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US 5,174,859 AGranted
Method for treating mechanical pulp plant effluent
AssigneeHpd, LLC
InventorsTimothy J. Rittof, Jean-Claude Patel
Life of this patent
Estimating the term…
Abstract
A method for treating a mechanical pulp plant effluent waste stream by freezing the effluent stream and separating frozen product. The frozen product contains between about 50 to 150 ppm chemical oxygen demand (COD), and may be reclaimed.
Claims12
A process for producing high purity water from a mechanical pulp plant effluent waste stream and recycling said water to the mechanical pulping process, said process comprising:
- a) indirectly cooling the effluent stream to a temperature near the freezing point of the stream;
- b) crystallizing a portion of the effluent stream to obtain a frozen product and a liquid concentrate;
- c) separating the frozen product from the liquid concentrate;
- and
- d) recovering and recycling a portion of the frozen product to the mechanical pulping process.
2 more elements
A method for treating a mechanical pulp plant effluent waste stream and recycling a portion of the stream to the mechanical pulping process, said process comprising:
- a) cooling the effluent stream by indirect means to a temperature near the freezing point of the stream;
- b) crystallizing the cooled effluent stream to obtain a crystalline water product and a liquid waste concentrate;
- c) separating the crystalline water product from the liquid waste concentrate;
- and
- d) recovering and recycling a portion of the crystalline water product to the mechanical pulping process.
2 more elements
Dependencies are inferred from the claim text.