Abstract: A concentric tube type recuperative heat exchanger that includes an outer transparent tube 22 and an inner metallic tube 24 connected to suitable headers 12 and 14. The outer tube 24 is closed at the bottom end and open at the top end in order that cool air may be directed down through the open ended inner tube and up through the annular space therebetween where it may accept radiant energy transmitted through transparent tube 22. A tubular heat shield 36 of apertured metal lying in the annular space between tubes absorbs radiant heat passing directly through transparent tube 22 and that which is reflected from inner tube 24. Shield 36 serves simultaneously as a means for increasing the turbulence of fluid flowing through the annular space between tubes and as a heat sink that absorbs heat radiated between tube walls.

Abstract: A centrifugal spreader type feeder that supplies a mixture of particulate limestone and coal to the top of a fluidized bed reactor having a flow of air upward therethrough. Large particles of particulate matter are distributed over the upper surface of the bed to utilize the natural mixing within the bed, while fine particles are adapted to utilize an independent feeder that separates them from the large particles and injects them into the bed.

Abstract: An organoclay functional as a rheological modifier for control of the viscosity and thixotropy of polyester-styrene compositions is prepared by a dry process wherein a quaternary ammonium salt is reacted with unfractionated smectite in an aqueous dispersion thereby eliminating the fractionating step required in the typical prior art wet process as exemplified by U.S. Pat. No. 4,240,951 and permitting the preparation of the organoclay rheological modifier to be carried out at a high solids content thereby reducing drying costs in the recovery of the product organoclay.

Abstract: An organically modified smectite is produced by reacting unfractionated pulverized bentonite with an aqueous dispersion or solution of a methyl benzyl dialkyl ammonium halide salt via cation exchange. The product organoclay is equivalent in quality to a "wet" processed organoclay, and has particular utility as an ingredient in forming invert emulsion drilling mud for enhancing the rheological properties of the mud. An invert emulsion drilling mud derived from an organoclay produced by the method of the present invention will have a viscosity of at least seventy (70) centipoise at 26 C and a 10-second gel strength at 26 C of at least thirty (30) pounds per 100 square feet.

Abstract: A centrifugal cleaner and assembly thereof for separating solids from a fluid suspension. Each cleaner has an accepts plenum chamber, a slurry inlet plenum chamber adjacent thereto, a rejects plenum chamber disposed in alignment with and spaced from the accepts and slurry inlet chambers, and an axially elongated tubular shell for defining a centrifugal separating chamber disposed between the accepts chamber and rejects chamber. A multiplicity of cleaners are nested in side-by-side alignment so that the slurry inlet chambers, the accepts chambers, and the rejects chambers are interconnected with their respective counterparts to form a longitudinally elongated accepts plenum, a longitudinally elongated slurry inlet plenum, and a longitudinally elongated rejects plenum which serve to provide fluid communication between each of the cleaners and the accepts collection tank, the slurry supply tank and the rejects collection tank.

Abstract: A multiple module heat exchanger having a serpentine path for one fluid to flow transversely through adjacent modules while a second fluid flows longitudinally therethrough. A guide pin carried by one module and a mating receptacle carried by a module adjacent thereto cooperate to permit relative longitudinal movement between modules while precluding relative transverse movement therebetween. The mating guide pin and receptacle are located at the central axis of adjacent modules whereby there may be a limited amount of pivotal movement between adjacent modules.

Abstract: A method of processing naturally occurring kaolin clay wherein ion exchange resins are utilized to remove charged soluble impurities from the clay thereby eliminating the filtration step required in conventional clay beneficiation process. Further, by saturating the ion exchange resin utilized with a bleaching agent, ferric ions in the clay will be reduced to soluble ferrous ions and removed from the clay without the conventional acid leaching.

