POWER April 2014 - 30

PLANT MAINTENANCE
1. Ground control. This photo shows
a typical ground station for the drones, with
dual screens and dual control. Courtesy: United
Aerobotics
2. MAGNEBOT as a boiler wall
would see it. Rotors enable the visual inspection
tool to move from one area of interest
to another. Courtesy: United Aerobotics
4. Climbing the walls. Using both
its rotors and rollers, the MAGNEBOT can
smoothly travel up a boiler wall, capturing
photos or real-time video. Courtesy: United
Aerobotics
cessing areas that are inaccessible due to safety
concerns or other regulatory restriction.
Drone Models
United Aerobotics has two drone models (see
Table 1). The trademarked MAGNEBOT
v1.0 was designed for interior structure
evaluations, such as inside the boiler proper,
while the ELECTRABOT v1.0 is used outdoors
and in areas experiencing drafts.
What separates MAGNEBOT and ELECTRABOT
from basic remote-controlled
helicopters is live, real-time streamed footage,
allowing for real-time inspections and
reporting. The MAGNEBOT also is capable
of landing vertically on a furnace waterwall
and can turn off its rotors for energy savings
while continuing to operate the camera and
lighting system within high-priority inspection
areas.
Each drone also comes equipped with a
fully functional operating ground station. Although
more than one ground station design
exists, they all include:
■ Pelican case housing to resist the elements
■
Flight control electronics to provide support
for the flight team
■ High-power computer for processing and
editing captured footage
■ High-definition monitors to provide a live
view for the inspector
■ High-speed battery charger for continuous
flight operations
Ground stations are used by the flight technician
as well as lead inspector performing
the evaluation. The station used on a given
inspection depends on the application and requirements
for the flight project, access point
(door) dimensions, travel considerations, and
other factors.
The larger ground station (Figure 1) was
designed to allow for both inspection technician
and flight technician to view flight footage
with ease, eliminating any interference
(crossover) between them. The flight technician
can be watching for flight pattern and
30
safety, while the inspector can be viewing for
evaluation accuracy. The inspector is evaluating
in real time and may ask the flight technician
to stop and return the drone to an area
based on potential deficiencies that may have
been observed. We have learned that technician
interference is typically not an issue,
which led to the smaller, more transportable
and manageable ground stations with one
main viewing screen.
The Technology at Work
Different inspection locations and tasks require
different capabilities, which is why the
two models have some specialized features.
MAGNEBOT. During any inspection,
there are regions or areas on the list that require
more attention or time. To best manage
inspection of boiler furnace waterwalls, the
MAGNEBOT, flown by four rotors, was dewww.powermag.com
3.
Evidence. This image shows results
from a MAGNEBOT inspection of a wall blower
unit. The drone is inspecting for wall wastage
due to sootblower erosion, cracked peg
fin, cracked or missing blower head, missing
refractory from wall box, any debris lodged
in blower sleeve restricting proper blower
function, fatigued or eroded blower sleeve,
and condition of wall box, if visible. Courtesy:
United Aerobotics
5. Lights, camera... The MAGNEBOT
housing box is the " brain center " of the drone
and includes both LED lighting and high-definition
camera. Courtesy: United Aerobotics
signed to land vertically (Figure 2).
Run time on the MAGNEBOT is approximately
10 to 15 minutes with all attached
equipment in operation. The MAGNEBOT
has the ability to zone in on a high-priority
location for inspection, such as a wall blower
opening (Figure 3). Wall blower locations are
typically a high-priority item on the inspection
checklist due to potential erosion rates
and patterns, blower lance head cracking,
alignment, and overall deterioration, refractory,
wall box fatigue, and the infamous peg
fin cracking mechanisms. The only thing the
drone cannot do at this point is take an ultrasonic
reading on an eroded tube; we can only
tell the customer that it is worn. (An upgrade
in progress will enable UT readings.) The
value to plant managers in seeing burners
and wall blowers is that they can determine
if they have immediate action items, but in
most cases inspections are used to determine
parts to be ordered for the next scheduled
shutdown.
Due to the enormous amount of energy
consumed by the blade motors, having the
ability to land the drone on the wall (Figure
4) while eliminating power to the rotors allows
for longer, more detailed inspection
POWER | April 2014
http://www.powermag.com
POWER April 2014

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