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1、INTERNATIONAL IS0 STANDARD 8130-5 First edition 1992-l 2-l 5 Coating powders - Part 5: Determination of flow properties of a powder/air mixture P oudres pour revefemenf - Parfie 5: Dated in the wall of the vessel, 10 mm above the top of the porous disc. 4.1.2 Air regulation unit B, with flowmeter F
2、for ad- justing the air flow. 4.1.3 Container C, sufficiently large to collect the powder discharged during measurement of the powder flow rate (see figure 1). 4.2 Supply of clean dry air, sufficient to undertake the test. 100 , A / _- Alr Dimensions in millimetres 5 Powder (mass m) Sintered-bronze
3、bottom Height of fluldlzed powder Height of fluldlzed powder Height of powder “at rest” Height of powder “at rest” ,-Powder Powder Stopper E Stopper E Figure 1 - Example of an apparatus for the determination of flow properties (for illustrative purposes only) Copyright International Organization for
4、 Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:37:41 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8130-5:1992(E) 4.3 Timer, accurate to 1 s. 4.4 Analytical balance, of capacity 500
5、g, capable of weighing to 0,l g. 4.5 Device for measuring the height of the powder in vessel A, graduated in millimetres. 4.6 Spatula. 5 Sampling Take a representative sample of the product to be tested, as described in IS0 8130-g. The quantity of the sample shall be sufficient for three determinati
6、ons (see 7.3). NOTE 4 A sample of 1 kg is recommended. 6 Procedure 6.1 Calibration of apparatus Calibrate the apparatus at a temperature of 23 “C and an air pressure of 101,3 kPa (1 013 mbar) (see annex A for guidance). 6.2 Determination of flow propertles Carry out the determination in duplicate. (
7、b is as given in 7.1. Close opening D with stopper E and charge vessel A with (250 + 10) g of the coating-powder sample. Introduce clean dry air (4.2) through the porous bot- tom at a rate sufficient to achieve optimum fluidization of the powder, normally (200 + 10) I/h. Note the air flow rate as me
8、asured on the flow meter F. To prevent “channelling” and “bubbling” during fluidizing, stir the powder with the spatula (4.6) until the height of the bed remains constant between stirrings. 7.3 If the results differ by less than 5 % of the lower value, calculate the arithmetic mean of 4 and R. If th
9、e difference between the two results exceeds 5 %, carry out a third determination and calculate the arithmetic mean of all three results. If the differ- ence between the result of the third determination and those of the other determinations is greater than 5 %, state this and the individual results
10、 in the test report. NOTE 5 This takes about 1 min to 2 min. 8 Test report If optimum fluidization takes place at air flow rates outside the range 190 I/h to 200 I/h, use the appro- priate air flow rate. NOTE 6 Direct comparison of the performance of pow- der fluidized at different air flow rates ma
11、y not be valid. Measure the height h, of the fluidized bed to an ac- curacy of 2 mm. Switch off the air and allow the powder to settle (this may require 1 min to 2 min). Measure to within 2 mm the height b of the powder at rest. Fluidize the powder again at the same rate of air supply, assist fluidi
12、zing by stirring and wait until the fluidized powder bed has reached a constant level. Remove stopper E from opening D, starting the timer (4.3) at the same time, and collect the powder dis- charged through the opening during (30 + 1) s. Close opening D with stopper E. Weigh the collected powder (m)
13、 to the nearest 0,l g. 7 Expression of results 7.1 Calculate the fluidization factor (b, using the equation where 43 is the height, in millimetres, of the pow- der at rest; 4 is the height, in millimetres, of the fluidized powder bed. 7.2 Calculate the using the equation R=rm$ where powder flow rate
14、 R, in grams, m is the mass, in grams, of powder col- lected in container C; The test report shall contain at least the following information: a) all details necessary to identify the product tested; b) a reference to this part of IS0 8130 (IS0 8130-5); c) the temperature and pressure of the air in
15、the test room; d) the air flow rate; 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:37:41 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8130
16、-5:1992(E) e) an indication of irregularities in the fluidized bed (such as “channelling” or “bubbling”), if ob- served; 9 the results of the test as indicated in 7.3; g) any deviation from the test method specified; h) the date of the test. 4 / Copyright International Organization for Standardizati
17、on Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:37:41 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8130-5:1992(E) Annex A (informative) Notes on apparatus and procedure A.1 Construction of apparat
18、us To prevent cleaning difficulties and/or clogging of the sintered-bronze bottom, it is strongly recom- mended that the air entrance compartment G (below the porous bottom of vessel A) be example by a screw mechanism). A.2 Corrections Usually flow meter F is calibrated removable (for with air under
19、 standard conditions of temperature and pressure. Mostly, however, it is used under other conditions, so it is necessary to make corrections to obtain the real flow rate of 200 I/h. If C is the correction factor and qr the required flow rate e.g. (200 L- 10) I/h as given in 6.21, then the flow meter
20、 reading qf is given by: This correction factor C ( = C,C,) depends on a) the difference in air pressure during the cali- bration and during the test: W c,= g J where T f is the temperature, in kelvins, of the air during the calibration, T2 is the temperature, in kelvins, of the air during the test.
21、 A.3 Example A test is carried out using a flow meter that has been calibrated in litres of air per hour at 23 “C and 101,3 kPa (1 013 mbar). If the test is carried out at 15 “C and 120 kPa (1 200 mbar), the following calculations can be used to determine the reading on the flow meter which will obt
22、ain a real flow rate of 200 I/h: where c,= -L?- J 1,013 = 1,088 is the air pressure, in kilopascals, during the calibration, h is the air pressure, in kilopascals, during the test; the difference in the absolute temperature of the air during the calibration and during the test: rF- c2= + J 2 c, = J
23、296 - 288 = 1,014 Thus 200 qf= 1,088 x 1,014 = 181 I/h To obtain a real flow rate of 200 I/h under the con- ditions of the test, the flow meter should therefore be adjusted to 181 I/h. 5 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Tec
24、hnical Standards 1/9972545001 Not for Resale, 04/24/2007 23:37:41 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8130-5:1992(E) Annex B (informative) Bibliography l DOUMA, G.H. and SELIER, P. I-Lack, 41, No.9, p. 361 (1973). 2 DE LANGE, P.G. I-Lack, 42, No. 9, p. 339 (
25、1974). 6 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:37:41 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8130-5:1992(E) UDC 667.62-492.2:66
26、7.644.3:667.612.62 Descriptors: coatings, powdery materials, paints, spraylng, sprayabllity, tests, determination, flow rate. Price based on 6 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:37:41 MDTNo reproduction or networking permitted without license from IHS -,-,-