显示标签为“steel making”的博文。显示所有博文
显示标签为“steel making”的博文。显示所有博文

2016年1月27日星期三

Fuel gases used in steel plant

Fuel gas is a fuel which under ordinary conditions is in the form of gas. Fuel gases are used in steel plants for different applications which include a source of heat as a reductant and cutting and welding application. Fuel gases usually used in steel industry are natural gas (NG), liquefied petroleum gas (LPG), acetylene, by product gases (blast furnace gas, coke oven gas and converter gas).

Natural gas
Natural gas is a gaseous fossil fuel which is extracted from deposits in the earth. It is a mixture of hydro carbons consisting primarily of methane (generally greater than 80 %) but includes varying amounts of other higher alkanes such as ethane, propane and butane etc. 
The main usage of natural gas in the steel industry is in iron making. For production of direct reduced iron it is reformed to produce reducing gases which are then used for the reduction of iron ore. 
In case of iron making in blast furnace, natural gas is being injected in some of the blast furnaces at the tuyeres to reduce the consumption of BF coke and to increase blast furnace productivity. In blast furnace, natural gas plays a double role of a reductant and a fuel.

Liquefied petroleum gas
Liquefied petroleum gas (LPG) is extracted from crude oil. The main components of LPG are hydro carbons containing 3 or 4 carbon atoms. 
LPG is a gas at atmospheric pressure and ambient temperature, but it can be liquefied when moderate pressure is applied or when the temperature is sufficiently reduced. It can be easily condensed, packaged, stored and utilized, which makes it an ideal energy source for a wide range of applications. 
In steel plants, LPG is stored in pressure vessels. 

Blast furnace gas
Blast furnace (BF) gas is a gaseous by product which is generated while producing hot metal (liquid iron) in a blast furnace. 
In steel plants, BF gas is normally being used mixed with either coke oven gas or converter gas or both. The mixed gas is used as a fuel in various furnaces of the steel plant.

Converter gas
During the process of steel making in basic oxygen furnace (BOF), converter gas is generated at a rate around 75 to 95 Cum /ton of crude steel. 

As a professional and experience manufacturer in China, We can give turn-key service from foundation excavation, rolling line design, equipment manufacturing, installation and debugging, technician training depending on prominent capacity of designing and manufacturing and abundant practical experience of installation.
 Continuous casting machine

2016年1月21日星期四

Reheating furnaces in steel Industry

In steel plants reheating furnaces are used in hot rolling mills to heat the steel stock (Billets, blooms or slabs) to temperatures of around 1200 deg C which is suitable for plastic deformation of steel and hence for rolling in the mill. 

Different type of batch and continuous furnaces are described below.
1.Batch furnace -These are the older type of furnaces which are capable of heating all grades and sizes of steel. 
2.Continuous pusher furnace– In this type of furnace cold steel stock is pushed forward with the help of pushers at the charging side. 
3.Rotary hearth furnace – A rotary hearth furnace is used for heating round billets in pipe plants and for heating short length blooms or billets in a forging plant.
4.Walking beam furnaces – Initially walking beam furnaces were designed with alloy steel walking beams which were exposed directly to the furnace heat and were also subjected to heat corrosion. 
5.Walking hearth furnaces – It is similar to the walking beam furnace when passage of steel stockl through the heating chamber is considered.
6.Roller hearth reheating furnaces – Roller hearth furnaces are used to advantage when heating very long billet, bloom or slabs in the situation where it is not practical for heating in a pusher or walking beam furnace.

Today we are talking about is continuous pusher furnace,Advantages of the pusher type furnaces are as follows:

  • High production per unit capital investments
  • High hearth area efficiency
  • Higher specific production per unit of space utilized.
  • Low maintenance cost
  • Ease of charging and discharging of material
  • Lower temperature differences between two pieces of material pushed.
  • More control of the rate of heating at all temperature levels.
  • Gradual rise in temperature permits charging of all grades of cold materials.
  • Can be built for larger length of the piece to be heated to have higher rolling mill yield
Re-heating furnace
As a professional and experience manufacturer in China, We can give turn-key service from foundation excavation, rolling line design, equipment manufacturing, installation and debugging, technician training depending on prominent capacity of designing and manufacturing and abundant practical experience of installation.