Dryer for fuel material

摘要

The invention relates to a dryer for drying fuel materials such as wood bark, wood chips, sludge, garbage, peat moss or the like. In a preferred embodiment the dryer comprises a conveyor, consisting of twin endless belts, which carries the material to be dried along a vertical path defined between parallel runs of the endless belts, and ductwork which serves to direct heated air (received from any appropriate source) across the vertical path to remove moisture from the material as it is being conveyed. The ductwork includes at least one feed duct for use in delivering the heated air to one side of the vertical path, and at least one exhaust duct for use in withdrawing moisture-laden air on another side of the vertical path.

主权项

1. A dryer for drying a material to be used as fuel using a drying gas, the dryer comprising:
conveying means for conveying the material to be dried along a substantially vertical path extending between an upper end of the conveying means where the material is received and a lower end of the conveying means where the material is discharged; and, directing means for directing the drying gas across the vertical path to remove moisture from the material as the material is conveyed along the vertical path, the directing means comprising a feed duct means for use in delivering the drying gas to the conveying means on a first side of the vertical path, and an exhaust duct means for withdrawing the drying gas from the conveying means on a second side of the vertical path; wherein the conveying means comprises a plurality of flights connected to a conveyor, the conveyor having a substantially vertical first run and a substantially vertical second run, the first run defining the first side of the vertical path and the second run defining the second side of the vertical path; wherein a first group of the plurality of flights is connected to the first run and a second group of the plurality of flights is connected to the second run, wherein the plurality of flights convey the material along the vertical path, wherein the plurality of flights move through the vertical path in pairs, each pair of flights being defined by a flight of the first run and a flight of the second run disposed in side-by-side relationship, wherein the vertical path is substantially closed by each pair of flights, thereby constraining the material from moving along the vertical path faster than the flights; anda feed conveyor located at an upper end of the conveying means for receiving the material to be dried and distributing the material across the top of the vertical path;wherein the feed conveyor comprises:
a feed conveyor housing having a first end portion where the material to be dried can be received, a second end portion, and an opening running along the bottom of the feed conveyor housing between the first and second end portions, the opening in the feed conveyor housing being substantially aligned with the top of the vertical path; and, a worm gear rotatable in the feed conveyor housing for moving material received at the first end portion towards the second end portion, whereby, the material is distributed along the opening in the bottom of the feed conveyor housing and falls under gravity into the conveying means; anda feed sensor end switch attached to the second end portion of the feed conveyor housing for detecting when a predetermined quantity of the material has accumulated at the upper end of the conveying means between the first and second endless belts.