CA1123248A - Method relating to discontinuous treatment of fibre material - Google Patents
Method relating to discontinuous treatment of fibre materialInfo
- Publication number
- CA1123248A CA1123248A CA337,919A CA337919A CA1123248A CA 1123248 A CA1123248 A CA 1123248A CA 337919 A CA337919 A CA 337919A CA 1123248 A CA1123248 A CA 1123248A
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- Prior art keywords
- liquid
- treatment
- fibre material
- line
- subsequent
- Prior art date
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Abstract
Abstract Method relating to discontinuous treatment of fibre material, where the material after a first treatment is transferred to subsequent treatment. A substantial portion of the liquid constituent of the material is separated from the first treatment step in one or several intermediate steps preceding subsequent treatments and conveyed to a pressure accumulator from which the heat energy contained in the liquid constituent is recovered and the liquid constituent subsequently subjected to a continuous treatment.
Description
~2329~3 The present invention is concerned with a method relating to dis-continuous treatment of fibre material, where the fibre material after a first treatment is transferred via a rotary feed valve to a further treatment.
It is known practice in the treatment of fibre material to use rotary feed valves for transfer of the material between various treatment stages, whereby the different treatment ]iquids of the process can be kept separated from one another to a great extent. The transfer between different circuits of circulating liquid is effected by the rotary feed valve having a rotor formed with one or several pockets, which rotor is brought into different positions where communication is established between circulation lines connected to dif-ferent treatment vessels. Thus, it is known, for example, in connection with digestion of fibre material and subsequent washing to transfer the fibre mater-ial from several discontinuously operated digesters via a rotary feed valve to a subsequent continuously operated washing step. In the rotary feed valve, treatment liquid such as digesting liquor is hereby separated from the fibre material and returned to the digesters or withdrawn for separating off the digesting chemicals in separate subsequent treatment stages. The fibre mater-ial in the rotary feed valve i5 fed to the subsequent washing vessel through a separate circulation line.
The object of the present invention is to improve this method in order continuously to utilize the heat content contalned -ln the treatment liquid such as the digesting liquor. Another object is to reduce dilution in the circuit of circulating washing liquid, and further objects are to reduce losses of dry substance and the BOD-load.
Thus by one aspect of this invention there is provided a method for discontinuous treatment of fibre material in which the fibre material after a first treatment is transferred to subsequent treatmènt, and wherein a substantial portion of the liquid cnnstituent of the material from the first treatment step in one or several intermediate steps preceding subsequent treatments is separated and conveyed to a pressure accumul~tor from which - 1 - .
:- :.
~: `! `` ; ' ~. .
,: ` ' ' ' ~23Z~3 -the heat energy contained in the liquid constituent is recovered and the liquid constituent subsequently sub~ected to a continuous treatment.
The invention will hereinafter be described ln more detall in conjunction with the appended drawings in which:
Figure 1 shows diagrammatically an overall view of a digester house where the digester vessels via a rotary feed valve are connected to subsequent treat-ment stages, the diagram showing a plant for low yield;
~ igure 2 shows a plant similar to that presented in Figure 1 but modifled for high yield;
Figure 3 shows diagramatically a further plant with another type of rotary feed valve; and Figure 4a-4c show diagrammatically the rotary feed valve of the plant in Figure 3 in three different positions.
The plant diagrammatically shown in Figure 1 has two treatment vessels such as digesters 10, 12, through a line 14 connected to a rotary feed valve 16 of a construction known per se, as disclosed, for example in Canadian Paten~
Number 1,082,258. In the embodlment according t~ Figure 1, the rotary feed valve 16 has two positions, in which a pocket arranged in the rotary feed valve interconnects two lines attach~d at diametrically opposed places~ Attach-ed at the side opposed to line 14 is a line 18 which connects the rotary feedvalve with an accumulator 20. Fibre material and treatment liquor Çrom the di-gesters 10, 12 which througtl the line 14 are .Lntroduced into the rotary feed valve 16 will be separated from one another in the same by the rotary valve be-ing provided with an appropriate screening means so that the treatment liquor through the line 18 ls fed into the accumulator 20 whereas the Eibre material remains in the pocket of the rotary valve. A portion of the treatment liquor . may be recycled to the digesters via a pump not labelled in detail and line 22.
In the second position of the rotary feed valve 16 the fibre mat-erial contained in the pocket of the rotary valve will be fed through a line 24 into a blow tank 26 by becoming displaced out of the pocket by means of liquid which through lines 30, 28 is recycled as deducted liquid from a filter--~ - 2 -:~
- ` 1123~
-euipped washing station 32 positioned behind the blow tank.
