Загально-технічного спрямування

Англійська мова

Загально-технічного спрямування

Методичні рекомендації

до самостійної роботи

студентів ІІ курсу

 

Київ

НТУУ «КПІ»

Міністерство освіти і науки України

Національний технічний університет України

«Київський політехнічний інститут»

 

Англійська мова

Загально-технічного спрямування

Методичні рекомендації

до самостійної роботи

студентів ІІ курсу

інженерно-хімічного факультету

Затверджено Методичною радою НТУУ «КПІ»

 

 

Київ

НТУУ «КПІ»

 

Навчальне видання

 

Англійська мова

Методичні рекомендації

до самостійної роботи

студентів другого курсу

інженерно-хімічного факультету

 

Укладачі: Ящук Ольга Вікторівна Цепкало Олексій Володимирович
Відповідальний редактор Лавриш Юліана Едуардівна, канд. пед. наук
Рецензент: Мигляченко Лариса Григорівна, канд. філол. наук, доц.  

Передмова

 

Методичні рекомендації з дисципліни "Англійська мова" до самостійної роботи студентів IІ курсу інженерно-хімічного факультету побудовані відповідно до робочої навчальної програми та спрямовані на формування у студентів зазначеного факультету навичок читання та перекладу технічних та науково-технічних текстів, збагачення словникового запасу та формування компетенції у монологічному мовленні.

Методичні рекомендації містять добірку неадаптованих текстів на базі сучасних оригінальних підручників, технічних журналів та газет, що виходять англійською мовою. Це дає можливість студентам ознайомитись з мовними стилями різних авторів та різних джерел.

Метою цього видання є розширення та закріплення студентами термінологічної лексики за фахом, а також удосконалення ними лексичних навичок та вмінь професійно-орієнтованого говоріння.

З метою удосконалення у студентів навичок перекладу та розуміння спеціальної термінології без перекладу до текстів додано вправи на закріплення знань з фахової лексики.

Виконання студентами методичних рекомендацій сприятиме інтенсифікації процесу вивчення англійської мови професійного спрямування та розуміння науково-технічних текстів за фахом.


LESSON 1

1. Read and memorize the following words:

  ties зв’язки
  beneficial вигідний, корисний
  alliance союз, співпраця
  essential суттєвий, основний
  fertilizers добрива
  fabrics тканини
  relevant суттєвий, важливий

2. Read and memorize the following word combinations:

  pilot plant дослідна установка
  manufacturing facility промислове обладнання
  strong background серйозна освіта (кваліфікація, підготовка)
  process design розробка виробничого або технологічного процесу; технологічна підготовка виробництва
  production engineering технологія виробництва
  invaluable contributions безцінний внесок
  to cure diseases лікувати хвороби
  advanced materials сучасні матеріали
  beverage industries виробництво напоїв
  hazardous wastes небезпечні відходи
  frontier areas суміжні сфери діяльності
  fluid particle systems системи часток рідини

Read and translate the text into Ukrainian.



Pick up the key words from the text “Chemical engineering and chemistry”. Make up your own sentences with them.

Write an abstract to the text “Chemical engineering and chemistry”.

 

Get ready for presenting the topic “Chemical engineering and chemistry” at the conference ”Innovations in Science and Engineering” based on questions of Task 4.

LESSON 2

1. Read and memorize the following words:

  to sum up узагальнювати
  evaporation випаровування
  pulverization подрібнення в порошок
  screening просіювання
  sieving просіювання, відсіювання
  flotation спливання, флотація
  kiln обпалювальна піч
  thawing розморожування, декристалізація

 

Read and memorize the following word combinations

  unit operations окремі циклічні дії
  fluid flow processes обробка потоку рідин
  solids fluidization псевдорозрідження твердих речовин
  mass transfer processes процеси масопередачі, масообміну
  gas liquefaction розрідження газу
  electrostatic precipitation електростатичне осідання
  solvent extraction екстрагування розчинниками

Read and translate the text into Ukrainian.

Pick up the key words from the text “Unit operations in chemical engineering”. Make up your own sentences with them.

10. Write an abstract to the text “Unit operations in chemical engineering”.

 

Get ready for presenting the topic “Unit operations in chemical engineering” at the conference ”Innovations in Science and Engineering” based on the following questions of Task 4.


