Specific Surface

Spec

ific

ener

gy re

quire

men

t of

grin

d ab

ility

test

er

Types of Grate Coolers

A)Traveling grate cooler

B) Reciprocating grate cooler

Grate line ConfigurationGrate line Configuration

Single grate cooler

Combi-coolerCombi-stage cooler

Mechanical Features

Grate Plates

• Perfect in critical zones (nose and hook)

• Residual stresses: must be avoided by heat treatment for stress relieving

1. Chromium (Cr):1. Chromium (Cr):•Melting point 1890oC

•It increases the tensile strength of steels by 80-100 N/mm2 per 1% Cr

•Increases wear resistance•High temperature strength

3-Clinker hardness3-Clinker hardness (500 – 700) Hv

22 - -Nickel (Ni)Nickel (Ni)::•Melting point 1458oC

•High temperature strength

1 mm

Air compartments

& flap valves :

Discharge hopper of Under Grate

Grate cooler operation and controlGrate cooler operation and control

Clin

ker T

emp.

Air Te

mp.

500500

10001000

15001500

250250500500

75075010001000

20-55% 0-40% 0-40% 0-45%

Hammer type breakerHammer type breaker

11 m/sm/s4040 m/sm/s

22 m/sm/sGrateplate problems

Air beam technology

Design Design features of features of

modern modern grate grate coolercooler

Moving FrameMoving Frame

2562 ±2

840 ±1840 ±1

682 ±13452 ±4

Moving frames Central Beam