TM 5-3895-374-10
......................................................................................................................................................... EDIT PROCESS DELAYS
Actual interval measurement is usually done in two parts. First material is run from the furthest bin and the time for this
material to travel between bins is measured and recorded. The travel time from the furthest bin to the scale can also be
measured and recorded. Next, the travel time of material from the scale to the point of asphalt injection is estimated. This
interval is hard to accurately measure as it is affected by materials, rates, burner air etc. Often it is easier to estimate this
number and correct it under actual operating conditions.
For example:
(in this example Bin 1 is the furthest bin) Actual material
travel times are measured as follows:
Bin 1 to Bin 2
=
3 seconds Bin 1 to Bin 3
=
4 seconds Bin 1 to
Vir Scale = 25 seconds
Assume Vir Scale to A/C = 70 seconds
Then
Vir Scale to A/C
=
70 sec.
Bin 1 to A/C = Bin 1 to Scale + Scale to A/C
=
95 sec.
Bin 2 to A/C = Bin 1 to A/C - Bin 1 to Bin 2
=
92 sec.
Bin 3 to A/C = Bin
1 to A/C - Bin 1 to Bin 3 = 91 sec.
Enter these numbers in the computer. Now suppose on making actual mix some 5 seconds worth of material must be
rejected because it was not coated. This happens when material actually gets to the point of A/C injection before
expected. All time intervals should be shortened by 5 seconds because the A/C injection point is 5 seconds closer than
thought.
The new values would then become:
Vir Scale to A/C
= 70 - 5
= 65 sec. Bin 1 to A/C
= 95 - 5
= 90 sec.
Bin 2 to A/C
= 92 - 5
= 87 sec. Bin 3 to A/C
= 91 - 5
= 86 sec.
The rules are:
On normal startup-if reject has too little oil shorten all intervals-if reject has too much oil lengthen all intervals
On normal cleanout/shutdown-if reject has too much oil -shorten all intervals-if reject has too little oil lengthen all
intervals
Using the above rules the operator should be able to reach the point of having negligible waste at both startup and
shutdown because of incorrect oil content.
page F - 63
SYSTEMS Equipment Corp. 8/31/89 Page (34)
