- Lime vertical kiln should be pointed out that the kiln type especially suitable for the production Nanometer calcium carbonate. Investigate its reason that the concentration of CO2 in flue gas jet can reach more than 35%, CO2 recovery cost is low.
- Vertical lime kiln, just like its name, the shape is erect. It is used for calcination limestone. Due to has low energy consumption, less cover area, less investment, wide applicability fuel, and more advantages, the vertical lime kiln is also widely used in metallurgy, construction materials, calcium carbide, Nanometer calcium carbonate, aerated concrete, sugaring, etc.
There are various processes for the active lime production, mainly including: Advanced “Preheater-Rotary kiln-Vertical cooler" Energy-Saving Process, Traditional “Long Rotary Lime Kiln” Process, Mixed Buring Vertical Kiln Process, Gas-ﬁred or Oil-ﬁred Vertical Kiln Process. The vertical kiln was manufactured by ZK group with modern new technology, which is an environment protection, save energy, higher machanization and automaticity, quite modern lime kiln. The selection of the active lime process is effected by many factors, such as : the activity requirement, the fuel, the limestone sizes, production capacity, environmental-protection requirement. We will select the most workable and eﬃcient and economical solution based o the clients’ speciﬁc requirement and conditions.
Mixed Burning Vertical Lime Kiln Process
The qualified raw materials and solid fuels are mixed uniformly according to a certain proportion and then sent to the vertical kiln through a single bucket elevator for calcination. After calcination, the final lime products are discharged from the bottom of the vertical kiln through a discharge device to the conveyor, and the conveyor sends the finnal lime products to the storage silo. The hot flue gas generated by calcination will firstly go into the dust collecting system, and then the clean flue gas will be emitted through chimney to the atmosphere.
Low Heat Value Gas Vertical Lime Kiln Process
The qualified raw materials are sent to the vertical kiln through a single bucket elevator. The calcination heat energy is supplied by the low heat value gas burner distributed around the vertical kiln. After calcination, the final lime products are discharged from the bottom of the vertical kiln through the discharge device to the conveyor, and the conveyor sends the ﬁnal lime products to the storage silo. The hot ﬂue gas generated by the calcination coming out from the top of vertical kiln, and will enter into heat-exchanger and the dust collecting system, and then the clean air is emitted to the atmosphere by chimney. The heat-exchanger also will be used for heating the gas and the combustion air.
High Heat Value Vertical Lime Kiln Process
The qualified raw materials are sent to the vertical kiln through a single bucket elevator, and the calcining heat energy of lime is provided by the high heat value gas or special oil burner distributed around the vertical kiln. After calcination, the ﬁnal lime products are discharged from the bottom of the vertical kiln through the discharging device to the conveyor, and then the ﬁnal lime products are sent to the storage silo by the conveyor. Some of the hot ﬂue gas generated by the calcination will enter into the dust collecting system, and then the clean air will be emitted by the chimney. The other part of the hot flue gas will enter into the to improve the fuel diﬀusion speed and increase the uniformity of limestone calcination.
Structure : In order to guarantee the quality and capacity of lime, finalize the fully automatic production during the production, the special and main equipment for the kiln as follows :
- Limestone batching electric weighing system : Required limestone and coal mixed as the feeding material in the kiln processing. The ratio of two mixed material is very important, the two weighing system can accurately measure the raw material quality, and mix them with special batching method. In addition, if any changeable in particle size of raw material or calorific value of coal, should adjustable the ratio of two raw material, operation the computer will finalized in control room.
- Intelligent master controller : Main winch system, make the rotation motor change into frequency control of motor speed. During the handcart route from feeding to 0 ~ 6 m after adopt step-less speed 6 m is set to 1 m/s running smoothly, terminal schedule 6 m for step-less speed running ahead of time, until discharge. This design ensures the skip smooth operation, greatly reduce the vibration and the failure rate of inclined bridge. The elevating capacity will improve 60% than no frequency control of motor speed. Make the main winch system greatly reduced maintenance. The handcart running status and adjustment wire rope length no more downtime. Practical life of wire rope improve more than 3 times.
- Rotary distributing devices : The key of feed material inside kiln ensure the uniform flat, rotary distributing devices could make the raw material even scattering into the material surface, the shape of surface is adjustable. Application of frequency conversion governor, PLC control, makes the fabric are accurate and reliable.The case of the key structure, such as cylinder, baffle, cloth guide groove, and tablets, etc. With high temperature resistant, corrosion resistant stainless steel. Rotating parts with special high temperature resistant surface bearing, makes the equipment operation and reliable, and can in a terrible environment without any medium. For the high quality of the calcined limestone provides a good technological conditions.
- The special structure of the case after mixing limestone and coal can be scattered to the material surface. Greatly reduced due to uneven fabric in furnace nodules, waste of fuel. Like Shuicheng steel, Jinan steel and other units in the replacement after this kind of case, after the measured production ash per ton coke saving (or coal) in more than 15 kg.
- Intelligent detection of material level gage : Level gage install the top of kiln, though remote control in the industrial control can be very convenient to detect a material fabrics, to control to determine whether the skip loading, lime discharge device is working. Detection of material level gage part adopts high temperature (above 600 ℃) corrosion resistant materials. Control system adopts imported transducer and PLC module, in order to meet the measurement system can long-term reliable operation in harsh environment.
- Simulation hood : Active lime vertical kiln in the calcination process, for the size of the wind and uniformity, the degree of the activity of lime and calcined raw cooked evenness is important.The hood cap is to use the computer simulation design. It can make for uniform wind. The furnace condition caused by uneven air supply partial burn, over burnt, less burnt phenomenon is greatly reduced, greatly improving the quality of active lime. In addition, because of the special structure, hood it than other cap to avoid blowing ash up clogging gas path and influence the furnace condition. At the same time also cap ash discharge smoothly than others. In the rough supply environment, it also has properties, such as pressure and resistance to high temperature deformation.
- Pan discharging lime machine : This equipment is mainly composed of motor, reducer, transmission shaft, rotary blade, and other parts.
- Two section seal valve lime discharging machine : In the vertical kiln production, to ensure the quality and quantity of finished products of lime, must be kept combustion air continuous production. The two section seal valve lime discharging machine is one of key equipment during the efficient automatic discharging lime. A full set equipment is composed of upper and lower two dampers connection in series. Each damper is consists of damper box, damper, damper shaft, damper spacer, inspection door, pneumatic system and lubrication system. Two damper take turns to open and close alternately, discharge the continuous fall lime to the final belt conveyor. Due to the damper seal during the discharging lime, make the combustion air continuously supplied, no any link from the bottom.
Our Advantage :
- Energy Saving : There are preheating zone, calcination zone, cooling zone from the top to bottom of kiln inside. The cooling air blow into the cooling zone from the bottom, though the heat transfer, the goods were cold, and the cooling air was heated, then put into the calcination zone with the heat for burning, thus reduce the energy consumption. The flue gas from the fuel after calcination enter into the preheating, make the material heat to pre-dissociation temperature. The flue temperature fall to 170-300℃, then come out from the kiln.
- Good Effect : The shell of kiln use four layer refractory in vertical masonry, good effect of thermal insulation, the temperature of shell will be controlled higher 60deg C than environment, save energy remarkably.
- Long Lifetime : Long service life of refractory, the material not directly crash the work surface of refractory, but its fraction with work surface by gravity setting. Thus it greatly reduces the wear rate of refractory, the refractory will be used in 6-10 years in normally.
- Less cover area : because the vertical kiln in vertical layout, feeding use the single bucket elevator in high angle layout, each functional area is decorated compact, greatly reduces the cover area.