Brick Kilns
Brick Kilns
Brick Kilns can be classified as intermittent and continuous. Clamps, Scotch, Scove and Downdraft kilns are intermittent while the Bull Trench (BTK), Hoffman, Zig-zag, Tunnel and Vertical Shaft Brick Kilns (VSBK) are continuous. The continuous kilns are more efficient as they have heat recovery features from both the heat in fired bricks and flue gases unlike the intermittent ones.
Intermittent Kilns
The oldest kiln is the clamp.Invented in 4000 BCE, these are still very common in India. Clamps are temporary constructions made of green bricks or clinker. The clinker can be reused while the green bricks are sold. A slight variation is the Scove with a pile of dried bricks with tunnels at the bottom allowing heat from fires to pass through and upward in the pile of bricks. It is plastered with mud (scoved) to insulate it. Certain brick makers use permanent clamps made of refractory bricks. Two basic variations of kilns are the updraft and the downdraft kilns, named after the direction of heat movement. The updraft ones or Scotch have flues running through the floor of the kiln with spaces between the stacks of bricks to allow heat to circulate, while the top is covered for insulating the kiln. The downdraft ones are circular with the flue running from the floor to the chimney stack. The hot air is then directed downwards from the dome through the stacks of bricks.
Continuous Kilns
Continuous Kilns can be based either on the principle of moving fire or on moving ware. The Hoffman, BTK and Zig-zag work on the principle of moving fire. In the Tunnel and VSBK, the firing zone remains constant while the bricks move.
Hoffman’s kilns are continuous domed kilns invented in Germany. They have a permanent arched masonry and tall chimney. The circular arched tunnel surrounding the chimney has various chambers where green bricks are placed and the fuel is added via vents in the roof.
The Bull Trench Kiln (BTK), which is very popular in the Indian sub
Brick Kilns can be classified as intermittent and continuous. Clamps, Scotch, Scove and Downdraft kilns are intermittent while the Bull Trench (BTK), Hoffman, Zig-zag, Tunnel and Vertical Shaft Brick Kilns (VSBK) are continuous. The continuous kilns are more efficient as they have heat recovery features from both the heat in fired bricks and flue gases unlike the intermittent ones.
Intermittent Kilns
The oldest kiln is the clamp.Invented in 4000 BCE, these are still very common in India. Clamps are temporary constructions made of green bricks or clinker. The clinker can be reused while the green bricks are sold. A slight variation is the Scove with a pile of dried bricks with tunnels at the bottom allowing heat from fires to pass through and upward in the pile of bricks. It is plastered with mud (scoved) to insulate it. Certain brick makers use permanent clamps made of refractory bricks. Two basic variations of kilns are the updraft and the downdraft kilns, named after the direction of heat movement. The updraft ones or Scotch have flues running through the floor of the kiln with spaces between the stacks of bricks to allow heat to circulate, while the top is covered for insulating the kiln. The downdraft ones are circular with the flue running from the floor to the chimney stack. The hot air is then directed downwards from the dome through the stacks of bricks.
Continuous Kilns
Continuous Kilns can be based either on the principle of moving fire or on moving ware. The Hoffman, BTK and Zig-zag work on the principle of moving fire. In the Tunnel and VSBK, the firing zone remains constant while the bricks move.
Hoffman’s kilns are continuous domed kilns invented in Germany. They have a permanent arched masonry and tall chimney. The circular arched tunnel surrounding the chimney has various chambers where green bricks are placed and the fuel is added via vents in the roof.
The Bull Trench Kiln (BTK), which is very popular in the Indian sub