LESSON 3

1. Read and memorize the following words:

  drying висушування
  to encounter зустрічатися, стикатися з…
  moisture волога
  tank бак, резервуар, цистерна
  multiple численний
  essential необхідний, важливий
  gauge датчик
  control технічне регулювання (кнопки, ручки, важіль)
  seam шов, стик
  endure витримати, переносити
  encompass включати, охоплювати
  instantly негайно
  to shoot up викидати, підносити (вгору)
  rely on залежати від …, розраховувати на …
  wavelength довжина хвилі
  feedstock вихідна сировина

 

2. Read and memorize the following word combinations:

  manufacturing capacity виробнича потужність
  infrared drying висушування інфрачервоним випромінюванням
  spray drying висушування розприскуванням гарячої пари
  shared characteristics загальні, спільні характеристики
  multiple численний
  intake/output valve впускний/випускний клапан
  continuous-able безперервний
  to work in batches працювати періодично
  cubic foot кубічний фут
  bolted or welded скріплений болтом чи приварений
  anticipated product очікуваний продукт
  freeze drying сублімаційне висушування
  fluid bed dryer сушарка зі псевдорозрідженим шаром
  flash drying термічне висушування
  rotary dryers барабанні сушарки
  burst of heat тепловий імпульс
  to sublime away випаровувати
  infrared dryer інфрачервона сушарка
  absorption rate швидкість поглинання
  jet of hot steam струмінь (потік) гарячої пари
  bulk density щільність маси, об'ємна щільність
  residual moisture content залишкова вологість
  perforated plate перфорована пластина

 

3. Read and translate the text into Ukrainian:

Industrial dryers

Drying is one of the most frequently encountered chemical engineering operations. Drying generally signifies the removal of liquid from a solid by evaporation, although gases are also dried.

Industrial dryers are used for removing moisture from substances, products or materials in a business or manufacturing capacity. The term "industrial dryer" is a general reference that applies to dryers no matter what their particular method of drying is: air, infrared or spray drying. Because of the variety, there is no single design or model of industrial dryer, though there are some shared characteristics.

Many dryers are made from stainless steel because it is strong, sanitary and corrosion resistant. They are often cylindrical tanks or rectangular boxes with multiple intake and output valves, connections, openings, gauges and controls. Some may be continuous-able to dry a constant flow of materials and utilize a conveyor belt while others work in batches. The capacity depends on the kind of dryer and the material that will be dried. Certain dryers can dry over 25,000 pounds an hour while others can be built to hold only one cubic foot. Dryers are essential for the pharmaceutical, food processing, manufacturing, agricultural, pollution control, water treatment and paper industries and have multiple functions when working with chemicals, dairy products, fertilizers, grains, minerals, paper, plastics, refuse and more.

Most industrial dryers are bolted or welded together, depending on the importance of the seams, the anticipated product and any motion the dryer will endure. The three main methods of drying encompass a variety of models that carry out the task in different ways.

Air dryers are the most common industrial dryers. They bring materials into direct contact with hot air which causes moisture to evaporate and diffuse into the air, leaving behind a dry product.

Flash dryers, freeze dryers, fluid bed dryersand rotary dryers all fit in this category though their designs vary. Flash dryers use a short intense burst of heat to dry materials almost instantly while freeze drying uses cold air and vacuums to freeze moisture and sublime it away.

Fluid bed dryers shoot steam up through a perforated plate in order to cause the solid material to behave like a fluid; rotary dryers are large drums that dry products as they turn and tumble the material through the hot air contained inside.

Infrared dryers rely on electromagnetic radiation from a certain segment of the wavelength to dry solid materials quickly and without overheating them because the wavelength can be matched to the absorption rate of the product to maximize energy and resources.

Spray drying introduces the material to jets of hot steam which causes the moisture to flash dry and evaporate. Spray drying is highly suited for the continuous production of dry solids in either powder, granulate or agglomerate form from liquid feedstocks as solutions, emulsions and pumpable suspensions. Therefore, spray drying is an ideal process where the end-product must comply to precise quality standards regarding particle size distribution, residual moisture content, bulk density, and particle shape.

 

4. Answer the questions to the text:

1. What does drying signify?

2. What are main methods of drying?

3. What shared characteristics do industrial dryers have?

4. What are dryers essential for?

5. What is the principle of action of air dryers?

6. What do flash dryers use to dry materials?

7. What dryers rely on electromagnetic radiation from a certain segment of the wavelength?

8. What is spray drying highly suited for?

 

5. Complete the word combinations according to the context and translate them into Ukrainian:

  Ukrainian translation
1. particular method of __________  
2. intake and output __________  
3. water treatment and paper _________  
4. direct contact with hot __________  
5. a short intense burst of heat _________  
6. steam up through a perforated plate__________  
7. to dry solid materials quickly and without __________  
8. to flash dry and __________  

6. Match the words from the text with their synonyms on the right:

1) moisture a) production 1)  
2) method b) flood 2)  
3) characteristic c) movement 3)  
4) utilize d) expected 4)  
5) manufacturing e) vapor 5)  
6) anticipated f) feature 6)  
7) motion g) make 7)  
8) cause h) humidity 8)  
9) flow i) use 9)  
10) steam j) way 10)  

7. Point out the sentences containing information directly from the text:

1. Because of the variety, there is no single design or model of industrial dryer, though there are some shared characteristics.

