Orimulsion Spill Response R&D
Jump to part | 1 |
2
| 3 |
4
| 5 | of this article series
Part 3 - Bitumen
Pump Transfer Test at DESMI 2001-02-20 to 03-01
Sponsored by Bitor (PDVSA), Ro-Clean DESMI, and DESMI
Planned and conducted by flemingCo environmental
Brief Summary Report
Background:
Two of the most widely used heavy oil spill transfer pumps on the spill
response market (GT-185 and DESMI DS/DOP-250) have previously been tested on
refloated bitumen originating from a tank test spill of OrimulsionŽ and had
at 14 – 18 °C difficulties transferring the product from pump inlet to
pump discharge, meaning that feeding the product into the pump inlet showed
difficult and/or the pressure/friction losses inside the pump itself could
just about be overcome. It was therefore deemed necessary to test various
techniques which might improve the pumps’ ability to transfer bitumen.
Unless the problem could be overcome, a large number of otherwise bitumen
capable mechanical feeder skimmers would have had to be considered
unsuitable.
Executive Summary:
Initial analytic pre-testing unveiled high friction in both pump and
skimmer, therefore higher torque hydraulic motors were mounted. The DESMI
belt skimmer recovered and scraped off the cold bitumen at a high rate.
Pre-test pumping through 5 m of 6" hose indicated that heating the
bitumen from 14 to 30 °C could be enough to ensure a reasonable pump
performance, while cold water injection, on inlet side or discharge side,
did not seem to significantly enhance pump performance on cold bitumen (14
°C). Steam/hot water injection at the pump’s inlet lube flange had great
positive impact on pump performance. At the final pump test on cold bitumen
with a bulk temperature of 14-15 °C (> 3 million cSt) it was
demonstrated that steam injection via a lube flange specially designed for
the pump inlet could create concentric stratification of the bitumen in the
20 m long 6" hose, so that a 3" "snake" of water
lubricated bitumen was shot through the hose at a rate of 45 m3/h.
Extreme viscosity pump transfer improvement techniques
which were tested:
Annulus ring water lubrication after pump (cold water only)
Annulus ring water lubrication before pump (steam, hot water, and
cold water)
Heating of bulk
Combinations of 1 -3
Main equipment:
- Reflotation- and skimming tank: 10 m3 H2O
w. 3% salinity.1.6 m3 Orimulsion released
- Bitumen tank: 1.4 m3
- Reflotation pump: DESMI 45 m3/h sewage pump
- Skimmer: Ro-Clean DESMI Belt Animal
- Pump: DESMI DOP-250, OMTS 200 motor: 0.2014 L/rev., OMTS 315:
0.3263 L/rev.
- Power Pack: 50 kW DESMI Silent, multi function, remotely
controlled
- Water Lubrication Flanges:
Inlet side: flemingCo designed 280 mm inner diameter steam/water
lube flange
Discharge side: DESMI 6" ANSI water lube flange,
USCG/GPC/FRAMO type
- Discharge side lube water pump: DESMI Rotan gear pump
- Steam heating: GERNI 5000 Steam/HW Cleaner, 79 kW heating
effect, 14.5 l/min
The tests:
The skimmed bitumen was delivered into the bitumen tank, from where the pump
- mounted low on the tank side - should transfer the product. During the
pre-test runs, the 3 m flexible 6" riser tube was replaced with a
longer tube (5 m) which made it possible to discharge the product on the
rotating belt skimmer, thus draining off lube water to the skimmer tank, so
that only bitumen would enter the bitumen tank. The same method was later
used at the 20 m hose tests.
See Viscosity-Temperature
Curves for natural and refloated bitumen
DOP-250 with inlet side steam/HW injection flange
(right) and
discharge side water lube flange (left). Note the feed lines.
The pump is mounted with end suction side low on tank side.
Steam/HW injection, 33 m3/h at 9 bar just before
water lubrication
starts working. 20 m 6" hose.
Steam/HW injection, 33 m3/h as pressure starts
dropping.
20 m 6" hose.
Steam/HW injection, 45 m3/h at 2 bar. 100% water
lubrication
(Note how the bitumen snake jumps into the air as it hits the
bitumen piled up on the belt skimmer). 20 m 6" hose.
[top]
