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Used to produce quicklime by the calcination of limestone (calcium carbonate)
The chemical equation for this reaction is: CaCO3 + heat → CaO + CO2
This reaction takes place at 900°C (at which temperature the partial pressure of CO2 is 1 atmosphere), but a temperature around 1000°C (at which temperature the partial pressure of CO2 is 3.8 atmospheres) is usually used to make the reaction proceed quickly
Excessive temperature is avoided because it produces unreactive, dead-burned lime
Rotary kilns started to be used for lime manufacture at the start of the 20th century and now account for a large proportion of new installations
The early use of simple rotary kilns had the advantages that a much wider range of limestone size could be used, from fines upwards, and undesirable elements such as sulfur can be removed
Our lime kiln features in, convenient and reliable control of the production process, less wearing parts, high rates of operation, the Lime kiln also has strong structure, stable operation, low energy consumption, high-quality products,large capability from the kiln and so on advantages, we can also offer advanced efficient shaft preheater, five grade cyclone preheater
Technical features:
Take the 300T/d kiln as example, it can be regulated within 180 to 300T/d range without influencing quality and consumption targets
Chalk size: 400mm to 80mm
Size range ratio: 1:2
Kinds of fuel: natural gas, oil, cola dust, coke oven gas, coal gas of low heat value, and mixed fuel of all kinds of fuel (gas and gas, gas and liquid, gas and solid, liquid and solid, and more)
Lime products: fine lime and high activity (reaching 360mL, 4N HCL 10 minutes)
The ratio of lime stone under-firing and over-baking is 5 to 8%
Low heat wastage: they can make full use of heat energy when primary air passes, fuel gas is preheated when secondary air passes, cooled lime is preheated, fuel is burned completely
Structure features and process instruction
Kiln body: rectangular or cylindrical
With double-deck burner girders in the kiln body with periphery burners in the middle kiln body
Waste gas drawing-out girder is set on the kiln top
Divided into five parts: material storage zone, preheated zone, calcining zone, posterior calcining zone,cooling zone
Storage zone: a part between kiln gas drawing-out device and crown, it is used for storing adequate lime stone in order not to stop producing when the crown feed device needs short-term maintenance
Preheating zone: a part between kiln gas drawing-out device and upper burner girder, used to preheat lime stone
Calcining zone: a part between upper burner girder and lower girder, where lime stone is calcined into fine lime, it's height can be regulated according to requirement of quality or lime stone physical property
Posterior calcining zone: a part between lower burner girder and lower gas drawing-out girder, 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
Cooling zone: a part between lower burner and lime output, cooling air comes into the kiln from the bottom cools lime stone to 75c and comes out of the kiln, heated secondary air comes into calcining zone to help burn
Safely when medium (water or heat oil) temperature rises above certain temperature
The quantity of pipes is decided by the kiln size
There are many evenly-distributed opens downside of the pipes kiln gas is extracted by the gas extracing girder through the opens to ensure negative pressure of the kiln section is evenly distributed
The regulating range of air quantity is 10 to 100%
Regulating burning air quantity makes the kiln working under the best operating condition, saves energy and cuts down production cost
Lime Kiln with high quality