Process Outline
• Vendor Approval
• Order
• Testing On Receipt
• Storage & Issue for Use
Testing
Spectrophotometric Analysis for Composition And Impurities
Alloy Blending
Equipment
Alloy Blending Pots – Made In India
Procedure
Lead, Antimony & Other Alloying ingredients are blended in molten condition with the help of a stirrer.Temperature of the blend is monitored through out the blending process.
Testing
Optical Emission Spectrophotometry’ checks the composition of the alloy in the laboratory before use. The Spectrophotometer is procured from Spectro, Germany.
Oxide Manufacturing
Equipment
Ball Mill, Li – Shan, Taiwan & M-40 Mill, India
Process Layout
Small cylindrical lumps of Pure Lead is fed into the rotating mill shell. Air is blown over the lead lump surface. The frictional heat converts the lead surface of the lumps into Oxide.
Parameters
Percentage Oxidation, Apparent Density, Water Absorption characteristics.
Testing
The shell temperature, The load of the mill are continuously monitored to control the outgoing Oxide quality.
Grid Casting
Equipment
Grid Moulds & Casting M/c from WRITZ, USA.
Process
Grids are cast for manufacturing of negative plates. Antimonial lead made in house in the alloy blending process is used for the casting. Molten lead from alloy-blending pots is pumped into a ladle which pours the molten metal into the moulds. The mould surfaces are coated with cork.
Parameters
Mould temperature and the Ladle temperature are controlled in the casting process.
Testing
The weight of the casting is checked throughout the casting process. The castings are also inspected for physical features.
Paste Mixing
Equipment
Ox-Master, Simpson Mixer, India & Drums, India.
Process Outline
Lead oxide, expanders, water & sulphuric acid are mixed in the mixer to form a paste. The mixer has water & air-cooling arrangement for dissipating the heat generated during the mixing. The mix on completion is taken in trolley, inspected and used in the plate pasting operation.
Testing
The paste mix is checked for the density, moisture content &, temperature.
Pasting & Flash Drying
Equipment
• PASTING MACHINE - MAC, USA
• FLASH DRYING MACHINE - MAC, USA
• WEIGHING SCALES - INDIA
• MOISTURE BALANCE EQUIPMENT - INDIA
Process Outline
Grids are fed into the pasting machine by the feeder arrangement of the machine. The paste is added through the hopper.
Testing
The pasted plate are weighed and tested for moisture content on samples.
Plate Curing
Equipment
Curing Oven, India
Process Outline
The pasted negative plates immediately after pasting are kept inside the cubicle. The plates are kept for specified duration inside the cubicle and then outside in ambient condition.
Testing
The residual free lead in the plates is checked after completion of the curing period.
Spine Casting
Equipment
Machine & moulds from Hadi, Austria
Process Outline
Antimonial lead is used. Lead alloy is melted in a pot and then pumped up at high pressure in a finely machined mould. The spine is trimmed and threaded into the gauntlet.
Testing
The weight, trimmed height & physical features are checked.
Properties
High Pressure
Low Pressure
Gravity
(Vicker’s Micro Hardness, HV)
Uniform Micro Hardness Of 24.3 through out the sample
Non-Uniform Micro Hardness varying from 21.5 to 28.4
Low Micro Hardness, varying from 17.5 to 18.2
Grain Size
Coarse
Coarse & Fine
Inconsistent
Grain Orientation
Single Directional
Random
Random
Surface Condition
No Voids
Voids (Small Black Spots)
Bigger Voids Than Low Pressure
Scanning Electron Microscope Pictures
Oxide Filling
Equipment
Polypropylene tanks and furniture
Process Outline
Acid pickling of tubular Positive plates
Testing
The specific gravity of the acid is checked prior to putting the plates; the temperature is monitored throughout the process. The lead sulphate content in the plates is checked on samples.
Ammonia Dipping
Equipment
Plastic Tanks
Process Outline
• The oxide filled spines are dipped into aqueous solution of ammonium sulphate and stay for a minimum of one minute.
• The plates are brushed to remove oxide adhering to the outer surface of the filled plates.
Testing
The plates are checked for proper cleaning and Wetting.
Acid Pickling
Equipment
Polypropylene tanks and furniture
Process Outline
Acid pickling of tubular Positive plates
Testing
The specific gravity of the acid is checked prior to putting the plates; the temperature is monitored throughout the process. The lead sulphate content in the plates is checked on samples.
Process
• The +VE & -VE plates are put alternately inside the tanks in the furniture slots.
• The positive & negative plates in each tanks are connected in parallel. The plates are then immersed in sulphuric acid of specified gravity. DC power is fed to the circuits at a fixed rate for a specified duration. The tank voltages are checked at the end of the duration. The connections are then broken off and the plates are taken out, washed & dried. The specific gravity of the acid at start, the current in ampere and temperature are monitored throughout the formation process.
Testing
The specific gravity of the acid is checked prior to putting the plates; the temperature is monitored throughout the process. The lead sulphate content in the plates is checked on samples.
Plate Drying
Equipment
Drying Ovens
Process
The positive plates are dried in hot air oven at 65 Deg C. To a moisture content as specified. The negative plates are dried in inert gas oven.
Testing
The positive and negative plates are checked for their moisture content.
Lug Brushing
Equipment
ELECTRIC DRIVEN BRUSHING WHEELS.
Process Outline
• CLEANING OF FRAMES AND LUGS OF PLATES
• LUGS ARE CLEANED TO REMOVE THE OXIDE COATING.
• THE PLATES ARE CHECKED VISUALLY FOR DEFECTIVES.
Testing
PHYSICAL CHECK OF THE LUGS & THE FRAMES.
Components
Assembly
Equipment
• BURNING COMBS & JIGS, INDIA
• HEAT SEALING OF LID & CELL BOX
• BIELOMATIK MACHINE, GERMANY
Process
ASSEMBLY OF TRACTION CELLS
Components
• CELL BOX & LID - FROM PLASTAM, ITALY
• CELL BOX & LID - FROM INDIA
• PE SEPARATOR - FROM DARAMIC, AUSTRALIA
• LEAD PILLARS - FROM INDIA
Testing
THE CELLS ARE CHECKED ON LINE FOR SCREENING OUT DEFECTIVES.