Download Process Flow Chart - Fluid-O

Fluid-O-Matic
Battery Assembly Plant
B-24, Sector-60, Noida (U.P.) India
[email protected]
www.fluidomatic.net
Mobile No. 9811222014, 9873334982- 81
Lead Sub Oxide Process Chart
Air Out
(Ball Mill Process)
CYCLONE
VENCHURI SCRUBBER
Air In
LEAD
BULLION
INGOTS
LEAD REFINING KETTLE
Air In
Air Out
LEAD BALLS
CASTING
MACHINE
BALL MILL
Fluid-O-Matic
Battery Assembly Plant
CYCLONE
VENCHURI SCRUBBER
BAG HOUSE
To Pasting Section / Battery Manufacturer / Dispatch
LEAD SUBOXIDE
Lead Sub Oxide Process Chart
(Barton Pot Process)
Air Out
LEAD BULLION
INGOTS
Air In
LEAD REFINING
KETTLE
VENCHURI
SCRUBBER
CYCLONE
Fluid-O-Matic
BARTON POT
VENCHURI
SCRUBBER
Battery Assembly Plant
CYCLONE
BAG HOUSE
To Pasting Section / Battery Manufacturer / Dispatch
LEAD SUBOXIDE
LEAD ALLOY
INGOTS
Grid Casting Section
Air Out
VENCHURI
SCRUBBER
CYCLONE
MELTING POT
(455-480 C)
LADLE
Air In
Air In
COOLING WATER
To Pasting
Section
WATER TO
COOLING
TOWER
GRID
MOLD
Fluid-O-Matic
Battery Assembly Plant
AGED GRID PANEL
AGEING
CHAMBER
TRIMMING
DIES
GRID
PANEL
Small Part Casting Section
Air Out
LEAD ALLOY
INGOTS
VENCHURI
SCRUBBER
CYCLONE
MELTING POT
(455-480 C)
Battery Assembly Plant
Fluid-O-Matic
Air In
WATER TO
COOLING
TOWER
LADLE
SMALL
PART
MOLD
LEAD ROD MOLD
TRIMMING
OPERATION
LEAD ROD
COOLING WATER
SMALL
PART
To Cell Assembly Section
BATTERY PLATE MANUFACTURING
PLANT
Plate Section
(Flat Plate)
BARIUM
SULPHATE
AGED GRID PANEL
Lead Sub Oxide
CARBON
BLACK
SULPHURIC
ACID
DISTILLED
WATER
Fluid-O-Matic
Battery Assembly Plant
FIBER
(FLOCK)
PASTING
MIXER
PASTING
MACHINE
PLATE PARTING
& BRUSHING
MACHINE
POSITIVE
FLAT
PLATES
FLASH DRY
OVEN
PLATE
DRYING
CHAMBER
NEGATIVE
FLAT PLATES
CURING
CHAMBER
BATTERY PLATE MANUFACTURING
PLANT (MANUAL SYSTEM)
Plate Section
(Flat Plate)
BARIUM
SULPHATE
AGED GRID PANEL
Lead Sub Oxide
CARBON
BLACK
SULPHURIC
ACID
DISTILLED
WATER
Fluid-O-Matic
Battery Assembly Plant
FIBER
(FLOCK)
PASTING
MIXER
SEMI AUTO
PLATE PARTING
& BRUSHING
MACHINE
POSITIVE
FLAT
PLATES
MANUAL
PASTING
AIR
DRYING
PLATE
DRYING
CHAMBER
NEGATIVE
FLAT PLATES
CURING CHAMBER
MADE IN FACTORY
AS PER OUR
DRAWING
LEAD ALLOY
INGOTS
Lead Sub Oxide Section
LEAD
BULLION
INGOTS
Grid Casting Section
(Ball Mill Process)
CYCLONE
Air Out
Air Out
VENCHURI
SCRUBBER
VENCHURI
SCRUBBER
CYCLONE
MELTING POT
(455-480 C)
LADLE
VENCHURI
SCRUBBER
Flue Gas
Out
GRID
MOLD
WATER TO
COOLING
TOWER
COOLING
LEAD
REFINING
KETTLE
LEAD
BALLS
BALL
MILL
CYCLONE
WATER
BAG
HOUSE
AGEING
CHAMBER
Air In
GRID
PANEL
TRIMMING
DIES
Air In
BARIUM
SULPHATE
AGED GRID PANEL
BATTERY PLATE
MANUFACTURING PLANT
FIBER
(FLOCK)
CARBON
BLACK
SULPHURIC
ACID
DISTILLED
WATER
Fluid-O-Matic
Battery Assembly Plant
Lead Sub Oxide
PASTING
MACHINE
PASTING
MIXER
PLATE PARTING &
BRUSHING
MACHINE
POSITIVE
FLAT
PLATES
FLASH DRY
OVEN
PLATE DRYING
CHAMBER
NEGATIVE
FLAT
PLATES
CURING
CHAMBER
Plate Section
(Flat Plate)
BATTERY
ASSEMBLY
PLANT
CONTAINER
LID
POSITIVE
FLAT
PLATES
NEGATIVE
FLAT
PLATES
GROUP WORK TABLE
SMALL
PART
PLATE
PLACEMENT
IN TOOLS
LPG TORCH
CONNECTION
BURNING
PROCESS
BATTERY
CONTAINER
LEAD
ROD
GROUP
DETACHMENT
FROM TOOLS
CELL
FORMATION
CONTAINER PUNCHING
MACHINE WITH
PUNCHING DIE
CELLS INSERTION
IN BATTERY
CONTAINER
SECTION
BATTERYCELLS
CELLASSEMBLY
ASSEMBLY
SECTION
HEAT SEALING
MACHINE
STRESS TESTING
MACHINE
POLE WELDING
STATION
LEAKAGE TESTING
MACHINE
Fluid-O-Matic
Battery Assembly Plant
BATTERY WASHING
& DRYING
MACHINE
INTER CELL
WELDING
MACHINE
HIGH VOLTAGE SHORT
CIRCUIT TESTING
MACHINE
FOIL SEALING
MACHINE