The blow tank 26 and the washing station 32 are connected to a line 34 which feeds fibre material to the washing sta-tion. A portion of -the recycled exhaust liquid may be fed into the blow tank 26. From the washing station 32 the fibre material or pulp is discharged to subsequent stages of treatment or utilization through a line 36.
Attached to the top of the digesters 10~ 12 via a line 38 is a cyclone 40 for removal of gases from the digesters 10, 12. The liquid portion from the cyclone 40 is conducted over a line 42 to the top portion of the blow tank while the gaseous phase is fed to a condensor 44 from which a line 46 leads to a decanting vessel 48. Gases obtained from this decanting vessel are conducted in a line 50 to combustion, for example, while recovered turpentine is withdrawn via a line 52 and residual liquid phase via a line 54 is fed to a subsequent separation by expulsion, as will be described in more detail more below. The top portion of the blow tank 26 may be connected through a line 56 to the discharge line 50 for those yases which shall be removed from the process.
From the pressure accumulator 20 disposed according to the invention the treatment liquid, such as the digesting liquor, obtained from the first, discontinuous treatment, is fed through a line 58 to a flash tank 60. Phases separated ;n the tank or receptacle 60 are fed to an evaporation sta-tion 62 via lines 64, 66, and the concentrate obtained from the evaporation~station 62 is supplied to an expelling device 64, to which also the line 54 from the decanting vessel 48 is connected for feed of liquid ob-tained in said vessel. Gases from the expelling device 64 are conducted through a line 66 to the gas discharge line 50 whereas the liquid phase is recycled via line 6~ to the washing station 32.
In the process illustrated in Figure 1 and described in conjunction therewith there is obtained after the dis-continuous treatment in the vessels 10, 12 in the continua-tion behind the rotary feed valve 16 a continuous treatment .
, . : -- : :, --32~3 of both the fibre material and the extracted treatment liquid. Here the pressure accumulator 20 serves as a store for the extracted treatment liquid, from which liquid the preponderant portion of the heat conten-t can be utilized, for example by setting free vapour by expansion, while at the same time a subsequent treatment with flashing, eva-poration and expulsion permits effective recovery of the chemical constituents in the treatment liquid.
The plant shown diagrammatically in Figure 2 where the same reference numerals are employed for details having a counterpart in Figure 1, dif-Fers from the plant of Figure 1 by the fibre material from the rotary feed valve 16 being fed through the line 24 to a combined washing and blow tank 70 from which the fibre ma-terial via line 72 is fed to a final washing station 74. Furthermore, the outlet line 18 from the rotary feed valve 16 is not connected directly with the accumulator 20 but to the return line 22 for digesting liguor, a line l~a starting -from said line to the accumulator 20. Connected to the line 18a is also a branch 28a from that line 28 which feeds washing liquid to the rotary feed valve for displacement o-f fihre material therefrom. The equipment shown in the top portion of Figure 1 for separating the gaseolls and li~uid phases from one another and the equipment for concentration by evapora-tion and expulsion are identical in Figure 2 for which reason they have been omitted in the latter fi~ure, as will be understood from the dot-ted lines set out in Figures 1 and 2.
In the plant shown in Figure 3, one digester 100 only is shown, which di~ester by a line ln2 is connected to a rotary feed valve 104. A line 10~ may, For example, come from other, discontinuously opera-ted digesters in the system. A line 108 may lead from the top portion o-f the digester to a decanting system of the type shown at 40 and the following items in Figure 1.
The shown rotary feed valve 10~ is of the type where the valve pocket takes three positions. In the posi-tion represented by continuous lines, the line 102 is in -~2~2~3 connection with an outlet line 110 for the digesting liquor.
In the next--following position of the clockwise rotating feed valve 104 a line 112 which supplies washing liqu;d from a subsequent washing station which will be described more below, is connected with a line 114 which to~ether with the line 110 is connected to a pressure accumulator 116. The washing liquid supplied through the line 112 expels the residual digesting liquor from the pocket of the rotary feed valve and washes at the same time the fibre material in the pocket in counter-current to the direction in which the digesting liquid was ex-tracted. As is marked diagrammatically in the figure, the extractions of liquid from the rotary feed valve 104 is effected by means of appropriate screens dis-posed at the liquid outlets. In the third position of the feed valve pocket, a line 118 which recycles liquid frcm the pressure accumulator 11~, is connected with a line 120 for transfer of the fibre material to a blow tank 122. From the blow tank 122 gases are carried off through a line 124 for combustion, for example, while the fibre material via a line 126 is fed to a final washing station 128. From the final washing station pulp is discharged through a line 130, washing water being fed to the washing station 128 via a line 132.
