Abstract: Method and apparatus for enhancing the heat transfer efficiency and lowering the temperature of tube walls used in a tubular gas to gas heat exchanger. The heat exchanger utilizes essentially flat sided tubes for the transfer of heat from hot gas flowing over the tubes to a cooler gas flowing therethrough. The apparatus of the invention includes a metallic heat shield inserted into the tubes between sides thereof to intercept radiation from the outer walls of said tubes and transfer it to the cooler gas flowing therethrough.

Abstract: Regenerative heat exchange apparatus (12) for the transfer of heat from a heating fluid (hot gas) to a fluid to be heated such as air. Valve means (16-A, 18-A, 22-A, 24-A) control the flow of heating fluid and the fluid to be heated to and through their respective ducts in the heat exchanger. A bypass duct (38) reversely directs heating fluid through the heat exchanger (12) to displace heated air trapped therein after the valve (24-A) controlling the air supply has been closed.

Abstract: A magnetohydrodynamic generator (30) is fired with a clean, medium BTU combustible gas produced in an oxygen atmosphere. The combustible gas is generated in an oxygen blown coal gasifier (10) and cleaned of sulfur compounds, nitrogen compounds, and particulate matter before being delivered to the burner (32) of the MHD generator (30). An air separation plant (70) is provided to supply oxygen to both the MHD burner (32) and the coal gasifier (10). Nitrogen from the air separation plant (70) is preheated and utilized to dry the coal supplied to the gasifier (10). A vapor generator (40) is disposed downstream of the MHD generator (30) to receive and cool the hot gases exiting therefrom thereby generating steam.

Abstract: A method of operating an entrained flow coal gasifier (10) via a two-stage gasification process. A portion of the coal (18) to be gasified is combusted in a combustion zone (30) with near stoichiometric air to generate combustion products. The combustion products are conveyed from the combustion zone into a reduction zone (32) wherein additional coal is injected into the combustion products to react with the combustion products to form a combustible gas. The additional coal is injected into the reduction zone as a mixture (60) consisting of coal and steam, preferably with a coal-to-steam weight ratio of approximately ten to one.

Abstract: The method of effecting an evacuated space above a quantity of vaporizable fluid contained in a conventional heat pipe. A quantity of vaporizable fluid 10 is admitted into the heat pipe 12 through an inlet assembly to displace residual air in the heat pipe for exhaust through vent 24. When the heat pipe is full of fluid, the inlet assembly including valve 16 and fitting 24 is removed and coupling 26 plugged. Pump 26 having a suction connection to the heat pipe is actuated, and fluid is withdrawn from the heat pipe through check valve 18 leaving an evacuated space to form above a predetermined quantity of vaporizable fluid. A cylindrical standpipe 38 above check valve 18 precludes the evacuation of vaporizable fluid from said heat pipe lower than the upper rim of said standpipe.

Abstract: In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.

Abstract: A fossil fuel is burned substoichiometrically in the combustor (10) of a MHD power plant to produce a high temperature, fuel-rich product gas (7). The product gas is passed through a MHD channel (12) to generate electricity. A reducing agent (9), preferably natural gas or hydrocarbon, is injected into the fuel-rich product gas (7) leaving the MHD generator (14); and the resulting mixture is held at a temperature in the range of 950.degree. C. to 1500.degree. C. for about 1 second to permit the reducing agent to decompose a portion of the nitrogen oxides formed in the combustor. The fuel-rich product gas (11) then passes thru an afterburner (18) wherein combustion is completed and any excess reducing agent is consumed.

Abstract: A soot blower assembly (10) for use in combination with a coal gasifier (14). The soot blower assembly is adapted for use in the hot combustible product gas generated in the gasifier as the blowing medium. The soot blower lance (20) and the drive means (30) by which it is moved into and out of the gasifier is housed in a gas tight enclosure (40) which completely surrounds the combination. The interior of the enclosure (40) is pressurized by an inert gas to a pressure level higher than that present in the gasifier so that any combustible product gas leaking from the soot blower lance (20) is forced into the gasifier rather than accumulating within the enclosure.

Abstract: A method for rapidly changing the amount of pulverized coal supplied to a coal-fired furnace (10) equipped with a coal pulverizer (20) from a first steady-state level to a second steady-state level in response to a change in operating load demand. The amount of pulverized coal supplied to the furnace is instantaneously increased by providing pulverized coal to the furnace from a source (42) independent of the pulverizer or instantaneously decreased by diverting away from the furnace a portion of the pulverized coal being supplied by the pulverizer.

Abstract: A method of burning a sulfur-containing fuel in a fluidized bed of sulfur oxide sorbent wherein the overall utilization of sulfur oxide sorbent is increased by comminuting the bed drain solids to a smaller average particle size, preferably on the order of 50 microns, and reinjecting the comminuted bed drain solids into the bed. In comminuting the bed drain solids, particles of spent sulfur sorbent contained therein are fractured thereby exposing unreacted sorbent surface. Upon reinjecting the comminuted bed drain solids into the bed, the newly-exposed unreacted sorbent surface is available for sulfur oxide sorption, thereby increasing overall sorbent utilization.

