- •Предисловие
- •Unit 1 chemistry as a science
- •Chemistry
- •The scope of chemistry
- •7. Основные положения химии необходимы для многих специалистов, включая с/х работников, биологов, дантистов и т. Д. Text c
- •D. I. Mendeleyev
- •Properties of water
- •The most important chemical substance
- •The water problem
- •Hydrogen
- •Hydrogen peroxide
- •Properties of hydrogen peroxide
- •Unit 4 man and environment
- •Population and the environment
- •Ecology is a priority
- •Preserving the environment
- •Pollution
- •Traffic and air pollution
- •Water pollution. The water crisis
- •Wastewater treatment
- •Industrial wastes
- •Greenhouse effect
- •Unit 7 nature of manufacturing plastics
- •1. A) Translate the following words, word combinations and chemical terms into Russian:
- •3. Read the text and translate it using a dictionary.
- •The age of polymers
- •Plastics
- •Types of plastics
- •3. Read the text and translate it using a dictionary.
- •Abs plastics
- •General Properties of abs Plastics
- •Plastics in the chemical age
- •Some applications of a polymer
- •Unit 9 the world of rubber
- •Synthetic rubber
- •Mixing efficiency and quality: a view from a synthetic rubber producer
- •Quality of raw materials
- •Unit 10
- •The nature of rubber-like elasticity
- •Rubber latex
- •Internal mixer – закрытый резиносмеситель;
- •High energy radiation – радиация с высокой энергией.
- •Vulcanization
- •Unit 11
- •Environmental engineering
- •Chemical engineering
- •Chemical reactors
- •Unit 12
- •Ultrafiltration
- •Distillation
- •Gas separation
- •Тексты для дополнительного чтения
- •Vocabulary List
- •Text 2 Butlerov and His Theory of Chemical Structure
- •Vocabulary List
- •Text 3 The States of Matter
- •Vocabulary List
- •Text 4 Substances
- •Vocabulary List
- •Text 5 Classification of organic compounds
- •Vocabulary List
- •Text 6 Scope of environmental engineering
- •Text 7 Modern chemical engineering
- •Text 10 Membrane filters
- •Text 11 Lava filters
- •Text 12
- •Text 13
- •Vocabulary List
- •Synthetic Rubber
- •Vocabulary List
- •Reverse process – обратный процесс;
- •Rubberlike – каучукоподобный;
- •Direct Uses of Latex
- •Vocabulary List
- •Applications of polyurethane elastomers today and in the future
- •Era of elastomers
- •Phenolic, non-staining antioxidants
- •Chemical processes
- •Devices for transporting and compressing gases and liquids
- •Filtering Devices
- •Dust Collectors
- •Bag Filters
- •Coolers
- •Polymers
- •City of Madison Plastic Recycling Guidelines
- •Информационный справочник
- •Список химических элементов
- •Образец чтения химических формул и уравнений
- •Грамматический материал Active Voice (активный залог)
- •Passive Voice (пассивный залог)
- •Modal Verbs and their equivalents (Модальные глаголы и их эквиваленты)
- •Participle I, II (причастие I, II)
- •Функции Participle I Indefinite Active в предложении
- •Participle II Причастие прошедшего времени
- •Функции Participle II в предложении
- •Absolute Participle Clause (Независимый причастный оборот)
- •Infinitive (Инфинитив)
- •Формы инфинитива
- •Функции инфинитива в предложении
- •Complex Subject (Сложное подлежащее)
- •Complex Object (Сложное дополнение)
- •Gerund (Герундий)
- •Синтаксические функции герундия в предложении и способы его перевода на русский язык
- •Conditionals (Условные предложения)
- •Англо-русский словарь-минимум
- •Библиографический список
- •Оглавление
- •394036, Воронеж, пр. Революции, 19
Chemical reactors
In chemical engineering, chemical reactors are vessels designed to contain chemical reactions. The design of a chemical reactor deals with multiple aspects of chemical engineering. Chemical engineers design reactors to maximize net present value for the given reaction. Designers ensure that the reaction proceeds with the highest efficiency towards the desired output product, producing the highest yield of product while requiring the least amount of money to purchase and operate. Normal operating expenses include energy input, energy removal, raw material costs, labor, etc. Energy changes can come in the form of heating or cooling, pumping to increase pressure, frictional pressure loss (such as pressure drop across a 90o elbow or an orifice plate), agitation, etc.
There are two main basic vessel types: a tank and a pipe.
Both types can be used as continuous reactors or batch reactors. Most commonly, reactors are run at steady-state, but can also be operated in a transient state. When a reactor is first brought back into operation (after or in operation) it would be considered to be in a transient state, where key process variables change with time. Both types of reactors may also accommodate one or more solids (reagents, catalyst, or inert materials), but the reagents and products are typically liquids and gases.
There are three main basic models used to estimate the most important process variables of different chemical reactors:
batch reactor model (batch),
continuous stirred-tank reactor model (CSTR), and
plug flow reactor model (PFR).
Furthermore, catalytic reactors require separate treatment, whether they are batch, CST, or PF reactors, as the many assumptions of the simpler models are not valid.
Key process variables include
residence time (τ, lower case Greek tau)
volume (V)
temperature (T)
pressure (P)
concentrations of chemical species (C1, C2, C3, ... Cn)
heat transfer coefficients (h, U)
3. Make up the plan to the text.
4. Give a brief summary of the text.
Text D
1. Read the text and choose the most suitable title out of the given ones:
a) Microfiltration membranes
b) Microfiltration
c) Membrane filters
Microfiltration is a filtration process which removes contaminants from a fluid (liquid & gas) by passage through a microporous membrane. A typical microfiltration membrane pore size range is 0.1 to 10 micrometres (µm). Microfiltration is not fundamentally different from reverse osmosis, ultrafiltration or nanofiltration, except in terms of the size of the molecules it retains.
Developed by Professor Sigmondy University of Goettingen, Germany, in 1935, membrane filters were first commercially produced by Sartorius GmbH a few years later. Membrane filters found immediate application in the field of microbiology and in particular in assessment of safe drinking water. Further development of microfilters in the mid 1970's led by the FDA's requirement for non-fibre releasing filters to be used in the production of injectable solutions. Microporous membranes are used by the micro-electronics industry as an integral part of water production. Membrane filters are widely used in biotechnology and food and beverage applications where sterile product is required.
Increasingly used in drinking water treatment, it effectively removes major pathogens, contaminants and large bacteria. For this application the filter has to be rated for 0.2 micrometres or less. For mineral and drinking water bottler the most commonly used format is pleated cartridges usually made from Polyethersulfone(PES) media. This media is asymmetric with larger pores being on the outside and smaller pores being on the inside of the filter media.
Microfiltration membranes were first introduced to the municipal water treatment market in 1987 and applied primarily to waters that were relatively easy to treat. These were cold, clear source waters that were susceptible to microbial contamination. Low pressure membranes were selected to remove turbidity spikes and pathogens without chemical conditioning. As low pressure membranes increased in acceptance and popularity, users began to apply the technology to more difficult waters which contained more solids and higher levels of dissolved organics. Some of these waters required chemical pretreatment, including pre-chlorination. These shifts in water quality triggered change in low pressure membrane technology. New products and processes were introduced to deal with higher solids and chemical compatibility.
2. Write out:
а) key words and terms;
b) the sentences expressing the main idea of each paragraph.