CODE PRINTING
MACHINE
BATTERY HEAT SEALING SECTION
HIGH RATE
CHARGER &
DISCHARGER
ACID
LEVELLING
MACHINE
BATTERY
CHARGING
SYSTEM
ACID
FILLING
MACHINE
LABORATORY
BATTERY FORMATION SECTION
CAPACITY TESTING
MACHINE (RANDOM)
LIFE CYCLE TESTER
(RANDOM)
UNIQUE BAR
CODING
MACHINE
SHRINK
WRAPPING
MACHINE
CORRUGATED
BOX PACKING
BATTERY PACKING & DISPATCH SECTION
DISPATCH
SMALL
PART
POSITIVE
FLAT PLATES
NEGATIVE
FLAT PLATES
LEAD ROD
BATTERY
CONTAINER
CONTAINER PUNCHING
MACHINE WITH
PUNCHING DIE
LPG TORCH
CONNECTION
Fluid-O-Matic
Battery Assembly Plant
GROUP
WORK TABLE
BURNING
PROCESS
PLATE
PLACEMENT
IN TOOLS
CELL
FORMATION
GROUP
DETACHMENT
FROM TOOLS
BATTERY CELL ASSEMBLY SECTION
CELLS
INSERTION IN
BATTERY
CONTAINER
TO
ASSEMBLY
SECTION
CONTAINER
LID
Fluid-O-Matic
FROM BATTERY CELL
Battery Assembly Plant
ASSEMBLY SECTION
HEAT SEALING
MACHINE
INTER CELL
WELDING
MACHINE
HIGH VOLTAGE
SHORT CIRCUIT
TESTING
MACHINE
STRESS
TESTING
MACHINE
POLE WELDING
STATION
FOIL SEALING
MACHINE
LEAKAGE TESTING
MACHINE
CODE PRINTING
MACHINE
BATTERY HEAT SEALING SECTION
TO FORMATION SECTION /DISPATCH
(IF DONE AT DISTRIBUTOR END)
FROM BATTERY HEAT SEALING SECTION
Fluid-O-Matic
Battery Assembly Plant
ACID FILLING
MACHINE
ACID LEVELLING
MACHINE
BATTERY WASHING &
DRYING MACHINE
HIGH RATE
CHARGER &
DISCHARGER
BATTERY
CHARGING
SYSTEM
BATTERY FORMATION SECTION
TO BATTERY PACKING & DISPATCH SECTION
TO ELECTRICAL LABORATORY FOR RANDOM TESTING
FROM BATTERY
FORMATION SECTION
Fluid-O-Matic
Battery Assembly Plant
UNIQUE BAR
CODING
MACHINE
CORRUGATED
BOX PACKING
SHRINK
WRAPPING
MACHINE
DISPATCH
ELECTRICAL
LABORATORY
BATTERY PACKING &
DISPATCH SECTION
CAPACITY TESTING MACHINE
(RANDOM)
TO BATTERY DEALER
LIFE CYCLE TESTER (RANDOM)
LEAD BULLION INGOTS
LEAD REFINING KETTLE
Details of Refining Kettle or
Refining Pot
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Refining Pot or Refining Kettle
This is also called Kettle Furnace.
This assembly comprises of mainly two parts:
1. A cylindrical pot or hemispherical Pot
which is indirectly heated by Fire/ Flame. This is insulated by
refractory Bricks and Insulation Bricks. So Heat is transmitted from
the outer surface of pot to the metal ingots or metal pieces or molten
metal which are inside.
2. Stirrer is a device which can cause
unrest, here, it is driven by electrical power. Stirrer does two job,
first, it assist in transmission of heat from bottom to top
homogeneously, Secondly it implies centrifugal force to the metal. In
metal propeller type Stirrers are used.
These stirrers produce axial primary flow with a radial
component and are particularly suitable for homogenization and
suspension. They are also suitable for general stirring duties with
simultaneous heat transfer (heating or cooling) between the liquid
being stirred and the vessel wall. They can also be used for dispersion
and emulsification.
Standard Refining Kettle consists of following:
It Consistes of following:
1. Shell with Material Pouring Valve.
2. Single Stirer with triplex Blades.
3. Driven Pulley
4. Drive Motor with Pulley
5. Suitable V- Belts
6. Mounting Stand for Stirrer
7. V-Belt Tension Adjustment Systems
8. V-Belt Guard
Lead Refining Kettle with
pollution Control Unit
PROCESS OF LEAD REFINING
Principle of Metal Refining or
Principal of Lead Bullion Refining
Cut view of Lead Refining Kettle
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All impurities which are mixed with Lead Bullion those are Converted to their
Oxides or Sulphates and then Separated mechanically.
