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2022

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08

MAERZ Lime Kiln Promotion (We chat)

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Typical Application of Roots Blower in MAERZ Lime Kiln

 

 

MAERZ Lime Kiln (also called Co-Current Heat Accumulated Kiln with Double Shafts) is developed by a Switzerland company named MAERZ OFENBAU AG and awarded the technology patent in 1965. This company is the leading engineering company providing patented technology Lime Kiln used for producing high quality Lime and Dolomite. More than 500 units Lime Kilns have been established in more than 50 countries all over the world. 

MAERZ Lime Kiln descriptions as listed hereunder:
(1)Basic Description and Working Principle:
MAERZ Lime Kiln is a kind of Vertical Kiln composed by two kiln chambers internal connected to each other. The working principle as shown in Figure.

 

 

(2)Process Descriptions:
The mineral will be calcined and preheated in two chambers alternately. There provide crossover channel at the bottom of the two chambers of calcination area.
Shift every 15 minutes to change the chamber’s working condition accordingly. Mineral is fed into two chambers alternately during working stage and the fuel is transported from the kiln top. There are many spray guns installed at bottom of the preheating area to make the fuel well-distributed on the sectional surface of the kiln. The mineral would be calcined uniformly. Combustion air is transported from the top of kiln by Roots Blower. The combustion air is preheated prior its mixing with the fuel. Then the calcination fire will meet the mineral at calcination area to calcine the mineral. The off-gas will go through the crossover channel between two chambers and then be discharged from the preheating area of the other chamber.
(3)Technical Improvement:
To fulfill the diverse requirement from different clients, the technical modification and improvement is made in:
A, The kiln adopts round-shape hanging over structure that suitable for 600 t/day size or above kilns
B, Adopt patented technology on material feeding to increase the capacity and get higher coefficient of utilization of Limestone.
C, The patented technology on burning system could apply coal gas of low thermal value or two-fuel system using solid and gas fuel. The kiln could be big size designed (the max size at present is 800 ton/day established in 2007 in Brazil and is successful running until now)
D, MAERZ company develops a new kiln could calcine small granular size of 10/15-40mm size as a milestone product in this field.
(4)Character:
A, Combustion air is fed from kiln top, the calcination fire will meet the mineral at calcination area. MAERZ kiln has the longest calcination area, and the finished product quality is good.
B, Two chambers operated alternately, the off-gas will preheat the mineral directly and its heat is sufficiently utilized. The unit has the lowest heat consumption that means the lowest operating cost.
C, Diverse fuel applicability. MAERZ kiln is designed to apply kinds of fuels of gas, liquid and solid type.
D, The hanging over structure could be expanded freely in vertical direction, no rigid limitation.
 E, The limestone granular size of MAERZ kiln is >30mm, maximumly utilize the mineral from quarry.
F, MAERZ kiln create “Sandwich” style feeding method, the ratio of Limestone between small size and big size could be increased to 1:5 or 1:6.
G, Min off-gas discharge (NOx and others)
H, Max capacity range (100 to 800 ton/day)
I, Verified design on refractory could apply 100% of Made-in-China refractory and working for 6-7 years.
J. Dust content and temperature is low in off-gas, less pollution.
K. Wide capacity and automatic control could be realized.
(5)Typical 600 ton/day size MAERZ system process description:
   Whole system including: Raw material classify system and feeding system, Kiln, Finished product storage, transportation and classify, Flue Gas dust abatement system, Coal powder making system, Electrical control system and Water circling system.
   Detail diagram listed hereunder:

 

 

(5) Roots Blowers are required in:
Combustion Blower, Cooling Blower, Coal Powder Transportation, Coal Gas Blower and etc


Optimal Designed Roots Blower Specialized for MAERZ Kiln(SZB Manufactured)
Japanese Tech Roots Blower: RR Series/3H Series

 

Character:Japanese Technology, low rotary speed, reliable running NSK, NACHI Brearings

USA Technology Roots Blower: ZG Series

 

Character: USA Technology, air cooling style up to 98kpa pressure rise, heavy duty style
SKF, FAG Brearings