Контрольная работа по Английскому языку на тему: "Перевод технических текстов"

Вариант 2

1. Translate the text in writing.

Scavenging

In the two-stroke cycle engine the scavenge air is admitted through scavenging ports located at the bottom of the cylinder (Fig.7).

In the scavenging arrangement we describe, the exhaust ports are placed on one side of the cylinder and on the opposite side are scavenging ports. The exhaust ports are slightly higher than the scavenging ports so that the piston uncovers the exhaust ports first, thus allowing the pressure in the cylinder to fall before the scavenging ports are opened. By the time the scavenging ports are uncovered the pressure in the cylinder has fallen to atmospheric and the scavenging air rushes in. By inclining the scavenging ports and shaping the piston head, the entering air is deflected upward, as shown by the arrows, and sweeps the burned gases out of the upper part of the cylinder and out through the exhaust ports. When the piston covers the ports on its up stroke, the air is 'trapped in the cylinder and then is compressed. This arrangement of scavenging does away with the necessity for the scavenging valves in the cylinder head. The only cylinder head valves then required are the spray valve and starting air valve. This simplifies the head, makes cooling easier and reduces the liability to crack.
 

2. Answer the questions to the text.

1. Where are the scavenging ports located?
2. Where are the exhaust ports located in a two-cycle Diesel engine?
3.  What can you say about the pressure when the piston uncovers the exhaust ports?
4. By means of what method is the air deflected upward?
5. When is the air trapped in the cylinder?
6. What valves are located on the cylinder head? What is the advantage of this arrangement?
7. What are different systems of scavenging in Diesel engines?
8. What are the four items which show the advantage of uniflow scavenging?
9. Does it ensure better removal of gases?
10. What does rotary motion of scavenging air give?
11. What do flow conditions provide?
12. What ensures even mixture of air and oil?
 

3. Translate the text in writing.

Main propulsion system

Hassi R’Mel is the vessel powered by the turbine, which is the subject of the following article. This unit develops a maximum of 16,25 bhp at 120 rev/min to drive a Lipsudest propeller through a Maag type DTA reduction gearbox. The service rating of the main turbine is 13,000 shp at 112 rev/min, with the H.P. turbine developing 55% of the output and the L.P. turbine developing 45%. At maximum horsepower the specific steam consumption of the turbines is 2.48 kg/shph while at the service output the steam requirement is 2.51 kg/shph. The main condenser, which has a tube surface area of 1465 m², is bolted directly to the end exhaust flange of the L.P. turbine and is of the horizontal double-flow type fitted with aluminium brass tubes.

Propelling machinery....


Вариант 2

COOLING SYSTEM

The principal function of the cooling system is to dispose of the heat transferred from the burning fuel to the metal adjacent to the combustion chamber, but for convenience it is usually extended and put to uses, such as cooling the scavenging air, lubricating oil, exhaust manifold, crosshead guides, etc. ...

 

2. Answer the questions to the text.

1. Is the cooling system extended?

2. What working medium does this system cool?

3. What parts of Diesel engines does it cool? Use the figure.

4. Enumerate the cooling systems you know.

5. What can you say about enclosed fresh water system? Where does the water enter?

6. Does it pass upward to the exhaust manifold jacket? What is the function of the thermostat in the system?

7. If pistons are cooled with oil, is it a separate cooling system? Where is sea water used in such cases?

8. The salt-water method of cooling is the simplest arrangement, isn’t it? Explain why.

9. What are the advantages and disadvantages with fresh water cooling?
 

3. Translate the letter in writing.

Letter confirming preliminary negotiations about repairs and asking to quote prices.

Messrs. N. C. Warwick & Co.,
Shipbuilders and Repairers,

Plymouth, 27th Oct., 20…

 

31 Upper Fleet Street,
Plymouth, England.

Dear Sirs,

We confirm our to-day’s conversation with your representative,
Mr. W. G. Hollace, regarding the following repairs to be done to our ship:

1. 15 economizer tubes, 40 mm in outside diameter and 3800 mm in length, to be removed and replaced. Tubes to be supplied by your Company.

2. Two sections of steam superheater (tubes 4800 mm in length, 30 mm outside diameter, heat-resisting steel) to be examined, hydraulically tested and, if necessary, replaced.

3. 12 safety valve stems, 380 mm in length, 32 mm in outside diameter, to be made of chrome nickel steel and machined to model.

4. 12 steel springs for safety valves with the length of a single coil of 110 mm and total vertical height of 300 mm for a 10 tons load to be made as per drawing and fitted into position.

5. 1 boiler furnace for temperature of up to 1800 deg. C. to be lined up with fire bricks and coated with plastic chrome ore refractory.

6. 400 figure-shaped refractory bricks for boiler furnace to be made to model and supplied to the ship.

7. Four supporting beams for superheaters to be arc welded (the beams are of heat-resisting steel).

8. Two boiler foundation frames to be re-riveted.

9. Double safety valve for boiler to be made as per drawing. Diameter of bore for each valve — 65 mm. Valves to be ground in and tested in assembly for working pressure of 45 atmospheres.

10. Fifteen safety valves of stainless steel to be made to model.

11. 4 gears and 4 pinions for the maximum speed regulator to be cast and machined as per drawing.

12. One worm wheel drive for feed water pump reduction gear to be cast and machined as per drawing.

13. One cylinder of the servo-motor for the condensate level regulator to be welded and tested.

14. Fifteen spare ball-bearings, No. 2732 as per your catalogue, to be supplied to the vessel.

To conclude the negotiations we would request you to quote us your prices for all the above items and inform us within how many days you will be able to complete the work.

Yours faithfully,