From the pressure accumulator 116 the liquor is introduced into a flash tank 134 via a line 136, and gases separated oFf from the flash tank are -fed through a line 138 to a preliminary evaporation station 140 to which also the dischar~e from the bot-toM o-F the -Flash tank 134 is fed through a line 142; through a line 144 steam is fed to the preliminary evaporation station 140. From the prelimina-ry evaporation station 140 the liquor is discharged via a line 146 to a l.iquor container 148 wherein separation is effected of e.g. soap which is removed in a line 150, 152 denoting the final liquor discharge. The preliminary e~apora-tion equipment 140 is connected with an expulsion device 154 from which starts a line 156 for non-condensable gases which - .
, - . . : .
.. - . : . . : . .
~;23Z9~
are conducted to combllstion, for e~ample, a line 15~ being provided for draina~e of purified condensate which can be used as washing water by the line 158 being connected to the line 132.
In the plant presented in Figure 3 thus firstly the heat from the digesters is recovered by the digesting liquor discharged to the pressure accumulator steam being released continuously by e~pansion, which expansion steam may be used, for example, for preliminary concentration by evaporation of the same digesting liquor. Steam from the last step of the preliminary concentration by evaporation can be used for expulsion of the secondary condensate pro-duced by the evaporation and for driving off gases from formed turpentine mother lye. The expulsion of the conden-sate may be carried out under atmospheric pressure, -for example, and the expelled condensate may, as mentioned above, be used in the washing station as washin~ wa-ter. The gases which are set free in connection with -the expulsion and non-condensable gases from the degasifying of the digester and the blow tank are conducted to common combustion.
The condensate from the condenser of the expelling apparatus may also be concentrated in a separate concentrating column for recovery of by-products, in which connection turpentine may be decanted also from the condensate ahead of the said concentrating column in order to prodllce me-thanol in l`.quid phase. The methanol liquid obtained From the concentrating column may also be burned together with those non-condensable gases which are produced in various parts of tile system. An other or complementary way of utilizing the heat energy is to employ the digesting liquor from the pressure accumulator in some other digester for filling with liquid.
The rotary feed valve 104 shown in Figure 3 is shown in more detail in the Figures 4a - 4c. In Fi~ure 4a, there is shown the body of the valve 104 in position for filling the valve feeder or pocket 160, the material arriving through the line 102 and remaining in the pocket 160, whereas the ~, .
. : ~
~l1232~8 digesting liquor escapes through the screen 162 into the line 110. The valve pocket 160 is provided with an interior screen plate 164 disposed in spaced relation to the pocket 160 and which between itself and the wall of the valve pocket 160 forms liquid channels 166 for quicker drainage of liquid from the fibre material in the valve pocket 160.
In the nextfollowing position which is shown in Figure 4b, washing liquid is supplied through the line 112 which liquid displaces the residual digesting liquor in the valve pocket 160 through a screen plate 168 and the line 114.
In the nextfollowing position which is shown in Figure 4c the line 118 is connected with the line 120 whereby fibre material and washing liquid in the valve 160 are displaced by-means of liquor fetched from the pressure accumulator 116 and supplied via the line 118.
It is clear that the shown and described embodiment is an example only of realization of the invention and that the same can be changed and varied within the scope of the appended claims.
.
. : : .
It is known practice in the treatment of fibre material to use rotary feed valves for transfer of the material between various treatment stages, whereby the different treatment ]iquids of the process can be kept separated from one another to a great extent. The transfer between different circuits of circulating liquid is effected by the rotary feed valve having a rotor formed with one or several pockets, which rotor is brought into different positions where communication is established between circulation lines connected to dif-ferent treatment vessels. Thus, it is known, for example, in connection with digestion of fibre material and subsequent washing to transfer the fibre mater-ial from several discontinuously operated digesters via a rotary feed valve to a subsequent continuously operated washing step. In the rotary feed valve, treatment liquid such as digesting liquor is hereby separated from the fibre material and returned to the digesters or withdrawn for separating off the digesting chemicals in separate subsequent treatment stages. The fibre mater-ial in the rotary feed valve i5 fed to the subsequent washing vessel through a separate circulation line.
