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US 2005/0133359 A1Published application
Process for recovering methylene chloride
AssigneeXerox Corporation
InventorsThomas Glenwright, Warren Smith, Betsy Dodge, Steven Wazenkewitz, Ronald Swift
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Abstract
A system for recovering methylene chloride from an aqueous waste stream is disclosed. The system includes a distillation unit, at least one heat transfer unit, receptacles for methylene chloride and waste product, a temperature probe and a controller configured to selectively divert product flow from the distillation unit to either of the receptacles or to a recycle line back to the distillation unit depending upon the temperature measured by the probe. Also disclosed is a related process of recovering methylene chloride with such a system.
Claims13
A system for recovering methylene chloride from an aqueous waste stream, said system comprising:
- a distillation unit having an inlet adapted to receive an aqueous waste feed stream containing methylene chloride and produce a product stream at an outlet of said unit;
- at least one heat transfer unit in communication with said product stream and adapted to transfer thermal energy from said product stream, said heat transfer unit having an inlet and an outlet for said product stream, said inlet of said heat transfer unit being in communication with said product stream of said distillation unit;
- a methylene chloride receptacle having a first selectively controllable inlet valve;
- a waste receptacle having a second selectively controllable inlet valve,
- a recycle flow line having a third selectively controllable inlet valve, said recycle line being in communication with said feed stream;
- wherein each of said methylene chloride receptacle, said waste receptacle, and said recycle flow line is in selective communication with said outlet of said heat transfer unit for receiving said product stream;
- a first temperature sensor adapted to measure the temperature of said product stream exiting said distillation unit;
- a second temperature sensor adapted to measure the temperature of the bottoms of said distillation unit;
- and
- a controller in communication with said first and said second temperature sensors, said first selectively controllable inlet valve, said second selectively controllable inlet valve, and said third selectively controllable inlet valve;
- whereby upon said first temperature sensor sensing said product stream having a particular temperature, and said second temperature sensor sensing said distillation unit bottoms having a particular temperature, said controller independently actuates each of said first, second and third inlet valves to recover methylene chloride from said aqueous waste stream.
8 more elements
A system for reclaiming methylene chloride from a mixture including methylene chloride and water, said system comprising:
- a distillation unit having an inlet for receiving said mixture and an outlet for a product exiting said unit;
- a plurality of control valves having an inlet and at least a first, a second, and a third outlet, said inlet of being in communication with said outlet of said distillation unit, said plurality of control valves adapted to divert flow from said valve inlet to one of said first, second, or third valve outlets upon actuation;
- a flow line providing communication between said third valve outlet and said inlet of said distillation unit;
- a plurality of temperature sensors adapted to measure the temperature of said product exiting said distillation unit and the temperature of a lower region of said distillation unit, and providing at least one output signal indicative of said measured temperatures;
- a controller adapted to receive said at least one output signal from said temperature sensors and actuate said plurality of control valves;
- whereby upon said temperature sensors measuring a particular temperature of said product exiting said distillation unit and a particular temperature of said lower region of said distillation unit, said controller actuates said plurality of control valves to divert flow from said inlet to one of said first, second, or third outlets of said valves.
3 more elements
A process for improving the reclaim efficiency of methylene chloride from a mixture including water and methylene chloride, said process comprising:
- providing a system including (i) a distillation unit having an inlet and an outlet, (ii) a plurality of selectively positionable control valves, each having an inlet and an outlet, one of said outlets being in communication with said inlet of said distillation unit, (iii) a plurality of temperature sensors and means for providing a control signal corresponding to sensed temperatures, and (iv) a controller in communication with said temperature sensors and said control valves;
- directing said mixture including water and methylene chloride to said inlet of said distillation unit;
- operating said distillation unit to produce a product stream at said outlet of said distillation unit;
- measuring the temperature of said product stream and at a lower region of said distillation unit with said temperature sensors;
- providing said control signal from said temperature sensors to said controller;
- operating said controller to selectively position said control valves based upon said control signal;
- whereby upon measuring the temperature of said product stream to be greater than 101.5° F. and the temperature at said lower region of said distillation unit to be greater than or equal to 104.5° F., said controller positions said control valves to direct said product stream to said inlet of said distillation unit.
4 more elements
Dependencies are inferred from the claim text.