II. Home Appliances II: Vacuum-Cleaner

Vacuum cleaners are of two types: canister and upright. The canister type consists of a metal or plastic cylinder that holds the motor, the fan, and the bag that collects the dirt. A flexible hose with a nozzle is attached to the canister. Different removable nozzles are available to vacuum carpets, bare floors, furniture, and draperies.

The upright vacuum cleaner has a long handle and is pushed on wheels. The motor, fan, and a rotating cylindrical brush are located in one compartment. When the vacuum cleaner is switched on, the brush rotates by a belt, and air is drawn over it by the fan to carry dirt from the carpet and into a bag suspended from the handle. Some upright cleaners have attachments for other types of vacuuming.

Rug and carpet cleaners, powered by electricity, use concentrated liquid detergents added to water in a small tank. The detergents are applied to the rug and scrubbed with a brush until the lather has disappeared. When the rug is dry it is vacuumed to remove leftover dirt and detergent.

1. Electrolux	2. BSA 2877 Sphera Pro-Hygienic

20. Scan the biography. Put questions to the given answers.

Robert Boyle was born January 25, 1627, in Ireland and died December 30, 1691, in London. He was a chemist and a natural philosopher. He was noted for his pioneer experiments on the properties of gasses. (Turn to page 107 for further information). Sent to Eton College in 1635, Boyle read Galileo's works during a European tour (1639-44). At Oxford he took part in constructing an air pump. Beginning in 1668, he lived in London and continued experimental work on the calcination of metals and the distinction between acids and alkalis. Celebrated during his lifetime, Boyle's law called Mariotte's Law in Europe (by the name of French physicist (who also recognized a relationship of volume and pressure), is the relation concerning the compression and expansion of a gas at constant temperature. This empirical relation, formulated by Boyle in 1662, states that the pressure (p) of a gas varies inversely as its volume (v) at constant temperature; in equation form, pv=k, and is a constant. The law can be derived from the kinetic theory of gasses assuming a perfect (ideal) gas. Real gasses obey Boyle's law at sufficiently low pressures, although the product pv generally decreases slightly as the gas pressure is raised to appreciably higher values.

1.-------------------------- No, he was both a chemist and a philosopher.

2.----------------------- On the properties of gases.

3.------------------- Yes, he was celebrated during his lifetime.

4.--------------- Boyle’s Law and Mariotte’s Law mean the same.

5.----------- They were Irish and French.

6.-------- From the kinetic theory of gases.

7.----- Real gases.

8.-- At sufficiently low pressures.

21. Various pumps are widely used in vacuum industry. Each pump has its name and symbol according to the standards. Study some of the following pump signs in Russian. Be ready to read about them in English.

I. Обозначения вакуумных насосов (ГОСТ 2. 796 – 95)
1.1 Насос вакуумный. Общее обозначение
1.2 Насос вакуумный механический. Общее обозначение
1.2.2 Турбомолекулярный
1.2.4 Водокольцевой
1.4.1 Насосы вакуумные адсорбционные.
1.4.4 Криогенный
1.4.5 Испарительно-ионный
1.4.6 Магнитный электро-разрядный
1.4.7 Комбинированный