The object of the present invention is to improve this method in order continuously to utilize the heat content contalned -ln the treatment liquid such as the digesting liquor. Another object is to reduce dilution in the circuit of circulating washing liquid, and further objects are to reduce losses of dry substance and the BOD-load.
Thus by one aspect of this invention there is provided a method for discontinuous treatment of fibre material in which the fibre material after a first treatment is transferred to subsequent treatmènt, and wherein a substantial portion of the liquid cnnstituent of the material from the first treatment step in one or several intermediate steps preceding subsequent treatments is separated and conveyed to a pressure accumul~tor from which - 1 - .
:- :.
~: `! `` ; ' ~. .
,: ` ' ' ' ~23Z~3 -the heat energy contained in the liquid constituent is recovered and the liquid constituent subsequently sub~ected to a continuous treatment.
The invention will hereinafter be described ln more detall in conjunction with the appended drawings in which:
Figure 1 shows diagrammatically an overall view of a digester house where the digester vessels via a rotary feed valve are connected to subsequent treat-ment stages, the diagram showing a plant for low yield;
~ igure 2 shows a plant similar to that presented in Figure 1 but modifled for high yield;
Figure 3 shows diagramatically a further plant with another type of rotary feed valve; and Figure 4a-4c show diagrammatically the rotary feed valve of the plant in Figure 3 in three different positions.
The plant diagrammatically shown in Figure 1 has two treatment vessels such as digesters 10, 12, through a line 14 connected to a rotary feed valve 16 of a construction known per se, as disclosed, for example in Canadian Paten~
Number 1,082,258. In the embodlment according t~ Figure 1, the rotary feed valve 16 has two positions, in which a pocket arranged in the rotary feed valve interconnects two lines attach~d at diametrically opposed places~ Attach-ed at the side opposed to line 14 is a line 18 which connects the rotary feedvalve with an accumulator 20. Fibre material and treatment liquor Çrom the di-gesters 10, 12 which througtl the line 14 are .Lntroduced into the rotary feed valve 16 will be separated from one another in the same by the rotary valve be-ing provided with an appropriate screening means so that the treatment liquor through the line 18 ls fed into the accumulator 20 whereas the Eibre material remains in the pocket of the rotary valve. A portion of the treatment liquor . may be recycled to the digesters via a pump not labelled in detail and line 22.
In the second position of the rotary feed valve 16 the fibre mat-erial contained in the pocket of the rotary valve will be fed through a line 24 into a blow tank 26 by becoming displaced out of the pocket by means of liquid which through lines 30, 28 is recycled as deducted liquid from a filter--~ - 2 -:~
- ` 1123~
-euipped washing station 32 positioned behind the blow tank.
The blow tank 26 and the washing station 32 are connected to a line 34 which feeds fibre material to the washing sta-tion. A portion of -the recycled exhaust liquid may be fed into the blow tank 26. From the washing station 32 the fibre material or pulp is discharged to subsequent stages of treatment or utilization through a line 36.
Attached to the top of the digesters 10~ 12 via a line 38 is a cyclone 40 for removal of gases from the digesters 10, 12. The liquid portion from the cyclone 40 is conducted over a line 42 to the top portion of the blow tank while the gaseous phase is fed to a condensor 44 from which a line 46 leads to a decanting vessel 48. Gases obtained from this decanting vessel are conducted in a line 50 to combustion, for example, while recovered turpentine is withdrawn via a line 52 and residual liquid phase via a line 54 is fed to a subsequent separation by expulsion, as will be described in more detail more below. The top portion of the blow tank 26 may be connected through a line 56 to the discharge line 50 for those yases which shall be removed from the process.
From the pressure accumulator 20 disposed according to the invention the treatment liquid, such as the digesting liquor, obtained from the first, discontinuous treatment, is fed through a line 58 to a flash tank 60. Phases separated ;n the tank or receptacle 60 are fed to an evaporation sta-tion 62 via lines 64, 66, and the concentrate obtained from the evaporation~station 62 is supplied to an expelling device 64, to which also the line 54 from the decanting vessel 48 is connected for feed of liquid ob-tained in said vessel. Gases from the expelling device 64 are conducted through a line 66 to the gas discharge line 50 whereas the liquid phase is recycled via line 6~ to the washing station 32.
In the process illustrated in Figure 1 and described in conjunction therewith there is obtained after the dis-continuous treatment in the vessels 10, 12 in the continua-tion behind the rotary feed valve 16 a continuous treatment .
