Tempress is Scandinavia's
largest manufacturer of quality gauges for measuring of temperature,
pressure and level. The 70 employees in the company produce
over 100,000 units annually, of which by far the majority
is produced to customer orders and exported throughout the
world. Since it was founded in 1956, the company has been
involved in five key areas:
- Refrigeration
- Marine
- Food/pharmaceutical industry
- Processing industry
- Machinery/apparatus industry
A new railway network for high-speed trains is currently
being built in Korea, and the project includes a completely
new distribution network for electricity. Tempress has been
awarded a major contract to supply this railway network with
advanced measuring equipment, including a monitoring and alarm
unit with thermometer and pressure gauge.
The Tempress gas density monitor is a combined monitoring
and alarm unit that prevents the formation of electric arcs
when the trains' electricity supply is switched on and off.
Because of the extremely high voltage in the electricity supply,
such an electric arc can cause an explosion and create dangerous
situations for both the railway personnel and the equipment.
An electric arc is a constant strong electric discharge in
the air. The high-voltage circuit breakers are therefore mounted
in sealed chambers that contain SF6 gas, which is protective
because it displaces oxygen and forms ions that prevent electric
arcs from developing.
The Tempress monitor checks that the density of the SF6 gas
remains constant, irrespective of temperature fluctuations.
Any fall in the density of the SF6 gas below a certain critical
level sets off an alarm that also ensures the appropriate
high-voltage circuit breaker is disconnected.
SF6 is listed as one of the gases that contributes to damaging
the ozone layer, so it is important to prevent any such emissions
for environmental reasons. All the equipment used here must
therefore be hermetically sealed and thoroughly tested. Tempress
uses helium to test all its SF6 equipment, and then places
this equipment in a near-vacuum. A special sensor that can
trace a mere few molecules of helium is used, and if this
reacts, the unit is immediately discarded.
The Korean railways have placed an initial order for 550
Tempress gas density monitors.
"The approval process for being accepted as a supplier
took two years, and now we have to prove that we can live
up to the Korean expectations. There is considerable potential
in their overall supply network. The country uses approximately
20,000 units of this type every year," says Managing
Director Bj?rn Sahl.
The circuit breakers can also be protected by oil or a vacuum,
but a solution using SF6 gas makes it possible to provide
equipment that is both simpler and lighter.
Tempress Website www.tempress.dk
email tempress sales@tempress.dk |