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In process of mechanical Separation these impurities are lift to the top layer due
to specific Gravity Difference, From top these impurities are Separated / lifted
mechanically . to accelerate the lifting Process Stirrer adds Centrifugal Force to the
Molten Liquid. More the Separation is done more purity will be Achieved.
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Refining Process of Lead in Detail:
Removal of Impurities from Lead Bullion:
a. Removal of Copper : Copper is the first of the impurities to be removed. The lead bullion is melted at about 300–600
°C and held just above its melting-point so Copper starts Solidifying ( Due to Copper Melting Temperature being
1080 C) when solid copper rises to the surface and is skimmed off. Then Sulphur is mixed with the Molten Lead
and Stirred. Sulfur is stirred into the melt to facilitate the operation by producing a dry powdery dross of Copper
Sulphate which is more readily removed. Once copper has been removed, there are a number of processes available
for the extraction of the other impurities from the bullion. These include, in which elements are removed one or
more at a time in several stages.
b. Removal of antimony, arsenic and tin: After the removal of copper, the next step is to remove antimony, arsenic and
tin.
There are two methods available — the softening process (so-called since these elements are standard hardeners for
lead) and the Harris process. In the softening process, the lead bullion is melted and agitated with an air blast,
causing preferential oxidation of the impurities which are then skimmed off as a molten slag. In the Harris process,
the molten bullion is stirred with a flux of molten sodium hydroxide and sodium nitrate or another suitable oxidizing
agent. The oxidized impurities are suspended in the alkali flux in the form of sodium antimonate, arsenate and
stannate, and any zinc is removed in the form of zinc oxide.
c. Removal of silver, gold & Bismuth
After the removal of antimony, arsenic and tin, the softened lead may still contain silver and gold, and bismuth. The
removal of the precious metals by the Parkinson’s process is based on the fact that they are more soluble in zinc
than in lead. In this process, the lead is melted and mixed with zinc at 480 °C. The temperature of the melt is
gradually lowered to below 419.5 °C, at which point the zinc (now containing nearly all the silver and gold) begins to
solidify as a crust on the surface of the lead and can be skimmed off.
An alternative procedure, the Port Pirie process, used at the Port Pirie refinery in Australia, is based on similar
metallurgical principles.
d. Removal of zinc
The removal of the precious metals leaves zinc as the main contaminant of the lead. It is removed either by oxidation
with gaseous chlorine or by vacuum distillation. The latter process involves melting the lead in a large kettle covered
with a water-cooled lid under vacuum. The zinc distils from the lead under the combined influence of temperature
and reduced pressure and condenses on the underside of the cold lid.
LEAD BALLS CASTING MACHINE
• Lead Ball Casting Machine is used
after Refining Kettle:
• Metal from Rotary Valve flows to
Tundish and tundish guides metal
to funnel of Ball casting Machine.
In Ball casting Machine, Lead is
poured from funnel to Ball
Moulds. Mould Plate rotates and
ball gets cooled. By the time,
Mould Plate approaches to
ejection point, Ejector Pin ejects
Ball and it is directed by a guide to
ejection Tray. From their it drops
to ground. Container or Container
trolley may be placed underneath
the Ejection tray so these balls are
collected into Tray.
• These Balls are used in Lead Oxide
Mill to manufacture Lead Oxide
Introduction of Lead Oxide Process
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The quality of the electrodes, Battery Plates that will produce the necessary electrical
performance in the battery will depend on the properties of lead oxide.
During the oxide manufacturing process, various properties of the oxide are carefully monitored
to ensure that they comply within predetermined specifications.
These specifications include particle size, density, reactivity, surface area and free lead.
Electrical current flows on the surface, so our objective is to have maximum surface area
compacted into smallest volume, means smallest average particle size with the consistency with a
high surface area of particle. More surface will react better with Sulphuric acid and give storage of
power.
There are mainly two process in Battery industry by which Lead Oxide is produced.
A. Ball Mill Process
B. Barton Pot Process
The Barton pot and Ball mill processes, both manufacture a lead oxide that differs in their
respective physical properties, and therefore also influence the characteristics of their final
application differently.
Lead oxide commonly used in Lead acid battery manufacturing process is also known as leady
oxide or Lead Sub-Oxide or Grey Oxide or Battery Oxide. It is a mixture of finely divided lead (freelead) and lead monoxide. Chemical formula is 2PbO.Pb.H2O
History of development of Equipment to produce Leady oxide:
Barton Pot process was developed by GEORGE VINCENT BARTON from England in 1898 and he
improved this process more and more by adding few more innovations to it.
Ball Mill Process was developed by Gonzo Shimadzu , from Kyoto, Japan in 1926. This is also
known as Shimadzu mill and used in many industry for grinding different media, i. Paint, Cement,
Different ores.
The differences between Ball Mill Process and Barton Pot are as follows:
Properties
Barton Pot Method
Ball Mill Method
Rounded
Flatter ( Flake shaped)
0.7
2.5
150-200
200-250
3-4
2-3
18%-26%
25%-35%
5-30 % β- PbO, Balance α- PbO
100% α- PbO
Makes Softer Paste which is easier to paste
Makes a Stiffer Paste which require careful
Control
Paste Curing
Average Curing Rate
Slightly faster Curing Rate
Batter Performance
( Lead Oxide Mixture Performance)
Lower Initial Capacity
Good Initial Capacity
Usually Good
Sometimes Good
Investment Considerations
Lower
Higher
Operating Cost
Lower
Higher
Noise Level
Lower
Higher
Maintenance Cost
Lower
Moderate
Control Parameters
Difficult
Easy
Particle Shape
Average BET Surface Area (m2/gm)
Acid Absorption No. ( mg H2So4/gm of PbO)
Average Particle Size (mm)
Free Lead (in %)
Oxide Crystal Structures (wt %)
Paste Mixing Characteristics
Deep Cycle Ability
Ball Mill Oxide Production Process
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Following steps are done for lead oxide production.
