BS 6035-2-1982 Methods for determination of the drainability of pulp - Canadian Standard freeness method《纸浆湿强度测定方法 第2部分 加拿大标准打浆度法》.pdf

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1、BRITISH STANDARD BS 6035-2: 1982 ISO 5267-2: 1980 Methods for Determination of the drainability of pulp Part 2: “Canadian Standard” freeness method ISO title: Pulps Determination of drainability Part 2: “Canadian Standard” freeness method UDC 676.017.3BS6035-2:1982 This British Standard, having been

2、 prepared under the directionof the Paper StandardsCommittee, was published under the authority ofthe Board of BSI and comes intoeffect on 31 May 1982 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference PAM/11 Draft for comment 78/60851 DC ISBN 0 580 127

3、55 9 Cooperating organizations The Paper Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: British Paper and Board Industry Federation (PIF)* British Printing industries Federation* Envelope Makers and Manufacturing Station

4、ers Association* HM Customs and Excise Her Majestys Stationery Office* Institute of Trading Standards Administration National Association of Paper Merchants National Economic Development Office Pira (The Research Association for the Paper and Board, Printing and Packaging Industries)* Royal Institut

5、e of Public Health and Hygiene The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: British Fibreboard Packaging Association British Wood Pulp Associatio

6、n Chemical Industries Association Man-made Fibres Producers Committee Ministry of Defence Paper Sack Development Association Ltd. Post Office Society of British Printing Ink Manufacturers University of Manchester Institute of Science and Technology Amendments issued since publication Amd. No. Date o

7、f issue CommentsBS6035-2:1982 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii 0 Introduction 1 1 Scope 1 2 Field of application 1 3 Reference 1 4 Definition 1 5 Principle 1 6 Apparatus 1 7 Preparation of sample 1 8 Procedure 2 9 Expression of results 2 1

8、0 Test report 2 Annex A The “Canadian Standard” freeness tester 3 Annex B Maintenance of the “Canadian Standard” freeness tester 6 Annex C Calibration service 6 Annex D Authorized laboratories 7 Annex E “Canadian Standard” freeness tester (Table of freeness corrections to 0,30 % consistency) 8 Annex

9、 F “Canadian Standard” freeness tester (Table of freeness corrections to 20 C) 9 Figure 1 “Canadian Standard” freeness tester 4 Figure 2 Bottom orifice 5 Publications referred to Inside back coverBS6035-2:1982 ii BSI 12-1999 National foreword This Part of this British Standard has been prepared unde

10、r the direction of the Paper Standards Committee and is identical with ISO5267-2 “Pulps Determination of drainability Part 2: “Canadian Standard” freeness method” published in1980by the International Organization for Standardization (ISO). Part 1 of this standard is identical with ISO5267-1:1979 “Pu

11、lps Determination of drainability Part 1: Schopper-Riegler method”. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in

12、 British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this sta

13、ndard, they should be read as “British Standard”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obli

14、gations. Cross references International Standard Corresponding British Standard ISO 4119:1980 BS 5878:1980 Method for determination of stock concentration of pulps (rapid method) (Identical) ISO 5267-1:1979 BS 6035 Methods for determination of the drainability of pulp Part 1:1980 Schopper-Riegler me

15、thod (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment t

16、able on the inside front cover.BS6035-2:1982 BSI 12-1999 1 0 Introduction The “Canadian Standard” freeness number depends on the conditions of measurement, particularly the geometric characteristics of the instrument. The only practical means of achieving the required degree of accuracy is by the ca

17、libration procedure specified inAnnex C. The reproducibility of this method is entirely dependent on these arrangements being established within and between countries. 1 Scope This International Standard specifies a method for determination of the drainability of a pulp suspension in water in terms

18、of the “Canadian Standard” freeness (CSF) number. The “Canadian Standard” freeness test is designed to provide a measure of the rate at which a dilute suspension of pulp may be dewatered. It has been shown that the drainability is related to the surface conditions and swelling of the fibres, and con

19、stitutes a useful index of the amount of mechanical treatment to which the pulp has been subjected. Results of this test do not necessarily correlate with the drainage behaviour of a pulp material on a commercial paper machine. A method for the determination of drainability in terms of the Schopper-

