Read and memorize the following word combinations
| Pozzocrete cement | пуцолановий цемент (різновид цементу з додаванням попелу) | |
| bulk solids | сипучі матеріали, сипучі тверді речовини | |
| batch cycle | періодичний цикл роботи | |
| batch mixers | змішувач періодичної дії, циклічний змішувач | |
| continuous-feed mixers | змішувач неперервної подачі | |
| steady flow | рівномірний потік, безвихровий рух | |
| low-shear mixing | змішування з низькою швидкістю зсуву | |
| inline mixer | одновальний змішувач горизонтального типу | |
| medical ointment | лікарська мазь |
Read and translate the text into Ukrainian.
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. |
7. 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.
8. Pick up the key words from the text “Mixing and blending”. Make up your own sentences with them.
9. Write an abstract to the text “Mixing and blending”.
10. Get ready for presenting the topic “Mixing and blending” at the conference ”Innovations in Science and Engineering” based on the following questions of Task 4.
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
7. Which of the following sentences from the text contain the Passive Voice forms? Explain how you define these forms.
1. A solid wall may separate the fluids.
2. Fins or corrugations are sometimes used with the wall
3. Heat exchangers have found their use in several industries.
4. The main use of heat exchangers is in industrial procedures.
5. In the counter-flow heat exchanger, the fluids enter the exchanger from opposite sides.
6. The set of tubes present in a shell and tube heat exchanger is called a tube bundle.
7. The tube bundle is comprised of several different tubes in all shapes and sizes.
8. A regular and timely examination of heat exchangers is essential.
6. Say if the following statements are true or false. If the statement is false explain why:
| 1) A heat exchanger is a specialized device that separate the fluids and prevent them from mixing. | |
| 2) Fins or corrugations are sometimes used with the wall in order to minimize the fluid flow resistance. | |
| 3) Heat exchangers are used to recover lost heat energy in industries | |
| 4) Because of transferring the greatest amount of heat cross-flow heat exchanger is the most efficient design. | |
| 5) The most typical type of heat exchanger is the shell and tube design. | |
| 6) The strength of the tubes that make up a shell and tube heat heat exchanger enables it to handle temperatures high. | |
| 7) Regenerative heat exchangers can be made with the shell and tube design or the plate design. | |
| 8) To prevent contamination and any impurities collected in a heat exchanger, a regular and timely blockage of heat exchangers is essential. |
7. Imagine that you are a representative of the company that manufacturesfour different designs of heat exchangers: shell and tube, plate, regenerative and intermediate ones. At this moment you are at the engineering fair. There are some representatives of competitive companies designing the same types of heat exchangers. You have to exert every effort in order to persuade the potential customers of buying nothing but your manufactured articles. So think over a brief informative presentation.
8. Pick up the key words from the text “Heat exchangers”. Make up your own sentences with them.
9. Write an abstract to the text “Heat exchangers”.
10. Get ready for presenting the topic “Heat exchangers” at the conference ”Innovations in Science and Engineering” based on the following questions of Task 4.