Exercise 1. Say whether the statements are TRUE or FALSE. 1. The piezoelectric actuator can move something due to changes in shape

1. The piezoelectric actuator can move something due to changes in shape. 2. David Henderson suggested a big-sized linear motor that can move very big objects. 3. Henderson founded his company in 2000. 4. The company New Scale Technologies Inc. is situated in New York City. 5. The parts of the device are made of stainless steel. 6. The frequency of the voltage applied to the plates of the device ranges from 200 to 300 kilohertz. 7. Henderson compared the movement of the nut in the device with a squirrel in a cage. 8. Henderson’s company cooperates with Japan and Austria.

Exercise 2. Give synonyms to the following words from the text:

a device, to change, a few, to cause, to manufacture, small, to receive, to found, to call, properly, fine, a manufacturer, simultaneously, to offer.

11. Super Induction

plc (public limited company	відкрите акціонерне товариство	a downside	недолік
fair	ярмарок	so far	досі
brass	мідь, латунь	preliminary	попередній
to extrude	формувати видавлюванням	a trial	випробування
alternating current	перемінний струм	commissioned	введений в експлуатацію
eddy current	вихровий струм	distribution	розподіл
to resist	опиратись	alloy	сплав
a coil	котушка, виток	a billet	заготівка
homogeneous	однорідний

British superconductor developer Zenergy Power plc and German machine manufacturer Bültmann GmbH have begun selling an industrial-scale, superconductor-based induction heater for metal processing. The technology, which they say is twice as efficient as conventional induction heaters, won the prestigious 100,000-euro Hermes Prize at this year’s Hannover Fair in Germany.

Metal fabricators use induction heaters to soften aluminum, brass, bronze, and copper in order to shape or extrude such parts as heat exchanger tubes, pipes, window frames, computer components, and automotive profiles.

The induction heaters themselves are electromagnets driven by high-frequency alternating currents. This induces eddy currents in the workpiece. The resistance of the eddy currents to changes in direction induced by the alternating current causes the metal to heat up. Induction heaters typically have energy efficiencies of 35 to 45 percent, and can consume an astonishing 1 to 5 percent of an industrial country’s total energy production, according to Zenergy.

One reason that induction heater efficiency is so low is hysteresis, the tendency of the magnetic cores to resist the rapid cycling of the magnetic fields. Superconductors provide a solution to that problem. They have zero electrical resistance, so there is no hysteresis, no matter how fast the current alternates to switch the polarity of the magnetic field.

This greatly reduces the amount of energy needed to power the induction coil. Superconductor induction heaters achieve efficiencies of 90 percent. The technology produces highly homogeneous and precisely controllable temperature gradients in the workpiece, with no risk of damage from local overheating. Superconducting induction heaters start up quickly. Their only real downside is expense, but Zenergy claims that companies can pay off the purchase price within five years based on energy cost savings alone.

So far, Zenergy and Bültmann have sold two commercial units. The first one, in September 2007, went to aluminum fabricator Weser Alu GmbH, which used it to replace an existing copper-based aluminum heater at its manufacturing plant in Minden, Germany. Based on preliminary trials, Weser Alu expected to decrease energy use to 160 kilowatt-hours, from 280 kilowatt-hours, while reducing heating times and improving temperature distribution.

The second unit builds on lessons learned in the first heater, the developers said. They said it has been sold to a manufacturer that makes automotive, electrical, air conditioning, and refrigeration components. The manufacturer will use the induction heater in a newly commissioned facility to extrude copper and copper alloy billets.

Дата добавления: 2015-10-30