Feeding system for a lime reburning kiln
AssigneeA. Ahlstrom Corporation
InventorArto J. Ahvenainen
Life of this patent
Estimating the term…
Abstract
A method and apparatus for heat treatment of lime mud comprises drying of the lime mud to be introduced into the lime reburning kiln in a pneumatic dryer by means of flue gases discharged from the lime reburning kiln in order to regenerate the lime content of the lime mud. From a drying filter, the lime mud thickened to a dry solids content of over 75%, preferably to 80%, is introduced into a feed chamber through which an adjustment portion of the flue gas is conducted. Depending on the gas amount, 100% or less of the lime mud is entrained with the gas into the dryer, the remaining portion falling into the lower section of the feed chamber, wherefrom it is further transferred into the lime reburning kiln.
Claims9
A method of introducing lime mud into a rotary lime reburning kiln using a pneumatic dryer, and having a feed chamber with an upper section and a lower section, the upper section divided by a partition wall into two adjacent flow channels that are substantially vertical, said method comprising the steps of:
- feeding lime mud into the feed chamber from one of the adjacent flow channels so that at least a portion of the lime mud is entrained in an upwardly moving flow of flue gas emanating from the lime reburning kiln and flowing in at least one of the flow channels, so that the entrained lime mud is dried;
- feeding any remaining portion of the lime mud not entrained in the flue gas flow directly into the lime reburning kiln;
- separating the dried lime mud from the flue gas;
- and
- introducing the dried lime mud into the lower section of the feed chamber so that it is in turn introduced into the lime reburning kiln.
An apparatus comprising:
- a rotary kiln having an inlet, and first feeding means for feeding lime mud into said inlet,
- a feed chamber having an upper section and a lower section, said upper section divided by a partition wall into two adjacent flow channels, said flow channels being substantially vertical;
- said lower section of said feed chamber encasing at least a part of said first feeding means;
- a cyclone;
- said feed chamber connected to a substantially vertical part of a drying pipe, said drying pipe leading to said cyclone;
- a control baffle disposed at an upper part of said partition wall;
- a feed screw for dosing lime mud into said feed chamber from one of;
- and
- means for introducing dried lime mud separated by said cyclone into said lower section of said feed chamber.
Dependencies are inferred from the claim text.