LIME SHAFT KILN_KILN MACHINE_Henan Yuhong Heavy Machinery Company( Yuhong Group

Lime shaft kiln , which also called vertical kiln, due to the vertical position of its kiln shell does not rotate, is always used to produce the products, such as cement, refractory materials (bauxite and mullite), lime, etc. Thus, the commonly used shaft kiln is also known as cement vertical kiln, lime vertical kiln and so on.

Lime shaft kiln has many forms, the vertical kiln with continuous operation is mostly adopted. Its heating fuel includes coal, nature gas and coal gas,and oil. The solid fuel can be added together with the limestone, it can also be burned into gas outside the kiln and then introduced into it. The former is called mixing shaft kiln, the latter is called gas kiln and oil kiln. Mixing shaft kiln has the advantages of large production capacity, fully mechanized procedure, high concentration of kiln gas, high thermal efficiency, good lime quality and so on, so it is often adopted.

With the development and application of shaft kiln, Yuhong lime shaft kiln, with its small investments and yield quick returns, and the continuous improvement of the lime shaft kiln technology, it is still widely used in china and foreign areas, such as Southeast Asia area, Central Asia area, the Middle East area and Africa area, etc.

After mixed well, blocks of limestone and coke are put into the kiln above. They do top-down movement and go through three areas: preheating zone, calcining and cooling zone. Preheating zone is located in the upper part of kiln, accounting for 1/4 of the total height, and it uses the hot kiln gas from the calcining zone to preheat and dry the limestone fuel and evaporate the moisture. When the temperature exceeds 70 degrees, furnace burden starts to burn. Hot kiln gas conducts nearly half heat to furnace burden, and its temperature drops to 50-100 degrees, discharged from the kiln crown. Calcining zone is located in the middle of the kiln, accounting for 1/2 of the kiln height. To avoid over-sintering, this zone temperature should not exceed 1200 degrees. Cooling zone is located in the bottom of the kiln, about 1/4 of the total kiln height, its main role is to preheat the air in the kiln to cool the hot lime to 30-60 degrees, not only recycle the heat but also protect the kiln gate from burning-out.
The main technological conditions to maintain the normal operation of lime kiln is to maintain the normal and stable temerature distribution inside the kiln.

1. Using energy-saving way of calcination.
2. Dust removal system makes flue gas and dust keep clever collocation flue gas emissions meet standards;
3. Scientific process the waste heat can be most effectively used.
4. Distributing equipment has unique structure and uniform distributing quantity.
5. Uniform wind supplying maintains good furnace condition.
6. High automation level.

Capacity	Effective volume	Effective height	Cross section diameter	Limestone size	Heat consumption	CaO	Active Degree
(t/d)	(m3)	(m)	(m)	(mm)	(KJ/kg)	(%)	(ml)
100	98	20	Ø2.5	40~80	<4600	>90	>300
120	141	20	Ø3.0	40~80	<4600	>90	>300
150	202	21	Ø3.5	40~80	<4500	>90	>300
200	301	24	Ø4.0	40~80	<4500	>90	>300
300	397	25	Ø4.5	40~80	<4400	>90	>300
400	491	25	Ø5.0	40~80	<4200	>90	>300
500	735	26	Ø6.0	40~80	<4200	>90	>300