Abstract: A hybrid, wet electrostatic precipitator has multiple precipitation zones for removing particulate and contaminants from a flue gas stream. A first precipitation zone has at least one discharge electrode and at least one collection plate made of a metal or a fiber glass reinforced plastic. A second precipitation zone has at least one discharge electrode and at least one collecting electrode which is a porous membrane sheet. The precipitation zones are in series with one another.

Abstract: An over fire air (OFA) port arrangement for a pulverized coal-fired boiler or furnace has at least one OFA port through each of the sidewalls for injecting OFA to increase residence time for each burner level. Plural OFA ports may be employed, staggered both vertically and horizontally to effectively deliver over fire air to the burner flames at the appropriate time and location to most efficiently reduce the formation of fuel NOx. OFA port configurations for both single-wall and opposed-wall fired furnaces and boilers are provided.

Abstract: A particulate separator includes a plurality of perforated screens which remove ash particulate from flue gas. A rapper assembly dislodges ash deposits on the perforated screens by exerting a vibrating force thereon. Shafts, which are operatively connected to a rapping device, are received in the openings of perforated screens and welded thereto. The rapper exerts a force on the shaft, which, in turn, vibrates the perforated screen. The vibration of the perforated screens causes the ash deposits to fall off into the hopper.

Abstract: A steam generator circulation system is provided and includes a boiler feed pump for forcing water through an economizer, and through the waterwall tubes of an evaporator. A separator receives a mixture of steam and water and sends the steam to a steam utilization unit such as a superheater. A valve is provided below the separator. If the valve is open, the saturated water from the separator is mixed with feedwater and recirculated through the tubes of the evaporator. If the valve is closed, recirculation is terminated. At loads below the critical point, the valve below the separator system would be open and the boiler would operate like a natural circulation drum boiler. At loads above the critical point, the valve below the separator system would be closed resulting in a boiler that operates like a once-through boiler.

Abstract: A heat exchanger is provided in an air duct between an air heater and a windbox of a combustion means such as a boiler. Dilution air is carried to the heat exchanger from a dilution air fan in a separate duct. The heat in the air from the air heater is transferred to the dilution air via the heat exchanger and the heated dilution air is sent to vaporize ammonia before the ammonia is introduced into an exhaust duct with a selective catalytic reduction (SCR) chamber. A bypass valve is provided around the heat exchanger for blending heated and unheated air to control the temperature of the dilution air.

Abstract: A radiant syngas cooler used to contain and cool the synthesis gas produced by coal gasification processes employs radiant and convection surfaces in a specific arrangement to achieve a cost-effective, compact design.

Abstract: The present invention is related to a system for removal of moisture and contaminants from recirculated flue gas. The system includes a spray tower for spraying the flue gas with a liquid reagent to remove contaminants from the flue gas. A heat exchanger, integrally connected to the spray tower, cools the liquid reagent before the reagent is sprayed onto the flue gas stream. Cooled liquid reagent improves the condensation of the water vapor in the flue gas during the spraying process and provides a lower moisture content flue gas exiting the system. Combustion process efficiency improves as flue gas redirected to the burner for combustion contains.

Abstract: A gas temperature control system for maintaining a desired economizer outlet gas temperature across a range of boiler loads comprises a plurality of tubular configurations having surfaces that are in contact with the flue gas. Each tubular configuration, preferably, comprises a plurality of serpentine or stringer tubes arranged horizontally or vertically back and forth within the economizer, and each tubular configuration having a separate feedwater inlet. Heat transfer from the flue gas is accomplished by controlling the feedwater flow rates through the tubular configurations. In a temperature control system having two tubular configurations, the overall heat transfer capacity of the economizer may be reduced to maintain the desired economizer outlet gas temperature during low boiler loads by reducing feedwater flow through one tubular configuration and by overflowing the other tubular configuration, such that total flow of feedwater through the economizer is maintained substantially constant.

Abstract: End support for parallel tubes of a superheater or reheater with a bend tubular portion, a linear tubular portion extending away from each end of the bend tubular portion, and a supporting member formed on a curved section of the bend tubular portion. The tubular portions form a connection between two consecutive parts of a fluid passage. In a preferred embodiment, the tubular portions and the supporting member are integrally formed, molded or cast of a suitable material, such as carbon steel, stainless steel, chromium-nickel alloy, or other suitable alloys that have high temperature strength and oxidation resistance. The supporting member is configured to securely attach the end support configuration to the wall support brackets on the wall support tube. Preferably, the supporting member and the wall support bracket slide on one another to provide relative movement between the superheater tubes and the wall support or boiler tubes.