Lead is refined in Refining Kettle. 99.97% pure lead is used to manufacture lead oxide.
Then this lead is casted by Cylinder Casting Machine into shape of cylinders of lead, usually called Balls.
The solid balls of lead are fed into a rotating reactor vessel.
As the lead balls rub against each other, friction and impact causes the temperature to rise.
Air is introduced into the reactor vessel by creating a draft through the system by using an extractor fan (FD
Fan).
• The lead reacts with the oxygen in the air to form lead oxide. Fine lead oxide is carried away by the air flow to
classifier. Classifier classify heavier (coarser) particles from the fine and returned to reaction vessel.
• Alternatively this is achieved by screw conveyor which is mounted in the exit port of ball mill /
reaction vessel which return coarser particles to the ball mill, this restrict the flow and coarser
particle strike to the revolving screw and returned to ball mill and fine particles carried away by
the flow of air to Cyclone and subsequently to bag House.
• In Cyclone coarser particle drop to the bottom of cyclone due to swirling action created on
the particle.
• Bag House filters air and separate Lead oxide particles from air and drop to the bottom due
To pulse jet system. From Bottom Lead Oxide is collected by revolve valve or screw conveyor
mounted at bottom of bag house.
• Air is further treated by scrubber or venturi scrubber to eliminate lead emission to the
atmosphere. Hence saves our environment and get extra lead particle
which adds up to production.
• Since solid lead balls are added to the reactor vessel, this process
is often referred to as a low temperature process.
Lead Oxide Plant ( Ball Mill)
Capacity Available:
1. One ton/ Day
2. Two Ton /Day
3. Five Ton / Day
4. Six Ton/ Day
5. Ten Ton / Day
LEAD ALLOY INGOTS
Alloys used to cast Grids for Battery Plates
The choice of grid alloy compositions used in a battery directly impacts the grid and product design, the plate manufacturing and assembly
process, as well as long term product performance and reliability of the product. Manufacturability is a major issue, as the chosen alloy directly
impacts the physical strength and hardness of the grid for the ability to handle without distortion and breakage. Grid alloy selection also
influences grid corrosion and grid growth, which impacts battery performance and life via tensile strength, conductivity, and the degree of
positive active material adhesion to the plate grid.
Lead, as a malleable metal, is generally too soft to be used as a production grid material.
Antimony was first identified and used as a lead alloy. Antimony is used to strengthen and harden the lead grids for improved handling and
casting, as well as having good conductive properties. Now a Days, common concentration levels in batteries using lead antimony alloys are in
the 3-6% range.
The long-term impact of more antimony to the cell is an increase in the self-discharge rate of the battery, increased rates of electrolyte gassing,
over time, the cell requires increasingly higher levels of float current, so the rate of gas evolution and water loss accelerates as the battery ages.
lead calcium alloy composition, which addressed the maintenance issues while giving the lead grids good density, conductivity, and tensile
strength (comparable to the lead antimony alloys). It was found that by adding calcium to the lead, with the best results in concentrations of
0.065% - 0.09% (not to exceed 0.10%) , created a battery grid with some improved characteristics over the high antimony alloys.
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Benefit of Lead-Calcium Alloys:
Good grid density, conductivity, and tensile strength
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Reduced water consumption over the life of the battery
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Reduced electrolyte evolution and generation of hydrogen
gas
Better self-discharge characteristics (typically 0.5%/day at •
25C)
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Stable rate of under float charge over the life of the battery;•
consistent current draw
Selenium acts as stabilizer with antimony below 2%
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Benefit of Lead Selenium Alloys:
Good grid density, conductivity, and tensile strength
• Reduced water consumption and little antimony
migration
• Stability under float charge, consistent cell voltages
• No positive plate growth.
• Corrosion resistant and virtually eliminates intergranular corrosion
• Superior cycling and deep discharge performance
Battery Plate Grid Alloy Properties
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It is designed based on material property, electrical conductivity. These all input will depend upon use.
Whether it will be used as stand by Battery or automotive battery. Grid mesh is designed based on hold
active material, conduct current, casting ability and Mechanical Strength, Corrosion to contact material.
Different Lead alloys are used for different purpose of battery i.e. Antimony alloy, Selenium Lead Alloy,
Calcium Lead alloy, Calcium Aluminum Alloy etc.
Battery Plate Grid should hold Active Material
Hold active material means the grid should have the capacity to hold the pasted material. Otherwise during charging and discharging process it
will leave grid and active material will crack which will not be able to complete electrical circuit hence capacity of plates will drop and affect
performance of Battery.
Battery Plate Grid Conduct Current from different part of Plate
Grids work as a conductor in a cell. To get good conductivity, mesh density is kept high in lug side because Grid Wires are always connected
with grid lug and it gives path to current while charging and discharging through the Lugs. So, radial mesh is more preferable for grid design. It
also depends on grid thickness and active materials. If the thickness of grid is thin and grid has less active material then rectangular mesh
design is more preferable than radial mesh design.
