- •Vocabulary
- •Give English equivalents.
- •2. Ask questions according to the models.
- •3. Supply prepositions.
- •4. Complete the sentences. Choose the right word from the list. There are more words than necessary!
- •5. Answer the questions.
- •6. TranslateintoEnglish.
- •7. Write a dictation.
- •Vocabulary
- •1. Choose the proper verb form.
- •2. Answer the questions.
- •Vocabulary
- •1. GiveEnglishequivalents:
- •2. Complete the sentences:
- •3. Give English equivalents to the words in brackets:
- •4.Self-assessment questions:
- •5. Translate into English:
- •1. Translate the word combinations into Russian and use them in your own sentences.
- •2. Choose the proper verb form, active or passive.
- •Vocabulary
- •1. TranslateintoEnglish.
- •2. Supply the proper preposition.
- •Vocabulary
- •Give English equivalents:
- •Answer the questions according to the models:
- •Match the type of the boiler with its principle of classification:
- •Self-assessment questions:
- •5.Translate into English:
- •1. Find the corresponding English translation in the text and memorize the words.
- •2. Put questions to the sentences.
- •Vocabulary
- •1. Give answers to the questions:
- •2. Translate into English:
- •Vocabulary
- •1.Give English equivalents:
- •2. Ask questions according to the model:
- •3. Complete the sentences:
- •4. Answer the questions:
- •5. Translate into English.
- •2. Translate the word combinations and use them in your own sentences.
- •Vocabulary
- •1. Supply prepositions.
- •2. Answer the questions.
- •Vocabulary
- •1. GiveEnglishequivalents:
- •2.Change these sentences using the modal verbs may, can, must:
- •3. Change these sentences into the passive:
- •4. Supply prepositions:
- •5. Answer the questions:
- •6. TranslateintoEnglish:
- •2. Complete the sentences.
- •Vocabulary
- •1. Change these sentences using the modal verbs may, can, must:
- •2. Change these sentences into the passive:
- •Vocabulary
- •1. Give English equivalents.
- •2. Supply prepositions.
- •3.Self-assessment questions.
- •4. Translate the words into Russian.
- •5. Choose the proper verb and put it into the correct form. There are more verbs than necessary.
- •6. Translate into English:
- •Unit VI. The superheater
- •Vocabulary
- •1. GiveEnglishequivalents:
- •Saturation, inlet, tubes, outlet, drums, safety valve, uptake, headers
- •3. Answer the questions:
- •Vocabulary
- •1. GiveEnglishequivalents:
- •2. Insert prepositions and conjunctions:
- •3. Answer the questions:
- •4. Translate the phrases containing comparatives and superlatives:
- •5. Translate into English:
- •1. Find English equivalents in the text.
- •2. Write down all the imperative phrases typical for this instruction.
- •3. Put questions to the sentences.
- •Vocabulary
- •1. Combine these pairs of sentences by using “if”.
- •2. TranslateintoEnglish.
- •Irregularities in operation, causes and remedies
- •Vocabulary
- •1. Replace the imperative sentences (remedy) by the following structures:
- •2. Translate these phrases into Russian:
5. Answer the questions:
1. What is feed water?
2. By what device is the feed water supplied to the boiler?
3. What substances remain in the boiler as the water is evaporated?
4. What problems may water containing impurities lead to?
5. How can a soft sludge be removed?
6. What salt produces a hard scale?
7. What may foaming be the result of?
8. What may priming be due to?
9. What gases cause corrosion?
10. How often must a chemical analysis of the feed water be run?
6. TranslateintoEnglish:
1. Питательная вода подается в котел насосом.
2. Примеси воды остаются в котле в виде отложений.
3. Мягкий шлак может быть удален из котла продуванием.
4. Некоторые соли образуют твердую накипь.
5. Для предотвращения накипи в котле используются щелочи и фосфаты.
6. Содержание в воде органических веществ может привести к вспениванию.
7. В случае вскипания применяется продувание и добавляется свежая вода.
8. Растворенные в питательной воде кислород и углекислота вызывают
коррозию стенок котлов.
9. Химический анализ питательной воды должен производиться на судне не
реже одного раза в день.
TEXT B
Purity of boiler feed water
Modern boilers require very pure feed water. The water required for boiler feed purposes, i.e. for steam generation should be of very high quality and thus requires a lot of treatment. Untreated water, containing impurities may lead to the following problems in boilers.
Most pure water will contain some dissolved salts. These salts then adhere to the heating surfaces as a scale and reduce heat transfer, which can result in local overheating and failure of the tubes. Other salts remain in solution and may produce acids which will attack the metal of the boiler. An excess of alkaline salts in a boiler will cause cracking of the metal which may lead to serious failure.
The presence of dissolved oxygen and carbon dioxide in boiler feed water can cause considerable corrosion of the boiler and feed systems. When boiler water is contaminated by suspended matter, an excess of salts or oil, foaming may occur. This is foam which collects on the water surface in the boiler drum. Foaming leads to priming which is the carry-over of water with the steam leaving the boiler drum. Any water present in the steam entering a turbine will do considerable damage.
Various amounts of different metal salts can be found in water. These include the chlorides, sulphates and carbonates of calcium, magnesium. These dissolved salts in water make up the 'hardness' of the water. Calcium and magnesium salts are the main causes of hardness.
E X E R C I S E S
1. Find the corresponding Russian translation. Memorize the phrases.
1. to require pure feed water |
a. вести к проблемам |
2. to contain impurities |
b. прилипать к поверхности |
3. to lead to the problems |
c. приводить к местному перегреву |
4. to adhere to the surface |
d. содержать примеси |
5. to result in local overheating |
e. требовать чистой воды |
|
f. собираться на поверхности воды |
|
g. вызывать растрескивание металла |
|
h. составлять жесткость воды |
|
i. вызывать коррозию |
|
j. поступать в турбину |