Abstract: A once-through boiler for producing steam from water comprising a boiler vessel having an interior portion, an inlet for passing the water into the boiler vessel, and an outlet. A first conduit is attached to the inlet for passing the water through said boiler vessel and is disposed in the interior of the vessel. A heater positioned within said interior portion and operable to generate heat for evaporating the water in the first conduit. A second conduit is connected to said first conduit at one end of the second conduit and to the outlet at the other end of the second conduit; wherein the second conduit passes the steam generated in the first conduit, and the heater is operable to heat the steam passing through the second conduit; wherein the second conduit attaches to the first conduit in the interior of the boiler vessel, passes externally to the vessel, and thereafter passes into the interior of the boiler vessel where the second conduit connects to the outlet.

Abstract: A single-drum recovery boiler comprising a superheater (2), boiler bank elements (3a) forming a boiler bank, and elements (3b) forming an economizer. In the recovery boiler, a plurality of boiler bank elements (3a) and economizer elements (3b) are disposed alternately so that a boiler bank--economizer unit (3) is achieved where the ratio between the boiler bank elements and the economizer elements is optimized in relation to the operating conditions of the boiler.

Abstract: The firing rate and the feedwater flow rate of a universal pressure boiler are controlled using a cascaded steam temperature control system. The secondary superheater outlet temperature comprises an outer loop for the control system, while the convection pass outlet temperature comprises an inner loop for the control system. Control variables for the system include the secondary superheater outlet temperature, the convection pass outlet temperature and the difference between the primary superheater outlet temperature and the secondary superheater inlet temperature.

Abstract: A superheater spray water control system for variable pressure applications produces an output signal representative of expected superheater absorption as a function of measured steam flow, compensates the signal for temperature variations within the superheater and adjusts it for over/under fire transients. An output signal representative of required superheater absorption from the drum to the superheater outlet, together with a spray water enthalpy signal obtained as a function of measured stem flow, is used with the compensated and adjusted actual superheater absorption and measured steam flow signals to produce a spray quantity demand signal.

Abstract: A system is disclosed for increasing the main steam temperature in a boiler/turbine installation to the maximum level consistent with safe operation of the installation. The difference between the main steam temperature and a system parameter is determined and used as an index to adjust the main steam temperature set point upward or downward. The system parameter selected for comparison with the main steam temperature may be the allowable variance between the main steam temperature and the main steam temperature set point or may be a "safety margin" temperature selected so as to be below the maximum allowable temperature for the installation.

Abstract: A cyclic velox boiler is described wherein solid carbonaceous fuels are burned in pressure vessel containers by cyclic compression and expansion with air or with air and steam as usual gas reactants. During compression air is forced deeply into the pores of the solid fuel and rapid primary burning to carbon monoxide results due to the large internal pore area available. During expansion the primary reacted gases emerge from the pores to mix and react fully with secondary air retained outside the pores in the container. Rapid and complete burning of the char fuel can be obtained in this two step, cyclic burning process and net useful mechanical work can be obtained from an expander engine. The containers and portions of the expander are cooled with water and the resulting steam can be used to generate additional work output via a steam power cycle.

Abstract: A superheater supported in a furnace and composed of a plurality of piping lengths in which the individual pipe lengths are supported in the furnace by a pair of hanger rods pivotally mounted to the pipe lengths substantially at the ends of the pipe lengths, the rods being slidably mounted to a support surface exterior of the furnace whereby the rods are free to move in a longitudinal direction parallel to the longitudinal axis of the pipe lengths. The inlet and outlet headers to and from the superheater can comprise the support surface for the hanger rods.

Abstract: Steam is generated by moving liquid into contact with a (pre-heated) heat retaining substance, typically metal. The heat retaining subtance is maintained at essentially a predetermined temperature by a heat responsive switch that electrically commences and terminates the combustion of fuel for heating the heat retaining substance. Fluid is moved into contact with the heat retaining substance in response to pressure changes in the apparatus so that the pressure within the apparatus is maintained at essentially a predetermined pressure. Superheated gas (steam) may or may not be formed in the process. An expanded surface area for heating the heat retaining substance is provided; an expanded surface area for heating fluid by the heat retaining substance is provided; and an expanded surface area for heating liquid by superheated gas, if present, is provided for generation of steam.

Abstract: Boiler outlet temperature in a sliding pressure operation is controlled in a routine way by varying the fluid or heat distribution in the boiler. The effect a change in pressure has on steam temperature is anticipated by supplying a feedforward signal to the temperature control system from drum pressure so as to minimize temperature variations at the boiler outlet.

Abstract: A boiler device comprises a cold water input for supplying cold water through a feed water heating system. A bottom ring is spaced from and positioned below the heating system for producing uniform distribution of feed water. A delivery pipe supplies heated water from the heating system to the bottom ring. The delivery pipe extends from the heating system to a point spaced from and above the bottom ring. A generating coil system is provided above the bottom ring for heating water supplied from the bottom ring and producing steam. A superheater coil system is provided above the generating coil system for superheating steam. Incline headers between the generating coil system and the superheater coil system supply steam from the generating coil system to the superheater coil system. A standpipe supplies superheated steam from the superheater coil system to an upper ring above the superheater coil system for storing superheated steam.