After text activity. Exercise 1.Read and memorize using a dictionary:

I. Reading Exercises:

Exercise 1. Read and memorize using a dictionary:

Flywheel; cellular biology; reservoir;dung; charcoal; LPG abbreviation liquefied petroleum gas; coal tar; naphtha; coke oven gas; CNG abbreviation compressed natural gas; occurrence; smokeless coal; thereof; Limited liability company; coal-water slurry fuel (CWS) technology; availability and accessibility; in collaboration with; own expense; fire-safe and blast-proof; porous; worked-out air; self-cost reduction; profitability  

Exercise 2. Answer the questions:

1) How long has the company been working in the coal industry?

2) What does Research department of the Company conduct?

3) What does the Company pay much attention to?

4) Where can the wastes of the coal-water fuel combustion be used?

Exercise 3. Match the left part with the right:

1. Due to the availability and accessibility of coal resources on the territory of Ukraine,	a) providing full range of data on CWS’s characteristics. (coal-water slurry)
2.In collaboration with research institutes our Company has initiated advanced study	b) the world’s leaders of coal-water slurry fuel from China and Russia.
3. Laboratory has all modern technical facilities	c) on the capabilities of implementation and improving of coal-water slurry technology.
4. Our Company pays much attention to cooperation with	d) usage of the technology based on the raw coal seems very promising.

Exercise 4. Open brackets choosing the right words:

The coal-water fuel technology provided by the company "Ukrainian heat" – it is a systematic (approach/access) to the heat generation: from (preparation/readiness) of coal-water slurry fuel, transportation and (storage/keeping custody), into its combustion.

II. Speaking Exercises:

Exercise 1. Learn the definitions: “Ukrainian heat”; research; natural gas.

“Ukrainian heat” - Limited liability company “Ukrainian heat”, the leader of Ukrainian heat and power generation market using coal-water slurry fuel (CWS) technology.    

Research-systematic investigation to establish facts or principles or to collect information on a subject  

Natural gas - a mixture of hydrocarbon gases that occurs with petroleum deposits, principally methane together with varying quantities of ethane, propane, butane, and other gases, and is used as a fuel and in the manufacture of organic compounds.  

Exercise 2. Ask questions to the given answers:

1) Question: _________________________________________________________________?

Answer: The Company has been working in the coal industry for more than 14 years.

2)Question: _________________________________________________________________?

Answer: The wastes of the coal-water fuel combustion are highly porous and can be used as raw material in the construction industry.

3) Question: _________________________________________________________________?

Answer: Our Company pays much attention to cooperation with the world’s leaders of coal-water slurry fuel from China and Russia.

III. Writing exercises:

Exercise 1. Complete the sentences with the suggested words: fuel; porous; industry; emissions;

The temperature of the coal-water 1 combustion is 950 – 1100° C. The wastes of the coal-water fuel combustion are highly 2 and can be used as raw material in the construction 3. The worked-out air passes through the three-stage purifying system. The rates of 4 to the atmosphere are in conformity with current Ukrainian standards.

Exercise 2. Compose a story on one of the topics (up to 100 words):

“Limited liability company “Ukrainian heat”

“The coal-water fuel combustion”

“Chemical fuels”

Lesson 10

Read the text: Boiler and boiler installation of small capacity

The term boiler is used for a closed vessel in which water or other fluid is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including central heating, boiler-based power generation, cooking, and sanitation. The pressure vessel of a boiler is usually made of steel (or alloy steel), or historically of wrought iron. Stainless steel is virtually prohibited (by the ASME Boiler Code) for use in wetted parts of modern boilers, but is often used in superheater sections that will not be exposed to liquid boiler water. However electrically-heated stainless steel shell boilers are allowed under the European "Pressure Equipment Directive" for production of steam sterilizers for and disinfectors.

In live steam models, copper or brass is often used because it is more easily fabricated in smaller size boilers. Historically, copper was often used for fireboxes (particularly for steam locomotives), because of its better formability and higher thermal conductivity; however, in more recent times, the high price of copper often makes this an uneconomic choice and cheaper substitutes (such as steel) are used instead.