Battery Plate Castability Characteristic
Melted lead is poured into mold of grid. It should have good flowabilty so it can flow uniformly from top to bottom most part with same rate.
There should be enough space for deposition otherwise it will have a cold joint. These joint will open during charging and shorten its service
life.
Strength of Battery Plate Grid
Strength is an important part of grid designing. There are two types of strengths, cycling strength and operational life strength. A grid that has
both types of strengths is considered proper for designing battery.
Cycling Strength of Battery Plate Grid
Cycling strength means the grid can perform repeatedly in the same cycle. Charging and discharging happen in a cycle in service life. As a part
of this, heat is produced and the grid is expanded. When the grid is cooled down, it is contracted. For this reason if this grid does not have
enough strength then the interconnection of the grid will be damaged. This will cause shorter service life.
Battery Plate Grid Operational Life Strength
In operational life, the grid should have the paste holding ability otherwise when the active material are pasted on the grid, it will not hold the
active materials and it could be bent when it put on the pasting machine. This strength is called operational life strength. It should have the
hanging capacity otherwise it cannot stay in skid. The grid should have the strength to align properly otherwise it could not assemble in a cell
properly.
TYPES OF BATTERY PLATE GRID
Main Requirement of Battery Plate Grids
Battery Plate Grids collects the electrical charge/ energy to & fro from lug of battery plate and in turn suffers a differing
level and type of corrosion to the negative grid. It is well known that by increasing the adhesion between the paste mixture
and the grid, formation efficiency can be improved. Among other things, Battery plate grid should be able to perform
following characteristics, increased adhesion between the grid and the paste, which provides for improved interfacial
contact between the grid and paste thereby improving current flow by reducing capacitance, electrical resistance and
increasing contact area between the grid and paste with mechanically bonding. Accordingly, certain efforts to improve
battery formation efficiency have focused on improving the adhesion between the battery grid and paste. It is also
recognized that improved adhesion between battery paste and the grid can increase the service cycle life of a battery.
Electrochemical action corrodes the grid surface and reduces the adhesion between the active material and the grid. In
most instances, failure of the battery occurs when the grids are no longer able to provide adequate structural support or
current flow due to the separation of the active material from the grid. Therefore, there have been efforts to improve the
service life of a lead-acid battery by increasing the adhesion of the grid material to the active paste material.
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Main types of Techniques used to manufacture Grids for Battery Plates:
Gravity Casting Method
Pressure Die Casting Method
Stamping of Grid from Lead Alloy Sheets
Stamping and Coining of Grids wires
Strip Expansion Process
How Battery Plate Paste Holds Battery Plate Grid or
Life of Battery Plate Grid
• When the battery paste is cured and dried, it will shrink and generate tensile
force at the paste/grid interface. The tensile force at the paste/grid wire
interface is at a maximum when the wire surface is perpendicular to the grid
surface and at a minimum when the wire surface is parallel to the grid
surface.
• As a result, a gap is formed between the grid wire and the paste at the
location where the tensile force is the maximum. This type of plate is weak
and the paste will fall off easily. Because of a lack of contact between the
paste and the grid, a battery made with this type of plate is much more
difficult to form, performs poorly in certain reserve capacity tests, and does
not exhibit satisfactory cycle life.
• A method that increases the formation efficiency of a battery by enhancing
the adhesion between the battery paste material and the battery grid, along
with a method that can modify the wires of a battery grid. so that the paste
can flow around the grid wires to improve the plate strength, will give an
ideal outcome for the total battery performance. It is an objective to provide
a method of making battery grids that allows a battery manufacturer to take
advantage of a low cost continuous grid making process without the
drawbacks associated with inadequate paste adhesion such as reduced
formation efficiency and reduced cycle life.
Description of Positive Plate construction types
Pasted Plates :
Pasted plates are flat, positive plates made by pasting the lead oxide active mass on a mesh grid.
Tubular Plates :
Tubular plates use a frame structure consisting of a series of vertical spines connected to a common bus bar. The tubular design keeps
the active material mechanically together and presses it onto the grid. The paste is held in microporous, non-conductive tubes
(gauntlets), which are placed over the individual spines. Assembling the spines, gauntlets, lead oxide, and end cap together makes a
positive plate. Volume changes during discharge and charge are mostly compensated by a high mass porosity, and gas bubbles help to
distribute remaining free particles in the cell. Pressing the PbO2 corrosion layer onto the grid surface also helps to protect the lead grid
against further corrosion. Figure 3 shows classic tubular plate
Characteristics
Flat Plates
Tubular Plates
Reliability
Average
Better Reliability
Charge Cycles ( at 80% DOD)
50-1000
1200- 2000
Electrolyte Stratification Risk
Average
Low
Float Current
Average
Low
Thermal Dissipation of Heat
Average
High
Interface Surface Area
Average
High
Electrical Resistance
Average
Low
Life Expectancy
Average
Better
Charge Retention
Average
Better
Main Uses
SLI Application or where
high current for short
duration required
Storage Application or
where low current for long
duration required
Manufacturing Process of
Battery Plate Grid
• Process of Manufacturing of grid
is simple if taken into broad
consideration. Molten Lead Alloy
is poured into Grid Mould and
when solidifies, take out and
shave it for extra pendants.
• Mainly grids are casted in pairs
for reduction in manufacturing
expanses for automotive
batteries, and multi grids are
casted for Motorcycle batteries
where as tubular Grids are
casted in single cavity.
