Maguire Products Weigh Scale Blender WSB, Operation & Maintenance Manual

Page: 67 / 99

M A G U I R E P R O D U C T S , I N C .
Edition: August 5, 2014
67
W E I G H S C A L E B L E N D E R
®
FLOW RATE NUMBERS
: (DATA line 2)
Check the RATE numbers, (DATA line 2), to determine each dispense device.
In the example above:
In the component 1 column, 18224 and 976 translates to 1822.4 grams in 4 seconds (244 interrupts = 1 sec). This is 455.6 grams
per second, typical for a regrind flowing through 3" round or 2"x3" dispense valves.
In the component 2 column, 19993 and 488 indicate 1999.3 grams in 2 seconds, or 999.6 grams per second flow rate. This is a
heavy natural material, not polyethylene. Perhaps Lexan or a glass filled material.
In the component 3 column, 12973 and 31232 indicate 1297.3 grams per 31232 interrupts, or 128 seconds, for a flow rate of 9.99
grams per second. This is a 1” auger feeder, from which we would typically expect about 8 grams per second. More recent auger
feeders use faster motors delivering about 16 grams per second.
In the component 4 column, 10240 and 31232 indicate a flow rate of 8 grams per second EXACTLY. Since it is exact, and since
these two numbers are, in fact, the "default" settings from when the blender was first installed, we know that "component 4" has
never been run on this blender, or at least not since the last "CLEAR ALL" was performed.
DATA line 3 dispense weight of 0.0 for component 4, and the TOP-OF-PAGE heading showing component 4 set to 00.0 percent
also confirm that component 4 is not being run.
The following information will help you determine what devices are in place on a blender.
Material Dispense Device: Approx. Grams
per Second:
½” Auger Feeders, Micro Pulse Valves 0.5 - 02
1” Auger Feeders 06 - 10
Vertical Valves 20 - 40
WSB 100 - Slide Gates 250 - 450
WSB 220, 420 - 3” Round Slide Gates 500 - 900
WSB 240, 260, 440, 460, 940, 960, 1840, 1860 - 2” x 3” Slide Gates 500 - 900
WSB 240, 260, 440, 460, 940, 960, 1840, 1860 - 3” x 6” Slide Gates 3000 - 5000
Regrinds are always lower then naturals. Bulk density will also cause wide variations in flow rates.
ERROR CORRECTIONS: RATE NUMBERS:
(DATA line 2)
The RATE numbers are used by the software, each cycle, to calculate material dispense times. They are adjusted every cycle
until flow rates stabilize. When a significant error is detected, the software adjusts the RATE numbers.
The GRAM number is adjusted first. The TIME number (interrupts) is changed only if the GRAM number goes below 16,000 or
above 32,000 (approximately). In this event both GRAM and TIME numbers are doubled or halved to bring the GRAM number
back to between 16,000 and 32,000.
This serves to keep all numbers as large as possible allowing for the most accurate math, but not so large as to overflow the
registers.
Only the GRAM number changes from cycle to cycle, except under the conditions noted above.
Check the GRAM number for a series of consecutive cycles. If it remains unchanged, then the dispenses are accurate enough to
not trigger error corrections. Another possibility is that the parameters (MI and NC) that determine when error corrections occur
are somehow out of range preventing corrections that should be occurring.
The PRC parameter limits adjustments to 10 percent. Do not expect any single GRAM number change larger then 10 percent.
A gradual decrease in the GRAM number indicates a slowing rate, a hopper that is becoming empty for example. A jump in rate
(increased GRAM number) occurs when the hopper is refilled.
If Errors are occurring, but the GRAM number is NOT adjusting, check the NC parameter and the MI parameter. These control
weather or not error corrections occur. Both are set and adjusted automatically by the software. MI is set after each start up, after
10 cycles have run without retries. MI will be set to indicate 50 percent of normal dispense rate expressed as grams per second.
NC adjusts slowly over extended periods of running. NC indicates, in grams, the upper limit of the error in 60 percent of the
dispenses. A high number usually indicates poor flowing material. Vibration or drifting load cells are other possibilities.
DISPENSE TIMING
: (DATA line 3)