Title: ISO 9001:2000 Registered
1ISO 90012000 Registered
INEFFICIENT SCREENING
Presentation 102, March 2006
Presentation 102, March 2006
2Screening is the process of sorting various sizes
of aggregate on a screen deck.
3If a screen was 100 efficient
100 of the aggregate would be sorted. However,
many things prevent this. Two of the worst are
blinding pegging.
4Blinding can reduce screen efficiency by 70
or more, effectively making an 8x20 screen
deck into a 4x12.
All metal self cleaning wire with a 3/8
opening and stainless steel wire in a sand
gravel application. Blinding after one 5-hour
shift.
Slotted wire in a limestone application. In
operation for just 2 hours.
5Pegging - Where the stone becomes wedged into
the screen cloth. Can have the same effect as
blinding and cause inefficient screening.
Slotted tempered wire in a sand gravel
wash plant. In operation for just three 8-hour
shifts.
Square opening stainless wire in a crushed
limestone application - 80 pegged after 4 hours.
6The Costs Of Inefficient Screening From Blinding
Or Pegging.
- Complicated Process Add-Ons
- Effects On Other Equipment
7Lost Production
- Lost production due to shutdowns to clean screens.
- Lost capacity due to blinding and reduction of
open area on the screen deck.
- Lost production due to inefficiency.
- Lost production due to product size material
circulating in closed-circuit loops.
8Poor Product Quality
- Cost to re-screen products.
- Inconsistent gradations cause asphalt/concrete
mix design problems.
- Products meet only lower grade requirements (low
selling price).
- Producer loses customer to competitors that can
maintain high product quality.
9Complicated Process Add-Ons
- Increased cost of operating and maintaining
additional screens to remove fines, clean
products, etc.
- Increased cost of washing products to meet spec
when they could be produced dry.
Additional equipment added to the screening
process to remove fines or clean products.
Additional cost maintenance of spray systems,
pumps, settling ponds, etc.
10Effects On Other Equipment
- Erratic crusher power draw increased
fuel/electric costs.
- Difficult to optimize crusher operation (manually
or by computer).
- Increased wear costs and poor wear patterns (cone
liners, impactor blow bars, etc.) due to high
re-circulating loads or from feeding fines to
secondary or tertiary crushers.
- Extreme inefficiencies can cause crusher
mechanical/structural problems.
Inefficiently screened fines being sent to
secondary cone crusher.
11Labor Costs
- Cost to clean and change out screens.
- Time spent cleaning shut-down screens could be
used for more important jobs like operating the
crushing plant!
12The real cost of inefficient screening for a 500
TPH stationary plant.
500 TPH x a 9-hour day 4,500 tons per day.
4,500 TPD x 5 days a week 22,500 tons per week.
22,500 TPW x 48 weeks per year 1,080,000 tons
per year.
Average price of material sold is 5.00 a ton.
Annual potential revenue if producer sells all of
his production (1,080,000 tons) _at_ 5.00 per ton
5,400,000.00
13The real cost of inefficient screening for a 500
TPH stationary plant.
- Each production interruption of one hour to clean
a screen results in a production loss of 500 tons
(potential revenue of 2,500).
- Two interruptions per week will result in the
loss of 1000 TPW or 4000 tons per month
(potential revenue of 20,000 per month).
- With 48 weeks of production, potential loss is
48,000 tons at 5 a ton.
- An amazing loss of 240,000 in potential revenue
from one inefficient screen!
Just to shut down his plant for 2 hours a week to
clean his screen cloth!
PLUS
14The real cost of inefficient screening for a 500
TPH stationary plant.
- Screen decks that are fully loaded and partially
blinded will result in a production loss equal to
the blinded of the screen deck. Just an average
percentage of blinding at 5 and production
capacity will decrease by 5.
- At 1,080,000 tons per year, a 5 reduction in
production capacity equals 54,000 tons.
- At 5 per ton, 54,000 tons represents a potential
revenue loss of 270,000.00 for the year.
Potential loss of revenue due to inefficient
screening
240,000
To shut his plant down for two hours a week to
clean screens.
270,000
Due to running a fully-loaded plant with a 5
average blinding.
510,000
15The real cost of inefficient screening for a
350 TPH portable crushing screening plant.
500,000-Ton Contract
350 TPH x 9-hour day 3,150 tons per day.
500,000 tons 3,150 TPD 159 working days.
Working 5 days a week the contract would take 31
weeks, 4 days to complete.
- If the operator has to shut down twice a week for
one hour to clean screens, it adds 64 hours to
the length of the contract a little over 7
working days.