2. Fluidized spray dryers are operationally flexible and enable production of a wide range of physical properties and optimum thermal efficiency because of the drying at the low temperature.

3. Flash dryers are extensively used for drying powders and granules, crystalline material.

4. Many dryers are made from stainless steel because it is strong, sanitary and corrosion resistant.

5. All spray dryers use some type of atomizer or spray nozzle to disperse the liquid or slurry into a controlled drop size spray.

6. The three main methods of drying encompass a variety of models that carry out the task in different ways.

7. In chemical synthesis, products are often freeze-dried to make them more stable, or easier to dissolve in water for subsequent use.

8. Spray drying introduces the material to jets of hot steam which causes the moisture to flash dry and evaporate.

9. Air heating increases the driving force for heat transfer and accelerates drying.

10. Every spray dryer consists of feed pump, atomizer, air heater, air disperser, drying chamber, and systems for exhaust air cleaning and powder recovery.

 

LESSON 4

1. Read and memorize the following word and word combinations:

  by interposing шляхом установки
  recovery відновлення
  for the sake of … для, для того, щоб…
  to purify очищувати
  in respect to у відношенні до
  mixture суміш
  slurry суспензія
  septum септа, перегородка
  to accumulate накопичуватися
  filter cake осад після фільтрування
  continuous filter неперервний фільтр, аналоговий фільтр
  intermittent filter імпульсний фільтр
  interruption зупинка, перерва
  rotary drum filter ротаційний барабанний фільтр
  soluble розчинний компонент
  clarified effluent очищений потік
  sticky липкий, клейкий
  sludge відстій
  unit агрегат
  to designate визначати
  to discharge розгрузити, звільнити
  filter medium фільтруюче середовище

Filtration and filters

In many industrial processes it is necessary to separate finely divided solid materials from liquids. Filtration is a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass. Filtration is also important and widely used as one of the unit operations of chemical engineering. It may be simultaneously combined with other unit operations to process the feed stream. The process of filtration consists in passing the liquid through a porous medium, which retains the solid particles. In some cases the recovery of the solid material is the main object; in others the filtration is done for the sake of purifying the liquid.

The mixture to be separated is called the slurry: the fluid that passes through the septum is called the filtrates and the septum is called the filter medium, and the equipment assembly that holds the medium and provides space for the accumulated solids is called a filter. The fluid may be a gas or a liquid. The solid particles may be very fine, and their concentration in the suspension may be extremely low (a few parts per million) or quite high (>50%).

When the separated solids accumulate in amounts that visibly cover the medium, they are called the filter cake or simply the cake.

Filter media are manufactured from cotton, wool, linen, silk, glass fibre, porous carbon and other solids, rayons and other synthetics, porous rubber, etc. Many types of filters are in use today. They differ in respect to the various materials which are available for filtration, and the construction of the apparatus in which these are applied.

Filters used in chemical processing are classified into two distinct groups: continuous and intermittent. Filters that operate without interruption for weeks to months are classified as continuous filters. The main types are the rotary drum and disk filters and various horizontal designs.

Rotary drum filters are the most widely used continuous filters in the chemical process industries. The design provides means for concentrating slurry solids to dry (moist) cakes, washing solubles from such cakes when required, and producing a clarified effluent.

Many design configurations have been developed to utilize most effectively the basic principle for the varying filtration characteristics of slurries, ranging from extremely fine particles to very coarse particles (50 - 150 mm) and from thin, sticky cakes to thick, fairly dry sludges. These filters are used in some form in practically every process operation involving slurries where solids must be recovered from the liquor for further processing.

Rotary disk filter is a version of the rotary drum filter. A series of parallel disks provides vertical filtering surfaces in place of the cylindrical surface on the rotary drum. Thus, the rotary-disk unit provides more filter area (up to 3.5 times) than a drum type. When the filtering surface operates in a horizontal plane, the filter is designated as a horizontal type.

Filters whose continued vibration is limited by their solid-collecting capacity are known as intermittent filters. Their cycle must be interrupted periodically when the solids accumulation has to be discharged.

