Visitors to Blackpool Pleasure Beach can be sure of a warm reception
after a ride on the £15 million Valhalla, the world's biggest dark water
ride, thanks to an innovative drying system powered by a drive and four
motors
The Valhalla ride at Blackpool Pleasure Beach takes the form of a voyage
in a Viking longboat, plunging visitors down several drops into a series
of water pools. As with most water rides people can end up with damp hair
and clothes; however, the Valhalla experience ensures that its passengers
are able to leave the ride exhilarated - not moistened - which is where a
sophisticated 'people' dryer comes into play.
The dryer, installed by Haystack Dryers, is an open framed air
conditioning system, which uses four high-volume cross-flow fans to
create a vortex of warm air around the users, drying up to two adults and
three children at a time. The four 80W fans are powered by ABB motors,
driven by an ABB 1.1kW ac drive. The decision to use a variable speed
drive was made in order to avoid customers being blasted by a high-speed
jet of hot air as soon as they enter the cabinet. The drive is used in
two modes, 'idle' and 'operational'.
Idle mode is used when the dryer is unoccupied, and the drive operates
the fans at a low speed to continually recycle the air. In the
operational mode, the fans are driven to full speed, recycling the air at
an increased rate to remove moisture. Used in conjunction with infra-red
lamps, this produces a sensation similar to that of a warm, windy day.
After the drying cycle is complete, the infra-red lighting is dimmed and
the fans are reduced to idle speed. Variable speed drives also allow the
use of frequencies above 50 Hz. This gives higher fan speeds and provides
up to 20 percent more drying capacity compared to running at 50 Hz, due
to the improved air flow. The fans achieve an air velocity of 9m/s,
changing the air in the dryer four times per second. Brian Trim,
technical director of Haystack Dryers, explains why he chose ABB for the
drive and motor combination.
ABB was the only company that could give us a complete drive and motor
package. We couldn't find any other company able to give us what we
wanted at the right price. Cost was a key concern when developing the
dryer, as was the availability of the drives and motors. We have had a
great response from ABB; drives and motors have always been available
whenever we wanted them. Mike Brown, director, Blackpool Pleasure Beach,
adds that as far as he knew, this is the first time this type of facility
has been offered at a theme park.
The dryers have other applications in sports centres, swimming pools,
nursing homes and hospitals. Haystack Dryers are particularly keen to
break into the medical market and see the capabilities of the ABB drive
and motors as a key to this goal. Speed control across the range is
vital for this application in the medical field, as patients may have
burn injuries that are obviously sensitive to blown air, comments Mr
Trim. We also need to be able to interrogate the system for fault
finding and the serial link of the drive can be linked to our PLC to
provide the data we need.