20、Riegler number is specified in ISO5267-1. 2 Field of application In principle, this method is applicable to all kinds of pulp in aqueous suspension. NOTEHowever, treatments which produce a large proportion of fines may induce an anomalous rise in freeness (false freeness) as a rule at values below10

21、0CSF number. 3 Reference ISO 4119, Pulps Determination of stock concentration. 4 Definition For the purposes of this International Standard, the following definition applies: “Canadian Standard” freeness number the volume, expressed in millilitres, of the filtrate collected from the side orifice of

22、the “Canadian Standard” freeness tester 5 Principle Drainage through a fibre mat formed during the test on a perforated screen plate of a given volume of pulp in aqueous suspension into a funnel provided with a bottom and a side orifice. Collection of the discharge from the side orifice in a measuri

23、ng cylinder. 6 Apparatus Ordinary laboratory apparatus, and 6.1 “Canadian Standard” freeness tester, as described inAnnex A. Instructions for maintenance of the apparatus are given inAnnex B. Details of the Calibration Service for the apparatus are given inAnnex C. Information concerning authorized

24、laboratories is given inAnnex D. 6.2 Measuring cylinder, calibrated in millilitres and capable of measuring volume with an error less than1,0ml. 7 Preparation of sample Take a sample of an aqueous suspension of the disintegrated pulp. If the concentration is not known exactly, dilute the suspension

25、to approximately0,32% mass/mass using distilled or deionized water (see note3), and determine the stock concentration in accordance with ISO4119. Then dilute the suspension to a stock concentration of0,3 0,005% mass/mass and adjust the temperature to20,0 0,5 C (see note4). Throughout the preparation

26、 of the sample, take care to avoid the formation of air bubbles in the suspension. NOTE 1With time, an aqueous pulp suspension withdrawn from the stock preparation system or laboratory pulp evaluation equipment, can undergo a change in freeness number. To avoid the effect of this reversion phenomeno

27、n, pulp suspensions subjected to testing more than30min after sampling should first be treated in the disintegration apparatus for 6000revolutions of the propeller, at or near the stock concentration specified for the CSF test. NOTE 2The test result is sensitive to the quantity of pulp fines, or “cr

28、ill”, in the suspension. Thickened pulp samples may lose some of this fibre fraction. To avoid such losses during the course of thickening, the filtrate should be recirculated through the pulp pad until the filtrate is clear and the pulp redispersed by disintegration, as described in note1. This pro

29、cedure should be used to concentrate dilute pulp suspensions to the stock concentration required for the freeness test. NOTE 3As the drainage of a pulp suspension is affected considerably by dissolved solids and the pH of the water, either distilled or deionized water of equivalent quality should be

30、 used throughout the test. NOTE 4Where necessary for climatic reasons, a temperature of25 5 C may be applied, provided that this is noted in the test report. In any case, during the test the basic temperature chosen should be kept constant within 0,5 C.BS6035-2:1982 2 BSI 12-1999 NOTE 5In some appli

31、cations,i.e.process control, larger deviations than0,005% for consistency and 0,5 C for temperature may be allowed and corrected with the aid of correction tables given inAnnex E andAnnex F. 8 Procedure Clean the funnel and drainage chamber of the “Canadian Standard” freeness apparatus (6.1) thoroug

32、hly, and finally rinse with water. Place the drainage chamber in position. Adjust the temperature of the apparatus by rinsing with water at20,0 0,5 C (see note4 in clause7). Place the receiving vessel (6.2) in position to receive the discharge from the side orifice. Whilst stirring, transfer1000 5ml

33、 of homogeneous pulp suspension to a clean measuring cylinder. Close the bottom of the chamber of the freeness tester and open the top lid and the air-cock. Mix the sample by closing the top of the cylinder with the hand and invert the cylinder180 three times. Avoid introducing air into the stock at

34、 this stage. Pour the stock gently but as rapidly as possible into the chamber. At the end of the pouring, the stock should be motionless in the chamber. Close the top lid and the air-cock and open the bottom lid. Allow5s to elapse from the time of pouring the stock, then open the air-cock to start

