Unit 6 (Total Score – 36 points)

I. Прочитайте текст и намагайтесь запам’ятати правила техніки безпеки під час роботи з ковальськими печами. (Score – 6 points)

Safety Engineering in Forge Furnace Operation

Forge furnace operators must observe all safety engineering rules. Before being allowed to operate a furnace, workers must be thoroughly instructed in these rules” Moreover, furnace maintenance instructions based on safety engineering rules must be hung in a visible place near the furnace.

The furnace maintenance instructions and safety rules depend to a considerable degree on the furnace design and the fuel on which it operates.

Gas-fired furnaces demand special attention, as this fuel contains poisonous gases (carbon monoxide, hydrogen sulphide etc.). Moreover, gas and air always form explosive mixtures.

However, there are certain general rules for operating forge furnaces, which, depending on the furnace design and local conditions of operation, need to be specified to a greater degree. They are:

1. All moving mechanisms (pushes, etc.) must be properly guarded.

2. The furnace must be equipped with screens, water-cooled frames and sliding doors, water screens, etc., to protect per­sonnel from flames and heat radiation from the charging openings and fore-boxes.

3. Exhaust hoods must be installed over the furnace for collecting and discharging any products of combustion escaping from the charging openings.

4. To improve working conditions furnaces must be equipped with air showers.

5. All gas pipes must be leak-proof, so as to prevent the possibility of gas-poisoning during operation of gas-fired furnaces. All joints must be welded. Flanged joints on gas lines may be permitted only for connecting valves; tarred asbestos cord gaskets must be inserted between the flanges of each flanged joint) and all gas lines must be periodically checked for leaks, all places which arouse suspicion being carefully checked with a soap solution which, in the case of leaks, will form soap bubbles. The welding of working gas lines must be executed according to special instructions, one of the obligatory conditions of which must be a positive pressure in the gas line.

6. Before lighting burners or atomisers, all charging openings, sliding doors and dampers must be opened and the furnace thoroughly aired. Otherwise, after the furnace is shut down gas or masout may leak through the burners into the furnace where, on mixing with the air, it will form an explosive mixture and thus create the danger of an explosion when the burners or atomisers are lit.

7. Burners or atomisers must always be lit with a torch attached to a long rod. When doing so, the worker must always stand to one side of the burner or atomiser so as not to be injured should the flame escape.

8. No person should be allowed to stand in front of the charging openings when the burners are being lit, owing to danger of flames escaping.

9. Burners must be lit as follows:

a) a burning torch is first applied with the aid of a long rod to the nozzle of the burner;

b) only a small amount of gas is first supplied to the burner and, after it has been ignited, the flow of gas is gradually increased unlil it burns with a stable flame;

c) air is added gradually, adjusting the proportion of gas and air until complete combustion of the gas is attained.

10. If, for any reason, the burner dies out on being lit, first the gas and then the air supply should be immediately cut off. Then, after the furnace has been aired the burner may again be lit.

11. On shutting a furnace down, the gas supply should be cut off before the air supply.

12. Should a break-down occur in the air supply during the operation of the furnace the gas or masout supply should be immediately cut off.

13. The following rules must be observed when igniting atomiser:

a) the wood stacked in front of the atomiser should be ignited with a torch and allowed to burn for 10-20 minutes; in the absence of a wood fire, a piece of hot metal should be places in front of the atomiser;

b) the air supply should be opened up after which the masout supply to the atomiser should be turned on, gradually increasing the air and then the masout until the flame is normal. If the furnace is equipped with several atomisers, they must be started up one after another;

c) in furnaces equipped with top and bottom burners or atomisers, the bottom rows must be ignited first, the top rows being ignited only after the temperature in the furnace has reached 600-650°C.

14. Never cool hot furnace hearths of high temperatures (1.000-1.200°C) with a stream of water, as this may result in severe burns to the furnace operators.

15. It. is strictly forbidden to walk on the roofs of furnaces in operation. Should it be necessary to inspect a roof, or make repairs to a hot roof, the roof of the hot furnace should first be covered with planks, over which it is permitted to walk.

16. Never attempt to extinguish burning masout with water, as this may lead to a fire.

Burning massout must be extinguished only with dry sand.

П. Складіть 4 питання до тексту і попросіть товариша відповісти на них. (Score – 8 points)

III. Скажіть, якиих правила безпеки необхідно дотримуватися під час роботи з ковальськими печами. (Score – 16 points)

IV. Складіть анотацію. (Score – 6 points)

(Total Score – 36 points)