For much of the Victorian age of steam", the only material used for boiler making was the highest grade of wrought iron, with assembly by riveting. This iron was often obtained from specialist ironworks, such as at Cleator Moor (UK), noted for the high quality of their rolled plate and its suitability for high-reliability use in critical applications, such as high-pressure boilers. In the 20th century, design practice instead moved towards the use of steel, which is stronger and cheaper, with welded construction, which is quicker and requires less labor.

Cast iron may be used for the heating vessel of domestic water heaters. Although such heaters are usually termed "boilers" in some countries, their purpose is usually to produce hot water, not steam, and so they run at low pressure and try to avoid actual boiling. The brittleness of cast iron makes it impractical for high pressure steam boilers.

The source of heat for a boiler is combustion of any of several fuels, such as wood, coal, oil, or natural gas. Electric steam boilers use resistance- or immersion-type heating elements. Nuclear fission is also used as a heat source for generating steam, either directly (BWR) or, in most cases, specialized in heat changers called "steam generators" (PWR). Heat recovery steam generators (HRSGs) use the heat rejected from other processes such as gas turbines.

Boilers can be classified into the following configurations:

" Pot-boiler" or "Haycock boiler": a primitive "kettle" where a fire heats a partially filled water container from below. 18th century Haycock boilers generally produced and stored large volumes of very low-pressure steam, often hardly above that of the atmosphere. These could burn wood or most often, coal. Efficiency was very low.

Fire-tube boiler. Here, water partially fills a boiler barrel with a small volume left above to accommodate the steam (steam space). This is the type of boiler used in nearly all steam locomotives. The heat source is inside a furnace or firebox that has to be kept permanently surrounded by the water in order to maintain the temperature of the heating surface just below boiling point. The furnace can be situated at one end of a fire-tube which lengthens the path of the hot gases, thus augmenting the heating surface which can be further increased by making the gases reverse direction through a second parallel tube or a bundle of multiple tubes (two-pass or return boiler flue); alternatively the gases may be taken along the sides and then beneath the boiler through flues (3-pass boiler). In the case of a locomotive-type boiler, a boiler barrel extends from the firebox and the hot gases pass through a bundle of fire tubes inside the barrel which greatly increase the heating surface compared to a single tube and further improve heat transfer. Fire-tube boilers usually have a comparatively low rate of steam production, but high steam storage capacity. Fire-tube boilers mostly burn solid fuels, but are readily adaptable to those of the liquid or gas variety.

Water-tube boiler. In this type, the water tubes are arranged inside a furnace in a number of possible configurations: often the water tubes connect large drums, the lower ones containing water and the upper ones, steam and water; in other cases, such as a monotube boiler, water is circulated by a pump through a succession of coils. This type generally gives high steam production rates, but less storage capacity than the above. Water tube boilers can be designed to exploit any heat source and are generally preferred in high pressure applications since the high pressure water/steam is contained within small diameter pipes which can withstand the pressure with a thinner wall.

Flash boiler. A specialized type of water-tube boiler.

Fire-tube boiler with Water-tube firebox. Sometimes the two above types have been combined in the following manner: the firebox contains an assembly of water tubes, called thermic siphons. The gases then pass through a conventional fire- tube boiler. Water-tube fireboxes were installed in many Hungarian locomotives, but have met with little success in other countries.

Sectional boiler. In a cast iron sectional boiler, sometimes called a "pork chop boiler" the water is contained inside cast iron sections. These sections are assembled on site to create the finished boiler.

A boiler explosion is a catastrophic failure of a boiler. As seen today, boiler explosions are of two kinds. One kind is a failure of the pressure parts of the steam and water the sides. There can be many different causes, such as failure of the safety valve, corrosion of critical parts of the boiler, or low water level. Corrosion along the edges of lap joints was a common cause of early boiler explosions.

The second kind is a fuel/air explosion in the furnace, which would more properly be termed a firebox explosion. Firebox explosions in solid-fuel-fired boilers are rare, but firebox explosions in gas or oil-fired boilers are still a potential hazard.

Дата добавления: 2015-10-26