- •Vacuum technology development
- •1. Words to be remembered.
- •2. Translate the sentences. Pay attention to the words in italics.
- •5. Decide whether the following statements are true or false according to text a.
- •6. Answer the following questions to text a.
- •7. Read text b carefully paying attention to the words in bold type.
- •8. Decide whether the following statements are true or false according to text b.
- •9. Answer the questions to text b.
- •10. Match the words with the synonyms.
- •14. Match the parts of the sentences.
- •16. Grammar Tutorials: Word Order, Miscellaneous
- •17. Translate the following sentences. Notice the difference in the underlined words.
- •19. Translate the text from Russian into English. Use the list of words below for help.
- •Unit II. Theory of pvd Coatings
- •1. Words to be remembered.
- •1. Words to be remembered.
- •2. Translate the sentences. Pay attention to the words in italics.
- •3. Read text a carefully paying attention to the words in bold type.
- •4. Decide whether the following statements are true or false according to text a.
- •5. Answer the following questions to text a.
- •6. Read text b carefully paying attention to the words in bold type.
- •7. Decide whether the following statements are true or false according to text b.
- •8. Answer the questions to text b.
- •10. Make sure you know the meanings of these words. Match the words with their definitions.
- •11. Match the words with the synonyms (text a).
- •12. Match the same words with the antonyms (text a).
- •13. Translate the text on theory and practical use of pvd coatings, study the structure of TiAln. Make its technical and non-technical description.
- •14. Scan the text about Copper (Cu) carefully. Use the scattered Nouns – Verbs – Adjectives – Adverbial Modifiers to make as many correct sentences-statements as possible.
- •17. See the difference in the following words. Use a dictionary. Read all of them aloud. Make some sentences of your own. Some eight examples are given for you.
- •20. Learn the poem “The Planets” by heart. Say, if gold, silver and lead are used in vacuum technologies. What does present-day science say about the content of metals in the planets? The Planets
- •21. Practice makes perfect. Translate the text on Vacuum history in a written form.
- •24. Scan the biography of Michael Faraday. Put questions to the answers given below.
- •25. Look through the texts a-b again and make notes under the following headings. Then use your notes to talk about it.
- •History
- •II. Home Appliances II: Vacuum-Cleaner
- •20. Scan the biography. Put questions to the given answers.
- •Reading, Vocabulary & Creative Practice
- •1. Words to be remembered.
- •2. Translate the sentences. Pay attention to the words in italics.
- •3. Read text a. Pay attention to the words in bold type.
- •4. Decide whether the following statements are true or false according to text a.
- •5. Answer the questions to text a.
- •6. Read text b. Pay attention to the words in bold type.
- •7. Decide whether the following statements are true or false according to text b.
- •8. Answer the questions to text b.
- •13. Special Quiz. Think of the better way to remember the most of the vocabulary and the vacuum pump classification. Share your opinion on it with your partner.
- •Russian English
- •II. Классификация вакуумных насосов по принципу действия
- •15. A) Open the brackets giving the right forms of the words; b) Translate the text “Cryopump” in a written form; c) Compare texts 15.1 and 15.2.
- •16. Grammar Tutorials: Question Technique Read and give a title to the text. Put questions to the given answers.
- •18. Translate from Russian into English. Use the proper grammar rules and the prompting words in brackets.
- •19. Read the text “Pump Accessories”. Pay attention to the abbreviations, and Stone Wall Constructions. Summarize the text.
- •20. Translate the following abbreviations and Stone Wall Constructions.
- •21. Read about some pumps’ features and benefits. Pay attention to the suffixes in the words, describing the pumps. Using the descriptive words, try to persuade the customers to buy the pumps.
- •23. Make notes under the following headings. Then use your notes to talk about it.
- •Unit VI. Pumps and Compressors
- •“First, be sure a thing is wanted or needed, then go ahead.” Thomas Edison.
- •1. Words to be remembered.
- •2. Translate the sentences. Pay attention to the words in italics.
