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 combustion and heating chamber into which a fluid is pumped under pressure is provided. A burner is positioned in the combustion and heating chamber to provide a heat load to the pressurized fluid in the chamber. As the fluid is heated its internal pressure is greatly raised providing a force for driving the heated air through a spiral conduit that encircles the combustion and heating chamber. An insulated outer wall is fitted around the spiral conduit and in contact with it. The individual wraps of the spiral conduit do not lay side by side, but are spaced apart. Relatively cool process air is drawn into the spaces between the separate wraps of the spiral conduit, which is thereby formed as a second spiral space intertwined with the spiral conduit between the combustion and heating chamber wall and the outer wall. The process fluid is therefore in contact with the walls of the spiral conduit.

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: 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 combustion air heating system includes both an air heater for preheating the combustion air by heat exchange with flue gases and an air preheater for preheating the combustion air prior to entry into the air heater. The air preheater operates by heat exchange between the combustion air discharge from the air heater and a bypass stream of combustion air located upstream of the air preheater. The amount of combustion air flowing through the bypass duct is controlled so that the temperature in the air heater does not fall below the dew point of the acid gases present in the flue gas.

Abstract: A compact and maintenance-free means and method of regenerating the sensible heat from flue gases of fossil fuel furnaces by heat exchange through two circular layers of rock beds rotating under two semi-circular mantles with the first mantle applying hot flue gases to the beds and the second withdrawing preheated ambient air needed for combustion by said furnaces. When used for power plant flue gas treatment, layers of acid-resistant pipes containing boiler feedwater are sandwiched between the two rock bed layers to usefully recover the heat units arising from moisture condensation. The enormous water of condensation collects flyash and sulphur dioxide thus removing these pollutants from the stack gases. The heavy rock beds rotate slowly beneath the fixed mantles in a circular, pan-shaped, steel vessel floating on and cooled by a circular pond of water. Friction of rotation is minimal and gas leakage principally prevented by liquid seals. When flue gas temperature rises, as above 600 degrees F.

Abstract: In the recovery of waste heat from flue gas containing particulate solids, CO.sub.2, SO.sub.2, SO.sub.3 and H.sub.2 O, several improvements are provided, e.g., passing hot flue gas, e.g., from a power plant, over heat exchange surface attackable by sulfuric acid, e.g., in a combustion air preheater, so as to release heat to said heat exchange surface and to partially cool said flue gas to a temperature within the range of about 350.degree. F.

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: Being a heat pipe heat exchanger wherein a group of heat pipes are arranged in box form and the central part thereof is partitioned, a high temperature fluid being let to flow into one and a low temperature fluid into the other one, respectively, so that, by the specific properties of the heat pipes, the heat given from the high temperature fluid is transferred to the low temperature fluid through the sealed-in fluid in the heat pipes, a plurality of heat pipes of which those on at least the high temperature fluid passage side are bare pipes are arranged to extend over both passages, and the heat pipes on the high temperature fluid passage side are inserted in finless outer pipes. At least the outer surface of these finless outer pipes is treated for resistance to corrosion. Also, these finless outer pipes and the heat pipes are joined by a heat conductive material, so that heat pipes can be easily demounted, and, therefore, the efficiency of the heat exchanger can be varied as required.

Abstract: A combustion air preheater for heating combustion air with heat energy provided from flue gas includes both a heat pipe type heat exchanger for effecting low temperature heat transfer between the flue gas and the combustion air and a tube-and-shell type heat exchanger for effecting higher temperature heat transfer. The preheater includes a first heat exchanger, having first and second heat transfer compartments with a plurality of heat pipes extending therebetween and a second, connected heat exchanger which includes a plurality of heat tubes supported by tube sheets within a shell. Ducting is provided to direct flue gas over the tubes of the second heat exchanger and then through one of the compartments of the first heat exchanger and additional ducting is provided to direct combustion air through the other compartment of the first heat exchanger and through the tubes of the second heat exchanger.

Abstract: A heat transferring device for transferring heat from an upper to a lower location utilizing a mechanical pump and motor to provide fluid transport. The device is entirely encased within a single vertically disposed member requiring no external plumbing and a minimum of fabrication. The resulting device is both compact and cost effective.

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: In a pulverized fuel-fired steam generator, a steam air heater is disposed in the air inlet duct to the main air heater. Steam from an auxiliary in-plant source or from the boiler itself is passed through the steam air heater thereby increasing the temperature of the air entering the main air heater. The flow rate of steam passed through the steam air heater is regulated to maintain the flue gas temperature entering dust collection equipment located in the flue gas stream downstream of the main air heater above the dew point of water vapor and the condensation point of sulfuric acid during start-up and low load operations.

Abstract: A system for recovering the waste heat normally exhausted into the atmosphere by chemical or other processing plants. The invented system comprises a substantially self-contained apparatus for receiving hot exhaust gases and extracting the waste heat therefrom for some beneficial use, such as pre-heating inlet air in an inlet plenum. The system may include temperature and pressure controls which enhance the safety and efficiency of the system's operation, and further may include flow controls in a multiple burner installation so that the desired fuel air ratios and heat distribution may be achieved. By building the present invention as a substantially self-contained and self-supporting assembly, on site installation time and the required alternation of pre-existing on site equipment may be minimized, thereby affecting substantial economic savings by minimizing the resulting down time of the processing plant.

Abstract: A system for recovering heat from the exhaust gases of a heat generator in which a conduit connects the heat generator to the discharge stack and a fan forces the hot gases from the heat generator to the stack. A heat recovery unit removes heat from the gases as they pass through the conduit and an inner stack is disposed in the discharge stack and has an inlet in communication with the conduit and an outlet for discharging the gases. An additional conduit connects the heat generator to the discharge stack for permitting a natural flow of the gases from the heat generator to the discharge stack during inoperation of the fan.

Abstract: Combustion air feed to a fuel burner is warmed with water otherwise destined for evaporative cooling in a cooling tower or spray pond; then the resulting warmed air is sent to combustion while the resulting cooled water is further cooled by evaporation for recycle use.