ІІ. Read and translate the text:

 

The cupola is the oldest type of furnace and the most economical. It may be obtained in different sizes and can be operated for as long a time as may be required to produce a given amount of melted metal. It is difficult to produce metal of precisely uniform quality in the cupola as compared to furnaces in which uniformity of the molted material can be controlled by frequent and periodic tests and adjustment. Cupola capacities vary from 1 to 15 tons of metal per heat (the amount of metal melted at one time).

The cupola is a cylindrical shell constructed from boiler plate and lined with firebrick. The main furnace structure is usually supported on cast-iron legs, and the opening at the bottom of the furnace may be closed by cast-iron doors, which swing up into position and are held closed by an iron upright at the center.

Refractory sand protects these doors during the melting of the charge, which is placed over the layer of sand. At the end of the melting operation, the doors swing out of the way and materials remaining from the charge drop down through the opening.

On one side of the cupola, level with the bottom, is the breast opening for lighting the fire. This opening is also used as the tap hole. Opposite the tap hole, and somewhat higher, is the slag hole. The charging door is located approximately halfway up the vertical shell. The top of the cupola is open except for a metal shield.

A single row of openings or tuyeres is arranged around the circumference of the shell's interior at its base as a means of introducing air to the coke bed. A wind box, externally circling the cupola at the level of the tuyeres, supplies the air.

 

 

III.    Answer the following questions:

 

4. Give the meaning of the word “cupola”.

5. How can it be operated?

6. What is the possible cupola capacities?

7. What does the refractory sand protect?

8. Where is the breast opening for lighting the fire situated?

9. What supplies the air?

 

 

THE BESSEMER CONVERTER

 

I.  Read and memorize the following words:

luminous ['lu:minəs] світлий

diminish [di'miniʃ ] зменшується

 

II. Read and memorize the following phrases:

air is blown through the molten pig iron – повітря, яке продувається крізь розплавлений чавун

the oxygen of the air combines with – кисень з'єднується з

generates heat – виробляє тепло

frees the iron from the major parts of its impurities – звільняє чавун від    

                                                                більшої частини домішок

thus converting the iron into steel – таким чином перетворюючи

                                                                залізо в сталь

takes place – відбувається

pear - shaper tilting vessel – грушоподібний сосуд, який нахиляється

made of steel – зроблений із сталі

lined with – облицьований

the top of the converter is cut off to form a mouth – верхівка конвертора

                                          зрізана, утворюючи горловину

turned on – ввімкнений

a shower of sparks bursts from the mouth - потік іскор виливається з    

            горловини

Immediately thereafter appear short ruddy flames and a dense cloud of

 reddish-brown fumes caused by the burning of the silicon and      manganese in the iron. – Після цього з'являється коротке червоне полум'я і густа хмара червоно-коричневого диму, яку спричинили горіння кремнію та марганцю в залізі.

this part of the refining action is accomplished – ця частина очистки

                                                         виконана

the next stage, the removal of carbon, begins – наступна стадія –             видалення карбону починається

the glare continues – продовжує засліплюючи блищати

the converter emits a deep roar caused by the violent generation of gas

within it – конвертер виробляє сильний звук, який викликаний утворенням у ньому газів

suddenly the flame drops – раптово полум'я зникає

remove the metal – видаляє метал

Bessemer steel is used because of the low cost of the process. –

Бесемерівська сталь використовується через дешеву собівартість

                      процесу.

by a jet of nearly pure oxygen – за допомогою струменя майже чистого

                                                         кисню