calling in other personnel. Its main
features include:
n
n
All stainless steel construction
for long-term prevention of
corrosion.
n
n
Two alternating sample scoops to
reach both sides of the conveyor
(Figure 3).
n
n
The scoops are designed to reach
deeper than a person with a
shovel can.
n
n
The scoops operate in the same
direction of the material flow.
n
n
The frequency of sampling
is programmable, based on
the lot size and flow rate
calculations.
n
n
A small footprint on the conveyor
belts.
A number of North American coal
export terminals have already installed
an MPS or have orders in the pipeline.
Table 1 and 2 show data collected at two
different terminals (one for coal: Table 1;
and one for petcoke: Table 2) comparing
the MPS to a sample collected by a
mechanical sampling system.
The data is encouraging,
indicating that this device is a safe
alternative to full‑stream mechanical
sampling. Even though this device
was developed solely as a backup to
mechanical sampling at high‑volume
high‑capacity export terminals, its
performance has attracted the
attention of smaller terminals and
petcoke refineries where either
cost constraints, or the consistency
of the material, allow for the
MPS to become a primary
sampling option.
Conclusion
In summary, knowing about sampling
methods and their limitations is
important to both sides in any
commercial coal transaction. The
probability samples collected by
full-stream mechanical sampling will
always be paramount. But it is also
important to know the judgment
sampling alternatives. The
development of the MPS introduces
an important new alternative method
available to the coal industry.
Table 2. Comparison on petroleum coke – dry basis results
Method Moisture Volume
Ash
Sulfur
BTU
Calories
Mech.
7.53
10.72
0.51
5.59
15 242
8468
MPS
7.91
10.52
0.47
5.6
15 276
8487
Method Moisture Volume
Ash
Sulfur
BTU
Calories
Mech.
7.14
10.66
0.5
5.3
15 268
8482
MPS
7.46
10.71
0.49
5.33
15 311
8506
Method Moisture Volume
Ash
Sulfur
BTU
Calories
Mech.
7.97
10.75
0.54
5.66
15 189
8438
MPS
8.01
10.74
0.54
5.63
15 229
8461
Table 1. Comparison on blended coal – dry basis results
Method Moisture Volume
Ash
Sulfur
BTU
Calories
Mech.
7.62
35.17
14.21
0.87
12 688
7049
MPS
7.12
35.27
14.5
0.84
12 652
7029
Method Moisture Volume
Ash
Sulfur
BTU
Calories
Mech.
7.68
34.23
14.08
0.85
12 663
7035
MPS
8.14
34.89
14.19
0.85
12 639
7022
Method Moisture Volume
Ash
Sulfur
BTU
Calories
Mech.
7.52
33.3
15.11
0.86
12 631
7017
MPS
7.78
33.91
14.61
0.87
12 688
7049
Figure 3. The MPS includes double sample scoops (Note:
during operation, they alternate via a timer).
Figure 2. Installation of a Mechanical Part-steam Sampler
(MPS).
32
|
World Coal
|
August 2015