- •3. Read the text a. Pay attention to the words in bold type.
- •4. Decide whether the following statements are true or false according to text a.
- •5. Answer the questions to text a.
- •6. Read text b. Pay attention to the words in bold type.
- •7. Decide whether the following statements are true or false according to text b.
- •8. Answer the questions to text b.
- •10. Match the words with the synonyms.
- •11. Match the words with the antonyms.
- •12. Fill in the correct prepositions.
- •13. Open the brackets. Give the right forms of the words in bold. Translate the text in a written form.
- •14. Special Quiz. Read about the uses of compressors. Match the parts of the sentences making the sentences complete. Start from: Gas compressors are used … … .
- •17. Study the key words to the crossword from Unit III.
- •18. Engineer tested. Do you believe …
- •19. Study the compressor refrigerator schematic, operation and construction. Discuss the information in dialogues. How do you see the compressor refrigerator in the future?
- •Construction
- •20. Scan the biography both I) in English and II) in Russian. Make a close look at English and Russian versions. Find and write down the differences.
- •Follow-up Activity
- •21. Make notes under the following headings. Then use your notes to talk about it.
- •1. Kinetic Devices (General View).
- •Unit VII. Vacuum Engineering and Its Prospects
- •1. Words to be remembered.
- •2. Translate the sentences. Pay attention to the words in italics.
- •3. Read text a. Pay attention to the words in bold type.
- •4. Decide whether the following statements are true or false according to text a.
- •5. Answer the questions to text a.
- •6. Read text b. Pay attention to the words in bold type.
- •7. Decide whether the following statements are true or false according to text b.
- •8. Answer the questions to text b.
- •9. Make sure you know the meanings of these words. Match the words with their definitions. Consult the dictionaries.
- •10. Match the words with the synonyms.
- •11. Match the same words with the antonyms.
- •12. Fill in the correct prepositions.
- •13. Scan the text. Make its summary in Russian then give English translation of the summary.
- •14. 1) Scan the biography of Sir William Crookes. Pay attention to the underlined words and notions. Say or write what you know about them.
- •14. 2) Scan the biography of John Dalton. Put questions to the given answers.
- •15. Scan the article “Vacuum Technology Developed to Control Insects in Wood.” Divide the text into logical parts.
- •17. Read the advertisement. Make everybody trust the method described.
- •19. Read the article “Japanese Camera Used to Test Innovation.” Make up some 3–5 statements of your own which might be a summary to the article.
- •20. Study the suggested key answers to the previous tasks.
- •21. Make notes under the following headings. Then use your notes to talk about it.
- •Permissible pressure units including the torr 1) and its conversion
- •Vocabulary Terms And Abbreviations Used In Vacuum Engineering
- •Casing n оболочка, обшивка; отливка, литье
- •Confine V удерживать
- •Deliberate adj умышленный, обдуманный
- •Develop V развивать, строить, подготавливать, совершенствовать
- •Drastic adj глубокий, интенсивный, резкий
- •Drift n наклонный ствол, отклонение
- •Neutral n нейтральный
- •Vacuum technology development
- •220013, Минск, проспект Независимости, 65.
