Sterlco SPV Remote Proportioning Devices - Manual (Page 21)

Remote Proportioning Valve Chapter 4: Operation 21 of 28
4-4 Weight Test for Accurate Proportioning
To get an accurate proportion of regrind and virgin materials, run the test described below to
determine the conveying rate of your particular installation using your materials. The test will
determine the ratio settings needed to deliver the desired mix.
1. Determine the total throughput of the machine. This is equal to the amount (pounds)
of material your processing machine uses in an hour.
2. Weigh out a known quantity of regrind into the container from which the regrind is
conveyed. This amount should be enough to service the processing machine for the
duration of the test.
3. This test should be run for at least 15 minutes.
4. Set the Remote Proportioning Valve controls to approximate the desired proportions
of virgin and regrind.
5. Note the time and begin processing.
6. Stop processing after at least 20 minutes. Note the total processing time.
7. Weigh the regrind remaining in the container.
8. Determine the amount of regrind that would have been used if the test had been run
for an hour (Lbs. Regrind/Hour). For example, if you tested for 15 minutes, multiply
by four.
9. Divide the (Lbs. Regrind/Hour) by the (Lbs./hour) throughput figure to determine the
percentage of regrind at the current setting.
10. If the percentage is not acceptable, re-adjust the controls and repeat steps 2 through 9
until the proportions are correct.