Tyler Ro-Tap RX-29, Руководство по эксплуатации

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The key to successful, repetitive particle analysis is developing standard testing procedures.
Basic Elements of Testing
1. Sample Preparation.
2. Test sample sizes or weights.
3. Test Equipment.
4. Testing times or intervals.
5. Recording results.
Sample Preparation
When deciding how much material to test, consider the type of material, screen ability of the material and the
range of particle sizes.
If the particle range of material representing feed to a screen or product from a crusher is wide, use a large
sample (from 500 to 1,000 GRAMS). If the material is finely ground, use a smaller sample of 25 to 100 grams.
Do not use too large a sample in the test. The smaller the sample, the more consistent the results (as long as
the sample is properly taken). To obtain an accurate sieve test sample, every particle must present itself to the
screen openings for retention or for passing through to the next finer sieve. Make sure the sample is large
enough so that the coarsest sieve retains enough representative particles.
For example, if a “stack” contains six sieves, a fine particle must repeat the passing process six times. The fine
particles cannot pass through to their proper end when overloading occurs.
As a general rule, limit the size of a sample in weight so that no sieve in the “stack” is overloaded. Overloading
usually occurs in testing closely graded materials, where the range of particle size is limited. In such cases,
determine the size by capacity of the sieve that retains the largest amount of the sample.
Use the following procedure to determine your sample size:
1. Accurately split out samples of varying weights (25, 50, 100, 150 and 200 grams) with a sample splitter.
2. Run the various samples on the selected sieves for five minutes.
3. Compare the results to get the correct sample size.
When two sample sizes provide similar results, use the larger of the two for your test size. For example, if the
100 gram sample shows approximately the same results as the 50 gram sample, but the 150 grams sample
produces differing results, use the 100 gram sample as the correct sample size.
Near-mesh particles (those with dimensions close to the sieve opening) require that you lightly load the sieves.
This allows presentation of the particles to the sieve opening many times, which allows maximum opportunity
for accurate classification.
Wet Testing
Some materials do not test well under dry conditions. If the material is not water soluble, you can perform an
accurate sieve analysis with special equipment.
The Sieve Shaker with a Wet Test Kit will be required. The wet test kit ensures there will be no splashing or
contamination of the samples.
The test should be performed the same as dry material (previous section) with one exception.
Water, as called for by the test procedure, must be added to the sample prior to the test run.