US 9,964,303 B2 · Combustion boiler with pre-drying fuel chute

Abstract

A solid fuel boiler with one or more fuel chutes configured to pre-dry wet solid fuel prior to loading into a combustion chamber of the boiler, enabling higher thermal efficiencies and burning less fuel to produce the same steam quantity. The pre-drying fuel chutes pass through the boiler where hot combustion gases radiantly and convectively—heat the chute walls to dry the wet solid fuel by radiant, convective, and/or conductive heating. Agitator mechanisms or structures within the chute mix the fuel for uniform heating, break up clumps of wet fuel, regulate the speed of falling fuel, prevent sticking, dry the fuel by means of steam and/or hot air, transport and deliver a cooling medium while a chute is offline in an operating boiler, and suppress fire using steam injection. Fuel from the chute can flow into a fuel storage bin or directly into the combustion zone of the furnace.

Claims31

Dependent claims

A solid fuel boiler, comprising:

walls defining a combustion chamber;
a combusting zone within the combustion chamber into which solid fuel is delivered for combusting;
a heated zone within the combustion chamber and above the combusting zone through which gases heated in the combustion zone pass;
and
a fuel chute positioned within the heated zone adjacent one of the walls, the fuel chute including:
walls separating the fuel in the chute from the hot gases in the heated zone, the walls being heated by hot gases in the heated zone and radiating heat to the fuel within the chute, wherein the fuel within the chute absorbs heat, and is thereby partially dried;
a first opening through which solid fuel enters the fuel chute from outside the combustion chamber, the solid fuel having a first moisture content;
and
a second opening through which the fuel exits the chute, the fuel exiting the chute having a second moisture content, the second moisture content being lower than the first moisture content.

6 more elements

Dependencies are inferred from the claim text.

Combustion boiler with pre-drying fuel chute

Life of this patent

Combustion boiler with pre-drying fuel chute

Life of this patent

Abstract

Claims31