 

3. Answer the questions to the text:

1. What is filtration? What does the process of filtration consist in?

2. Why may filtration be combined with other unit operations?

3. What is the main object of filtration?

4. What is a filter?

5. What is a filter cake?

6. What are filter media manufactured from?

7. What are continuous filters? How do continuous filters operate?

8. What are the main types of continuous filters?

9. What does the design of a rotary drum filter provide?

10. What are intermittent filters? How do intermittent filters operate?

 

4. Match the words from the text with their synonyms on the right:

1) operation a) aim 1)  
2) simultaneously b) persistent 2)  
3) retain c) restore 3)  
4) object d) grain 4)  
5) coarse e) at the same time 5)  
6) cake f) construction 6)  
7) apparatus g) action 7)  
8) continuous h) rough 8)  
9) design i) sediment 9)  
10) particle j) settling 10)  
11) sludge k) device 11)  
12) recover l) hold 12)  

 

5. Fill in the gaps with the words from the text and translate them into Ukrainian:

  Ukrainian translation
1. to process the feed __________  
2. to provide __________ for the accumulated solids  
3. visibly cover __________  
4. two __________ groups  
5. operate without __________  
6. various __________ designs  
7. producing __________ effluent  
8. must be recovered from __________ liquor  
9. solid-collecting __________  

Work in pairs. One of the student is a journalist from a scientific journal whose task is to write an article about innovative solutions to the filtration in industrial processes. The second student to be interviewed is an engineer working on filtration equipment design. Think over possible questions and answers. Act the interview out.

LESSON 5

1. Read and memorize the following words:

  immiscible незмішуваний, розшарований
  tangentially побічно, побіжно
  vortex вир, вихровий потік
  induce сприяти, призводити до …
  regardless of незалежно від …
  outwardly зовні
  inwardly всередині
  spinner обертач
  impel приводити в рух
  permeability проникність, прохідність
  ratio співвідношення, пропорція
  adjustment настройка
  capability робоча потужність
  option вибір, варіант вибору
  micron мікрометр, мікрон
  footprint площа, ділянка

Centrifuges

A centrifuge is a piece of equipment, generally driven by a motor that puts an object in rotation around a fixed axis, applying force perpendicular to the axis. The centrifuge works using the sedimentation principle, where the centripetal acceleration is used to separate substances of greater and lesser density.

The first successful centrifuge was built in 1883 by Carl G. P. de Laval, a Swedish engineer, whose design was used chiefly for cream separators. The ultracentrifuge, devised in the 1920s by the Swedish chemist Theodor Svedberg, found wide application in scientific research.

A mechanical method of separating immiscible liquids or solids from liquids by the application of centrifugal force. This force can be very great, and separations which proceed slowly by gravity can be speeded up enormously in centrifugal equipment.

Centrifugal force is generated inside stationary equipment by introducing a high-velocity fluid stream tangentially into a cylindrical-conical chamber, forming a vortex of considerable intensity.

Much higher centrifugal forces than in stationary equipment are generated in rotating equipment (mechanically driven bowls or baskets, usually of metal, turning inside a stationary casing). Rotating a cylinder at high speed induces a considerable tensile stress in the cylinder wall. This limits the centrifugal force which can be generated in a unit of a given size and material of construction. Very high forces, therefore, can be developed only in very small centrifuges.

There are two major types of centrifuges: sedimenters and filters. A sedimenting centrifuge contains a solid-wall cylinder or cone rotating about a horizontal or vertical axis. An annular layer of liquid, of fixed thickness, is held against the wall by centrifugal force; because this force is so large compared with that of gravity, the liquid surface is essentially parallel with the axis of rotation regardless of the orientation of the unit. Heavy phases “sink” outwardly from the centre, and less dense phases “rise” inwardly. Heavy solid particles collect on the wall and must be periodically or continuously removed.

A filtering centrifuge operates on the same principle as the spinner in a household washing machine. The basket wall is perforated and lined with a filter medium such as a cloth or a fine screen; liquid passes through the wall, impelled by centrifugal force, leaving behind a cake of solids on the filter medium. The filtration rate increases with the centrifugal force and with the permeability of the solid cake. Some compressible solids do not filter well in a centrifuge because the particles deform under centrifugal force and the permeability of the cake is greatly reduced. The amount of liquid adhering to the solids after they have been spun also depends on the centrifugal force applied; in general, it is substantially less than in the cake from other types of filtration devices.

There are many different kinds of centrifuges, including those for very specialised purposes. The decision to use either a batch or a continuous machine depends on several factors. Unlike batch centrifuges, continuous machines are limited to a wash/solids ratio of approximately 10%, with only a short period allocated to the wash zone prior to the finish of the cycle.

