US4193839A — Flow control method and apparatus for continuous …

Claim 1

Independent Claim 283 words

A method for treating cellulose fiber material utilizing an inner vertically extending vessel having a diameter D and an outer vertically extending vessel having a diameter E greater than D, and a bottom portion of the inner vessel extending into the outer vessel and defining an annular liquid-filled space in the outer vessel between the innner vessel and the outer vessel, said method comprising the steps of passing cellulose fiber material through said inner vessel into said outer vessel to establish a column of cellulose fiber material extending downwardly from the bottom portion of the inner vessel, introducing cellulose fiber material treating liquid into said material column for treatment of said material, preventing channeling of liquid flow through said column by establishing at least three distinct stationary flow areas of fiber material treating liquid through said column to the annular space in the outer vessel, at least two of the three distinct stationary flow areas having liquid being withdrawn therethrough from the column through the annular space, and at least one of the flow areas not having liquid being withdrawn therethrough, withdrawing the liquid through the flow areas from the annular space in the outer vessel at a rate, relative to the dimensions of the vessels, such that a stilling well effect is created in said annular space and fiber material from said column is not entrained in liquid flow in said annular space and so that no screening of the liquid flow is necessary; forcing liquid back into said annular space through one of said flow areas while withdrawal of liquid takes place through at least two flow areas; and continuously switching which of the flow areas liquid is forced back into.

Claim 2

Independent Claim 283 words

A method for treating cellulose fiber material utilizing an inner vertically extending vessel having a diameter D and an outer vertically extending vessel having a diameter E greater than D, and a bottom portion of the inner vessel extending into the outer vessel and defining an annular liquid-filled space in the outer vessel between the innner vessel and the outer vessel, said method comprising the steps of passing cellulose fiber material through said inner vessel into said outer vessel to establish a column of cellulose fiber material extending downwardly from the bottom portion of the inner vessel, introducing cellulose fiber material treating liquid into said material column for treatment of said material, preventing channeling of liquid flow through said column by establishing at least three distinct stationary flow areas of fiber material treating liquid through said column to the annular space in the outer vessel, at least two of the three distinct stationary flow areas having liquid being withdrawn therethrough from the column through the annular space, and at least one of the flow areas not having liquid being withdrawn therethrough, withdrawing the liquid through the flow areas from the annular space in the outer vessel at a rate, relative to the dimensions of the vessels, such that a stilling well effect is created in said annular space and fiber material from said column is not entrained in liquid flow in said annular space and so that no screening of the liquid flow is necessary; forcing liquid back into said annular space through one of said flow areas while withdrawal of liquid takes place through at least two flow areas; and continuously switching which of the flow areas liquid is forced back into.

Claim 3

Dependent Claim 59 words

A method as recited in claim 1 wherein said step of establishing at least three distinct flow areas is accomplished by providing at least three baffles extending through said annular space past the lower portion of said inner vessel in said outer vessel, a separate outlet nozzle being associated with each of said flow areas defined by adjacent baffles.

Claim 4

Dependent Claim 43 words

A method as recited in claim 1 comprising the further step of introducing said cellulose fiber material treating liquid into said material column at a distance J below the inner vessel bottom portion, said distance J being equal to or greater than 1/2E.

Claim 5

Dependent Claim 27 words

A method as recited in claim 1 comprising the further step of heating the liquid withdrawn from the annular space and reintroducing it into said material column.

Claim 6

Dependent Claim 27 words

A method as recited in claim 1 wherein said fiber material treating liquid is digesting liquor, and wherein said outer vessel defines a continuous digester cooking zone.

Claim 7

Dependent Claim 25 words

A method as recited in claim 1 wherein said fiber material treating liquid is washing liquid, and wherein said outer vessel defines a washing zone.

Claim 8

Dependent Claim 38 words

A method as recited in claim 1 wherein said step of establishing at least three distinct flow areas is accomplished by providing at least three baffles extending through said annular space into the column of cellulose fiber material.

