Blast furnace. Cupola melting

Task 1. What types of furnaces do you know?

Task 2. Try to guess the meaning of the following words and word combinations (if you need you can use dictionary): metallurgical plant, iron ore, fusion, carbon, melting unit

Task 3. Read and translate the following text:

The modern blast-furnace constitutes the largest and most complicated type of metallurgical plant. Such a plant is capable of producing more than one thousand tons of pig iron a day. It consumes large quantities of raw materials. The material entering the blast furnace consists of the iron ore, the flux (limestone), and a fuel.

The blast-furnace derived its name from the fact that the air to support combustion must be forced into it under pressure, because of the resistance offered by the column of material within the shaft to passage of the combustion gases. The air is usually blown in the bottom through the tuyeres.

The term "charge" refers to the materials fed at the top and includes the fuel, the ore and the flux.

The blast-furnace is a circular shaft of varying dimensions made of fire brick. The furnace has cylindrical crucible at its base for the molten products to be collected. The diameter of the shaft is the biggest in the zone of fusion. Chemical reactions between carbon, oxygen, and iron and its oxides occur within the blast-furnace. As a result of these reactions pig iron and slag are produced.

The cupola is a small blast-furnace used to remelt pig iron for the purpose of making iron castings in the foundry.

Cupola Melting. Most of the gray cast iron produced in this country is melted in the cupola furnace. The cupola is a vertical cylindrical type of furnace, consisting of a steel shell lined with firebrick. Usually the charging door is located 15 to 25 ft above the bottom plate. At the lower end of the furnace is a wind box or air box. Air enters the cupola openings called tuyeres. Some cupolas are equipped with a single row of tuyeres; others have an auxiliary upper row of tuyeres. Opinion is divided as to whether a single or a double row is more desirable. A patented cupola known as the "balanced blast cupola", developed by the British Cast Iron Research Association, has three rows of tuyeres. A number of furnaces of this type have been instal­led in this country.

The cupola is a simple and economical melting unit, because the fuel and the metal are in intimate contact with each other. Fuel, metal and flux enter the cupola through the charging door. The initial charge of coke is known as the "bed charge". The metal is deposited on the coke. Then alternate layers of coke and iron are added.

Generally a flux is charged on the coke and the coke bed ignited by means of kindling wood or an oil torch. This bed usually extends from 36 to 60 in. above the top of the lower tuyeres. The make up of the charge and the charging are most important in obtaining uniform results in melting.

Task 4. Find in the text equivalents to the following words and expressions:

доменна піч, металургійний завод, чавун у чушках, сировина, руда, тиск, опір, фурма, шихта, матеріали, що подаються, шахта (печі), вогнетривка цегла, тигель, зона плавлення, шлак, виливки, купол, сірий чавун, вагранка, стальна оболонка, завантажувальний люк, подова плита, отвори, плавильна одиниця, холоста колоша (завалка), прошарок коксу, кільцева труба, необроблений матеріал, флюс, підтримувати процес згоряння, залізні виливки, розплавлені продукти, хімічні реакції, споживати, тиск, опір, продувати.

Task 5. Translate into Ukrainian the following words and word combinations:

to constitute, to be capable, to produce, pig iron, large quantities, raw materials, to consist of, iron ore, limestone, fuel, to be forced into, passage, combustion gases, to blow, bottom, charge, to feed, to include, flux, blast-furnace, varying dimensions, fire brick, cylindrical crucible, molten products, to occur, slag, cupola, to remelt, castings, foundry, wind box, single row, "bed charge", coke, alternate layers, to add, kindling wood, oil torch, uniform results, melting.

Task 6. Make word combinations from the words in column A and column B:

A	B
complicated	materials
raw	gases
pig	furnace
combustion	type
molten	castings
blast	iron
iron	crucible
cylindrical	products

Task 7. Complete the sentences using the given words:

… is the material entering the blast furnace. … is a small blast furnace used to remelt pig iron. … is the most complicated type of metallurgical plant. … is designed for the collection of molten products. … are the parts of the blast furnace through which the air is blown in.

the cupola the blast furnace the charge the tuyeres the crucible

Task 8. Fill in the gaps with the verbs given below. Put them in proper tense form:

equip produce blow include charge locate melt

1. Blast furnace _____ more than one thousand tons of pig iron a day.

2. The charge _____ the fuel, the ore and the flux.

3. Usually the air _____ in the bottom through the tuyeres.

4. Most of grey iron _____ in the cupola.

5. The charging door of the cupola _____ 15 - 25 ft above the bottom plate.

6. Some cupolas _____ with a single row of tuyeres; others - two or three rows.

7. A flux _____ on the coke.

Task 9. Fill in the table using the information from the text.

Melting unit	Design of the unit	Charge	Purpose
Blast furnace

Task 10. Give the detailed description of the blast furnace and cupola according to the table above.

Task 11. Answer the following questions:

1. What is the most complicated type of metallurgical plant?

2. List the materials entering the blast furnace.

3. How many tons of pig iron is the blast furnace capable to produce?

4. Give a detailed description of the blast furnace.

5. Give a detailed description of the cupola.

Task 12. Memorize the following words and word combinations:

1.	auxiliary	допоміжний
2.	blast-furnace	доменна піч
3.	circular shaft	кругла шахта
4.	combustion	згоряння
5.	to consume	споживати
6.	crucible	тигель
7.	cupola	вагранка
8.	to derive	отримувати, виводити
9.	fire brick	вогнетривка цегла
10.	flux	флюс
11.	fuel	паливо
12.	gray cast iron	сірий чавун
13.	to install	встановлювати, збирати, монтувати
14.	iron castings	залізні виливки
15.	kindling wood	деревина для розпалювання
16.	lime	вапно
17.	limestone	вапняк
18.	metallurgical plant	металургійний завод
19.	pig iron	залізо в чушках
20.	pressure	тиск
21.	raw material	сировина, необроблений матеріал
22.	slag	шлак
23.	to support	підтримувати, зберігати
24.	tuyere	фурма
25.	wind (air) box	повітряна коробка

UNIT 5