• Grids Mould will vary depend
upon sizes, weight and
construction Configuration.
What are the
Gauntlet Characteristics
for Tubular Plates
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High porosity and low electrical resistance Low electrical resistance can determine a well-defined
pore size that permits easy movement to the electrolyte, but at the same time reduces the active
material shedding to a negligible amount
Good mechanical resistance and elasticity The gauntlet resists the high pressure that the active
material produces during its cyclical expansion. The fabric holds the paste pressed to the conductive
lead spines ensuring stable performance. Mechanical resistance to abrasion during cell assembly
reduces scraps and pollution
Reduced release speed of antimony The fabric keeping the active material all around the spines acts
as a filter for the electrolyte, reducing the release speed of antimony from positive grids. In contrast,
for pasted plates there is almost no distance between grid wires and electrolyte
Semi-rigid stability The semi-rigid woven fabric gives the multitube bag a stable shape that permits
an easy and quick filling procedure with paste, powder or slurry methods
High short-circuit resistance
Why Tubular Plate is better for Stationary applications i.e. Solar Battery, Inverter Battery, E-Rickshaw
Batteries, Fork- Lift Batteries etc.
Also, due to increased positive plate surface area, tubular batteries have up to 20% more electrical capacity
than flat plate batteries of comparable size and weight. Tubular plates deliver energy faster due to:
Compact structure
Increased mass and surface area of the active material
Ease with which acid circulates around the tubular plate design
With less positive plate shedding, tubular batteries also provide up to a 30% longer service life than flat
plate batteries.
What is Battery Plate
Battery Plates have two main Parts :
Lead Grid and Lead Paste (Active Material)
Battery Plate Grid Casting Process in brief
Battery Plate Grid
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Plate Grid : It is designed based on
material property, electrical
conductivity etc. These all input will
depend upon use. Whether it will be
used as stand by Battery or automotive
battery or Solar Battery or E-Rickshaw
Battery.
Grid mesh is designed based on hold
active material, conduct current,
casting ability and Mechanical Strength.
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The quality of cast grids depends on temp. during
casting and alloy composition and crystallisation
behavior of casting alloys. Book type of molds are used
to cast grids.
Variable are to be controlled in specific range. Variables
are
Temperature in Lead Pot.
Required Temperature in Different part of mold to
maintain flow ability of alloy.
Rate of Flow of Alloys into mold.
Battery Plate Mould is made of two parts and alloys are fed into mold either by gravity pressure or
by Pressure Casting Process. One shot gives two flat plate Battery Grid where as single Spine.
Grid is casted in single shot.
There are mainly two processes are used in Battery Industry and these are as follows:
Gravity Casting Process: Lead alloy is poured into mold by different means, either by hand or by
pump into ladle which pours alloy into mold. Mold is closed mechanically.
Spine Casting Process: Lead Alloy is pumped into mould under high pressure. Mold are Locked by
High Pressure Hydraulics.
Different mold required for different Size of Battery and Different Wt. Plates. Different types of
Castings.
Grid Casting Section
There are four types of Grid Casting Machines
• Manual Grid Casting Machine:
• This machine is best suited for Small Scale
Production of Battery Plates. Molten Lead Pot is
placed in the center and Two to three Operators
with different Machine surrounds that pot. They
take lead by spoon and pour into mould. When
that is cooled operator ejects Solidified grid
panel out of Grid mould.
• Normal Production of one operator is 600 grid
panel/ shift means 1200 Plate Grids.
• For each configuration of plate one Manual Grid
Casting with mould is required
• It is operated manually so no electrical power is
required.
• Four Machines can Make 50 Batteries / Shift (N100 Size)
Semiautomatic Grid Casting Machine
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(Only Cutting and Shaving by another Machine or manual)
This machine is best suited for small scale & medium scale battery
plate & battery manufacturers. This can be used for longer Industrial
negative grid where the grid mould is heavy & manual casting is not
possible. It is a simple machine, which consists of a main platen on
which the grid mould is mounted. Then platen will does cycle of Grid
mould opening / closing & grid ejection. Mould is closed
pneumatically and Control Panel controls cycle of mould. Watercooling System is employed to cool the mould so Lead Alloy solidifies
faster and mould temperature is maintained for better flow ability of
Alloy. It gives better production of Grid Panels. Gate portion of Grid
is cut manually.
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Different type of grid moulds could be mounted on this.
Lead pouring could be manual or by a pneumatic operated ladle.
Lead is generally poured either directly into the mould or into the
ladle from the furnace by the pump. Grid moulds are provided with
water cooling lines & cartridge heater brackets. Automatic Digital
Controller controls temperature of grid mould.
The machine is semi-automatic in nature. Only trimming is manual
operation.
Suitable for Antimonial & Selenium Alloys for any type of Grids.
Most suitable to cast Twin Tubular Spine Grids of size 165 mm spine
length x 145 mm width
Digital Temperature Controllers for better Monitoring & Control
Power : 415 V, 31 KW (Electrically Heated Furnace) / 12 KW (Diesel
or LPG heated Furnace)
Capacity : 4 to 5
Grid Panels Per Minute
Furnace : 800 Kg
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Two machines will be required to make 60 Batteries / Shift.
