Abstract: A sector plate static sealing arrangement for a rotary regenerative air preheater employs a single rib attached to and extending along the center line of the sector plate toward the air preheater casing. The rib cooperates with a static seal attached to the casing to provide both the sealing and positioning functions. Braces for the rib provide support and form a sloped surface which reduces ash accumulation.

Abstract: A heat accumulator block for regenerative heat exchangers has a heat exchanger of a plurality of heat exchanger plates arranged substantially parallel to one another for formation of flow channels. A dirt collector is arranged upstream of a side of the heat exchanger exposed to an inflowing cold medium. The dirt collector consists of a plurality of protective plates which are arranged substantially parallel to the heat exchanger plates and have a plurality of spacers. The spacers are arranged between neighboring plates and connect the neighboring plates to one another. The spacers are positioned at a spacing to those edges of the protective plates which are exposed to an inflowing cold medium.

Abstract: A trisector air preheater includes sector plates between the primary air sector and the flue gas sector and between the secondary air sector and the flue gas sector which are of a large size so as to provide double radial seals. However, the sector plate between the primary and secondary air sectors is small and provides only a single radial seal. The one smaller sector plate reduces the pressure drop through the air preheater while sacrificing increased leakage only between air sectors. The axial seal between the primary and secondary air sectors may be maintained at a double seal size.

Abstract: A sealing arrangement for a quad sector rotary regenerative air preheater has a rotor rotatably mounted in a housing. The rotor has radially extending diaphragms forming compartments and radial seals extending along the edges of the diaphragms. Sector plates are positioned at the axial ends of the rotor to divide the preheater into a flue gas sector, a primary air sector and a first secondary air sector adjacent said flue gas sector and said primary air sector, and a second secondary air sector positioned adjacent said flue gas sector and said primary air sector. The sector plates between the flue gas sector and said secondary air sectors are in sealing engagement with two of the radial seals at all times and the sector plates between the primary air sector and the secondary air sectors are in sealing engagement with only one of the radial seals at any particular time.

Abstract: A twin-cell furnace for process stream preheat and utility steam superheat. The furnace uses a pair of vertical radiant cells with top supported, bottom guided, single row, multiple pass vertical coils fired on opposite sides by floor-mounted burners. An overhead convection section is centered between the radiant cells. Induced and forced draft fans are placed over the convection section to draw combustion gas into the stack and supply air through an air preheater, between the convection section and the stack, and to the floor burners and supplemental convection section burners. Additional convection coils are positioned in the hip section between the radiant cells and the convection section. The furnace design has reduced plot space requirements, increased flexibility in heating multiple services, and allows more even heating of the radiant tubes, and easier radiant tube replacement.

Abstract: An apparatus for introducing gas recirculation into a furnace to control steam temperature includes a hot air chamber for receiving hot air from an air preheater. The hot air chamber has at least one outlet communicating with the interior of the furnace. The apparatus includes a recirculation gas chamber for receiving recirculation gas from a recirculation fan and includes at least one outlet communicating with the interior of the furnace. Each of the chambers is disposed about at least a portion of the circumference of the furnace with one of the chambers disposed above at least a portion of the other. Ducts are provided between the hot air chamber and the air preheater and between the recirculation gas chamber and the recirculation fan to provide communication between the elements. A passageway is disposed between the hot air chamber and the recirculation gas chamber.

Abstract: A steam power plant for generating electric power has a fossil-fuelled boiler, a water-steam cycle for generating high-tension, superheated steam for a steam turbine, an economizer to transmit heat from flue gas to the feed-water, an air preheater to transmit flue gas heat to fresh air and devices for removing dust, sulphur and possibly nitrogen from the flue gases. In order to optimize heat exchange in the air preheater during operation and reduce the heat loses during start-up of the steam power plant, a heat exchanger system is provided with sections through which recirculated air and a heat vehicle medium flow, in which the section carrying the air is connected on the intake side to the fresh-air outlet of the air preheater and on the outlet side to the fresh-air intake of the air preheater.

Abstract: A method and a device for using excess heat of flue gas that is not required for operating a flue gas desulfurization device of a power plant is presented. Before being introduced into the flue gas desulfurization device. The flue gas is guided through preheaters for heating the combustion air and an electrostatic filter. The combustion air preheating step is achieved with two air preheaters, one arranged upstream of the electrostatic filter and one arranged downstream of the electrostatic filter. A partial flue gas stream is branched off at least before the first air preheater arranged upstream of the electrostatic filter. The partial flue gas stream is used to generate steam.

