Lime sludge kiln
AssigneeChampion International Corporation
InventorsJohn W. Boyden, II, James F. Schooling, Jr.
Life of this patent
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Abstract
A kiln for reclaiming quick lime for calcium carbonate sludge formed in the production of cooking liquors in a wood pulping process for the production of paper. The kiln provides increased output with lower energy input due to: measurement and control of oxygen content in the kiln; non-air mixing burner; castable refractory liner with tumbler ribs; a heat transferring chain system; and a variable speed exhaust fan and air flow control. The output of the kiln was increased by more than ten percent along with a forty-five percent improvement in energy efficiency at substantial cost reduction due to its efficient use of energy.
Claims2
A method of calcining lime sludge in a kiln, said method comprising the steps of:
- (a) providing a water-diluted supply of lime sludge;
- (b) removing a portion of the alkali content of the water-diluted lime sludge by vacuum filtration;
- (c) feeding the water-diluted filtered lime sludge into the kiln;
- (d) feeding the lime sludge in the kiln through a chain system wherein heat is added to the lime sludge to raise the temperature thereof and wherein the lime sludge is comminuted;
- (e) subsequently feeding the heated, comminuted lime sludge into a tumbling zone in the kiln wherein the lime sludge is mixed and tumbled by tumbling ribs within the kiln;
- (f) maintaining the temperature of the lime sludge in the range of about 1,800.degree. F. to about 2,000.degree. F. while in the tumbling zone;
- (g) maintaining the oxygen content in the kiln in the range of about 1% to about 2% during the calcining process;
- and
- (h) discharging calcined lime from the tumbling zone and the kiln.
Dependencies are inferred from the claim text.