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Automatic Grid Casting Machine
The machine is fully automatic and can produce up to 10 trimmed grid panels per minute depending upon the
lead alloy and the grid design. This equipment is ideal for high volume production battery and battery plate
manufactures. The construction of machine is rugged and built for low maintenance. The grid mould
opening – cum closing cum grid ejection and pneumatically operated ladle tilting is. Grid aligning chute, gridtrimming device, grid-stacking mechanical cams operate all mechanism. Heating is by electrical resistance
heaters (Also given provision for additional heating by LPG at the gate of the ladle). The operations are
simple and easy.
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The machine is fully automatic and can produce up to 15 trimmed grid
The machine is Fully Automatic and Suitable for any Alloy.
Built in trim scrap conveyor
Trimmed Grids are stacked for easy removal
Digital Temperature Controllers for better Monitoring & Control
Casting Thickness 1.4 to 4 mm
Maximum Casting size including lugs – 350 x 150 mm
Power : 415V, 33KW (Electrically Heated Furnace) / 15KW (Diesel 4 lt/hr. or
LPG heated Furnace)
Capacity : 8 to 10 Grid Panels Per Minute
Pneumatic Air : 4CFM at 6Kg/Cm2
WATER : 10 Ltrs per min at 2kg/cm2 (recycled)
MANPOWER : 1
Capable to cast Selenium & Antimonial Alloy Grid.
The Machine consists of a main machine,
Grid Mould - 2 no,
Lead Melting Furnace with Lead Pump capacity 800Kg
Cooling Water Tank.
To manufacture 100 Batteries / Shift one machine will be required
ADDITIONAL MOULD FOR ABOVE MACHINE (If Required)
Mould is suitable to cast Grid to as per customer specification. The Mould is made High Grade
of C.I namely Meehanite patented Process, with complete, vent bars for easy venting, 3 line
water cooling provision, Mould moving bracket, Ejection mechanism and heater brackets
without heaters.
Spine Grid Casting Machine:
Spine Grids are casted by molten Lead injected into moulds at high Pressure and when cooled ejecting and Collecting these grids for
further process.
This hydraulically operated machine can cast quality spine grids of length 550 mm (max.) With an accompanying 800 kg lead melting
furnace, continuous casting can be done for volume production. Production Speed is 2-3 grids/ minute depending upon the spine length
and lead alloy. During casting, three cams actuated by cylinders apply pressure on the outer surface of the mould using a clamping plate to
obtain grids with minimal flash. Thermostatically controlled electrical resistance heaters heat the furnace and the spine mould.
Ceramic bricks to reduce heat loss line the Furnace. Operations are all manually controlled and all the operating levers are provided for
easy and comfortable operations. Digital temperature controllers are used in the control panel for better readability. Machine operations
are simple.
Construction and Function of Machine:
The machine is of made of rigid channel frame construction. Bottom Platen is fixed on the
frame rigidly. The top platen moves in horizontal as well as vertically. Eccentric Cams
clamp mould mechanically. The hydraulic cylinder drives mechanical Eccentric cams.
The mould is made of alloy steel of high grade. Hydraulic cylinder drives mould in and
out in between the bottom plate and the top clamping plate. Control Panel controls
the mould cycle. The ejection mechanism in the mould ejects the grid from the mould
to eliminate the sticking. Still grid is to be picked and placed manually.
This machine is also equipped with Hydraulic Power Pack with a maximum operating pressure
of 110 bar.. Hydraulic power pack supply power to all hydraulic cylinders of machine.
Hydraulic Power pack has Bladder type Accumulator which also reduce power
consumption of Machine. This Accumulator Gives extra Power during Lead Injection to
the mould.
PLC based electrical control circuit is used. Panel is housed in Separate Floor mounted
Enclosure.
Digital Temperature Controllers maintain mould Temperature with help of Cartridge Heaters
and cooling. Water.
Furnace capacity - 800 Kg.
Utility Requirement:
380 TO 440V, 3 Phase, 50 HZ - 26.5 KW
Cold water at 30 C
Man Power Required:
Main Operator One No. +4 Unskilled
80 Batteries / Shift
Battery Plate Grid Aging Chamber:
This Chamber is used store grid Panels at raised
temperature so Grid Panels are oxidized faster. This
oxidation of Grid panel gives better adhesion to the Paste.
These Chambers are tailor made. Both calcium and
antimony alloys are soft after casting and require some
time to harden. Hardening is achieved by stacking the cast
grids on pallets for about three days at room temperature
by common manufacturers. Hardening can be accelerated
with heat. Some battery manufacturers employ controlledtemperature heating chambers. At 150°C (302°F) the grids
can be aged in less than 24 hours. The shorter aging time
reduces manufacturer inventory of grids in process.
Battery Plate Paste Making Process
• A battery paste is a complex chemical mixture. Its composition depends
on the materials used and the nature of the mixing process. A freshly
made paste is not at equilibrium and is still undergoing chemical and
physical reactions. If not used immediately, it will become hard and
unworkable. Thus, in a battery plant, plate mixing and pasting processes
are usually coupled so that fresh paste is constantly delivered to the
pasting machine and used right away.
• The paste manufacturing process is very important as battery
performance and life is determined by the properties of the paste. The
way the paste is applied to the grid is also important to reduce the
variability in both the weight of paste in the grid and the thickness of the
pasted plate
• The paste formulas and properties are different for positive and negative
pastes, each reaching its optimum performance at different densities.
Main types of Flooded Lead Acid Batteries
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Wet batteries (flooded) are classed mainly in three macro categories according to the design and
manufacturing technology of the electrodes (positive and negative plates):
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Ordinary maintenance battery: both grids of the positive and negative plates are of Lead-Antimony alloy
(PbSb/PbSb) and the level of electrolyte inside the individual cells must be checked periodically and
topped up by adding distilled water only (never use acid) through the degassing caps / Vent Plugs on the
cover.