, . : -- : :, --32~3 of both the fibre material and the extracted treatment liquid. Here the pressure accumulator 20 serves as a store for the extracted treatment liquid, from which liquid the preponderant portion of the heat conten-t can be utilized, for example by setting free vapour by expansion, while at the same time a subsequent treatment with flashing, eva-poration and expulsion permits effective recovery of the chemical constituents in the treatment liquid.
The plant shown diagrammatically in Figure 2 where the same reference numerals are employed for details having a counterpart in Figure 1, dif-Fers from the plant of Figure 1 by the fibre material from the rotary feed valve 16 being fed through the line 24 to a combined washing and blow tank 70 from which the fibre ma-terial via line 72 is fed to a final washing station 74. Furthermore, the outlet line 18 from the rotary feed valve 16 is not connected directly with the accumulator 20 but to the return line 22 for digesting liguor, a line l~a starting -from said line to the accumulator 20. Connected to the line 18a is also a branch 28a from that line 28 which feeds washing liquid to the rotary feed valve for displacement o-f fihre material therefrom. The equipment shown in the top portion of Figure 1 for separating the gaseolls and li~uid phases from one another and the equipment for concentration by evapora-tion and expulsion are identical in Figure 2 for which reason they have been omitted in the latter fi~ure, as will be understood from the dot-ted lines set out in Figures 1 and 2.
In the plant shown in Figure 3, one digester 100 only is shown, which di~ester by a line ln2 is connected to a rotary feed valve 104. A line 10~ may, For example, come from other, discontinuously opera-ted digesters in the system. A line 108 may lead from the top portion o-f the digester to a decanting system of the type shown at 40 and the following items in Figure 1.
The shown rotary feed valve 10~ is of the type where the valve pocket takes three positions. In the posi-tion represented by continuous lines, the line 102 is in -~2~2~3 connection with an outlet line 110 for the digesting liquor.
In the next--following position of the clockwise rotating feed valve 104 a line 112 which supplies washing liqu;d from a subsequent washing station which will be described more below, is connected with a line 114 which to~ether with the line 110 is connected to a pressure accumulator 116. The washing liquid supplied through the line 112 expels the residual digesting liquor from the pocket of the rotary feed valve and washes at the same time the fibre material in the pocket in counter-current to the direction in which the digesting liquid was ex-tracted. As is marked diagrammatically in the figure, the extractions of liquid from the rotary feed valve 104 is effected by means of appropriate screens dis-posed at the liquid outlets. In the third position of the feed valve pocket, a line 118 which recycles liquid frcm the pressure accumulator 11~, is connected with a line 120 for transfer of the fibre material to a blow tank 122. From the blow tank 122 gases are carried off through a line 124 for combustion, for example, while the fibre material via a line 126 is fed to a final washing station 128. From the final washing station pulp is discharged through a line 130, washing water being fed to the washing station 128 via a line 132.
From the pressure accumulator 116 the liquor is introduced into a flash tank 134 via a line 136, and gases separated oFf from the flash tank are -fed through a line 138 to a preliminary evaporation station 140 to which also the dischar~e from the bot-toM o-F the -Flash tank 134 is fed through a line 142; through a line 144 steam is fed to the preliminary evaporation station 140. From the prelimina-ry evaporation station 140 the liquor is discharged via a line 146 to a l.iquor container 148 wherein separation is effected of e.g. soap which is removed in a line 150, 152 denoting the final liquor discharge. The preliminary e~apora-tion equipment 140 is connected with an expulsion device 154 from which starts a line 156 for non-condensable gases which - .
, - . . : .
.. - . : . . : . .
~;23Z9~
are conducted to combllstion, for e~ample, a line 15~ being provided for draina~e of purified condensate which can be used as washing water by the line 158 being connected to the line 132.
In the plant presented in Figure 3 thus firstly the heat from the digesters is recovered by the digesting liquor discharged to the pressure accumulator steam being released continuously by e~pansion, which expansion steam may be used, for example, for preliminary concentration by evaporation of the same digesting liquor. Steam from the last step of the preliminary concentration by evaporation can be used for expulsion of the secondary condensate pro-duced by the evaporation and for driving off gases from formed turpentine mother lye. The expulsion of the conden-sate may be carried out under atmospheric pressure, -for example, and the expelled condensate may, as mentioned above, be used in the washing station as washin~ wa-ter. The gases which are set free in connection with -the expulsion and non-condensable gases from the degasifying of the digester and the blow tank are conducted to common combustion.