Abstract: An arrangement for utilizing the heat contained in the exhaust gas from a coal-fired boiler for preheating feed water for the boiler and for preheating primary air. The arrangement includes a rotating heat transfer unit and lines for conducting exhaust gas and preheated combustion air to the heat transfer unit. A heat shifting unit is connected in parallel to the heat transfer unit. A line conducts primary air to the heat shifting unit and another line conducts cooled exhaust gas from the heat transfer unit to the heat shifting unit. The exhaust gas line and the cooled exhaust gas line connecting the heat transfer unit and the heat shifting unit are connected through a bypass which bridges the heat transfer unit. The bypass includes a heat exchanger and/or steam generator, wherein the boiler feed water flows through the heat exchanger and/or steam generator.

Abstract: A heat exchanger assembly for a paint baking booth includes a horizontal cylindrical fire box with a vertical cylindrical hot gas riser chamber atop the fire box. A tube mounting plate across and sealed to the the top of the riser chamber extends outwardly from it. There is an array of circularly spaced fire tubes. Each tube has an entrance at the bottom of the mounting plate inside the top of the riser chamber, and extends upwardly and outwardly therefrom and then downwardly along side the riser chamber and then further outwardly and then upwardly parallel to the downward extending portion and then inwardly and upwardly into a stack for exhaust to the exterior of the building.

Abstract: A gas fired boiler for a domestic hot water and/or central heating system has a burner (25) (FIG. 1), a static heat exchanger (22) through which water is circulated, and a rotary heat exchanger (12) of which the body is a disc of ceramic material such as is currently used for catalytic conversion in automobile exhaust systems. The rotary heat exchanger recovers heat from the gases passing from the static heat exchanger (22) to the outlet flue 4, and uses this recovered heat for heating the fresh air entering through the air intake (3). A conduit (90) having a controllable valve (91) enables heated fresh air to be supplied for space heating purposes if required, while improving the thermal efficiency of the boiler by promoting condensation of water vapor from the combustion gases as they pass through the rotary heat exchanger.

Abstract: The exhaust air from the tenterframe (1) conveyed by a fan (7) is fed as combustion air to the burner (13) of a steam boiler (21). The burner (13) is operated with a variable and high excess of air of .lambda.=1,5 to .lambda.=3,5. The boiler output is regulated by the fuel supply. The excess of air is increased at low boiler load. The boiler exhaust gas is cooled down below the dew point via three heat exchangers (29,30,31). Thus complete combustion of the organic noxious substances in the tenterframe exhaust air and at the same time recovery, which can be readily utilized, of the tenterframe waste heat and a lowering of the fuel requirement of the steam boiler are achieved. The same method is also suitable for purifying the exhaust air from singers.

Abstract: A device for evacuating into the ambient air combustion products from a condensation boiler, in which at least one downstream section of the conduit for evacuating the combustion products is coaxial to the conduit for admission of the combustion air necessary for the burner. Means are provided for returning to the outside a fraction of the air collected in said admission conduit. The downstream section of the conduit for evacuating the combustion products, the coaxial section of the admission conduit and the means for returning to the outside a fraction of the collected air define a first heat exchanger. Means also are provided for diluting the combustion product with the fraction of collected air, the dilution means being located in the vicinity of the opening for suction of the combustion air and for rejection of the combustion products into the ambient air.

Abstract: Disclosed is a heating system of the multiple condensing boiler type wherein hot exhaust gases are in heat exchange relation with the condensate in a manifold common to the boilers. The exhaust gas conduits from the boilers open into the manifold at a level below the condensate level to prevent backflow of exhaust gases from active to idle boilers and enable the exhaust gases to bubble through the condensate in improved heat exchange relation therewith. A single outlet vents the exhaust gases from the manifold. The hot condensate is circulated in heat exchange relation with incoming atmospheric air in a second manifold common to the boilers for preheating the air flowing to the boilers. The cooled condensate is recirculated back to the first manifold. A single intake provides the incoming air to the second manifold.

Abstract: An exhaust gas boiler including a plurality of superheaters and reheaters disposed separately in a side-by-side relationship with each other in the upstream of exhaust gas flow and in a plane across the complete of said exhaust gas boiler, which comprises in combination a plurality of superheater means and reheater means separated into primary and secondary groups respectively in such a manner that the secondary superheater means and secondary reheater means are disposed side by side with each other, the primary reheater means being in the downstream of the secondary superheater means and the primary superheater means in the downstream of the secondary reheater means, the primary superheater means and the secondary superheater means being connected with each other, the primary reheater means and the secondary reheater means being connected with each other, respectively, and that there are provided a plurality of pass partition means between the superheater means and the reheater means.

