The method in a recovery boiler comprises estimating the first melting temperature T.sub.0 of the fly ash depositing on heat transfer surfaces, the estimating being based on potassium (K) content of the fly ash; measuring or estimating the temperature T.sub.ss of superheated steam; evaluating a temperature difference T.sub.D1 between the first melting temperature T.sub.0 and the temperature T.sub.ss of the superheated steam, the temperature difference T.sub.D1 providing an estimate of the risk of corrosion; and selecting a control action for influencing the temperature difference T.sub.D1. Alternatively or additionally, the method comprises estimating the sticky temperature T.sub.STK of the fly ash depositing on heat transfer surfaces, the estimating being based on potassium (K) and chlorine (Cl) contents of the fly ash; measuring or estimating the temperature T.sub.FG of the flue gases; evaluating a temperature difference T.sub.D2 between the sticky temperature T.sub.STK and the temperature T.sub.FG of the flue gases; the temperature difference T.sub.D2 providing an estimate of the risk of plugging; and selecting a control action for influencing the temperature difference T.sub.D2.

The method in a recovery boiler comprises estimating the first melting temperature T.sub.0 of the fly ash depositing on heat transfer surfaces, the estimating being based on potassium (K) content of the fly ash; measuring or estimating the temperature T.sub.ss of superheated steam; evaluating a temperature difference T.sub.D1 between the first melting temperature T.sub.0 and the temperature T.sub.ss of the superheated steam, the temperature difference T.sub.D1 providing an estimate of the risk of corrosion; and selecting a control action for influencing the temperature difference T.sub.D1. Alternatively or additionally, the method comprises estimating the sticky temperature T.sub.STK of the fly ash depositing on heat transfer surfaces, the estimating being based on potassium (K) and chlorine (Cl) contents of the fly ash; measuring or estimating the temperature T.sub.FG of the flue gases; evaluating a temperature difference T.sub.D2 between the sticky temperature T.sub.STK and the temperature T.sub.FG of the flue gases; the temperature difference T.sub.D2 providing an estimate of the risk of plugging; and selecting a control action for influencing the temperature difference T.sub.D2.

A process for producing fly ash in a fluidized bed boiler includes combusting a fuel in a fluidized bed combustor in the presence of limestone particles, recovering fly ash, and recovering bottom ash. The fuel contains hydrocarbons and sulfur. A majority of the sulfur from the fuel is recovered from the bottom ash. The fly ash may contain less than 5% by weight of sulfur oxides. This may be achieved by using limestone particles having certain properties and/or narrowing an inlet from the boiler into a cyclone.

A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

A grizzly apparatus includes a plurality of grizzly bars arranged at predetermined intervals in a second direction perpendicular to a first direction which is an extension direction of center axes of the grizzly bars. Each of the plurality of grizzly bars is rotatable in a direction opposite to a direction of rotation of its adjacent grizzly bar so that a slit through which a screening target object passes and a gap through which the screening target object does not pass alternately emerge, between adjacent grizzly bars. The guide includes an outer member forming its outer shape, and has at least one guide surface inclined with respect to the second direction in such a way that the guide surface descends as the guide surface advances in the second direction toward the slit to guide the screening target object having fallen onto the guide to the slit.

A grizzly apparatus includes a plurality of grizzly bars arranged at predetermined intervals in a second direction perpendicular to a first direction which is an extension direction of center axes of the grizzly bars. Each of the plurality of grizzly bars is rotatable in a direction opposite to a direction of rotation of its adjacent grizzly bar so that a slit through which a screening target object passes and a gap through which the screening target object does not pass alternately emerge, between adjacent grizzly bars. The guide includes an outer member forming its outer shape, and has at least one guide surface inclined with respect to the second direction in such a way that the guide surface descends as the guide surface advances in the second direction toward the slit to guide the screening target object having fallen onto the guide to the slit.

The present invention relates to a combustion generation apparatus which generates power using organic materials. According to one embodiment of the present invention, the combustion generation apparatus includes a fuel supply unit which includes a plurality of single fuel suppliers configured to supply different organic raw materials, a fuel mixer configured to mix the organic raw materials supplied by the single fuel suppliers, and a mixed fuel supplier configured to receive the organic raw materials uniformly mixed in the fuel mixer, a reaction unit which includes a combustion chamber configured to burn the organic raw materials supplied by the mixed fuel supplier, and a generation unit which includes an internal generator configured to generate power using heat energy generated by a combustion reaction of the organic materials in the combustion chamber and an external generator configured to generate power using heat energy released outward from the combustion chamber.

A pellet stove includes a hopper for storing pellets, a basket for receiving the pellets by gravity, a duct for conveying combustion air to the basket, and a conduit for conducting heated air away from the basket. The position of the basket is adjustable, such as by raising and lowering it, or by rotating it, so as to control the number of pellets in the area of most intense combustion. One or more optional burn plates, positioned below the basket, provide platforms on which pellets falling through the basket can burn down to a smaller size. The pellet stove requires no external source of power. The stove so constructed enables quiet, efficient and clean burning of the pellets.

A pellet stove includes a hopper for storing pellets, a basket for receiving the pellets by gravity, a duct for conveying combustion air to the basket, and a conduit for conducting heated air away from the basket. The position of the basket is adjustable, such as by raising and lowering it, or by rotating it, so as to control the number of pellets in the area of most intense combustion. One or more optional burn plates, positioned below the basket, provide platforms on which pellets falling through the basket can burn down to a smaller size. The pellet stove requires no external source of power. The stove so constructed enables quiet, efficient and clean burning of the pellets.