Claim 9

Dependent Claim 247 words

Apparatus for the treatment of cellulose fiber material comprising an inner vertically extending vessel having a diameter D; an outer vertically extending vessel having a diameter E wherein E is larger than D; a bottom portion of said inner vessel extending into said outer vessel and defining an annular liquid filled space in said outer vessel between said inner vessel and said outer vessel; means for introducing cellulose fiber material treating liquid into a column of fiber material in said outer vessel; means for drawing liquid introduced into said column in said outer vessel from said annular space to an area remote from said vessel, said means including a pump; and means for preventing channeling of liquid through said column, said means comprising: at least three vertically extending stationary baffles disposed in said annular space and partitioning said annular space into at least three distinct flow areas; a stationary outlet nozzle associated with each of said at least three distinct flow areas; means for operatively connecting each of said outlet nozzles to said liquid withdrawing means; means for selectively providing backflushing of a selected outlet nozzle and a flow area associated therewith while liquid is being drawn through the other outlet nozzles, said means including valve means, a valve means associated with each outlet; remote control means for operating said valve means and so that one outlet nozzle is being backflushed at all times and so that the outlet nozzle that is being backflushed is periodically changed.

Claim 10

Dependent Claim 247 words

Apparatus for the treatment of cellulose fiber material comprising an inner vertically extending vessel having a diameter D; an outer vertically extending vessel having a diameter E wherein E is larger than D; a bottom portion of said inner vessel extending into said outer vessel and defining an annular liquid filled space in said outer vessel between said inner vessel and said outer vessel; means for introducing cellulose fiber material treating liquid into a column of fiber material in said outer vessel; means for drawing liquid introduced into said column in said outer vessel from said annular space to an area remote from said vessel, said means including a pump; and means for preventing channeling of liquid through said column, said means comprising: at least three vertically extending stationary baffles disposed in said annular space and partitioning said annular space into at least three distinct flow areas; a stationary outlet nozzle associated with each of said at least three distinct flow areas; means for operatively connecting each of said outlet nozzles to said liquid withdrawing means; means for selectively providing backflushing of a selected outlet nozzle and a flow area associated therewith while liquid is being drawn through the other outlet nozzles, said means including valve means, a valve means associated with each outlet; remote control means for operating said valve means and so that one outlet nozzle is being backflushed at all times and so that the outlet nozzle that is being backflushed is periodically changed.

Claim 11

Dependent Claim 101 words

Apparatus as recited in claim 2 wherein said valve means comprises a first valve means disposed in said means for operatively connecting each of said outlet nozzles to said liquid withdrawing means, a first valve means associated with each connecting means, and wherein a return line is provided for each outlet nozzle extending between said line leading from said heater to said liquid introducing means and said connecting means, and wherein said valve means comprises a second valve means disposed in each of said return lines; and wherein said remote control means operates each of said first and second valve means.

Claim 12

Dependent Claim 28 words

Apparatus as recited in claim 8 wherein each of said baffles extends through said annular space past the lower portion of said inner vessel in said outer vessel.

Claim 13

Dependent Claim 33 words

Apparatus as recited in claim 8 wherein a column of cellulosic fiber material is established in said outer vessel, and wherein each of said baffles extends through said annular space into said column.

Claim 14

Dependent Claim 37 words

Apparatus as recited in claim 8 wherein said pump is operatively connected to a heater, and wherein a line leads from said heater to said means for introducing cellulose fiber material treating liquid into said outer vessel.

Claim 15

Dependent Claim 26 words

Apparatus as recited in claim 8 further comprising a perforated plate associated with each outlet nozzle for preventing large floatables from passing into each outlet nozzle.

Claim 16

Dependent Claim 70 words

Apparatus as recited in claim 8 wherein said means for introducing cellulose fiber material treating liquid into a column of fiber material in said outer vessel comprises an inlet pipe extending downwardly through said inner vessel into said outer vessel, and having an opening disposed a distance J into said outer vessel from the bottom portion of said inner vessel, said distance J being equal to or greater than 1/2E.

Claim 17

Dependent Claim 29 words

Apparatus as recited in claim 8 wherein said inner vessel defines a cellulose fiber material impregnation chamber, and wherein said outer vessel defines a cellulose fiber material digesting chamber.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1983-03-18	1983-09-17	1984-03-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1987-03-18	1987-09-17	1988-03-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1991-03-18	1991-09-17	1992-03-18	$7700.00	Window Closed / Lapsed

Flow control method and apparatus for continuous wood chip digester screenless liquor extractor

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