Apparatus for reclaiming waste gas treating chemical
First Claim
1. Apparatus for concentrating or reclaiming a waste aqueous solution of a chemical having a decomposition temperature, said apparatus comprising:
- a still for subjecting said solution, heated to a temperature below said decomposition temperature, to a high vacuum of at least 16 inches of mercury in order to produce a vapor and a liquid residue;
vacuum generating means communicating with said still to generate said high vacuum in said still;
a heater for heating a portion of said liquid residue received from said still, said heater comprising an internal space, at least one burner for producing combustion gases which pass through said internal space, and tube means for conveying said portion of said liquid residue in a single pass through said internal space in a direction generally co-current to said combustion gases;
pump means for moving said portion of said liquid residue from said still through said tube means at a velocity high enough to prevent a film of said liquid residue immediately adjacent to inner surfaces of said tube means from being heated to a temperature exceeding said decomposition temperature;
mixer means for thoroughly mixing said portion of said liquid residue from said heater with a feed of said waste aqueous solution of said chemical to effect heating of said feed solution;
cooler means for condensing vapor from said still to produce a liquid condensate; and
a plurality of pipe means for conveying said feed of said waste aqueous solution of said chemical to said mixer means, heated liquid residue from said heater to said mixer means, liquid from said mixer means to said still said portion of said liquid residue from said still to said pump means and from said pump means to said tube means of said heater, and vapor from said still to said cooler means.
1 Assignment
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Accused Products
Abstract
Process and apparatus for reclaiming or concentrating waste aqueous solutions of gas treating chemicals, such as alkanolamines, used for removing acid components or water vapor from natural gas. The process involves heating the waste solution under a high vacuum to form a vapor and a liquid residue. The temperature and vacuum can be varied to form a vapor consisting mainly of water vapor or a vapor containing both water vapor and vaporized gas treating chemical. The vapor is subsequently condensed or passed through a wash column to produce a concentrated solution. The liquid residue is heated by passing it through a single pass, generally co-current heater at a rate which avoids localized overheating of a liquid to a temperature above the decomposition temperature of the gas treating chemical. The heated liquid residue is then used to heat the feed waste solution by being thoroughly mixed with it, thus avoiding overheating of the feed solution. The production of corrosive elements and the use of prolonged residence times is avoided so that the apparatus may be made of carbon steel rather than more expensive stainless steel.
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Citations
8 Claims
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1. Apparatus for concentrating or reclaiming a waste aqueous solution of a chemical having a decomposition temperature, said apparatus comprising:
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a still for subjecting said solution, heated to a temperature below said decomposition temperature, to a high vacuum of at least 16 inches of mercury in order to produce a vapor and a liquid residue; vacuum generating means communicating with said still to generate said high vacuum in said still; a heater for heating a portion of said liquid residue received from said still, said heater comprising an internal space, at least one burner for producing combustion gases which pass through said internal space, and tube means for conveying said portion of said liquid residue in a single pass through said internal space in a direction generally co-current to said combustion gases; pump means for moving said portion of said liquid residue from said still through said tube means at a velocity high enough to prevent a film of said liquid residue immediately adjacent to inner surfaces of said tube means from being heated to a temperature exceeding said decomposition temperature; mixer means for thoroughly mixing said portion of said liquid residue from said heater with a feed of said waste aqueous solution of said chemical to effect heating of said feed solution; cooler means for condensing vapor from said still to produce a liquid condensate; and a plurality of pipe means for conveying said feed of said waste aqueous solution of said chemical to said mixer means, heated liquid residue from said heater to said mixer means, liquid from said mixer means to said still said portion of said liquid residue from said still to said pump means and from said pump means to said tube means of said heater, and vapor from said still to said cooler means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification