Abstract: An ammonia injection grid for a selective catalytic reduction (SCR) system that provides uniform distribution of ammonia to the SCR catalyst in NOx reduction systems for heat recovery steam generation systems, packaged boilers, simple cycle catalyst systems and fired heaters for superior operational efficiency. The ammonia injection grid includes an injection tube having at least one nozzle for injecting ammonia into a flow of flue gas. The ammonia injection grid also includes a corrugated turbulence enhancer associated with the injection tube to generate turbulent wake to enhance turbulent mixing.

Abstract: A multi-bed selective catalytic reduction system comprising a gas input duct, a first ammonia injection grid assembly located downstream from the gas input duct, a first selective catalytic reduction catalyst assembly located downstream from the first ammonia injection grid assembly, a second ammonia injection grid assembly located downstream from the first selective catalytic reduction catalyst assembly, a second selective catalytic reduction catalyst assembly located downstream from the second ammonia injection grid assembly, and an exhaust stack located downstream from the second selective catalytic reduction catalyst assembly.

Abstract: A fired equipment system and process for operating same is provided that combines stationary industrial burner technology and a catalyst bed that converts pollutants formed during combustion of fuel and air in the burner to yield stack gases that need no further treatment before discharge to the atmosphere. The system and process disclosed reduces CO, NOx and VOC's by at least 90 to 95%.

Abstract: An improved burner assembly and process for operating same using a burner design that produces very low levels of undesirable nitrogen oxides is provided. The burner assembly premixes primary fuel and air in a venturi system and recirculates combustion gases back to the burner through a plurality of recirculation conduits where it is mixed with the premix of fuel and air and secondary air prior to combustion in a primary combustion zone. Rapid premixing of the primary fuel and air in the venturi system and the dispersion of the recirculated furnace gases is believed to result in lower peak flame temperatures and therefore minimizing the formation of the pollutants, such as nitrogen oxides.

Abstract: A quench system for cooling hot flue gases from combustion systems is disclosed. The quench system includes a venturi mounted in a quench vessel. The water level in the quench vessel may be raised or lowered in accordance with the flow rate of the gases to be quenched. When the pressure drop across the venturi is insufficient to achieve the desired cooling to adiabatic saturation temperature, the water level is increased so that the downcomer connected to the venturi is submerged and the additional pressure drop further cools the flue gases.

Abstract: A system for reducing volatile organic compounds, particulates and carbon monoxide in exhaust from a wood products dryer is disclosed. The dryer exhaust is combined with waste wood or biomass fuel and partially combusted in a rotary gasifier, then fully combusted in a secondary combustion chamber. Hot flue gasses form the secondary combustion chamber are used to heat the conduits carrying the exhaust from the dryer, to heat oil, and to preheat air input to the dryer.

Abstract: A flare burner comprises a stack conduit, a plurality of gas distributing conduit extending radially from the stack conduit, and a plurality of gas supersonic gas nozzles connected to the gas distributing conduit. The stack conduit supplies flare gas to each of the gas distributing conduits, with gas communication therebetween. In one embodiment, the nozzles are directly connected to gas distributing conduit and in another embodiment the nozzles are connected to the gas distributing conduits via vertically extending burner conduits. The gas discharged through the supersonic nozzle flows at a supersonic velocity. The length of the burner conduits attached to the same gas distributing conduit becomes progressively shorter as the burner conduits are positioned further away from the stack conduit.

Abstract: A vapor recovery unit comprising a vapor inlet for taking up hydrocarbon vapor from a loading facility or the like, and thereafter alternately allowing the vapor to flow to one of at least two adsorber vessels. Each adsorber vessel includes an entry port in the bottom of the adsorber vessel for receiving vapor. Hydrocarbons are retained on activated carbon beds in the adsorber vessels, resulting in purified air or other carrier gas which is removed through a discharge port also in the bottom of each adsorber vessel and released through an elevated vent to the atmosphere. Hydrocarbon vapor is desorbed from the adsorber vessel by a vacuum system and directed to a separator/absorber vessel wherein the desorbed vapor which has passed through the vacuum system is brought into contact with a hydrocarbon absorbent liquid or condenser. In use, when one adsorber vessel is taking in vapor from the vapor inlet, the other adsorber vessel is having its adsorbent bed desorbed or regenerated.

Abstract: A burner assembly for process heaters or the like comprising a burner block, primary gas jets, secondary gas jets, a flame holder, and an air register for installation in a furnace wall or furnace floor is described. The burners are characterized in that primary fuel is introduced into the primary combustion zone of the burner at an angle horizontal to the flame holder whereby the fuel induces furnace gases from the furnace into the primary combustion zone. Similarly, the secondary fuel jets introduce a secondary fuel through the burner block for consumption in a combustion zone at the surface of the burner block. The secondary fuel also draws furnace gases into the combustion zone for consumption. The design provides for intense mixing of combustion air with the fuel and furnace gases, resulting in low NO.sub.x levels.