Abstract: The present invention relates to a process and a device for preheating by combustion gases, a combustive gas intended to be mixed with a combustible gas before its combustion, comprising a box member containing a first, upper vertical exchanger in which the combustive gas is first heated by heat-exchange in counter-current relationship to itself and then in co-current relationship to the combustion gases, and a second exchanger incorporated in a burner and arranged below the first exchanger, the second exchanger allowing the combustive gas to be heated by heat exchange in co-current relationship and then in counter-current relationship to the combustion gases to finally be mixed with the combustion gas.

Abstract: A device for evacuating into the ambient air combustion products from a condensation boiler, in which at least one downstream section of the conduit for evacuating the combustion products is coaxial to the conduit for admission of the combustion air necessary for the burner. Means are provided for returning to the outside a fraction of the air collected in said admission conduit. The downstream section of the conduit for evacuating the combustion products, the coaxial section of the admission conduit and the means for returning to the outside a fraction of the collected air define a first heat exchanger. Means also are provided for diluting the combustion product with the fraction of collected air, the dilution means being located in the vicinity of the opening for suction of the combustion air and for rejection of the combustion products into the ambient air.

Abstract: A boiler having a discharge gas duct divided into a plurality of passages, respective passages having reheaters and superheaters therein. Gas flow controllers are provided for adjusting combustion gas flow through the respective passages. Evaporators are provided in the passages which have reheaters therein, the convective evaporators being downstream of the respective reheaters.

Abstract: A system for recovering the waste heat normally exhausted in the atmosphere by blast furnace stoves or other variable temperature process heaters. The system comprises a heat exchange apparatus located in the exhaust stack, heat transfer means for carrying the waste heat absorbed from the exhaust gases to a location remote therefrom, and a second heat exchange apparatus for releasing the transferred waste heat for beneficial use at the remote location. This invention also includes a reservoir for storing the heat transfer fluid used in the system and also the reservoir acts as a heat sink to moderate the temperature variation of the heat transfer fluid. The system also includes means for controlling temperature of the first heat exchanger and means for controlling the temperature of the variable temperature process heater. The preferred heat transfer fluid is maintained as a liquid during its use in the system.

Abstract: A method of controlling an air heater of a coal-fired boiler system comprising an air heater for heating a primary air used to dry a pulverized coal and convey it into the boiler and a secondary air to combust the pulverized coal by a heat exchange utilizing the exhaust gas discharged from the boiler as a heat source. The air heater includes a primary air heater and a secondary air heater arranged in parallel and the exhaust gas is introduced therein from the boiler by an induced draft fan with the flow rate of the exhaust gas being introduced into each of the air heaters being controlled by a respective gas damper. The heater primary air is mixed with a cold air to have a suitable temperature to dry and convey the pulverized coal, wherein the opening of the damper for the cold air is maintained at a low value of approximate 0% for maintaining the flow rate of the cold air low, while the suitable temperature is obtained by controlling the gas damper for the primary air heater.

Abstract: In a method in the operation of a firing plant of the type comprising a combustion furnace and heat exchanger means to transfer thermal energy from the flue gas of the furnace to its combustion air, wherein a vaporizable liquid, such as water, is added to the combustion air of the furnace, the combustion air pressure is reduced in the portion of the heat exchanger means where the said liquid is caused to evaporate, the necessary evaporation heat being taken from the flue gas of the furnace before the flue gas is discharged to the atmosphere. A plant for performing the method is characterized by containing a pump (11) which has a relatively small inlet opening (10) so that the pump (11) creates a negative pressure in the portion (12) of the heat exchanger (9) where the liquid, fed by means of a nozzle (13), evaporates. This allows large amounts of water to evaporate, and flue gas, which flows through the heat exchanger portion (14), is cooled to a low temperature.

Abstract: The invention comprising a drying and sorting apparatus for preparation of solid fuel and other solid materials having substantial surface moisture. Ambient air/gas is preheated by indirect heat exchange or other unfired means sufficiently to provide heat needed by the downstream process. The air/gas is then passed up vertically through a bed containing the solid materials, heating and fluidizing them along with the surface moisture. When in a fluidized state, the smaller/lower density particles rise to the top of the bed. At least a portion of the surface moisture on the particles is evaporated. The quantity and temperature of the air/gas flow is sufficient to retain the evaporated surface moisture in the vapor phase. Feedstock of solid materials is added to an intermediate location of the bed. The larger/more dense fluidized particles are removed from bottom location/s of the bed. The smaller/less dense fluidized particles are removed from top location/s of the bed.

Abstract: A device for heating air by flue gases in steam boilers and furnaces, comprises a supply flue, sections mating therewith, and a device for protection of heat-exchange tubes against abrasive wear arranged in the flue. Each section comprises heat-exchange tubes attached to tube plates. The device for protection of the heat-exchange tubes against abrasive wear incorporates at least one screen formed by corrugated sheets facing each other and mating along the lines of contact of sheet convex portions, whereby cells are made up.