If, for example, the material to be processed has low residual impurities and a high washing requirement, the greater flexibility of the batch process allows the necessary adjustments such as extended washes and longer residence times.

Particle size, distribution and shape are also important factors when determining separation capabilities, and whether a batch or continuous centrifuge is the best option. Generally speaking, materials of 45 microns and above that are relatively incompressible are highly suitable for separation by filtration. On the other hand, finer or more compressible materials lend themselves to separation by sedimentation techniques.

Compared with other methods of liquid-solid separation, centrifugal processing provides a number of unique advantages. For example, centrifuges can be installed in a relatively small footprint, have a high washing capability, produce low cake moisture, achieve a high capacity throughput and provide the end user with a totally enclosed, vapour tight processing system.

 

4. Answer the questions to the text:

1) What is a centrifuge?

2) What was the first successful centrifuge used for?

3) How can separations be speeded up enormously in centrifugal equipment?

4) In what way is centrifugal force is generated?

5) What does rotating a cylinder at high speed induce?

6) What is the design of a sedimenting centrifuge?

7) What is the principle of action of a filtering centrifuge?

8) What are the advantages of batch machines?

9) What factors are important when determining separation capabilities, and whether a batch or continuous centrifuge is the best option?

10) What are the advantages of centrifugal processing compared with other methods of liquid-solid separation?

 

5. Change the following sentences according to the model:

Model A: If this mixture is placed in a test tube, it will glow dull red.
B: If this mixture were placed in a test tube in two hours, it would glow dull red. C: If this mixture had been placed in a test tube two hours ago, it would have glowed dull red.

 

1. If metals are heated, oxides will be formed.

2. If any liquid is in a vessel, it will take the shape of the vessel containing it.

3. If some air is allowed to mix with hydrogen, the reaction will take place with a characteristic sound.

 

6. Translate into Ukrainian paying attention to the word “since”:

1. Since diamond is the hardest substance known, it must be polished with diamond dust.

2. Many years have passed since Mendeleyev made his great discovery.

3. This method of mixing has been used since the days of World War II.

4. This process was developed twenty years ago, since then it has been used in many countries.

5. Carbon is one of the most important and interesting elements, since its compounds are widely distributed in nature and play such an important part in daily life.

 

Imagine that you are one of the leading design engineers working for a company which has cemented its reputation as a manufacturer of an innovative range of centrifuges. You’ve been invited to scientific-technical symposium to discover the benefits by taking advantage of the special demonstration of your equipment and presentation at recent developments in centrifuges, operating both by sedimentation and filtration. Make a brief report on technical characteristics of centrifuges manufactured by your company.

LESSON 6

1. Read and memorize the following words:

  ratio співвідношення, пропорція
  pre-specified передбачений, заданий, визначений заздалегідь
  complexity складність
  excipient в’яжучий, формоутворюючий наповнювач
  robust стійкий, надійний в експлуатації
  gamut діапазон, набір
  homogenize гомогенізувати, забезпечувати однорідність
  vat резервуар, бак, ємність
  leaching вилуговування, вимивання
  paddle лопать
  shaft привід
  sealant герметик, ізоляційний матеріал
  lotion рідкий крем, рідкий косметичний засіб
  detergent миючий засіб

Mixing and blending

Mixing is the process of thoroughly combining different materials to produce a homogenous product. The mixture is generally a combination of dissimilar materials, e.g. coal ash and cement are blended in a specified ratio to produce Pozzocrete cement. In other cases, a chemically homogenous material may be mixed to produce a uniform lot of a desired weight/volume with consistent particle size distribution, color, texture, and other required attributes, e.g. metal powders produced in 1 ton batch size are blended to a homogenous lot size of 4 tons (or pre-specified quantity).

The terms "mixing" and "blending" are often used interchangeably, but technically they are slightly different. Blending is a process of combining materials, but blending is a relatively gentle process compared to mixing. In terms of the phase of material, blending is the process of solid-solid mixing or mixing of bulk solids with small quantity of liquid. The terminology mixing is more closely associated with liquid-liquid, gas-liquid, and viscous materials.

