E X e r c I s e s

1. Give English equivalents:

Подогреватель питательной воды, топочные газы, греющая среда, поступать в котел, отработавшие газы, проходить через, состоять из, коллектор, с помощью, в одном направлении, в противоположном направлении, приводить к, теплопередача, при необходимости, поверхность теплообмена.

2. Insert prepositions and conjunctions:

1. … the economizer flue gases are used … a heating medium.

2. The economizer is interposed … the boiler and stack.

3. The economizer is placed … the uptakes.

4. Feed water passes … the economizer … its way … the steam drum.

5. The tubes are rolled … the headers.

6. Return bends are usually connected … flange joints … straight run … tubing.

7. The counterflow results … a greater heat transfer.

8. Drain valves enable the economizer to be emptied … water when required.

3. Answer the questions:

1. What is an economizer?

2. What is used as a heating medium in the economizer?

3. What is the economizer used for?

4. Where is the economizer interposed?

5. Does the economizer increase boiler efficiency?

6. What does a typical economizer consist of?

7. What is used when headers are not employed?

8. What is the diameter of the economizer steel tubes?

9. What can occur if the fed temperature falls below 115°C?

10. How are economizers classified according to their gas and water flow?

11. What are parallel and counterflow economizers?

12. Which flow is considered to be the more effective in economizers?

13. What must air vents be provided for?

14. What arrangements must be fitted to keep the heat exchange surfaces free from soot?

4. Translate the phrases containing comparatives and superlatives:

A great heat transfer – a greater heat transfer – the greatest heat transfer;

effective – more effective – the most effective; a large heating surface – a larger heating surface – the largest heating surface.

5. Translate into English:

1. Экономайзер – это подогреватель питательной воды.

2. Экономайзер увеличивает КПД котла.

3. Трубки экономайзера омываются с внешней стороны горячими топочными газами.

4. Возвратные колена подсоединены к прямому трубопроводу с помощью фланцев.

5. Противоток более эффективен, так как приводит к большей отдаче тепла.

6. На экономайзере устанавливают предохранительные клапаны, спускные дренажные клапаны и сажеобдувочные устройства.

UNIT 7

TEXT A

A Procedure for Starting a Boiler

A boiler is one of those machineries that gets the ship going. It is dangerous equipment which generates steam at extremely high pressure, and it is for this reason that proper care should be taken while operating it.

Starting a Boiler

The following steps may not apply to all types of boilers and each boiler requires some additional steps to be followed as for its system design. However, the basic steps remain the same:

1. Ensure that the vent valve on the boiler is open and check there is no pressure in the boiler.

2. Check that the steam stop valve is closed.

3. Check that all the valves for fuel are open, and let the fuel circulate through the system until it comes to the temperature required by the manufacturer recommendation.

4. Check and open the feed water valves to the boiler and fill the water inside the boiler drum to just above the low water level. This is done because it is not possible to start the boiler below the low water level due to safety feature which prevent boiler from starting. Also, the level is not filled much because if filled too much, the water inside the boiler might expand and over pressurize the boiler.

5. Start the boiler in automatic mode. The burner fan will start the purging cycle which will remove any gases present in the furnace by forcing it out through the funnel.

6. After the pre-set purge time the pilot burner will ignite.

7. The main burner which is supplied by heavy oil catches fire with the help of pilot burner.

8. Check the combustion chamber from the sight glass to ensure the burner has lit and the flame is satisfactory.

9. Keep a close eye on the water level as the pressure increases and open the feed water when the level of water inside the gauge glass is stable.

10. Close the vent valve after the steam starts coming outside.

11. Open the steam stop valve.

12. Once the working steam pressure is reached, blow down the gauge glass and check for the alarms.

Дата добавления: 2015-03-29