Page 34 - Industrial Technology September 2020 issue

MACHINE BUILDING

RFID tracks conveyor position

CONVEYORS

BULK MATERIAL-HANDLING EQUIPMENT USES RFID TECHNOLOGY TO
SENSE THE POSITION OF LARGE RAIL-MOUNTED RECLAMATION
CONVEYORS OPERATING IN A HOT, DUSTY ENVIRONMENT. A PAIR OF
READ-WRITE MODULES INTERROGATE A SERIES OF RFID TAGS, AND
THE THE CONTROL SYSTEM IDENTIFIES EACH TAG AND DETERMINES
THE POSITION OF THE MACHINE AND PREVENTS CRABBING

uring surface-mining operations, large mobile accommodate up to 10mm lateral movement of the
reclamation machines are used to recover bulk machine structure across either rail and must withstand
materials. On each machine, a bucket-wheel the hot, dusty environment of a desert climate.
Dexcavator collects material and deposits it onto Contrinex high-frequency RFID read/write modules and
a conveyor. As an area is cleared of material, the machine 30mm-diameter RFID transponder tags, available in the
moves along parallel steel travel rails to the next area, UK from Plus Automation, are ideal for this application.
allowing continuous operation without interruptions Rated up to IP67, the M30-diameter
for machine repositioning. read/write modules have PBTP As the machine passes a tag, the read/write module
The distance between the travel rails is sensing faces and V2A reads its identification number at high speed; this is
around 100 metres and travel speeds stainless-steel housings, transmitted via a Profibus DP interface to the customer’s
may reach 2m/sec (4.5 mph). If making them ideal for control system. A simple look-up table confirms the
machine movement along the two rails the demanding location of the tag and thus the position of the machine,
is not controlled accurately, the two environment. allowing movement of both sides of the structure to be
sides of the structure become The ConIdent passive synchronized without skewing. Operation is independent
misaligned, causing the machine to skew. transponders require no of the direction of travel.
In this event, production is halted while the internal power source and, Contrinex ConIdent RFID devices allow accurate and
machine is realigned; in the worst case, costly with PBTP synthetic housings, highly reliable sensing of machine position and the long
damage occurs. have the same IP67 rating. The selected sensing distance avoids any risk of collision damage. The
A sensing system is required that detects the position combination provides read/write distances of up to 45mm, customer enjoys extended service life and robustness not
of each side of the machine structure accurately and ideal for the specified operating conditions. Tags are available from alternative position-detection systems,
reliably along the entire length of the travel rails, allowing mounted at one-meter intervals along each travel rail, together with excellent value for money.
coordinated control of the drive systems. Sensors must each programmed with a unique identification number. MORE INFORMATION: www.plusax.co.uk

Vacuum conveyor for non-woven strips

K Profile Systems recently received a request eight-line conveyors. This allows the customer to switch
for an application in the production of non- the vacuum on or off in individual lines and configure the
woven strips which required cut sections of system for different strip widths. This ensures an optimal
Mnon-woven fabric to be transported from one suction pressure in all cases.
machining station to the next. The material was very thin The conveyors are equipped with ø19 mm rolling knife
and light with the system needing to run at a high speed edges on both sides to achieve short transfer distances.
of 140m/min. The conveyor frames are equipped with welding bolts for
The strips had to be transferred from one conveyor to mounting in the customer-provided frame. The conveyors
the next without any damage and it also had to be are arranged such that the hair removal strips can be
possible to cut them again as they passed through the transported from one conveyor to the next. The transfer
system. They had to maintain their position as they conveyors are positioned upside down with the running
passed through the system with the conveyor technology side facing downwards, allowing the hair removal strips to
needing to be integrated into a customer-provided frame. be transferred while suspended below the conveyor. They
The system was required to be able to handle strips of are then transferred to the top side of the next conveyor.
various formats without retooling. This ensures reliable transfer. In some locations two
MK used a vacuum conveyor consisting of a belt conveyors are arranged atop one another so that stacks of
conveyor with BC lower belt drive. The conveyor frames hair removal strips can be clamped between the conveyors
were made from square, stainless steel tubes, with each and then transported and cut without sliding.
having a suction nozzle that allowed for maximum flow The finished system has provided the customer with a
rate to establish the vacuum. Oblong holes run along the very fast and reliable way of conveying a small,
running side of the conveyor frames. A perforated belt lightweight product. It is extremely versatile in operation
allows the hair removal strips to be vacuum-gripped so and optimised for maximum flow rate with extremely
that they can be securely transported even at high speeds. short transfer distances.
The conveyors are only 50 mm wide and are configured as MORE INFORMATION: www.mkprofiles.co.uk

34 INDUSTRIAL TECHNOLOGY • September 2020