Mixing and blending are the most demanding unit operations in the chemical process industries (mixing and blending of specialty chemicals, explosives, fertilizers, dry powdered detergents, glass or ceramics, and rubber compounds). Pharmaceutical and food industries also rely heavily on mixing and blending technology (blending of active ingredients of a drug with excipients like starch, cellulose, or lactose; preparation of cake mix, spices, and flavours)

The wide variety and ever increasing complexity of mixing processes encountered in industrial applications requires careful selection, design, and scale up to ensure effective and efficient mixing. Improved mixing efficiency leads to shorter batch cycle times and operational costs. Today's competitive production lines necessitate robust equipment that are capable of fast blend times, lower power consumption, equipment flexibility, ease of cleaning, and a gamut of customized features. In addition to blending components, many modern mixers are designed to combine different process steps in a single equipment, e.g. coating, granulation, heat transfer, drying, etc.

At the numerous enterprises of chemical, food, pharmaceutical and other industries, the equipment with machine mixing devices is practised on a large scale in processes requiring dissolution, leaching, emulsification, formation of suspension as well as homogeneous and heterogeneous systems mixing. Industrial mixers are machines that blend, homogenize, emulsify or otherwise mix components into a homogenous substance.

Industrial mixers are used to thoroughly combine any type of liquid or solid during the manufacturing process. They are usually large tanks or vats with motorized blades or paddles that rotate on a stationary shaft or remain stationary themselves. Depending on the application, some models may have sharp blades while other may have large flat paddles. The attachments or heads are generally removable to maximize the mixer's effectiveness with different materials. Stainless steel is most commonly used, especially within the food and beverage industry because of the metal's sanitary and hygienic properties.

Other possible materials include aluminum, steel or cast iron. Industrial mixers are widely used across many industries including the cosmetic, pharmaceutical, chemical, agricultural, pulp and paper, automotive, water treatment, adhesive and sealant industries. These mixers are equipped to handle glue, petroleum products, cement, biodiesel, dry and wet chemicals, medicines, toothpaste, food colouring, syrups, medical ointment, lotions, creams, vitamins, shampoos, detergents, hair dye, petroleum products, silicone, adhesives, polyurethane and many other products or ingredients.

Within the single category of industrial mixers, there are many kinds and varieties of these machines that have been specialized. Blenders are very similar if not identical to mixers; some prefer to differentiate between the two because blenders sometimes have sharper blades that move at faster speeds. In terms of processing speed and style, there are two modes. Batch mixers are the more common of the two kinds. Mixing begins after a substance is poured into the industrial mixer. Once mixing is complete, the substance is poured out of the mixer for further processing and the mixer is then cleaned before being refilled. Continuous-feed mixers can handle a steady flow of material. Static mixers are inline and continuous feed mixers because they do not move. The materials are mixed as they flow around the strategically-placed blades and paddles.

Another kind of industrial mixer is a drum mixer which consists of a rotating drum on the frame. There are multiple mixers used to accomplish a solution or substance that is the same throughout. High shear mixers offer shorter mixing times than standard mixers. The speed of the product at the tip of the rotor is higher than the speed at the centre which emulsifies immiscible materials. Similarly, homogenizers and emulsifiers achieve the same results by forcing substances to pass through a screen. Also known as mixers, agitators are the only machines that can blend chemicals, foods and other low-viscosity materials with ease. Because they have relatively small blades, they're also best used for slow, low-shear mixing processes where it's more important to keep the mixture moving than it is to actually blend its ingredients.

 

4. Answer the questions to the text:

1. What is mixing?

2. What is blending?

3. What is the difference between the terms “mixing” and “blending”?

4. What different process steps in a single equipment can many modern mixers combine?

5. What are industrial mixers?

6. What materials are most commonly used in the design of industrial mixers?

7. How do batch mixers work?

8. What are agitators used for?

 

5. Fill in the gaps with the words from the text and translate these word combinations into Ukrainian:

  Ukrainian translation
1. to produce a homogenous __________  
2. consistent __________ size distribution  
3. dry __________ detergents  
4. effective and efficient __________  
5. metal's sanitary and hygienic __________  
6. handle a steady __________of material  
7. to consist of a rotating __________ on the frame  
8. to emulsify __________ materials  

 

6. Choose the correct grammar form for each sentence:

1. Blending_____ a relatively gentle process compared to mixing.

a) has

b) is

c) can be

 

2. Many modern mixers _______to combine different process steps in a single equipment.

a) designed

b) are designed

c) design

 

3. Mixing ______after a substance is poured into the industrial mixer.

a) is beginning

b) begins

c) has begun

 

4. Industrial mixers are widely used across many industries _______chemical, agricultural and water treatment industries.

a) having included

b) included

c) including

 

5. Air conditioning and refrigeration systems are some other important fields where heat exchangers_______.

a) are applied

b) apply

c) are applying

 

6. Pharmaceutical and food industries also _____heavily on mixing and blending technology.

a) relies

b) rely

c) will rely

 

