Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C11/00—Regeneration of pulp liquors or effluent waste waters
  • D21C11/06—Treatment of pulp gases; Recovery of the heat content of the gases; Treatment of gases arising from various sources in pulp and paper mills; Regeneration of gaseous SO2, e.g. arising from liquors containing sulfur compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C7/00—Digesters
  • D21C7/08—Discharge devices

Definitions

• the present invention is concerned with a method relating to discontinuous treatment of fi.bre material , where the fibre material after a first treatment is transferred via a rotary feed valve to a further treatment.
• treatment liquid such as digesting liquor is hereby separated from the fibre material and returned to the digesters or withdrawn for separating off the digesting chemicals in separate subsequent treatment stages.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 material in the rotary feed valve is 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 heafcontent contained in the treatment liquid such as the digesting liquor. Another object is to reduce dilution in the circuit of circulating washing liquid, and further object are to reduce losses of dry substance and the BOD-load.
• FIG. 1 shows diagrammatical an overall view of a digester house where the digester vessels via a rotary feed valve are connected to subsequen treatment stages, the diagram showing a plant for 1 ow yiel
• Figure 2 shows. a plant similar to that presented in Figure but modified for high yield.
• Figure 3 shows diagrammatical a further plant with another type of rotary feed valve.
• Figures 4a - 4c show diagrammatically the rotary feed valv of the plant in Figure 3 in three different positions.
• Th-e plant diagrammatically shown in Figure 1 has two treatment vessels, such as digesters 10, 12, through a lin 14 connected to a rotary feed valve 16 of a construction known per se, as disclosed, for example, in the Swedish " patent application 7609782-3.
• the rotary feed valve 16 has two positions, in which a pocket arranged in the rotary feed valve inter- connects two lines attached at diametrically opposed place Attach.ed at the side opposed to linel4 is a line 18 which • connects the rotary feed valve with an accumulator 20.
• Fib material and treatment liquor from the digesters 10, 12 wh through the line 14 are introduced into the rotary feed valve 16 will be separated from one another in the same by the rotary valve being provided with an appropriate screening means so that the treatment liquor through the line 18 is fed into the accumulator 20 whereas the fibre material remains in the pocket of the rotary " valve.
• a port of the treatment liquor may be recycled to the digesters v a pump not labelled in detail and line 22.
• the fibre material contained in the pocket of the rotary valve will be fed through a line 24 into a blow tank 26 by becom displaced out of the pocket by means of liquid which throu lines 30, 28 is recycled as deducted liquid from a filter- -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.
• a cyclone 40 for removal of gases from th.e 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.
• Th'fe top portion of the blow tank 26 may be connected through ' a line 56 to the discharge line 50 for ' those gases which shall be removed from the process.
• the treatment liquid such as the digesting liquor, obtained from the first, discontinuous treatment
• the treatment liquid is fed through a line 58 to a flash tank 60.
• Phases separated in 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 de.canting vessel 48 is connected for feed of liquid obtained 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 68 to the washing station 32.
• one digester 100 only is shown, which digester by a line 102 is connected to a rotary feed valve 104.
• a line 106 may, for example, come from other, discontinuously operated digesters in th system.
• a line 108 may lead from the top portion of the digester to a decanting system of the type shown at 40 an the following items in Figure 1.
• the shown rotary feed valve 104 is of the type where the valve pocket takes three positions. In the pos tion represented by continuous lines, the line 102 is in connection with ' an outlet line 110 for the digesting liquor.
• a line 112 which supplies washing liquid from a subsequent washing station which will be described more below, is connected with a line 114 which together 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 extracted.
• the extractions of liquid from the rotary feed valve, 104 is effected by means of appropriate screens dis ⁇ posed at the liquid outlets.
• a line 118 which recycles liquid from the pressure accumulator 116, 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.
• the liquor is introduced into a flash tank 134 via a line 136, and gases separated off from the flash tank are fe ⁇ d through a line 138 to a preliminary evaporation station 140 to which also the discharge from the bottom of the flash tank 134 is fed through a line 142; through a line 144 steam is-fed to the preliminary evaporation station 140.
• the liquor is discharged via a line 146 to a liquor 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 evapora- tion equipment 140 is connected with an expulsion device 154 from which starts a line 156 for non-condensable gases which
• the expulsion of the conde 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 washing water.
• gases which are set free in connection with the expulsio and non-condensable gases from the degasifying of the digester and the blow tank are conducted to common combu
• the condensate from the condenser of the expelling appar may also be concentrated in a separate concentrating col for recovery of by-products, in which connection turpenti may be decanted also from the condensate ahead of the sai concentrating column in order to produce-, methanol in liq phase.
• the methanol liquid obtained from the concentrati column may also be burned together with those non-conden gases which are produced in various parts of the system. other or complementary way of utilizing the heat energy i to employ the digesting liquor from the pressure accumul in some other digester for filling with liquid.
• the rotary feed valve 104 shown in Figure 3 is sh in more detail in the Figures 4a - 4c.
• Figure 4a the is shown the body of the valve 104 in position for fillin the valve feeder or pocket 160, the material arriving th the line 102 and remaining in the pocket 160, whereas th
• 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.
• washing liquid is supplied through the line 112 which liquid displaces the residual digesting liquor in the valve pocket 160 thr ⁇ ugh a screen plate 168 and the line 114.

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• Paper (AREA)
• Treatment Of Fiber Materials (AREA)
• Inorganic Fibers (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20334162

Family Applications (1)

Country Status (6)

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Family Cites Families (4)

• 1978
  • 1978-03-02 SE SE7802407A patent/SE416969B/sv not_active IP Right Cessation
• 1979
  • 1979-03-02 FI FI790719A patent/FI68272C/fi not_active IP Right Cessation
  • 1979-03-02 WO PCT/SE1979/000048 patent/WO1979000693A1/en unknown
  • 1979-03-02 JP JP50046279A patent/JPH0444037B2/ja not_active Expired
  • 1979-09-25 EP EP19790900247 patent/EP0011622A1/en not_active Withdrawn
• 1980
  • 1980-09-03 FR FR8019179A patent/FR2477192A1/fr active Granted

Non-Patent Citations (1)

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