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Reduced Maintenance batteries, also called “Hybrid technology” batteries: the positive grid is of LeadAntimony alloy but with a low antimony content (PbSb), while the negative grid alloy is of Lead-Calcium
(PbCa). When overcharged, these batteries have a lower "water consumption" than ordinary batteries that
require maintenance, therefore the levels of electrolyte are only restored when necessary and in
particular working conditions (extreme working temperature, extended overcharge, etc.). Even in this case
only add distilled water (never acid) through the degassing caps on the cover.
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Maintenance free batteries (MF): the grids of the positive and negative plates of these batteries are
manufactured using lead alloys without antimony and can be of the Lead/Calcium/Tin (PbCaSn) or
Lead/Calcium/Tin/Silver (PbCaSnAg) type for the positive plate and Lead/Calcium (PbCa) for the negative
plate. These batteries consume little water during overloads, therefore in normal usage conditions they do
not need to be topped-up; they do not normally have visible caps and can be inspected directly.
Maintenance free batteries often have an additional component called “Magic Eye” which is normally
positioned on the cover near the third battery cell, and which gives an approximate indication on the
battery conditions:
Gel Batteries
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GEL batteries are made using one of the production technologies used to
make VRLA-type batteries.
The major difference between AGM batteries and GEL batteries is that in the GEL
Type, the electrolyte is not a liquid but is contained in a special silica gel in which
the plate group is immersed, while with AGM batteries the electrolyte is completely
absorbed by the special glass microfiber divider.
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GEL batteries are not normally used for starting applications in the automotive
sector because high working temperatures inside the vehicle motor area
significantly increase the volume of the gel, which causes repercussions on electrical
performance and battery life. On the other hand, very low temperatures cause the
GEL to concentrate inside the cell, which increases the internal resistance of the
battery; this has a negative effect on the cold start current (-18°C), which becomes
much lower than that of AGM or flooded batteries.
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GEL batteries are therefore more suitable for energy applications than for power
applications, and they are used in industrial applications where high resistance to
discharge and charge cycles and/or greater buffer mode life are required. They are
also used for powering on-board services in the nautical and free time
(Motorhomes) sectors as an alternative to AGM batteries.
VRLA AGM batteries
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VRLA (Valve Regulated Lead-Acid battery) type batteries with AGM (Absorbent Glass Mat) technology are Pbacid batteries where the positive grid is made of a PbCaSn alloy and the negative grid is made of PbCa; they
are the only batteries that are completely maintenance free.
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The main characteristic that distinguishes a VRLA AGM battery from a traditional flooded battery is the
technology used to recombine the gases.
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With a traditional flooded lead battery, during the charge phase the two gases in water, namely hydrogen and
oxygen, separate. These two gases exit from the caps on the lid and the level of electrolyte inside the battery
consequently reduces.
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With VRLA AGM batteries, the acid is contained in a special microporous separator made of glass
microfiber(Absorbent Glass Mat) that is impregnated with a controlled quantity of electrolyte during the
production phase. During the recharge phase, the oxygen that is released by the positive plate because of
water dissociation can migrate towards the negative plate, to which it fixes. It then combines with the
hydrogen, which recovers the water that had dissociated.
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A closed electrochemical cycle is created in this way, which initially and during normal use does not emit gas
externally and/or does not consume water.
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Safety Valve for VRLA Batteries: If the battery is overcharged and a large quantity of gas develops inside it, the
excess is released by a safety valve, positioned inside the cover of each cell, that opens. This valve is designed
to open at a pressure of about 0.2 bar in new batteries, but in normal working conditions it is closed because
it must stop air from entering the battery (the oxygen would discharge the negative plate). This is why these
batteries are called VRLA (Valve Regulated Lead-Acid Batteries) with AGM (Absorbent Glass Mat) technology.
Expiry of Lead Acid Battery or
End of Life of Lead Acid Battery
How the end of battery life takes
place
Life of Lead Acid Battery
depends upon following Factors
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Lead Acid
When a lead acid battery is fully or partially
discharged, lead sulphate forms at the electrodes. If
the battery is allowed to remain for a prolonged
period in a discharged state or with a very low state
of charge the lead sulphate may form into large
crystals which are very difficult to convert back into
lead and sulphuric acid by the charging process. The
formation of these crystals is called sulphation and
causes a permanent loss of capacity of the battery.
To avoid this problem lead acid batteries should
therefore only be stored in a fully charged condition
and the charge should be topped up from time to
time during storage to compensate for the self
discharge of the cells.
To prolong shelf life without charging, the batteries
should be stored at 10°C or less but the electrolyte
should not be allowed to freeze. When the battery
is fully charged the electrolyte is sulphuric acid
solution and the freezing point is -36°C but it rises
to 0°C in the fully discharged state when the
electrolyte is simply water.
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Battery Cycle Life is defined as the number of
complete charge - discharge cycles a battery can
perform before its nominal capacity falls below 80%
of its initial rated capacity.
Key factors affecting cycle life are:
Temperature
Pressure
Depth of Discharge
Charging Rate
Discharging Rate
Memory Effect
Charging Voltage
Expansion and Corresion of Positive Grid
Under Charging
Cell Short or failure of Separator
Interconnection