7. To prevent any blockage due to impurities______ in a heat exchanger, a regular and timely examination of heat exchangers is essential.

a) collected

b) having collected

c) being collected

 

6. Say if the following statements are true or false. If the statement is false explain why:

1) Mixing is the process of thoroughly combining different materials to produce dissimilar materials.  
2) Blending is the process of solid-solid mixing or mixing of bulk solids with small quantity of liquid.  
3) Pharmaceutical and chemical process industries deal with mixing and blending of specialty chemicals, explosives, fertilizers, dry powdered detergents, glass or ceramics, and rubber compounds.  
4) Many modern mixers are designed to combine different process steps in a single equipment.  
5) Industrial mixers are usually large tanks or vats with stationary blades or paddles that rotate on a motorized shaft.  
6) Blenders are not identical to mixers.  
7) Continuous-feed mixers can handle a steady flow of material.  
8) Agitators are the machines that can blend chemicals, foods and other low-viscosity materials.  

 

Imagine you have gained over 5 years of experience in a scientific and industrial firm which is one of the world leading manufacturers for mixing equipment specializing in development of units with mechanical mixing devices. You belong to a team of experienced specialists who design, develop and supply equipment, system and modules for mixing. Every year the company's staff publishes articles in leading technical journals, takes part in international conferences and congresses. You’ve been given a task to make up a brief presentation on theoretical and practical issues of mixing to participate in the conference organized by one of the leading universities. Think over what you will report about.

LESSON 7

1. Read and memorize the following words:

  fin гофроване ребро, пластина
  corrugation гофрування, гофр
  regenerative рекуперативний
  baffles перегородка
  otherwise в іншому випадку
  examination перевірка, контроль
  simultaneously одночасно

2. Read and memorize the following word combinations:

  to induce turbulence викликати (спричиняти) турбулентність
  to eliminate the need усувати необхідність
  to put to use використовувати, вводити в експлуатацію
  flow arrangement організація потоку
  shell and tube heat exchanger кожухотрубний теплообмінник
  counter-flow противотік
  parallel-flow прямотік, паралельний потік
  cross-flow перехресний, поперечний потік
  in a perpendicular fashion у перпендикулярний спосіб
  tube bundle зв’язка труб
  intermediate fluid heat exchanger проміжний рідинний теплообмінник
  solid heat exchanger компактний теплообмінник

3. Read and translate the text into Ukrainian:

Heat exchangers

A heat exchanger is a specialized device that assists in the transfer of heat from one fluid to the other. In some cases, a solid wall may separate the fluids and prevent them from mixing. In other designs, the fluids may be in direct contact with each other. In the most efficient heat exchangers, the surface area of the wall between the fluids is maximized while simultaneously minimizing the fluid flow resistance. Fins or corrugations are sometimes used with the wall in order to increase the surface area and to induce turbulence.

The main use of heat exchangers is in industrial procedures. They are often brought to use in heating processes. They can also be applied for heat and energy saving as heat exchangers are used to recover lost heat energy in industries and the recovered heat energy is then used to heat another stream, thus eliminating the need for another heat source and putting the otherwise lost and wasted heat to use.

Heat exchangers have found their use in several industries; most importantly, the petroleum industry, food industry, waste water treatment industry and wine industry. Heat exchangers are used in chemical processing and power production. They are also used widely in spacecrafts and airplanes to heat fuel. Air conditioning and refrigeration systems are some other important fields where heat exchangers are applied.

There are three primary flow arrangements with heat exchangers: counter-flow, parallel-flow, and cross-flow. In the counter-flow heat exchanger, the fluids enter the exchanger from opposite sides. This is the most efficient design because it transfers the greatest amount of heat. In the parallel-flow heat exchanger, the fluids come in from the same end and move parallel to each other as they flow to the other side. The cross-flow heat exchanger moves the fluids in a perpendicular fashion.

There are also four different designs of heat exchangers: shell and tube, plate, regenerative, and intermediate fluid or solid. The most typical type of heat exchanger is the shell and tube design. This heat exchanger has multiple finned tubes. The tubes carry the liquids that will be processed by the exchanger. One set of tubes will carry the medium that will be in need of cooling. The other set of tubes will carry the liquid that will run through the other medium and provide the cooling for it. This process also goes the other way with the mediums either being cooled or heated.

The set of tubes present in a shell and tube heat exchanger is called a tube bundle. The tube bundle is comprised of several different tubes in all shapes and sizes. A shell and tube heat exchanger is usually used for jobs that would require high pressures. The pressures that this particular exchanger typically deals with can be around 30 bars and be as high as 260°C. The strength of the tubes that make up this particular heat exchanger enables it to handle pressures high.