35、the flow. When the discharge from the side orifice has stopped, read the volume of this discharge to the nearest1ml for values below100ml, to the nearest2ml for values between100ml and250ml, and to the nearest5ml for values exceeding250ml. 9 Expression of results Carry out two determinations on each

36、 sample. Report the mean of two determinations as the “Canadian Standard” freeness (CSF) number. Duplicate determinations differing by more than 2% from their mean value shall be repeated. 10 Test report The test report shall give the following particulars: a) the reference to this International Sta

37、ndard; b) all indications necessary for complete identification of the sample; c) the test temperature; d) the results, expressed in “Canadian Standard” freeness number; e) any unusual features observed in the course of the test; f) any operations not specified in this International Standard or in t

38、he International Standard to which reference is made or regarded as optional, which might have affected the results.BS6035-2:1982 BSI 12-1999 3 Annex A The “Canadian Standard” freeness tester A.0 The “Canadian Standard” freeness tester (seeFigure 1) comprises a drainage chamber and a rate-measuring

39、funnel, mounted on a suitable support. The rate-measuring funnel shown inFigure 1, represents a modified design, adopted by the Canadian Pulp and Paper Association Technical Section as a standard in1964. The dimensional and flow specifications given below are those required for the modified instrume

40、nt to provide freeness results which are in complete agreement with those obtained from the original CS-freeness tester design. Test equipment made to the original design (without the centred side orifice or volume-adjusting plug) may require adjustment to somewhat different values for calibration,

41、and these values should be stated by the manufacturer. Where careful calibration procedures are followed, CS-freeness results, from either tester design, can be made to agree within the limits prescribed in clauseA.4. A.1 The chamber is a metal cylinder whose bottom is closed by a perforated screen

42、plate and lid, hinged on one side of the cylinder and latched at the other. The lid shall be so fitted that not more than5ml of water will flow on opening of the bottom cover at the start of the test. The upper end of this cylinder is closed by a similar lid, attached to the shelf bracket in which t

43、he cylinder is held when in use. The hinge and latching mechanisms are so designed that they provide an airtight closure by means of a rubber gasket on the inside of the lid. An air-cock is inserted in the centre of the upper lid for the admission of air into the cylinder at the start of the test. T

44、he cylinder has an internal diameter of101,5mm with an internal height of127,0mm (from the upper surface of the screen plate to the rim). The diameter is a critical dimension. These dimensions provide a capacity which slightly exceeds1000ml above the screen plate. The air-cock bore is4,7mm. This dim

45、ension is not critical but should not be subjected to substantial reduction. A.2 The screen plate is cut into a circular shape, of diameter111,0 0,5mm, and thickness0,5mm, and has perforations of diameter0,50mm spaced at97percm 2 . As it has not been possible to standardize the performance of these

46、plates by reference to the dimensions or spacing of the perforations, all plates are calibrated according to the procedure described in Pulp and Paper Research Institute of Canada Standard Testing Procedure Nos. PBA8 and PBA3, so that their performance matches that of master plates maintained at the

47、 Pulp and Paper Research Institute of Canada, Montreal, or sub-master plates maintained by other centres (seeAnnex C). The plates shall be mounted with the burr side of the perforations downwards. A.3 The rate-measuring funnel has an open top diameter of204mm and an overall length of277mm. The main

48、cone has a slope of29 5 on the inside which flares out into a top cylindrical portion. The bottom (apex) terminates in a carefully machined bottom orifice piece attached to the funnel. The funnel is further provided with a side discharge orifice. The side discharge orifice consists of a hollow tube,

49、 of internal diameter13mm, which penetrates the wall of the funnel. This tube is so inserted that the distance between the overflow lip of the tube (inside the funnel) and the bottom of the funnel section is50,8 0,7mm. This measurement is extremely critical and is set precisely by the manufacturer. Any adjustment of this dimension will exert a significant effect upon the performance of the tester. The volume in the bottom section of the cone, between the bottom of the funnel and the overflow lip of the side orifice, is adjusted to23,5