What is difference between Cupola furnace and blast furnace?

Answer:

In essence nothing, a Cupola furnace is a type of blast furnace in that it is charged at the top and tapped at the bottom and air is blasted into the furnace via a wind belt and tuyres.
A blast furnace in a steel works is a huge structure operated for long periods of time; it is charged with iron ore, coke and limestone and reduces the iron ore into pure iron.
Cupola furnaces, as used in the foundry re melts pig iron, from the blast furnace, along with foundry scrap, steel scrap and scrap iron engine blocks and produced iron alloys of various specifications. A Cupola furnace is usually operated on a daily basis but some types can be continuously operated for several weeks

·       Cupola varies in sizes from diameter from 1 to 2 meters with height from four to five times the diameter.

·       With 1m diameter and 4m height it would melt about 2 tons of iron per hour.

·       It is operated when desired and not continuously and only when pigs are to be melted to form various irons or steel.

·       Coke fire is first lit at the bottom.

·       Then charging starts at the bottom with alternate layers of coke, pig iron and little lime stone.

·       The pigs before feed are broken into lengths of 0.25 meter and are mi8xed with agreed proportion of iron and steel scrap,

·       Adding low carbon scrap will reduce percentage of carbon in the melt.

·       After an hour or two when the charge is burnt the hot air blast is gradually increased and cupola is closed.

·       The Iron melts and sinks to the bottom from where it is tapped off into ladle or directly into moulds.

·        The amount of coke consumed is not large as iron ha just to be melt without any chemical change.

·       The coke of 50 to 125kg / ton of iron to be melted may be needed. Lime stone adds with sand at the bottom and forms a liquid slag floating above melted iron.

·       About 3 to 5 Kg of lime stone / ton of iron may be needed.

IMPACT OF MOVIES AND TV PROGRAMS ON SOCIETY

                  IMPACT OF MOVIES AND TV PROGRAMS ON SOCIETY

"I think that although movies or TV programs have some good aspects, they affect people and society more negatively. Children who spend a lot of time watching television tend to get lower grades. In addition, violent movies or TV programs make our society more aggressive. Now, I will state these reasons to support my opinion.

First of all, I state the relationship between children and TV programs. According to some surveys, children who spend much time watching the TV at home tend to get lower grades at school. They prefer to watch their favorite programs to do their home works. In particular, today, many children have their own TV set in their bedrooms. Therefore, more and more, they tend to indulge in watching the TV. To bu sure, if there are many valuable programs, we will not drag their children away from the TV. However, because there are little educational programs, it is difficult for us to allow children to sit in front of the TV for a long time.

Secondly, I state about the bad aspect of influence that movies or TV programs give to society. Although there are a wider variety of programs today, some of them are a little more violent. These programs often make people more aggressive because many viewers tend to be influenced by media. In fact, they say that some crimes were committed by young men who were inspired due to watching violent movies in the past."