In the plate heat exchanger, the fluid flows through baffles. This causes the fluids to be separated by plates with a large surface area. This type of heat exchanger is typically more efficient than the shell and tube design.

The regenerative heat exchanger takes advantage of the heat from a specific process in order to heat the fluid used in the same process. These heat exchangers can be made with the shell and tube design or the plate design. The intermediate fluid or solid heat exchanger uses the fluids or solids within it to hold heat and move it to the other side in order to be released. This method is commonly used to cool gases while removing impurities at the same time.

To ensure good condition of a heat exchanger and to prevent contamination and any blockage due to impurities collected in a heat exchanger, a regular and timely examination of heat exchangers is essential.

 

4. Answer the questions to the text:

1) What is a heat exchanger?

2) What separates the fluids and prevents them from mixing?

3) Why are fins or corrugations sometimes used with the wall?

4) What can heat exchangers be used for?

5) In what industries have heat exchangers found their use?

6) What are three primary flow arrangements with heat exchangers?

7) How is a shell and tube heat exchanger designed?

8) How does a regenerative heat exchanger work?

5. Choose the correct continuation to complete the following statements:

1) The fluids may be separated and prevented from mixing

a) by a solid wall

b) by a specialized device

 

2) In the most efficient heat exchangers, the surface area of the wall between the fluids

a) is maximized

b) is minimized

 

3) Heat exchangers are often brought to use in

a) heating processes

b) industrial procedures

 

4) Some other important fields where heat exchangers are applied.

a) air conditioning and refrigeration systems

b) spacecrafts and airplanes

 

5) The fluids come in from the same end and move parallel to each other as they flow to the other side

a) in the parallel-flow heat exchanger

b) in the counter-flow heat exchanger

 

6) For jobs that would require high pressures

a) a shell and tube heat exchanger is usually used

b) a plate heat exchanger is usually used

6. Fill in the gaps with the suitable words from the box:

a) treatment b) heat c) arrangements d) refrigeration d) tube e) spacecrafts f) finned g) flow

1. fluid _____resistance

2. waste water _______industry

3. to recover lost _______energy

4. primary flow _______with heat exchangers

5. multiple ______tubes

6. shell and _______design

7. to be used widely in______ and airplanes

8. air conditioning and______ systems

 

LESSON 8

1. Read and memorize the following words:

  crusher дробарка
  to break подрібнювати
  downtime непродуктивна витрата часу
  to dispose утилізувати
  to recycle переробляти
  mill млин
  reliability надійність
  querns ручний млин

 

2. Read and memorize the following word combinations:

  to compress material стиснення матеріалу
  solid mix тверда суміш
  waste materials відходи
  raw material сировина
  to resist deformation не піддаватися деформації
  jaw crusher щокова дробарка
  coarse material крупнозернистий матеріал
  higher production висока продуктивність
  cone crusher конусна дробарка
  rotating speed швидкість обертання
  crushing chamber камера подрібнення

3. Read and translate the text into Ukrainian:

Crushers

A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, or rock dust. Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated.

Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of the stone provided a boost to muscle power, used against a stone anvil. Querns and mortars are types of these crushing devices.

In industry, crushers are machines which use a metal surface to break or compress materials. Mining operations use crushers, commonly classified by the degree to which they fragment the starting material, with primary and secondary crushers handling coarse materials, and tertiary and quaternary crushers reducing ore particles to finer gradations. Each crusher is designed to work with a certain maximum size of raw material, and often delivers its output to a screening machine which sorts and directs the product for further processing. Typically, crushing stages are followed by milling stages if the materials need to be further reduced. Crushers are used to reduce particle size enough so that the material can be processed into finer particles in a grinder. A typical circuit at a mine might consist of a crusher followed by a SAG mill followed by a ball mill. In this context, the SAG mill and ball mill are considered grinders rather than crushers.

In operation, the raw material (of various sizes) is usually delivered to the primary crusher's hopper by dump trucks, excavators or wheeled front-end loaders. A feeder device such as a conveyor or vibrating grid controls the rate at which this material enters the crusher, and often contains a preliminary screening device which allows smaller material to bypass the crusher itself, thus improving efficiency. Primary crushing reduces the large pieces to a size which can be handled by the downstream machinery.

Some crushers are mobile and can crush rocks (as large as 16 in), concrete and asphalt into material as it is driven over material on road surface, thus removing the method of hauling oversized material to a stationary crusher and back to road surface. They are used, for example in road constructions.

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