History of science and invention

5000 B.C.: metals first made in Middle East.

400 B.C.: Greek scientist Democritus suggests that all things are made of atoms.

100 B.C.: Greeks invent the waterwheel.

A.D. 105: Chinese inventor Tsai Lam makes paper.

A.D. 650: Persians invent the windmill.

A.D. 1000: Chinese use gunpowder in warfare.

1657: Dutchman Christian Huygens constructs a pendulum clock.

1712: English engineer Thomas Newcomen builds first practical steam engine.

1775: Englishman Joseph Priestley discovers oxygen.

1789: French scientist Antoine Lavoisier explains chemical reaction.

1803: English scientist John Dalton explains existence of atoms.

1826: Frenchman Joseph Niepce takes first photograph.

1869: Russian Dmitry Mendeleev shows relationships of elements in his periodic table.

1879: Thomas Edison and Englishman Joseph Swan invent electric light bulb.

1885: German engineer Karl Benz builds first car.

1888: German scientist Heinrich Hertz discovers radio waves.

1898: French-Polish scientist Marie Curie discovers radium.

1911: English scientist Ernest Rutherford discovers nucleus of the atom.

1942: Italian scientist Enrico Fermi builds first nuclear reactor.

1959: Soviet Union launches first space probe.

Lesson thirteen Text: Steam boilers

I. Read and translate:

Most conventional steam boilers are classed as either fire-tube or watertube types. In the fire-tube type the water surrounds the steel tubes through which the hot gases from the furnace flow. The steam generated collects above the water level in a cylindrically shaped drum. A safety valve is set to allow escape of steam at pressures above normal operating pressure; this device is necessary on all boilers, because continued addition of heat to water in a closed vessel without means of steam escape results in a rise in pressure and, ultimately, in explosion of the boiler. Fire-tube boilers have the advantage of being easy to install and operate. They are widely used in small installations to heat buildings and to provide power for factory processes. Fire-tube boilers are also used in steam locomotives.

In the watertube boilers, the water is inside tubes with the hot furnace gases circulating outside the tubes. When the steam turbogenerator was developed early in the 20^th century, modern watertube boilers were developed in response to the demand for large quantities of steam at pressures and temperatures far exceeding those possible with fire-tube boilers.

The tubes are outside the steam drum which has no heating surface and is much smaller than in the fire-tube boilers. For this reason, the drum of the watertube boiler is better able to withstand higher pressures and temperatures. A wide variety of sizes and designs of watertube boilers aroused in ships and factories. The express boiler is designed with small watertubes for quick generation of steam. The flash boiler may not require a steam drum, because the tubes operate at such high temperatures that the feed water flashes into steam and superheats before leaving the tubes. The largest units are found in the centralstation power plants of public utilities. Units of substantial size are used in steel mulls, paper mills, oil refineries, chemical plants and other large manufacturing plants.

fire-tube watertube to flow shape device to set to allow to escape vessel ultimately explosion demand drum

газовые трубы водные трубы течь форма, придавать форму устройство устанавливать позволять избегать сосуд в конечном счёте взрыв спрос барабан

in response to exceed variety to arouse flash boiler to require feed water utilities substantial steel mills oil refineries to superheat

в ответ на превышать разнообразие приводить к, вызывать требовать подача воды предприятия значительный, важный металлургический завод нефтеперерабатывающий завод перегреваться