Chaeng Active Lime Production Process

15 Jul,2016 UTC+8 Views:


The successful lime industry application of environment-friendly,energy-saving, active lime stone with vertical preheated and vertical cooler breaks traditional pattern of lime production.Due to reduction of fuel consumption significantly and reducing exhaust emissions,coupled with the adoption of pulse-packs dust-catcher purity exhausting,it not only makes production cost and the energy consumption greatly reduced,but also the calcinations process of emission slandered.

Main advantages of Active Lime production Process :

1.Good quality,and high output,suitable for larhbe-scale activity of lime production lime and large-scale production.

2.Stable production,all the production with the negative pressure,air flow and higher security.

3.Simple structure,easy control and beneficial operation and maintenance.

4.Fine grade limestone can be calcined,full use of mine resources.

5.Low heat consumption per unit of product,installation in vertical kiln can take advantages of exhaust warm limestone,greatly reducing the fuel consumption.

6.Making full use of industrial waste gas as a fuel for lime burning(such as blast furnace exhaust gas,acetylene tail gas,charcoal blue exhaust,etc.)

7.Kiln head adopts the design of vertical cooler integrating kiln head cover, The construction area is small,good sealing,

8.Environment protection,the adoption of pulse bag filter collecting dust,discharge concentration less than 50mg/Nm3 and below national emission standard(less than 100mg/Nm3).

9.High automation level,the adjustment of production system operation,control and alarm.

Main Equipment of Active Lime production Process :

1. Raw material conveyor system

Limestone (dolomite) will be conveyed after screening. Qualified lime stone particle size 10 ~ 50mm will be conveying to top silo of preheater by lifting equipment. discharging finished size of 5 ~ 40mm above 90%.

2. Lime calcining system

Lime calcining system consists of a vertical preheater, rotary kiln, cooler.

Vertical preheater: Vertical preheater is consisting of a preheater body, a feeding pipe, a storage bin, hydraulic push rod device etc.

Preheater has polygonal and round using compartment partition device .Making the limestone gradually heating to avoid sharp warming burst into the kiln produces a large amount of powder, limestone decomposition rate is 30% ~ 40%, the average temperature of exhaust gas temperature is 230~260℃, thereby reducing the heat consumption.

Rotary kiln is composed of cylinder, supporting device, drive device, block wheel device, kiln tail and kiln head seal, burning device, kiln head cover etc.

The kiln body is a cylindrical vessel, equipped with supporting device; the roller bearing is the water-cooled oil lubricated bearings. Near the gears ring are also equipped with hydraulic blocking wheel, using frequency conversion motor driving kiln body, and an auxiliary driving kiln. Kiln head and kiln tail adopts sealing device, using frequency conversion motor driving kiln and with preheater decomposition rate, to control effectively calcination temperature and time, reached our burning requirements.

Lime is fed into the upper end of the cylinder. As the kiln rotates, material gradually moves down towards the lower end.

Vertical Cooler: vertical cooler is composed of cooler body, fixed screen, cooling device, electric vibrating discharging machine etc.

Vertical cooler has many cooling discharge area, each area discharging speed can be controlled separately according to material temperature; Cooling air meet hot lime directly, cooling has well effect, ash temperature is low, ash temperature higher than the ambient temperature 40 ℃; cooling air after cooling lime, temperature can be preheated to more than 600℃, one part is used as second combustion air in rotary kiln, the other part is used to dry pulverized coal. Cooler is without moving parts, good cooling effect, simple structure, less equipment repair.

3. Pulverized coal preparation system

Pulverized coal preparation system is an important part of lime rotary kiln system. There are generally two kinds of system; firstly, it is the wind swept coal mill tube mill pulverized coal preparation system with bag dust collector. It is convenient operation and clean environment etc. Its production process as follows: Block degree ≤ 25mm coal, from bucket elevator into the belt, then conveyed to coal bunker by belt, through disc feeder or electromagnetic vibration feeder that under coal bunker, the mill is a set of grinding, drying, when grinding, introducing hot air from rotary kiln system or flue gas from auxiliary combustion chamber to dry.

Gas out from separator, the dust discharged after purification by an exhaust fan, a part of exhaust gas recycled in coal grinding mill, another part exhaust gas into the atmosphere through the chimney. Pulverized coal collected by the dust collector is discharged into the kiln coal storage bin. According to the need of coal warehouse, into the kiln front burner with a Roots blower, through the burner combustion air blower air supply for combustion, used for calcining limestone.

4. Finished product conveying system

The final lime is conveyed to bucket elevator through bucket machine by cooler, then into top sieving grain silo by elevator, qualified part≧5mm conveying to finished product bin by belt conveyer, powder≦5mm conveying to powder bin.

5. Flue gas treatment system

High temperature flue gas from rotary kiln combustion, after the heat exchange with the limestone in preheater, the temperature dropped to 280 ℃ below, these gases will be cooled down by multi-tube cooler to 200°C lower. Cooling through multi tube cooler and then into the high-temperature bag type dust collector. After dust collector, high temperature fan into the atmosphere through the chimney, the dust concentration is less than 30mg/Nm ³.