Abstract: A flame scanner has a sensing circuit (10) utilizing a photosensitive device (12) for monitoring and a logic circuit (20) which includes a flame detection circuit (22) and a fault detection circuit (24). The photosensitive device produces a current signal (13) indicative of the intensity of the flame. The current signal is fed to a logarithmic amplifier (14) and converted to a voltage signal (15). The voltage signal (15) powers an LED (18) with its output (4) impinging on the photosensitive device (12). The voltage signal (15) is also transmitted to the flame detection circuit and the fault detection circuit for simultaneous and independent processing. The flame detection circuit continuously processes the signal to determine if a stable flame is present, while the fault detection circuit continuously monitors the integrity of the photosensitive device and its associated sensing circuitry.

Abstract: A Kraft pulping process by which spent pulping liquor is burned in a recovery furnace 12 to reduce inactive alkali sulfates therein to active alkali sulfides while producing molten smelt that when added to water forms green liquor and residual dregs bearing catalytic iron. The dregs are separated from the green liquor and divided into first and second portions. The first portion of the dregs is discarded while the second portion of dregs required to maintain a concentration of iron in the smelt at from 0.05% to 5% is recirculated back to the furnace to provide optimum catalytic reduction of alkali sulfates to alkali sulfides. A quantity of alkali metal compounds is added at 24 to the pulping liquor in line 10 to serve as a temperature depressor that, together with the co-addition of said dregs, lowers the temperature of the molten smelt in furnace 12 from approximately 800.degree. C. to a more favorable temperature of about 650.degree. C.

Abstract: A rotary regenerative heat exchange apparatus having a rotor 10 carrying a mass of heat absorbent material that is ultimately exposed to a hot and a cold fluid in order that heat absorbed from the hot fluid may in turn be transferred to the cold fluid. The rotor 10 is surrounded by a housing 18 including a sector plate 30 at the hot end of the rotor that separates the fluids. A turndown indicator 40 operatively associated with the hot end sector plate 30 is provided so that the operator may at any time determine the amount of turndown of the rotor thereby permitting adjustment of the sector plate or other sealing means to reduce to a minimum any fluid leakage between the hot and cold fluids throughout a wide range of temperature variation and thermal expansion.

Abstract: The temperature of the flue gas entering a spray dryer SO.sub.2 absorption chamber (26) is increased so as to maintain the temperature of the flue gas leaving the spray dryer SO.sub.2 absorption chamber (26) at a preselected temperature above the adiabatic saturation temperature of the flue gas so as to permit greater amounts of sulfur oxide absorbent slurry (36) to be sprayed into the flue gas, thereby allowing the treatment of flue gas containing high levels of sulfur oxide.

Abstract: A baghouse filter apparatus including a collapsible bag filter assembly (20) for separating from a gas solid particles entrained therein. The collapsible bag filter assembly comprises a plurality of fabric filter bags (22) extending between a grid sheet (26) and a tube sheet (24) with at least one sheet being movable toward the other sheet and the other sheet being slidably mounted on rails (42). Legs (40) are provided to guide the movement of the one sheet toward the other so as to keep the grid sheet and tube sheet parallel and properly aligned as the bag filter assembly is collapsed. Once the assembly is collapsed, it may be easily slid out of the baghouse (10) through an access opening (30) in the baghouse to facilitate inspection, repair, and bag removal at a location external of the baghouse.

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: A bag filter housing (10) having filter bag tensioning means for providing a predetermined tension on each filter bag (28). The tension may be quickly released by means of a lever (40) incorporated into the bag tensioning means thereby allowing the filter bags to be quickly removed and replaced as necessary to maintain optimum dust collection performance.

Abstract: A superconducting magnet assembly (10) having a channel (12) through which a high temperature, high pressure, ionized gas may be passed while immersed in a high strength magnetic field produced therein by a magnet substructure (16) disposed about the channel and a support superstructure (20) for absorbing and equilibrating the repulsive magnetic forces generated within the magnet substructure (16) when the magnet substructure (16) is energized. The inner surface of the magnet support superstructure (20) and the outer surface of the magnet substructure (16) are machined to provide a catenary-shaped interface (24) therebetween.

Abstract: A superconducting magnet assembly (10) suitable for use as a magnetohydrodynamic generator having an elongated channel (12) through which a high temperature, high ionized gas may be passed while immersed in a high strength magnetic field produced therein by a plurality of elongated saddle-shaped superconducting magnet rings (16) disposed side-by-side in planes parallel to the longitudinal axis of the channel as symmetrical pairs with the end turns of each of the rings outwardly directed. A compression member end support (30), preferably wedge-shaped, is disposed between the end turns of the symmetrical pairs of saddle-shaped superconducting magnet rings (16) so as to absorb the attractive forces generated between the end turns.

Abstract: A steam generating diffuser comprising a plurality of heat exchange tubes arranged to form a horizontally disposed, longitudinally elongated open-ended divergent duct. A refractory lining is laid up around the inner surface of the divergent duct so as to protect the heat exchange tubes. The inlet of each heat exchange tube is connected to a lower water distribution header disposed beneath the duct and the outlet of each heat exchange tube is connected to an upper steam and water distribution header disposed above the duct. Each tube provides a fluid flow path between the lower and upper headers which is continuously upwardly directed.