2. Translate the word combinations and use them in your own sentences.

to determine performance

to quote in specifications

to compare to the weight of water

to express as a ratio

to measure the ignition quality of fuel

to handle fuel

to release during combustion

to pass away as exhaust

to obtain measurement

TEXT C

FUEL OIL SYSTEM

A furnace provides steady burning of fuel. When burning fuel the following characteristics of it should be taken into consideration: viscosity, specific gravity, flash point, pour point, heating value and some others.

A furnace fuel oil system consists of a fuel tank from which fuel is drawn through a strainer by a pump. This pump delivers fuel under pressure through a filter and a heater to the burners. In the burners it mixes with air and is ignited inside the furnace.

The complete furnace fuel oil system consists of:

1. Oil fuel filling system – to replenish the fuel tanks.

2. Suction system – to allow any tank to be used and for transferring fuel from remote tanks.

3. Discharge system – to deliver fuel under pressure to the burners.

Fuel is burnt in the furnace in suspension. Therefore, a burner used for atomization is a very important element in fuel burning equipment.

Although there are a lot of types of burners they work on the same principle.

The fuel is heated to the burning temperature, which reduces viscosity and then delivered under pressure to the burner body. The fuel passes through the holes which give it a rotary motion and then through the orifice in a conical spray – to the furnace.

Vocabulary

provide, v обеспечивать

steady, adj устойчивый, постоянный

strainer, n сетчатый фильтр; приемная сетка

burner, n горелка

ignite, n зажигать; воспламенять; запаливать

fuel oil filling system системаприематоплива

replenish, v пополнять

transfer, v передавать

suspension, n суспензия; взвесь

therefore, adv поэтому

although, adv несмотря на то, что

burnerbody корпус горелки

orifice, n отверстие: сопло

e x e r c I s e s

1. Supply prepositions.

1. Fuel oil characteristics should be taken … consideration when burning fuel.

2. A furnace fuel oil system consists … a fuel tank from which fuel is drawn … a strainer … a pump.

3. Fuel is ignited … the furnace.

4. Fuel is delivered … pressure … the burners.

5. Suction system is used … transferring fuel … remote tanks.

6. The fuel passes … the holes and then through the orifice … a conical spray … the furnace.

2. Answer the questions.

1. What does a furnace provide?

2. What fuel oil characteristics should be taken into consideration when burning fuel?

3. Where is fuel drawn from?

4. Where does fuel mix with air?

5. What does the complete furnace fuel oil system consist of?

6. What is oil fuel filling system used for?

7. What system is used to deliver fuel under pressure to the burners?

8. What is the principle of burner operation?

UNIT 5

TEXT A

FEED WATER

Feed water is the water supplied to a boiler to generate steam or hot water. It is delivered to the boiler by the feed pump. As the water is evaporated, the impurities in it remain in the boiler in the form of the salt deposits.

Water containing impurities may lead to the following problems in boilers: scale, foaming, priming and corrosion.

The chief salts forming scale are those of calcium and magnesium. Magnesium sulphate is a salt commonly found in boiler water and it forms a soft, sludgy mass, not very harmful, which can be removed by blowing down. Calcium sulphate produces a hard brittle scale.

Alkalis or phosphate are sometimes put into marine boilers to prevent scale.

Foaming may be the result of dirty water, certain types of organic matter, oils in solution, the presence of excess alkalinity. Oil is very injurious to a boiler: it adheres to the tube surfaces and causes overheating and rupture of tubes.

Priming may be due to improper construction of boiler or extremely high ratings. The most common measure to prevent foaming and priming is to maintain the water at the lowest level. Avoiding high water levels, excessive boiler loads, and sudden load changes also helps. If foaming and priming occur, the blow off is opened several times, and fresh water is added.

The main cause of boiler corrosion results from the dissolved gases, oxygen and carbon dioxide, found in feed water. They will react with the metals in the boiler system and lead to boiler corrosion. In order to protect the boiler from these contaminants, they should be controlled or removed,usually by use of a deaerator.

Acids due to oils in solution may be neutralized by the addition of sodium carbonate.

For efficient boiler operation a chemical analysis of the feed water must be run at least once a day.