Apparatus for distillation column side stream withdrawal

Claim 2

In combination with a multi-stage countercurrent distillation column having an upper fractionation stage above a withdrawal outlet for use in withdrawing a liquid side draw from the column and a lower fractionation stage below said withdrawal outlet, an apparatus, for dividing a liquid source into a reflux portion of measured and controlled flowrate that passes by gravity flow to the lower fractionation stage, and a side stream portion that is withdrawn from the distillation column through said withdrawal outlet, which apparatus comprises (a) a liquid reflux reservoir adapted to collect said liquid source, said reservoir positioned at an elevation intermediate to that of the upper and the lower fractionation stages, said reflux reservoir having in association therewith (b) means for maintaining a liquid level within the reflux reservoir, said reflux reservoir being in liquid communication with said withdrawal outlet via (c) flow passage means adapted to direct the side stream portion of the liquid source to the withdrawal outlet, and said reflux reservoir being in liquid communication, through (d) first liquid conduit means, with (e) control valve means adapted to pass a controlled flowrate of said reflux portion of the liquid source, via (f) second liquid conduit means, to (g) a metering chamber positioned at an elevation below the reflux reservoir, said chamber having (h) at least one flow orifice through which passes the reflux portion to the lower fractionation stage, and said chamber having in association therewith (i) liquid level measuring means for monitoring of liquid level in the chamber.

Claim 3

In combination with a multi-stage countercurrent distillation column having an upper fractionation stage above a withdrawal outlet for use in withdrawing a liquid side draw from the column and a lower fractionation stage below said withdrawal outlet, an apparatus, for dividing a liquid source into a reflux portion of measured and controlled flowrate that passes by gravity flow to the lower fractionation stage, and a side stream portion that is withdrawn from the distillation column through said withdrawal outlet, which apparatus comprises (a) a liquid receiver transversely divided by a reflux weir into a reflux reservoir and a side stream reservoir, (b) a means for directing a portion of the liquid traffic flowing down the distillation column from the fractionation stage above the side stream outlet into the reflux reservoir of the receiver, said portion being of greater flowrate than the reflux flow, and for directing liquid traffic with the exception of said portion into the side stream reservoir of the receiver, (c) a control valve means positioned external to the column at a vertical elevation below that of the top of the reflux weir, (d) a first liquid conduit extending from the reflux reservoir to the control valve means, (e) a metering chamber positioned at a vertical elevation below the top of the reflux weir, said chamber having one or more flow orifices in liquid communication with the lower fractionation stage, (f) a means for measuring liquid level in the metering chamber, (g) a second liquid conduit extending from the control valve means to the metering chamber, and (h) a means for communicating side stream liquid from the side stream reservoir of the receiver to the side stream withdrawal outlet of the distillation column.

Claim 4

In combination with a multi-stage countercurrent distillation column having an upper fractionation stage above a withdrawal outlet for use in withdrawing a liquid side draw from the column and a lower fractionation stage below said withdrawal outlet, an apparatus, for dividing a liquid source into a reflux portion of measured and controlled flowrate that passes by gravity flow to the lower fractionation stage, and a side stream portion that is withdrawn from the distillation column through said withdrawal outlet, which apparatus comprises (a) a liquid receiver transversely divided by a reflux weir into a reflux reservoir and a side stream reservoir, (b) a means for directing a portion of the liquid traffic flowing down the distillation column from the fractionation stage above the side stream outlet into the reflux reservoir of the receiver, said portion being of greater flowrate than the reflux flow, and for directing liquid traffic with the exception of said portion into the side stream reservoir of the receiver, (c) a control valve means positioned external to the column at a vertical elevation below that of the top of the reflux weir, (d) a first liquid conduit extending from the reflux reservoir to the control valve means, (e) a metering chamber positioned at a vertical elevation below the top of the reflux weir, said chamber having one or more flow orifices in liquid communication with the lower fractionation stage, (f) a means for measuring liquid level in the metering chamber, (g) a second liquid conduit extending from the control valve means to the metering chamber, and (h) a means for communicating side stream liquid from the side stream reservoir of the receiver to the side stream withdrawal outlet of the distillation column.

Claim 5

In combination with a multi-stage countercurrent distillation column having an upper fractionation stage above a withdrawal outlet for use in withdrawing a liquid side draw from the column and a lower fractionation stage below said withdrawal outlet, an apparatus, for dividing a liquid source into a reflux portion of measured and controlled flowrate that passes by gravity flow to the lower fractionation stage, and a side stream portion that is withdrawn from the distillation column through said withdrawal outlet, which apparatus comprises (a) a liquid receiver transversely divided by a reflux weir into a reflux reservoir and a side stream reservoir, (b) a means for directing all liquid traffic flowing down the distillation column from the fractionation stage above the side stream outlet into the reflux reservoir of the receiver, (c) a control valve means positioned external to the column at a vertical elevation below that of the top of the reflux weir, (d) a first liquid conduit extending from the reflux reservoir to the control valve means, (e) a metering chamber positioned at a vertical elevation below the top of the reflux weir, said chamber having one or more flow orifices in liquid communication with the lower fractionation stage, (f) a means for measuring liquid level in the metering chamber, (g) a second liquid conduit extending from the control valve means to the metering chamber, and (h) a means for communicating side stream liquid from the side stream reservoir of the receiver to the side stream withdrawal outlet of the distillation column.

Claim 6

In combination with a multi-stage countercurrent distillation column having an upper fractionation stage above a withdrawal outlet for use in withdrawing a liquid side draw from the column and a lower fractionation stage below said withdrawal outlet, an apparatus, for dividing a liquid source into a reflux portion of measured and controlled flowrate that passes by gravity flow to the lower fractionation stage, and a side stream portion that is withdrawn from the distillation column through said withdrawal outlet, which apparatus comprises (a) a liquid receiver transversely divided by a reflux weir into a reflux reservoir and a side stream reservoir, (b) a means for directing all liquid traffic flowing down the distillation column from the fractionation stage above the side stream outlet into the reflux reservoir of the receiver, (c) a control valve means positioned external to the column at a vertical elevation below that of the top of the reflux weir, (d) a first liquid conduit extending from the reflux reservoir to the control valve means, (e) a metering chamber positioned at a vertical elevation below the top of the reflux weir, said chamber having one or more flow orifices in liquid communication with the lower fractionation stage, (f) a means for measuring liquid level in the metering chamber, (g) a second liquid conduit extending from the control valve means to the metering chamber, and (h) a means for communicating side stream liquid from the side stream reservoir of the receiver to the side stream withdrawal outlet of the distillation column.

Claim 8

The apparatus according to claim 4, wherein the flow orifices are located in one or more side walls of the metering chamber.

Claim 9

The apparatus according to claim 4, wherein the receiver is a draw tray equipped with transverse weir, vapor chimney, and overflow downcomer.

Claim 10

The apparatus according to claim 6, wherein the metering chamber is disposed in a space defined by the wall of the distillation column and the overflow downcomer.

Claim 11

The apparatus according to claim 4, wherein the control valve means is adapted to respond automatically to a control signal generated by an operating parameter of the distillation column.

Claim 12

The apparatus according to claim 8, wherein the means for measurement of liquid level in the metering chamber also serves a control function by generating signals in response to which the control valve means is automatically operated to maintain an essentially constant liquid level in the metering chamber.