Задания к тексту

I. Вместо пропусков вставьте подходящее слово в нужной форме. Получившиеся предложения запишите и переведите.

to fit, to operate, to supply, to use, to consist, to pass, to mix

1. Air for combustion is … to the burner. 2. The air supplied … through vanes. 3. The oil fuel and air … at the atomizer nozzle. 4. The oil fuel is … to the atomizer. 5. Oil-fuel burning equipment … of atomizer proper and air registers. 6. The diffuser is … for the flame protection. 7. Modern atomizers … with automatically controlled boilers. 8. Modern atomizers are … with viscosity valve and automatic ignition (запал, зажигание, воспламенение) system.

II. Письменно ответьте на следующие вопросы к тексту:

1. What does a furnace provide? 2. By what surfaces is a furnace restricted? 3. Under what condition must the mixture of oil fuel and air be burned in the surface? 4. What are furnace walls lined with? 5. What set of conditions is necessary to provide the efficient combustion process? 6. Are there many different types of burners? 7. How may mechanical atomizing oil burners be classified? 8. What does oil-fuel burning equipment consist of? 9. What controls the air supply to the atomizer? 10. What is the function of a diffuser? 11. What motion is the oil given in the burner inner chamber? 12. Where is the air for combustion supplied? 13. Does the air pass through vanes? 14. What does the whirling motion result in? 15. Why should the oil fuel be heated?

Контрольная работа №2

Переведите письменно текст “ STEAM TURBINES”.

STEAM TURBINES

The turbine is a heat engine consisting of a rotor carrying moving blades, a casing in which the rotor revolves, and stationary nozzles through which the steam is expanded or directed. Glands, bearings, throttle valve, governor and other devices are necessary for operation of the unit. In the steam turbine two steps are required to convert the potential energy of the steam into useful work. First step, the pressure energy is converted into kinetic energy as the steam expands through the stationary nozzles and the pressure drops. The steam is expanded from a high pressure to a lower pressure in such a way as to produce the maximum possible velocity of the steam jet. Second step, the kinetic energy of the jet is converted into useful work by changing the momentum of the steam by means of moving blades.

There are basically two types of turbines: impulse turbines and reaction turbines. All other combinations are derived from these two types.

Impulse turbines. The steam expands only through stationary nozzles, with a decrease in pressure and an increase in velocity; in this process the potential energy of the steam is converted into kinetic energy. The steam then impinges (impulses) against the moving blades causing rotation and mechanical work. No expansion takes place as the steam flows through the blading.

Reaction turbines. The steam drops in pressure and at the same time expands as it passes across both the moving blades and the stationary blades. In other words, both moving and fixed blades act as nozzles. The rotors increase in diameter in steps with corresponding step in the casing. Each of these steps constitutes an expansion. The steam fully expands from initial to exhaust pressure in the turbine.

There may be high and low pressure turbines; high, intermediate and low pressure turbines. The 2-casing

units predominate for ship propulsion. There may be single-cylinder turbines and compound. Compound turbines are tandem-compound and cross-compound. As to the direction of steam flow the turbines are axial-flow and radial-flow. As to drive connection there are geared units and turbo-electric installations. The turbines may be condensing and non-condensing.