Abstract: A horizontal cyclone separator in which a furnace section and a vortex chamber communicating with the furnace section and having an inlet which extends a fraction of the length of the furnace section receives a mixture of the gaseous products of combustion and solids entrained by the gases. A coaxially disposed tube extends partially into the chamber to allow the separated gases to exit the separator. A ring-shaped solids deflector is disposed on the vertical wall opposite the coaxially disposed tube to prevent solids from bouncing off the rear wall towards the center of the separator and into the path of the separated gas stream. The separated solids fall into an outlet trough formed in a lower portion of the furnace section for returning the solids to the furnace section.

Abstract: An over-fire air control system for a pulverized fuel furnace, in which a burner assembly is provided for discharging a fuel/primary air mixture along with secondary air to combust the fuel. The amount of primary air and secondary air discharge is controlled to achieve incomplete combustion, and an overfire air port is provided through which additional air is discharged to complete the combustion. The overfire air port receives two streams of air, one high in volume and low in velocity and the other low in volume and high in velocity. Dampers are provided for controlling the air streams to achieve optimum quantifies and velocities of the air. According to one embodiment, a source of one of the air streams is the primary air portion of the fuel/primary air mixture applied to the burner assembly. As a result, the formation of nitrous oxides are reduced and fairly precise air fuel ratios can be maintained despite variations in the quality of the fuel and the pressure and amount of primary air.

Abstract: A system and method for preheating a mixture of fuel and air as the mixture is introduced into a furnace combustion chamber comprises passing the mixture through a nozzle extending into an upstream portion of an opening defined in a wall enclosing the combustion chamber. The nozzle is sized so that an annular space is formed between the nozzle and the opening. Hot air is introduced through the annular space and mixes with and preheats, in a downstream portion of the opening, the mixture passing through the nozzle. The preheated mixture then passes into the furnace combustion chamber for combustion therein.

Abstract: A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided and includes a steam drum disposed adjacent the fluidized bed and a series of tubes connected at one end to the steam drum. A portion of the tubes are connected to a water drum and in the path of the air and the gaseous products of combustion exiting from the bed. Another portion of the tubes pass through the bed and extend at an angle to the upper surface of the bed.

Abstract: A jet pump is provided in the downcomer of a natural circulation fossil fuel burning vapor generator to enhance circulation in the vaporizer circuits of the vapor generator. A driving fluid pump is adapted to introduce liquid taken from the drum as driving fluid for the jet pump, and the liquid passing through the downcomer acts as driven fluid for the jet pump.

Abstract: A vapor generating system in which a vapor generating section and a superheating section are connected in a series flow relationship with a fluid separating section extending between the vapor generating section and the superheating section. The vapor generating section includes an upright furnace section formed by a plurality of tubes, a portion of which extend at an angle with respect to the horizontal plane for passing fluid through the length of the furnace section to convert a portion of the fluid to vapor or to heat the fluid.