Girder-Type Kiln

Specification and Technical Features

Two-girder-type active lime kilns are fit for many kinds of fuel, waste less energy and have high activity. For simple structure and Iow cost, they are widely used for iron and steel, and chemical industries to calcine high quality active lime, using blast furnace gas, coke oven gas and coal dust to raise lime quality and save energy.

This kind lime kiln has been registered, gained the national patent and to be used widely in large iron and steel enterprises and chemical industries throughout the whole country.

I. Technical features:

1. Production capacity: LOOt/d to 600t/d. Operation range is 70% to 100%. Take the 300t/d kiln as example. It can be regulated within 180t/d-300t/d range without influencing quality and consumption targets.
2. Grain size: 30mm to 60 mm; 40mm to 80mm, Scale factor 1: 2.
3. Kinds of fuel: Natural gas, oil, coal dust, coke oven gas, coal gas of low heat value(e. G pure blast furnace gas ) and mixed fuel of all kinds of fuel(gas and gas, gas and liquid gas and solid, liquid and solid and so on).
4. Lime: Fine lime and high activity (reaching 360ml, 4N HCl Ten minutes). The ratio of lime stone under-firing and over-baking is 3%-6%.
5. Low heat wastage: They can make full use of heat energy. Fuel gas will be preheated by primary air passing. Cooled lime is preheated as secondary air passes. Fuel is burned
Completely and fuel heat is utilized fully. Ratio of heat consumes is 800-900kal/kg.
6. High work ratio: They can operate continuously for 48 to 50 weeks each year.
7. Calcination way: Use our new technology, three-way pressure system to reduce lime raw burned rate and raise lime activity.

II. Structure features and process instruction:

1. The kiln body is rectangular or cylindrical. There are double-deck burner girders in the kiln body with periphery burners in the middle of the kiln body. Waste gas drawing out girder is set on the kiln top. The kiln is divided into five parts: Material storage zone, preheated zone, calcining zone, posterior calcining zone, cooling zone.
The part between the waste gas drawing-out girder and the kiln crown is storage zone, used for storing adequate lime stone in order not to stop producing when the kiln crown
Feed device needs short-term maintenance.
The part between the waste gas drawing out device and the upper burner girder is the preheating zone to preheat lime stone.
The part between the upper burner girder and the lower girder is the calcining zone, where lime stone is calcined into fine lime. Its height can be regulated according to requirement of quality or lime stone physical property.
The part between the lower burner girder and lower gas drawing-out girder is the posterior calcining zone The lime that was calcined will gain the even and refine quality and raise the activity, when through this zone that has the high temperature and no pressure.
The part between the lower gas drawing-out girder and the lime output is cooling zone; Cooling air enters the kiln from the bottom of the cooling zone, cools lime stone to
167F, then goes out of the kiln. Heated secondary air comes into calcining zone to help burning.