Checker bricks for hot blast furnace

Checeful bricks are heat -accumulating material, used in thermal equipment. It is mainly used in the middle and upper parts of hot blast furnace regenerator for heat storage. In the process of turning cold air into hot air, the regenerator is the most important part of the hot blast furnace, so checker bricks are crucial.

Types of checker bricks

Checker bricks of different materials — Checker bricks from different materials

According to the technical requirements of different temperature zones, high alumina bricks are usually used, flint check brick and clay brick. In some hot blast furnaces, mullite bricks, sillimanite bricks are also selected.

High alumina checker bricks

high alumina checker refractory bricks — High Alumina Checker Bricks

Brand index	DRL-135	DRL-145	DRL-150	DRL-165	DRL-155	DRL-48
Al2O3, % ≥	70	75	80	65	55	48
fire resistance℃ ≥	1790	1790	1790	1790	1770	1750
Compressive strength at normal temperature MPa ≥	20	20	19	24	24	24
Compressive strength at normal temperature MPa ≥	65	70	80	49	44.1	39.2
Reheat line change rate % ≥	±0.1	±0.1	±0.1	+0.1~-0.4	+0.1~-0.4	+0.1~-0.4
	1450℃x2h	1500℃x2h				1450℃x2h
0.2MPa Load softening initial temperature ℃ ≥	1500	1550	1650	1500	1470	1420
Creep rate at high temperature % ≤	0.6 1350℃×50h	0.6	0.7	–	–	–
Creep rate at high temperature % ≤	0.6 1350℃×50h	1450℃×50h	1500℃×50h	–	–	–

Silicate Fireproof Checker Bricks

silica refractory checker brick — silicate fireproof checker bricks

project	Ordinary sand-lime brick			Sand-lime brick for hot blast furnace
Product number/brand	GZ-95	GZ-94	GZ-93	Vault Kiln Bricks		Checker bricks
SiO2≥	95	94	93	95	96	95	96
Fe2O3 ≤	1.2	1.4	1.5	1.0
Fire resistance temperature ℃ ≥	1710	1710	1690	1710	1710	1710	1710
0.2Mpa Initial load softening temperature℃ RUL≥	1650	1640 (Cemented silica1620)	1620	1650	1660	1650	1660
Apparent porosity AP% ≤	22	23	25	22	22	22	22
Compressive strength at normal temperature CCS MPa≥	29.4	24.5	19.6	35	40	30	35
True density g/cm3≥	2.37	2.38	2.39	2.35
Creep rate at high temperature %≤				0.8
Thermal expansion coefficient %≤				1.26

How to choose Checker Bricks?

The choice of checker bricks has a great influence on the operation of the blow furnace. The operating effect and heat transfer efficiency of the regenerator are closely related to the size, shape and number of bricks in the holes for checker bricks. Here are some factors, Things to consider when choosing checkered tiles.

Checkered brick has the largest heating area per unit volume.
There must be a sufficient number of bricks in the heating zone to accumulate heat, to guarantee, that it will not cause the air temperature to drop excessively within a certain range.
Disturb the air flow as much as possible, Maintain high flow rate and increase convective heat transfer and rotation speed.
Have sufficient building stability
Easy to process, manufacturing, installation and maintenance at low cost.

Requirements for the location of holes in refractory checker bricks

The width of all holes must be the same. The holes are staggered in one or two directions.
The holes should be symmetrically up and down, left and right and distributed evenly. The direction of the length of the holes for hand gripping should be parallel to the strips of bricks.