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US3921918A - Mechanical refining of fiber material including steam recycle - Google Patents

Mechanical refining of fiber material including steam recycle Download PDF

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Publication number
US3921918A
US3921918A US489138A US48913874A US3921918A US 3921918 A US3921918 A US 3921918A US 489138 A US489138 A US 489138A US 48913874 A US48913874 A US 48913874A US 3921918 A US3921918 A US 3921918A
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steam
refining
preheater
space
pressure
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US489138A
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Viking Per Peterson
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SCA Development AB
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SCA Development AB
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
    • D21D1/00—Methods of beating or refining; Beaters of the Hollander type
    • D21D1/20—Methods of refining
    • D21D1/30—Disc mills

Definitions

  • the entire defibering and refining process to the finished product can in this way be carried out in a single step.
  • the refining may also be carried out in several, preferably two steps, but the portion of the total energy amount consumed in the first step immediately after preheating would still be so great that the steam developed during the process would cause serious disturbances, if the steam would be forced to pass out in its entirety through the gap between the beating discs, as is the case with conventional systems.
  • the preheater vessel is not in direct connection with the refiner, and the preheating of the fibre material usually takes place within the temperature range ll-l70C, the pressure during the preheating being higher than the pressure which prevails immediately after the preheater vessel and in the central space between the grinding discs, and the steam developed during the refining being entirely or partially led away by special means from said space. It was found suitable to carry out the refining at a steam pressure of 0.2-0.6 kg/cm corresponding to a temperature of about l-l C, within which range the refining energy consumption seems to be at a minimum.
  • One main object of the present invention is to establish a simplified system for producing mechanical pulps of high quality while maintaining the advantages involved with the refining of preheated fibre material, in such a manner, that a large part of the steam developed during the refining can be evacuated rearwards through the system from the space between the grinding discs, but at the same time this steam is utilized for preheating the fibre material in order to save energy.
  • the fibre material is exposed to heating with steam to ll0l 15C and to a pressure increased corresponding to the temperature. The temperature and pressure are maintained equal during the refining.
  • the steam developed during the refining is led away from the space between the grinding discs through the feed screw of the refiner or through another suitable device to the preheater vessel, which is in direct connection with the refiner. It is hereby possible, if desired, to consume in a single step the entire energy amount required for the process without giving rise to process disturbances. Contrary to conventional systems, the steam developed by the refiner is utilized in this way for heating the fibre material. No steam generated in a different way need be supplied to the system, so that substantial energy can be saved compared with conventional systems.
  • the refiner produces more steam than can be utilized for heating the fibre material, and the excess is removed from the preheater vessel through a pressure control valve. The energy savings thereby possible correspond to about -300 kWh/t of produced mechanical pulp, or 10-20 of the total refining energy.
  • the refining may, if desired, be carried out with the housing enclosing the beating discs being pressureless and open.
  • the embodiment according to the FIGURE comprises a rotary vane feeder l for feeding the fibre material into a preheater vessel 2.
  • the fibre material has a high concentration and is metered to a correct amount by means of a metering device (not shown) arranged before the rotary vane feeder l.
  • the fibre material is advanced through the preheater vessel 2 by means of a screw 3 with such a speed that the staying time is as long as desired, i.e'. k 3 minutes, preferably 15 1 /2 minutes.
  • the screw 3 is for this purpose provided with variable operation.
  • the heated fibre material after its passage through the preheater vessel 2 is allowed to fall freelythrough a chute 4 adjusted to local conditions, usually in the form of a pipe, which is drawn through a separation funnel 5 mounted on the opening 6 to the feeddevice 7 of the refiner which at the embodiment shown is an inclined double-screw.
  • the feed device may also be of another kind, such as one or two separate horizontal feed screws.
  • the chute 4 opens suitably spaced from the opening 6 to the feed screws, so that the chips unobstructedly can fall into the feed screws 8, which feed the fibre material between the grinding discs 11, 12 of the refiner through the feed opening 13 in the grinding disc 12.
  • Said discs ll, 12 are provided with refining surfaces 9, 10.
  • the feed screws 8 are operated at such a high number of revolutions that they are only partially filled. It is hereby possible for the greater part of the steam formed during the refining process to escape rearwards through the system, from the refining zone and the central space between the grinding discs out through the feed openings 13 and through the only partially filled feed screws 8 out into the steam separation funnel 5.
  • the chute 4 for the chip transport being drawn down to a point close to the opening 6 of the feed screws 8, the greater part of the steam coming from the refiner can be transported through a separate duct 14 to the preheater vessel 2 and be utilized for heating the fibre material to lO-l 15C.
  • the steam discharged from the refiner is the only heat source for heating the fibre material, and no further steam need be added.
  • the steam flows through the preheater vessel 2 in a direction opposite to and thereby heating the fibre material, and the excess steam is evacuated through the duct 15 and control valve 16 located at the end of the preheater vessel where the fibre material is charged.
  • the control valve 16 By means of the control valve 16, the pressure and temperature are adjusted to the desired level in the entire system, as described above.
  • the invention is not restricted to the embodiment shown, but can be varied within the scope of the claims.
  • the refiner for example, may be of the single-disc type and the fibre material can then be charged in a corresponding manner through the stationary disc.
  • I claim: 1. In a method of treating fiber material involving the steps of first preheating the material with steam under elevated temperature and superatmospheric pressure consisting of conductingpart of said developed pressurized steam back into the preheater space in order to maintain the temperature and pressure in said preheater space.

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  • Paper (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
  • Chemical Or Physical Treatment Of Fibers (AREA)
  • Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

Abstract

Refiner pulp is prepared by the steps of pretreating fibrous material with steam in a preheater followed by the step of refining the steam-treated material in a disc refiner whereby steam is developed, and at least a part of the developed steam is conducted back to the preheater for maintaining desired pressure and temperature conditions in the preheater.

Description

Umted States Patent [191 1111 3,921,918
Peterson 1 Nov. 25, 1975 1 MECHANICAL REFINING 0F FIBER 2,816,831 12/1957 Goddard 162/47 x MATERIAL INCLUDING STEAM RECYCLE 3,238,088 3/1966 Vi11avicencio et a1... 162/28 X 3,388,037 6/1968 Asplund et a1 162/23 1 Inventor: VIkmg Per Peterson, Sundsvall. 3,414,038 12/1968 Laakso 162/47 X Sweden 3,425,477 2/1969 Farin 162/47 X [73] Assignee: SCA Development Aktiebalagi 3,773,610 11/1973 Shouvlm 162/28 X Sundsvall, Sweden Primary ExaminerRobert L. Lindsay, Jr. 22 F1 (1. 1 17, 1974 1 1 6 y Assistant Examiner-Arthur L. Corbin [21] Appl. No.: 489,138 Attorney, Agent, or Firm-Pierce, Scheffler & Parker [30] Foreign Application Priority Data Sept. 6, 1973 Sweden 7312169 [57] ABSTRACT 52 us. c1. 241/28- 162/19' 162/23' Refine Pulp is Prepared by the Steps of Pretreating 162/47 brous material with steam in a preheater followed by 511 1m. (:1. 1302c 7/00- B271 1 1/08 Step refining the steam"reated material a disc 58 Field of Search 162/28 47 23 19- refinerwherebysteamisdevelopedand atleastapa'" 1 of the developed steam is conducted back to the preheater for maintaining desired pressure and tempera- [56] References Cited ture Conditions in the preheater.
UNITED STATES PATENTS 6 Claims 1 Drawing Figure 1,922,313 8/1933 Mason 241/28 x MECHANICAL REFINING OF FIBER MATERIAL INCLUDING STEAM RECYCLE This invention relates to a method of producing mechanical refiner pulp of various types of fibre material.
It is previously known to expose fibre material for a relatively short time to heating with steam to above 1 10C and to a pressure increased corresponding to the temperature. The pressure is thereafter allowed to expand to a value somewhat above atmospheric pressure before the preheated fibre material is introduced between the refining surfaces of a disc refiner. The steam developed during the refining can by special means entirely or partially be led away from the central space between the grinding discs. Steam possibly following along from the preheating zone may, of course, also be evacuated in the same way. This implies, contrary to conventional systems, a greater freedom of refining with smaller gaps between the grinding discs and, consequently, with higher energy supply, without giving rise to serious process disturbances. The entire defibering and refining process to the finished product can in this way be carried out in a single step. At the production of certain pulp grades the refining may also be carried out in several, preferably two steps, but the portion of the total energy amount consumed in the first step immediately after preheating would still be so great that the steam developed during the process would cause serious disturbances, if the steam would be forced to pass out in its entirety through the gap between the beating discs, as is the case with conventional systems. According to the method described above, the preheater vessel is not in direct connection with the refiner, and the preheating of the fibre material usually takes place within the temperature range ll-l70C, the pressure during the preheating being higher than the pressure which prevails immediately after the preheater vessel and in the central space between the grinding discs, and the steam developed during the refining being entirely or partially led away by special means from said space. It was found suitable to carry out the refining at a steam pressure of 0.2-0.6 kg/cm corresponding to a temperature of about l-l C, within which range the refining energy consumption seems to be at a minimum. It was found in a great number of mill experiments on an industrial scale that very good pulp grades can be produced also when the preheating of the fibre material takes place in the lower part of the aforesaid temperature range, or at about ll0-l 15C. Although the resulting mechanical pulps do not reach the same high quality levels as at preheating at higher temperatures, preferably 130C or above, their properties yet are so good that the pulps are fully acceptable for the production of a plurality of paper grades. This development has become possible by the application of increasingly finer patterns of the grinding surfaces on the segments mounted on the refiner discs, thereby rendering it possible to carry out a greater part of the defibering work with the segments and correspondingly reduce the energy consumption in the preheating phase. 1
One main object of the present invention is to establish a simplified system for producing mechanical pulps of high quality while maintaining the advantages involved with the refining of preheated fibre material, in such a manner, that a large part of the steam developed during the refining can be evacuated rearwards through the system from the space between the grinding discs, but at the same time this steam is utilized for preheating the fibre material in order to save energy. According to the invention, the fibre material is exposed to heating with steam to ll0l 15C and to a pressure increased corresponding to the temperature. The temperature and pressure are maintained equal during the refining. The steam developed during the refining is led away from the space between the grinding discs through the feed screw of the refiner or through another suitable device to the preheater vessel, which is in direct connection with the refiner. It is hereby possible, if desired, to consume in a single step the entire energy amount required for the process without giving rise to process disturbances. Contrary to conventional systems, the steam developed by the refiner is utilized in this way for heating the fibre material. No steam generated in a different way need be supplied to the system, so that substantial energy can be saved compared with conventional systems. The refiner produces more steam than can be utilized for heating the fibre material, and the excess is removed from the preheater vessel through a pressure control valve. The energy savings thereby possible correspond to about -300 kWh/t of produced mechanical pulp, or 10-20 of the total refining energy. The refining may, if desired, be carried out with the housing enclosing the beating discs being pressureless and open.
The invention is described in greater detail in the following, with reference to the FIGURE showing an apparatus for carrying out the process according to the invention.
The embodiment according to the FIGURE comprises a rotary vane feeder l for feeding the fibre material into a preheater vessel 2. The fibre material has a high concentration and is metered to a correct amount by means of a metering device (not shown) arranged before the rotary vane feeder l. The fibre material is advanced through the preheater vessel 2 by means of a screw 3 with such a speed that the staying time is as long as desired, i.e'. k 3 minutes, preferably 15 1 /2 minutes. The screw 3 is for this purpose provided with variable operation. The heated fibre material after its passage through the preheater vessel 2 is allowed to fall freelythrough a chute 4 adjusted to local conditions, usually in the form of a pipe, which is drawn through a separation funnel 5 mounted on the opening 6 to the feeddevice 7 of the refiner which at the embodiment shown is an inclined double-screw. The feed device may also be of another kind, such as one or two separate horizontal feed screws. The chute 4 opens suitably spaced from the opening 6 to the feed screws, so that the chips unobstructedly can fall into the feed screws 8, which feed the fibre material between the grinding discs 11, 12 of the refiner through the feed opening 13 in the grinding disc 12. Said discs ll, 12 are provided with refining surfaces 9, 10. The feed screws 8 are operated at such a high number of revolutions that they are only partially filled. It is hereby possible for the greater part of the steam formed during the refining process to escape rearwards through the system, from the refining zone and the central space between the grinding discs out through the feed openings 13 and through the only partially filled feed screws 8 out into the steam separation funnel 5. The chute 4 for the chip transport being drawn down to a point close to the opening 6 of the feed screws 8, the greater part of the steam coming from the refiner can be transported through a separate duct 14 to the preheater vessel 2 and be utilized for heating the fibre material to lO-l 15C. Thereby, only a part of the steam will be transported through the chute 4, and the fibre material, therefore, falls down through the chute without being disturbed by large steam amounts flowing in the opposite direction. The steam discharged from the refiner is the only heat source for heating the fibre material, and no further steam need be added. The steam flows through the preheater vessel 2 in a direction opposite to and thereby heating the fibre material, and the excess steam is evacuated through the duct 15 and control valve 16 located at the end of the preheater vessel where the fibre material is charged. By means of the control valve 16, the pressure and temperature are adjusted to the desired level in the entire system, as described above.
The invention, of course, is not restricted to the embodiment shown, but can be varied within the scope of the claims. The refiner, for example, may be of the single-disc type and the fibre material can then be charged in a corresponding manner through the stationary disc.
I claim: 1. In a method of treating fiber material involving the steps of first preheating the material with steam under elevated temperature and superatmospheric pressure consisting of conductingpart of said developed pressurized steam back into the preheater space in order to maintain the temperature and pressure in said preheater space.
2. The method according to claim 1,1wherein thesuperatmospheric pressure within the preheater space is controlled by evacuating any excess steamfrom said space.
3. Themethod according to claim 1, wherein pre-- heated material is fed from said preheater space to the disc refiner by causing the material to fall freely through a feeding chute. I I
4.. The method according to claim 1, wherein the fibre material is heated by the steam to lO5l 15C, I i
the steam pressure being 0.2-0.6 kg/cm 5. The method according to claim 1, wherein the refining is carried out in a single step.
6. The method according to claim l,wherein the re fining is carried out in two steps.

Claims (6)

1. IN A METHOD OF TREATING FIBER MATERIAL INVOLVING THE STEPS OF FIRST PREHEATING THE MATERIAL WITH STEAM UNDER ELEVATED TEMPERATURE AND SUPERATMOSPHERIC PRESSURE IN A PREHEATER SPACE AND THEN FEEDING THE MATERIAL AS A STREAM INTO A DISC WHICH COMPRISES A CARBURIZED FRICTION BEARING SURFACE FORMED ON SAID STEEL REFINER FOR REFINING THE MATERIAL DURING ITS OUTWARD PASSAGE FROM BETWEEN THE GRINDING DISCS OF THE DISC REFINER DURING BEARING PIN; BLY, THE IMPROVEMENT COMPRISING SAID BALL BEARING MEANS A BORONIZED SURFACE FORMED ON SAID CARBURIZED BEARING INCLUDING A RACE COMPRISING POLYURETHANE AND AN ACETAL RESIN. WHICH PASSAGE STEAM AT SUPERATMOSPHERIC PRESSURE IS DEVELOPED, THE IMPROVEMENT CONSISTING OF CONDUCTING PART OF SAID SURFACE; SAID CARBURIZED SURFACE BEING HARDENED AND TEMPERED BY DEVELOPED PRESSURIZED STEAM BACK INTO THE PREHEATER SPACE IN ORDER TO MAINTAIN THE TEMPERATURE AND PRESSURE IN SAID PREHEATER SPACE.
2. The method according to claim 1, wherein the superatmospheric pressure within the preheater space is controlled by evacuating any excess steam from said space.
3. The method according to claim 1, wherein preheated material is fed from said preheater space to the disc refiner by causing the material to fall freely through a feeding chute.
4. The method according to claim 1, wherein the fibre material is heated by the steam to 105*-115*C, the steam pressure being 0.2-0.6 kg/cm2.
5. The method according to claim 1, wherein the refining is carried out in a single step.
6. The method according to claim 1, wherein the refining is carried out in two steps.
US489138A 1973-09-06 1974-07-17 Mechanical refining of fiber material including steam recycle Expired - Lifetime US3921918A (en)

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SE7312169A SE386694B (en) 1973-09-06 1973-09-06 KIT FOR TREATMENT OF FIBER MATERIAL WHEN THE FIBER MATERIAL IS FIRST PREHEATED WITH ANGA IN A PRE-MAKER

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AT (1) AT333582B (en)
AU (1) AU475744B2 (en)
BR (1) BR7407049D0 (en)
CA (1) CA1004078A (en)
DE (1) DE2442627C3 (en)
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FR (1) FR2243297B1 (en)
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4009835A (en) * 1975-04-04 1977-03-01 Yhtyneet Paperitehtaat Oy Jylhavaara Procedure and apparatus for preparation of hot groundwood
US4033811A (en) * 1975-06-09 1977-07-05 Stig Gloersen Method and apparatus for filling of fiber material and liquid to steam phase in treatment vessel
US4059237A (en) * 1974-02-15 1977-11-22 Oy Keskuslaboratorio - Centrallaboratorium, Ab System for feeding a double disc refiner
DE2734832A1 (en) * 1976-08-06 1978-02-09 Isel Sa A WAY TO USE THE HEAT DEVELOPED IN THE DEVELOPMENT ZONE IN ORDER TO REDUCE THE STEAM PRESSURE DURING THE PRODUCTION OF FIBER MATERIAL FOR THE PRODUCTION OF FIBER BOARDS TO A MINIMUM
US4078964A (en) * 1973-12-10 1978-03-14 Kamyr Ab Method and apparatus for filling a pressure treatment vessel with a fiber material and liquid mixture
US4163525A (en) * 1977-01-03 1979-08-07 Reinhall Rolf Bertil Device for evacuating blow-back steam in pulp refining apparatus
US4190005A (en) * 1978-12-15 1980-02-26 COMCO - Dravo Corporation Process for pulverizing coal using combination gas in fluid energy pulverizers
US4265701A (en) * 1980-01-07 1981-05-05 Ecodyne Corporation Liquid concentration method
US4298425A (en) * 1978-05-03 1981-11-03 Defibrator Aktiebolag Method and apparatus for refining lignocellulose-containing material to produce fiber pulp
US5655718A (en) * 1993-11-10 1997-08-12 Anderson; Joseph Apparatus, system and method for treating process material such as waste material
US20120091239A1 (en) * 2009-03-27 2012-04-19 Flsmidth A/S Feed Shaft for Feeding Particulate Material to a Mill
CN109537338A (en) * 2018-12-21 2019-03-29 南京林业大学 Tortuous preheating channel rotary hopper-type defibrator feeding device
CN113152134A (en) * 2021-05-17 2021-07-23 中国制浆造纸研究院衢州分院 Closed tearing pulp grinding system
SE2050526A1 (en) * 2020-05-07 2021-08-17 Valmet Oy Method and apparatus for defibrating wood chips, and a return steam pipe for such an apparatus
WO2021225491A1 (en) 2020-05-07 2021-11-11 Valmet Ab A system and method for defibrating wood chips, and a return steam pipe

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE403916B (en) * 1975-06-04 1978-09-11 Rolf Bertil Reinhall DEVICE FOR MILLING APPARATUS FOR LIGNOCELLULOSE-MATERIAL
US4132366A (en) * 1977-06-03 1979-01-02 The Bauer Bros. Co. Infeed tube for disc refiners
US4261522A (en) * 1979-07-19 1981-04-14 The Bauer Bros. Co. Feed and vent apparatus for refiners
JPS6077798U (en) * 1983-10-31 1985-05-30 株式会社　山田製作所 Impeller device for internal combustion engine cooling pump
DE3903591A1 (en) * 1989-02-07 1990-08-09 Baehre & Greten METHOD AND DEVICE FOR THE PRODUCTION OF LIGNOCELLULOSE-CONTAINING FIBER FABRIC FOR THE PRODUCTION OF FIBERBOARDS AFTER THE DRYING PROCESS
US5335865A (en) * 1992-06-26 1994-08-09 Andritz Sprout-Bauer, Inc. Two-stage variable intensity refiner
CN102962876A (en) * 2012-11-30 2013-03-13 濮阳龙丰纸业有限公司 Steam device of wood chip tearing machine
CN111749037A (en) * 2020-05-26 2020-10-09 安徽华帆新材料科技有限公司 Pulping device for environment-friendly wood boards and working method of pulping device

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US1922313A (en) * 1931-06-27 1933-08-15 Masonite Corp Process and apparatus for disintegration of material
US2816831A (en) * 1949-04-02 1957-12-17 Goddard Harold Oliver Process for producing and concentrating residual waste sulphite liquor
US3238088A (en) * 1962-12-04 1966-03-01 Cia Ind De Ayotla Continuous digesting of cellulosic fibrous material at decreasing pressure with mechanical defibering therebetween
US3388037A (en) * 1963-05-31 1968-06-11 Defibrator Ab Method in the manufacture of wood pulp from chips in grinding apparatus in two stages
US3414038A (en) * 1965-06-21 1968-12-03 Kamyr Ab Heat recovery method and apparatus
US3425477A (en) * 1966-09-28 1969-02-04 Marathon Eng Inc Method for heat recovery in evaporating and burning spent liquor
US3773610A (en) * 1970-12-11 1973-11-20 Bauer Bros Co Pressurized system for pulp refining including pressurized double disk treatment

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Publication number Priority date Publication date Assignee Title
US1922313A (en) * 1931-06-27 1933-08-15 Masonite Corp Process and apparatus for disintegration of material
US2816831A (en) * 1949-04-02 1957-12-17 Goddard Harold Oliver Process for producing and concentrating residual waste sulphite liquor
US3238088A (en) * 1962-12-04 1966-03-01 Cia Ind De Ayotla Continuous digesting of cellulosic fibrous material at decreasing pressure with mechanical defibering therebetween
US3388037A (en) * 1963-05-31 1968-06-11 Defibrator Ab Method in the manufacture of wood pulp from chips in grinding apparatus in two stages
US3414038A (en) * 1965-06-21 1968-12-03 Kamyr Ab Heat recovery method and apparatus
US3425477A (en) * 1966-09-28 1969-02-04 Marathon Eng Inc Method for heat recovery in evaporating and burning spent liquor
US3773610A (en) * 1970-12-11 1973-11-20 Bauer Bros Co Pressurized system for pulp refining including pressurized double disk treatment

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4078964A (en) * 1973-12-10 1978-03-14 Kamyr Ab Method and apparatus for filling a pressure treatment vessel with a fiber material and liquid mixture
US4059237A (en) * 1974-02-15 1977-11-22 Oy Keskuslaboratorio - Centrallaboratorium, Ab System for feeding a double disc refiner
US4009835A (en) * 1975-04-04 1977-03-01 Yhtyneet Paperitehtaat Oy Jylhavaara Procedure and apparatus for preparation of hot groundwood
US4033811A (en) * 1975-06-09 1977-07-05 Stig Gloersen Method and apparatus for filling of fiber material and liquid to steam phase in treatment vessel
DE2734832A1 (en) * 1976-08-06 1978-02-09 Isel Sa A WAY TO USE THE HEAT DEVELOPED IN THE DEVELOPMENT ZONE IN ORDER TO REDUCE THE STEAM PRESSURE DURING THE PRODUCTION OF FIBER MATERIAL FOR THE PRODUCTION OF FIBER BOARDS TO A MINIMUM
US4136831A (en) * 1976-08-06 1979-01-30 Isel S.A. Method and apparatus for minimizing steam consumption in the production of pulp for fiberboard and the like
US4163525A (en) * 1977-01-03 1979-08-07 Reinhall Rolf Bertil Device for evacuating blow-back steam in pulp refining apparatus
US4298425A (en) * 1978-05-03 1981-11-03 Defibrator Aktiebolag Method and apparatus for refining lignocellulose-containing material to produce fiber pulp
US4190005A (en) * 1978-12-15 1980-02-26 COMCO - Dravo Corporation Process for pulverizing coal using combination gas in fluid energy pulverizers
US4265701A (en) * 1980-01-07 1981-05-05 Ecodyne Corporation Liquid concentration method
US5655718A (en) * 1993-11-10 1997-08-12 Anderson; Joseph Apparatus, system and method for treating process material such as waste material
US20120091239A1 (en) * 2009-03-27 2012-04-19 Flsmidth A/S Feed Shaft for Feeding Particulate Material to a Mill
CN109537338A (en) * 2018-12-21 2019-03-29 南京林业大学 Tortuous preheating channel rotary hopper-type defibrator feeding device
CN109537338B (en) * 2018-12-21 2024-02-23 南京林业大学 Feeding device of tortuous preheating channel rotary bucket type thermal mill
SE2050526A1 (en) * 2020-05-07 2021-08-17 Valmet Oy Method and apparatus for defibrating wood chips, and a return steam pipe for such an apparatus
SE543857C2 (en) * 2020-05-07 2021-08-17 Valmet Oy Method and apparatus for defibrating wood chips, and a return steam pipe for such an apparatus
WO2021225490A1 (en) * 2020-05-07 2021-11-11 Valmet Ab Method and apparatus for defibrating wood chips, and a return steam pipe for such an apparatus.
WO2021225491A1 (en) 2020-05-07 2021-11-11 Valmet Ab A system and method for defibrating wood chips, and a return steam pipe
EP4146861A4 (en) * 2020-05-07 2024-06-26 Valmet Ab A system and method for defibrating wood chips, and a return steam pipe
CN113152134A (en) * 2021-05-17 2021-07-23 中国制浆造纸研究院衢州分院 Closed tearing pulp grinding system

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NO742628L (en) 1975-04-01
FR2243297A1 (en) 1975-04-04
BR7407049D0 (en) 1975-09-09
AU7141474A (en) 1976-01-22
CA1004078A (en) 1977-01-25
FI229774A (en) 1975-03-07
SE386694B (en) 1976-08-16
DE2442627C3 (en) 1982-04-01
FR2243297B1 (en) 1977-11-04
NO142002C (en) 1980-06-11
DE2442627A1 (en) 1975-03-27
JPS5053601A (en) 1975-05-12
SE7312169L (en) 1975-03-07
NO142002B (en) 1980-03-03
DE2442627B2 (en) 1981-06-19
FI60580B (en) 1981-10-30
FI60580C (en) 1982-02-10
AU475744B2 (en) 1976-09-02
ATA635874A (en) 1976-03-15
AT333582B (en) 1976-11-25
JPS5245801B2 (en) 1977-11-18

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