4. Decide whether the following statements are true or false according to text a.
1. Compression of a gas decreases its temperature.
2. Compressors are similar to magnetrons.
3. Liquids are relatively incompressible.
4. The term compressor is used when the pressure of a gas is increased in a motor-driven machine.
5. Compressor is a gas pump.
6. Kinetic devices include centrifugal pumps and compressors.
7. Axial-flow compressors consist of a number of shafts.
8. The function of a liquid ring pump is similar to a rotary vane pump.
9. The liquid ring pump compresses gases by means of an impeller rotating within and eccentric to a cylindrical casing.
10. Typically a multi-stage pump will have up to two compression stages on a common surface.
11. Single stage vacuum pumps typically produce vacuum to 335 torr.
12. Liquid ring compressors are often used in Vapor recovery systems.
5. Answer the questions to text a.
1. What kind of device is a gas compressor?
2. Does compression of a gas increase its temperature or pressure?
3. In what way are compressors similar to pumps?
4. What is the difference between the terms “pump” and “compressor”?
5. What do kinetic devices include?
6. How many stages do axial-flow compressors consist of?
7. How can the liquid-ring pumps be used?
8. What can you say about the function of a liquid-ring pump?
9. How does the liquid-ring pump compress gases?
10. How many stages can liquid-ring systems have?
11. What is the capacity of a single-stage pump?
12. Where are liquid-ring pumps and compressors used?
6. Read text b. Pay attention to the words in bold type.
B. Designs and Operation of Compressors
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Reciprocating compressors – use pistons driven by a crankshaft. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines. But their numbers are declining (they are replaced by less costly rotary screw compressors). The picture of the reciprocating compressor is below.
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Rotary screw compressors – use two meshed rotating positive-displacement helical screws to force the gas into a smaller space. These are usually for continuous operation in commercial and industrial applications and may be either stationary or portable.
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Centrifugal compressors – use a vaned rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy. These are for continuous, heavy industrial uses and are usually stationary. Their application can be from 100 hp (75 kW) to thousands of horsepower. With multiple staging, they can achieve extremely high output pressures greater than 10,000 lb/in² (69 MPa). Many large snow-making operations (like ski resorts) use this type of compressor. They are also used in internal combustion engines as superchargers and turbo-charges. Centrifugal compressors are used in small gas turbine engines or as the final compression stage of medium sized gas turbines.
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Diagonal or mixed-flow compressor – are similar to a centrifugal compressor, but have a radial and axial velocity component at the exit from the rotor. The diffuser is often used to turn diagonal flow to the axial direction. The diagonal compressor has a lower diameter diffuser than the equivalent CF compressor.
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Axial-flow compressor – use a series of fan-like rotating rotor to progressively compress the gas flow. Axial-flow compressors are normally used in high flow applications, such as medium to large gas turbine engines. They are almost always multi-staged. See the picture of the Axial-flow compressor below.
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Scroll compressor – similar to a rotary screw device, it includes two interleaved spiral-shaped scrolls to compress the gas. Its output is more pulsed than that of a rotary screw compressor, and this has caused its declining industrial use. It can be used as an automotive supercharger, and in an air conditioner condensing unit.
Since being rediscovered three decades ago, scroll technology has been successfully adapted to vacuum use. Several innovations have allowed scroll-type pumps to produce vacuums lower than 10 m Torr; the pumps are used in many applications requiring an inexpensive, dry, long-lived pump. Look at the picture of the Scroll compressor; pay attention to the special note:
Archimedean Screw is known to be a device consisting of a spiral passage within an inclined cylinder for raising water to a height when rotated.
Thus, a scroll compressor, also known as scroll pump and scroll vacuum pump, uses two interleaved Archimedean spiral shaped scrolls to pump or compress fluids such as liquids and gases. One of the scrolls is fixed, while the other orbits eccentricallywithout rotating, thereby trapping and compressing pockets of fluid between the scrolls.
The device was first patented in 1905 but did not become efficient for fifty years. These devices are known to be used for operating more smoothly, quietly, and reliably than conventional compressors. However, due to their smaller available free volume (to accommodate refrigerant flooding) compared to reciprocating compressors, the reliability of scroll compressors is debatable. Many residential central heat pump and air conditioning systems and a few automotive air conditioning systems employ a scroll compressor instead of the rotary. Traditionally, reciprocating and wobble-plate compressors are used.
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Diaphragm Compressor is used for hydrogen and compressed natural gas (CNG).
Air compressors sold to and used by the general public are often attached on top of a tank for holding the pressurized air. Oil-lubricated and oil-free compressors are also available. Oil-free compressors are desirable because without proper consideration (additional parts) oil can make its way into the air stream. In a given use, for example as a diving air compressor, even minimal oil may be unacceptable.