Abstract: A heat regenerator indirectly utilizes the hot gases exhausted by a furnace or engine to heat the air supply to it, through the use of heat transfer fluids which function as an efficient heat transfer medium to implementation of the counterflow and direct contact heat transfer principles.

Abstract: The steam generator includes means for limiting the heat absorption of the economizer 28 during start-up and low load operation. An air bypass duct 54 is located to convey air from cold air duct 46 at a location between forced draft fan 44 and air heater 40 to the gas duct 38. The air is introduced upstream of economizer 28 where it mixes with hot flue gases to reduce the temperature of gas flowing through the economizer. Control dampers 56 are operated to maintain the desired temperature at the economizer outlet 30.

Abstract: An air heater comprises a plurality of passes, each having tube banks built into a gas conduit through which passes a flow of heating gas. It also comprises a plurality of delivery and collecting air ducts series-arranged one above the other. The delivery air ducts adjoin the tube banks of each pass and communicate therewith through outlets. The collecting air ducts adjoin the tube banks of each pass and communicate therewith by means of inlets. The collecting air duct is connected to the delivery air duct, the next-in-order along the flow of air, by means of interconnecting air conduits, which are positioned in the interspaces between the tube banks of each individual pass. Each interconnecting air conduit has an inlet orifice adapted to admit a flow of air passing from the collecting air duct, and an outlet orifice through which a flow of air passes from the interconnecting air conduit into the delivery duct.

Abstract: An apparatus and method for utilizing the heat of waste gases by exhausting the same at the head of a flue from a source into a heat extractor where the hot gases are caused to move and turbulate about heat exchanger walls to release their heat to such walls before being exhausted downward to the atmosphere so that fluids moved through the heat exchanger may be heated to perform useful work.

Abstract: A multiple pressure boiler is disclosed having a plurality of boiler sections, each section operating at a successively lower temperature and lower pressure than the preceding section. The intake air for the firebox is heated by the flue gases, then superheated by the steam, to provide heated air for combustion, and the steam from the highest pressure section is superheated by the flue gases prior to its being used in a steam turbine or other steam engine. The fuel for the firebox is heated initially by being used as the coolant for a steam condenser, and is superheated by superheated steam from the heat exchanger. It is contemplated that a sufficient quantity of heat will be removed from the flue gases that the solids will precipitate out, and the gas will be substantially at ambient temperature.

Abstract: In an air heater, mixers of hot and cold air are built into circulating air ducts between the passes of that portion of the air heater which is exposed to the danger of corrosion. Said mixers are provided in the form of tubes perforated lengthwise and located frontally in the respective pass. Headers serving the mixers are connected to cold air feeding ducts.Perforations the tubes of each mixer are provided with serve to direct jets of cold air at right angles to the flow of hot air.The tubes of the mixer are blanked off at the opposite ends of the adjacent tubes while the open ends of these tubes are connected to different cold air headers. Used as the tubes of a mixer can be a bunch of frontal tubes in the respective passes of the air heater.The air heater disclosed offers protection against corrosion by heating a mixture of cold and hot air to a minimum temperature, and said protection is achieved in a compact light-weight apparatus requiring minimum labor for its fabrication.

Abstract: An apparatus and method to permit the burning of high and varying moisture content fuels without requiring supplemental fuel (oil or gas) firing. The invention provides in-situ drying of the high and varying moisture content fuels by modulating the temperature of the combustion air entering the furnace (11) of the vapor generator (10). The variable flow paths taken by the air and flue gas are functions of the moisture content of the fuel being fired. The flue gas may be selectively by-passed around an economizer (20) for direct introduction into a first air heater (30). The gas is then passed through a precipitator (34) and a second air heater (40). Combustion air is passed through the second air heater (40) and may be then apportioned between the first air heater (30) and a by-pass (60) around the air heater (40) before introduction into the furnace (11).

Abstract: Heat is recovered from the flue gas stream discharged from a power plant combustion zone by heat exchange of the flue gas stream against the air stream which enters the combustion zone. Each gas stream flows through two rotating air preheaters, with a first preheater rotating at a constant rate and a second preheater rotating at a variable rate. The rate of rotation of the second preheater is varied to adjust the temperature of either the heated air stream or the temperature of the flue gas stream after passage through the preheaters.

Abstract: An air-cooled process heat exchanger is connected to a process fired heater which uses ambient air for combustion. The exhaust air from the heat exchanger is used as preheated air to the combustion furnace, resulting in energy savings and decreased fuel consumption.