The invention discloses a
lime kiln and a control method thereof. The
lime kiln comprises an online fuel switching
system, and the online fuel switching
system comprises a
coal gas supply device, a pulverized
coal supply device, N fuel switchers and N spray guns; when fuel of all the spray guns is switched from pulverized
coal to
coal gas, valve bodies at pulverized coal inlets in the fuel switchers and a pulverized coal stop valve are sequentially closed, and a pulverized coal conveying fan is adjusted to be in a standby state; the operation frequency of a
coal gas conveying fan is improved,after the
coal gas air pressure meets the
kiln entering requirement, a coal gas stop valve and the valve bodies at coal gas inlets in the fuel switchers are sequentially opened, and coal gas sequentially passes through a coal gas conveying pipeline, a coal gas ring
pipe, coal gas inlets and fuel outlets of the N fuel switchers and the N spray guns and flows into a kiln chamber; and a
combustion-supporting air stop valve is opened, the operation frequency of a
combustion-supporting fan is adjusted, the
combustion-supporting
air volume is matched with the coal gas volume, and the switching process is finished. According to the
lime kiln and the control method thereof, the defects that
lime kiln fuel is single in type and poor in production adaptability are overcome, and
lime kiln coal gas / pulverized coal online switching is achieved.