Abstract: A fume incinerator (10) wherein the off gas (1) from an industrial process is incinerated to eliminate obnoxious fumes contained therein. The process gas stream (1) is first preheated and then passed over and through an array of burner assemblies (30) disposed within the preheated process gas stream (3). Fuel gas is supplied to the burners (30) and combusted therein to incinerate the process gas stream. The fuel gas is shielded from the preheated process gas (3) stream by passing a cooling gas over the surface of the fuel gas supply conduits (34) to each of the burners (30) in order to prevent overheating and consequent coking of the fuel gas in the supply conduit (34).

Abstract: A fume incinerator (10) and a method of operating same for eliminating combustible fumes from an oxygen bearing process gas stream (1). A first portion (11) of the oxygen bearing process gas (1) is passed to a burner (30) and serves as the source of oxygen for combusting an auxiliary fuel (9) to establish a flame front (28) within the incinerator. The remainder (13) of the process gas stream (1) is passed through the flame front for incineration of any obnoxious fumes contained therein.

Abstract: In a pulverized fuel-fired furnace (10), the temperature of the mixture of pulverized fuel and primary air leaving the mill (36) is measured and compared to a preselected minimum acceptable temperature. Whenever the measured mixture temperature drops below a preselected minimum, the flow damper (78) disposed in the tempering air duct (44) is closed to minimize the flow of tempering air therethrough and a heating fluid (62) is passed in heat exchange relationship with any ambient temperature air leaking past the flow damper in the tempering air duct thereby preheating the tempering airflow. Preferably, hot water (62) is circulated from the waterwall inlet header (22) of the water-cooled water walls (12) of the furnace (10) through a heat exchanger (60) disposed in the tempering air duct (44) and then returned back to the water-cooling circuit (24) of the water-cooled furnace walls at a location upstream of the circulating pump (26).

Abstract: A liquid level sensing apparatus (32) senses the level of liquid surrounding the apparatus. A plurality of axially spaced sensors (36) are enclosed in a separator tube (86). The separator tube (86) tends to collapse the level of a two-phase fluid within the separator tube into essentially a liquid phase and a gaseous phase where the collapsed level bears a relationship to the coolant inventory outside the separator tube. The level of the liquid phase is sensed by level sensing apparatus (32). The separator tube (86) contains inlet-outlet ports (90,92) near the top and bottom thereof to equalize the liquid level inside and outside the separator tube (86) when the level fluctuates or the water within the separator tube (86) flashes to steam. Each sensor (36) is comprised of a heater (64), a heated thermocouple junction (68) and an unheated thermocouple junction (66) within an elongated heat conductive housing (62).

Abstract: An electrostatic precipitator (10) of the type having a casing (12) defining a precipitation chamber (6) wherein a plurality of discharge electrode frames (32) are disposed alternately between a plurality of collecting electrode plates (20). Paired probe devices (50) are mounted on the collecting electrode plates for sensing the strength of the electrostatic field generated by at least one discharge electrode wire (36) at at least one location on each of the collecting electrode plates (20) disposed adjacent thereto. The electrostatic field strength sensed by the paired probe devices are compared with each other to provide an indication of the degree of imbalance, if any, existing between the sensed electrostatic fields experienced by the bounding electrode plates.

Abstract: In a pulverized coal-fired steam generator having a generally vertical furnace (1) and a plurality of fuel-air admission assemblies (10) arrayed in a vertical windbox (40) in one or more walls of the furnace (1), at least one of the fuel-air admission assemblies (10) being a low load fuel-air admission assembly having a split coal bucket (30) with vertically adjustable upper and lower coal nozzles (32,34), the remaining assemblies having vertically adjustable single nozzle buckets (28), a tilt apparatus (50,60) for vertically adjusting all nozzles in unison in response to steam temperature at high loads and for vertically adjusting the lower coal nozzles of the split coal bucket of the low load fuel-air admission assembly independent of all remaining nozzles at low loads.

Abstract: When a pulverized coal-fired furnace is operating at low loads, the primary air and pulverized coal stream discharging from the coal delivery pipe is split into a first and a second coal-air stream and independently directed into the furnace by tilting at least one of the streams away from the other, thereby establishing an ignition stabilizing pocket in the locally low pressure zone created between the spread apart coal-air streams.

