion extending through a vacant space in the vertical casing above the fluidized bed, and this horizontal portion is provided with a plurality of spaced inclined fins which overlap with each other when viewed from above.