Technology - Industrial
Lead Procurement
Process Outline:
- Vendor
- Approval Order
- Testing On Receipt
- Storage & Issue for Use
Testing:
Spectrophotometric Analysis for Composition And Impurities
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.
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.
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.
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 throughout 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.
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.
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
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.
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.
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.
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.
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.
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.
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.
Forming
Equipment:
Rectiformers, Polypropylene Tanks & Furniture
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.