The condensate from the condenser of the expelling apparatus may also be concentrated in a separate concentrating column for recovery of by-products, in which connection turpentine may be decanted also from the condensate ahead of the said concentrating column in order to prodllce me-thanol in l`.quid phase. The methanol liquid obtained From the concentrating column may also be burned together with those non-condensable gases which are produced in various parts of tile system. An other or complementary way of utilizing the heat energy is to employ the digesting liquor from the pressure accumulator in some other digester for filling with liquid.
The rotary feed valve 104 shown in Figure 3 is shown in more detail in the Figures 4a - 4c. In Fi~ure 4a, there is shown the body of the valve 104 in position for filling the valve feeder or pocket 160, the material arriving through the line 102 and remaining in the pocket 160, whereas the ~, .
. : ~
~l1232~8 digesting liquor escapes through the screen 162 into the line 110. The valve pocket 160 is provided with an interior screen plate 164 disposed in spaced relation to the pocket 160 and which between itself and the wall of the valve pocket 160 forms liquid channels 166 for quicker drainage of liquid from the fibre material in the valve pocket 160.
In the nextfollowing position which is shown in Figure 4b, washing liquid is supplied through the line 112 which liquid displaces the residual digesting liquor in the valve pocket 160 through a screen plate 168 and the line 114.
In the nextfollowing position which is shown in Figure 4c the line 118 is connected with the line 120 whereby fibre material and washing liquid in the valve 160 are displaced by-means of liquor fetched from the pressure accumulator 116 and supplied via the line 118.
It is clear that the shown and described embodiment is an example only of realization of the invention and that the same can be changed and varied within the scope of the appended claims.
.
. : : .
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Method for discontinuous treatment of fibre material, in which the fibre material after a first treatment is transferred to subsequent treatment, and wherein a substantial portion of the liquid constituent of the material from the first treatment step preceding subsequent treatments is separated and conveyed to a pressure accumulator from which the heat energy contained in the liquid constituent is recovered and the liquid constituent subsequently subjected to a continuous treatment.
2. Method according to claim 1, wherein the liquid constituent is fed to the intermediate step from a plurality of discontinuous treatments.
3. Method according to claim 1, wherein the liquid constituent is separated from the fibre material in a rotary feed valve through a screen surface to the pressure accumulator in a position of the rotary feed valve and that the fibre material in another position of the rotary feed valve is fed to subsequent treatment by means of extracted liquid recycled from the pressure accumulator.
4. Method according to any of the claims 1-3, wherein a liquid is used for displacement of the fibre material from the rotary feed valve, which liquid cools the fibre material located in the valve and by its presence in the moment of emptying prevents expansion in the subsequent treatment, for example during feed to the blow tank in a subsequent washing step.
5. Method according to claim 1, wherein the treatment liquid tapped off from the pressure accumulator continuously sets free steam by means of expansion.
6. Method according to claim 5, wherein the expansion steam set free from the treatment liquid is used for preliminary evaporation of the said liquid.
7. Method according to claims 1, 2 or 3 wherein the treatment comprises digestion of the fibre material and that the subsequent treatments include washing of the same material.
8. Device for transferring fibre material and liquid between different treatment stages via a displacement apparatus inserted into the circuits of circulating liquid, said apparatus including sieve equipment operating in at least two steps and in the various positions establishing connection with the circuits of circulating liquid, and wherein the dis-placement apparatus is provided with interior sieve surfaces which are defined by longitudinally extending liquid channels which permit liquid to be withdrawn along substantially the entire length of the sieve equipment from fibre material present.
9. Device according to claim 8 wherein the displacement apparatus consists of one or several cylindrical sieve plates which are constituted by a cylindrical perforated or slotted sieve plate extending along the entire length of the displacement apparatus and disposed with a gap to the wall of the displacement apparatus to form liquid channels between the sieve plate and said wall.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA337,919A CA1123248A (en) | 1979-10-18 | 1979-10-18 | Method relating to discontinuous treatment of fibre material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA337,919A CA1123248A (en) | 1979-10-18 | 1979-10-18 | Method relating to discontinuous treatment of fibre material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1123248A true CA1123248A (en) | 1982-05-11 |
Family
ID=4115378
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA337,919A Expired CA1123248A (en) | 1979-10-18 | 1979-10-18 | Method relating to discontinuous treatment of fibre material |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1123248A (en) |
-
1979
- 1979-10-18 CA CA337,919A patent/CA1123248A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |