Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C7/00—Crushing or disintegrating by disc mills
  • B02C7/11—Details
  • B02C7/12—Shape or construction of discs
• • 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
  • D21D1/306—Discs

Definitions

• This invention relates to disc refiners for the mechanical processing of cellulose material and refers to the members constituting the processing surfaces, so-called refiner disc segments.
• Cellulose-containing material is defibred and refined by so-called refiners, which in many cases are of the disc refiner type. These refiners also are used for beating cellulose and mechanical pulps of various types when it is desired by mechanical processing to develop the paper-forming properties of these materials. All these defibring and refining operations have in common, that the desired result is obtained by mechanically processing the material while it is passing through the refiner.
• This processing effect is brought about in that the fibre material, after having been fed by various types of devices into the refiner, leaves the refiner through a narrow gap between two processing surfaces, which to this end are provided with processing members in the form of bars and intermediate grooves. Due to the rotation of one, and at times both said surfaces, the material is processed in the way desired and is transported out of the refiner by the rotation forces.
• the intensity and type of processing the fibre material is determined a.o. by the design and number of the bars and grooves on the processing surfaces and also by the size of the gap. A certain wear of the refining surfaces cannot be avoided and, therefore, the disc refiner is provided, for practical reasons, with exchangeable refiner disc segments. These segments are provided at their manufacture with a pattern and profile adapted to the type of work to be carried out in the refiner. The energy required for defibring and processing is transferred to the fibre material via the edges and surfaces of the bars.
• Fig. 1 The design of a refiner disc segment is shown in Fig. 1.
• the pattern generally is divided into three zones22, 3 and 4 where in the outer zone 4 bars and grooves are designated by 5 and, respectively, 6.
• Fig. 2 shows how the bars conventionally are formed with walls 7,8 and a plane surface 10 so that a gap 9 is formed.
• the design of the bars and grooves of the refiner disc segments is of importance for the energy consumption at the refining of cellulose material, especially at high concentration, above 20%. Even seemingly small variants in the refiner disc segment pattern can cause great variations in the energy consumption.
• the design of the patterns is very important also for the properties resulting from the refining/processing.
• this is achieved in that the surface slightly is curved downward along its centre line in relation to its edge.
• Fig. 3 is a cross-section of two opposed bars according to the invention
• Figs. 4-7 show other variants of the bar according to the invention.
• Fig. 3 a cross-section of two bars is shown, which are located each on a refiner disc segment of contra-rotating refiner discs (not shown).
• the bars have walls 11,12 of conventional design.
• the processing surface 13 of the bars is formed with a concave deflection, which in the present case is at least 0,1 mm.
• Figs. 4 and 5 two further embodiments are shown, which are characterized in that the angle ⁇ between the bar surface 7 and at least the upper portion of the bar wall is smaller than 90o.
• the wall consists of a straight vertical portion 13 and an inclined upper portion 12, so that a cutting edge 9 along the edge of the bar is formed.
• the processing surface has a depression with a plane bottom 17, which depression is defined by inclined or straight walls. Along the edges of the surface a plane edge zone 16 is formed.
• Fig. 7 an embodiment is shown where the depression is formed by two surfaces inclined to the centre line of the surface.

Landscapes

• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Paper (AREA)
• Crushing And Grinding (AREA)
• Table Devices Or Equipment (AREA)
• Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20349019

Family Applications (1)

Country Status (7)

Families Citing this family (5)

Family Cites Families (6)

• 1982
  • 1982-12-15 SE SE8207175A patent/SE441649B/sv not_active IP Right Cessation
• 1983
  • 1983-12-06 JP JP84500277A patent/JPS60500127A/ja active Pending
  • 1983-12-06 WO PCT/SE1983/000429 patent/WO1984002285A1/en active Application Filing
  • 1983-12-06 AU AU23454/84A patent/AU2345484A/en not_active Abandoned
  • 1983-12-06 EP EP84900132A patent/EP0158637A1/en not_active Withdrawn
• 1984
  • 1984-08-14 NO NO84843233A patent/NO843233L/no unknown
• 1985
  • 1985-01-14 FI FI850155A patent/FI850155L/fi not_active Application Discontinuation

Non-Patent Citations (1)

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