Abstract:
A process for energy recovery and transfer including: warming fresh air in a heat recovery and pressure control unit; feeding waste feed and the warm fresh air into a processor; reducing a moisture content of the waste feed by breaking the waste feed into a fuel powder in the warm fresh air in the processor; filtering contaminated air through an initial filter to remove the fuel powder from the contaminated air; pre-heating the contaminated air in the heat recovery and pressure control unit; raising the temperature of the pre-heated contaminated air in a chamber; passing the chamber discharge air through the heat recovery and pressure control unit to pre-heat contaminated air passing on to the chamber and to warm fresh air passing on to the processor; and filtering terminal air through a terminal filter to remove particles from the terminal air.
Abstract:
According to a method for drying fuels in the form of dust, particularly to be fed to a gasification process, such as coal, petroleum coke, biological waste, or the like, wherein the fuel (1) is crushed in a mill (2) and fed to a filter/separator (3) by means of a propellant and drying gas, and at least part of the propellant/drying gas in the circuit is returned to the mill (2) after heating, the known disadvantages are not only to be avoided, but particularly a cost-effective milling and drying method and a corresponding system are to be provided, having low emissions and a low inert gas requirement. This is achieved according to the method in that part of the propellant/drying gas flow in cooled down and dehumidified in a spray tower (6), or the like, wherein part of the dried gas exiting the spray tower is fed to the environment and/or a firing process, and the other part is returned to the propellant/drying gas flow.
Abstract:
The invention relates to a method for burning coal in a combustion chamber (1), preferably in large steam boiler facilities, in which combustion air (31) and coal (30) are introduced into the combustion chamber (1) via at least one burner (22a, b, c) and burned therein and part of the flue gas (31) produced is fed back to the combustion chamber (1), wherein coal (30) is fed pneumatically to the burner or to each burner (22a, b, c) by means of primary air. The inventive method is characterized in that part of the feed-back flue gas (31) is added to the primary air (32). The essential advantage of the inventive method is that NOx formation in coal furnaces is considerably reduced while maintaining constant efficiency, taking into account that a low oxygen concentration in the combustion of decay products (HCN, NH3, etc.) arising after the coal pyrolysis process is of key importance for the conversion rate of fuel nitrogen to NOx. Furthermore, by implementing the inventive measures, NOx emissions are reduced in such a way that the existing method for flying ash melt down in a melt cyclone can be used without exceeding the 200 mg/Nm limit value.
Abstract:
An apparatus and method for fuel preparation for example by milling and drying to produce a pulverous fuel supply are described. The apparatus includes a fuel preparation unit adapted to receive a mixture of fuel and a gas and to prepare the fuel for combustion in a pulverous state; an output conduit defining an output flow path for a mixture of pulverous fuel and gas from the fuel preparation unit; a phase separator disposed to receive the mixture from the output conduit and to separate the mixture into a gas phase comprising at least a major part of the gas from the mixture and a fuel phase comprising the pulverous fuel; a gas phase conduit defining a flow path for the gas phase from the separator; a heat exchanger preferably being a process fluid heat exchanger such as a feed water heat recovery heat exchanger fluidly connected to the gas phase conduit and adapted to receive and dry the gas phase. The method applies the principles embodied in the apparatus.
Abstract:
A system and method for drying pulverized high moisture fuel for use in a selective catalytic reduction system equipped combustion system is provided. The combustion system includes a mill for pulverizing fuel, an air heater, a booster air heater and a fuel duct for feeding dried pulverized fuel to a combustion furnace.