Abstract: A pulverized coal-fired burner having a longitudinally elongated coal delivery pipe through which a stream of pulverized coal entrained in air is passed into the furnace and at least two air plenum chambers, one along the top and one along the bottom of the coal delivery pipe, connected in fluid communication with the interior of the coal delivery pipe at the discharge end thereof. A high pressure working fluid, such as air or flue gas, is passed through the plenum chambers into the coal delivery pipe so as to impinge against the coal-air stream passing therethrough thereby causing the coal-air stream to be deflected away from the longitudinal axis of the coal delivery pipe.

Abstract: A direct-fired, pulverized coal-fired furnace 2, wherein the fuel supply system is modified so that a load carrying pulverizer 10 supplying pulverized coal to the furnace through a plurality of burners 4 may simultaneously also supply pulverized coal to a storage bin 16 for storage therein until needed to start-up, warm-up and stabilize the low load firing of the furnace 2 at a later time.

Abstract: A dry, lightweight refractory mixture which can be shipped and stored in a dry form, but which becomes plasticized upon the addition of water to yield a moldable, air-setting, insulating refractory composition, the dry refractory mixture including from about 35 to about 70% by weight ceramic fiber; from about 10.5 to about 40% by weight setting agent, preferably a mixture of aluminum phosphate powder and calcined magnesia powder; from about 5 to about 20% by weight of dry, water-soluble, powdered resin binder prepared from urea formaldehyde or melamine formaldehyde, and from about 0.3 to about 2% by weight of dry, water-soluble, non-ionic, powdered organic polymer gelling and cohesion enhancing agent. The dry mixture also preferably includes from about 0.5 to about 2.0% by weight of a dry, water-soluble acidifying agent for catalyzing the air-setting of the plasticized composition.

Abstract: A method of casting a hollow bodied plate type recuperative heat exchange envelope. The heat exchange envelope comprises first and second envelope halves cast independently, then bonded together by fusion of molten metal of the second envelope half with solidified metal of the first envelope half. The first envelope half includes a lateral flange on opposite sides thereof that is confronted by the molten metal of the second envelope half to form a flange that connects envelope halves providing an increased area of contact therebetween. The flange of the second envelope half includes multiple surface areas that become fused to opposite sides of the first envelope half to form a strong connection impervious to fluid leakage.

Abstract: The method of casting a plate type recuperative heat exchange envelope that encloses a hollow space therein in a single casting operation. A sand core with a heat sensitive binder therein defines the hollow space within the envelope. The sand core is supported by end extensions and lateral protuberances which rest on the sides of a sand mold to provide a space therebetween that is subsequently filled with molten metal to comprise an envelope casting. Lateral openings through the envelope casting produced by the lateral protuberances and end openings produced by the end extensions provide passageways for venting gases produced within the sand core during the casting operation, and after completion of the casting operation the same openings in the envelope assist in the removal of the sand core therefrom. The lateral openings are subsequently plugged while the end openings are maintained open to direct the flow of fluid therethrough.

Abstract: A programmable controller (41) based logic system places two electronic output converters (14,18) in series for redundant protection against the inadvertent energization, due to the failure of an image register (66,68) or due to the shorted failure of a triac (10,12) on the output converters (14,18), of an energize-to-start, deenergize-to-stop field device (28). A control and monitor circuit monitors the image registers (66,68) and the output converter (14,18) triacs (10,12) that switch power on and off to the field device (28) to assure that the triacs (10,12) have not failed in an unsafe mode or that the image registers (66,68) have not failed. The monitor circuit continuously monitors both image registers (66,68), the first triac (10) and the series combination of the two triacs (10,12). The monitor circuit intermittently monitors the second image register (66) and the second triac (12). A failure of either or both triacs (10,12) or either or both image registers (66,68) energizes an alarm.