MANUFACTURING OF BRICKS

BRICK MANUFACTURING Preparation of clay Moulding Drying Burning

BRICK MANUFACTURING PREPARATION OF CLAY Unsoiling Digging Cleaning Weathering - Mellowing Blending Tempering

TEMPERING – PUG MILL PUGGING – Plastic state

MOULDING Hand Moulding Steel or Wooden mould Mould size - larger Types Ground moulded bricks Table moulded bricks

A) GROUND MOULDED BRICKS Level the ground & sprinkle sand Place the mould 750 Bricks / day Slope moulded bricks or Sand moulded bricks FROG Pallet boards Bricks placed on Longer side

B) TABLE MOULDED BRICKS Table size – 2mx1m Mould, Water pots and Pallet boards Efficiency of moulder decreases Cost of moulding increases

MACHINE MOULDING Plastic clay machines Rectangular opening Cut into strips by wires Dry clay machines Strong clay to Powder form Plastic paste Pressed bricks

DRYING Laid Longitudinally in stacks Stacks has 8 to 10 tiers Placed on edge Up to 2%

DRYING Artificial drying – Tunnels or Hot flue gases 1200o 1 – 3 DAYS Circulation of air Drying Yard – Sand cover Period for drying – 3 to 10 days Screens

BURNING Imparts hardness & strength Overburnt – Brittle Underburnt – Soft Properly burnt – Durable Upto 650C At 1100C – Alumina + Silica Above 1100C - Vitrified

BURNING CLAMPS – Temporary structure KILNS – Permanent Structure

CLAMPS Trapezoidal Brick wall in mud Fuel – Grass, Cow dung Thickness 70cm to 80cm Total height – 3m to 4m Period – 1 to 2months

CLAMPS ADVANTAGES Burning & Cooling – Gradual Cheap & Economical No skilled labour required DISADVANTAGES Irregular shape Slow process Not possible to regulate fire Quality not uniform

KILNS INTERMITTENT KILNS Irregular process Rectangular or circular TYPES:- Intermittent Up-Draught kilns Intermittent Down-Draught kilns

INTERMITTENT UP-DRAUGHT KILNS Laying – Thickness – 2 to 3 bricks Height – 6 to 8 bricks Arch like opening Loading End doors – Dry bricks + Mud Fired Firing – 48 to 60 hours Draught rises upward Cooling – 7days Disadvantage – Not uniform

INTERMITTENT DOWN-DRAUGHT KILNS Rectangular or Circular Closed roof Floor of kiln – Chimney stack Hot gases move downward by chimney draught Evenly burnt Better than up-draught

CONTINUOUS KILNS Bull’s trench kiln Hoffman’s kiln Tunnel kiln

BULL’S TRENCH KILN Underground or partially projecting 1 – Loading 2 – empty 3 – Unloading 4 – Cooling 5 – Burning 6 – Pre Heating

HOFFMAN’S KILN Overground Each chamber – Main door Communicating door Radial flue Fuel holes to drop fuels Chamber 1 – Loading 2 to 5– heating 6 & 7 – Burning 8 to11 – cooling 12 - Unloading

ADVANTAGES Uniform burning Regulate heat Continuous process No air pollution

BRAIN TEASERS

You are a cyclist in a cross-country race You are a cyclist in a cross-country race. Just before the crossing finish line you overtake the person in second place! What place did you finish in?

In a year there are 12 months. 7 months have 31 days In a year there are 12 months. 7 months have 31 days. How many months have 28 days?

A plane crashes on the border of the U. S. and Canada A plane crashes on the border of the U.S. and Canada. Where do they bury the survivors?

Please add the following numbers in your head. Start with 1000 Please add the following numbers in your head. Start with 1000. Add 40 Add 1000 Add 30 Add 20 Add 10 Write down your answer. Many will get 5000. But the actual answer is 4100!

What are the next 3 letters in the following sequence What are the next 3 letters in the following sequence? J, F, M, A, M, J, J, A, __, __, __

You are in a room that has 3 switches and a closed door You are in a room that has 3 switches and a closed door. The switches control 3 light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

Jimmy's mother had 4 children. She named the first Monday Jimmy's mother had 4 children. She named the first Monday. Named the second Tuesday. The third is named Wednesday. What is the name of the fourth child?

Which is heavier? A pound of feathers, or a pound of rocks?

Your sock drawer contains 24 white socks and 30 black socks Your sock drawer contains 24 white socks and 30 black socks. The lights in your room are off, so you cannot see the color of the socks. How many socks must you grab to ensure to have at least one matching pair?

What can run but never walks, has a mouth but never speaks, has a head but never weeps, and has a bed but never sleeps?

What is full of holes but can still hold water?