- If the plant has just a 5 reduction in screening
efficiency due to blinding, it adds 8 days to the
length of the contract. Each extra day reduces
profit.
16500,000-Ton Contract
In total, 15 additional days to complete the
contract.
- 15 additional days of electric power or diesel
fuel consumption.
- 15 more days additional wear and tear on the
producers crushing plant, generators, loaders
trucks.
- 15 additional days of salary for his plant
operators.
- 15 less days that could be dedicated to a
different contract.
While difficult to measure, the cost to the
producer would be significant. Some producers
will know their exact per-day cost.
17Inefficient screening costs your customers
thousands of dollars each year.
18Flex-Mat 3 can
- Eliminate blinding pegging.
- Make screens more efficient by increasing open
area on each deck. - Increase plant production rates.
- Improve product quality by removing retained
fines (overs). - Reduce the cost per ton to produce aggregate
products.
19Why does Flex-Mat 3 work?
- Flex-Mat 3 is not a woven wire product.
- With no cross wires, Flex-Mat 3 is able to
vibrate. - Vibration allows the screen to shake off dust
mud or eject pegged stones. - The urethane cross strips, screen deck crown and
tension prevent Flex-Mat 3 from passing oversize
material.
20- What kind of results canyou expect from
Flex-Mat?
21Eliminated blinding while screening limestone in
Missouri.
- Customer was using 1/4 opening SS .092 square
opening woven wire on bottom deck. - Blinding reduced capacity, caused frequent plant
shut downs, made retained stone dirty. - Flex-Mat D SS .072 wire eliminated blinding
and increased plant capacity. - Shut downs were eliminated, material
specification improved as it was cleaner.
22Eliminated blinding while screening caliche in
Nevada.
- Customer had severe consistent blinding problem
screening caliche. - Plant was being shut down daily to clean screens.
- Flex-Mat D SS 3/16 opening with .054 wire was
installed as a test. - Photo shows woven wire and Flex-Mat 3 on same
screen deck after 6 weeks.
23Eliminated pegging while screening sand gravel
in Minnesota.
- Customers cloth was 5/64 by 5/16 slot with
.072 wire. - Pegging reduced screen plant capacity by 50.
- Screen cloth was thrown away before it had worn
out due to excessive pegging. - Flex-Mat 3 D with SS wire, 5/64 opening shown
1 week after installation.
24Eliminated heated decks while screening
limestone in Texas.
- Electric heated decks were used to eliminate
blinding. - Very high maintenance, required special screen
cloth clamp rails. - Was able to eliminate heated decks with no loss
of production. - Also increased screen life saved customer
thousands of .
25Eliminated specialized equipment in New York
Georgia.
- ? Customers had to use a wash plant to clean rock
for asphalt specifications. - Added expensive equipment, wet screens, pumps,
settling ponds, etc. - ?Increased labor and handling costs in Georgia,
had to truck material across plant re-screen.
26Eliminated specialized equipment in New York
Georgia.
- ?Both customers tried Flex-Mat 3 as a test.
- Both found that material now met specifications
without washing. - Substantial savings for both customers.
- Georgia customer saved 200 an hour in labor
alone. - ?Both were able to eliminate pumps. New York
plant eliminated settling ponds.
27Improved product quality for gravel
operation in Ontario.
- Wet, sticky fines blinded screens.
- Made it impossible to produce clean stone that
met required material specifications.
28Improved product quality for gravel
operation in Ontario.
- Asphalt stone with fines was now removed. Met
asphalt plants requirements for clean stone. - Plant production (TPH) went way up!
- ?As an added bonus, the producer could now make a
new sand product that he was never able to
produce and sell before!
29But your customer never has a blinding or
screening problem???
30Your customer never has a blinding or screening
problem.
- ?Flex-Mat 3 can still increase his production
rates, eliminate bottlenecks reduce his cost
per ton. - ?Flex-Mat 3 has 15 to 30 more open area than
equivalent square opening woven wire screen
cloth!
31Importance Of Screen Open Area
More holes
- Flex-Mat 3 can still increase his production
rates, eliminate bottlenecks and reduce his cost
per ton. - ?Flex-Mat 3 has 15 to 30 more open area than
equivalent square opening woven wire screen
cloth!
More chances for material to fall through!
32Importance Of Screen Open Area
- Open area is directly related to screen capacity.
- Every chance an undersized particle has of
contacting a screen opening increases the
probability of the particle passing through.
- A Flex-Mat 3 screen with 10 more open area than
woven wire will potentially have 10 more
capacity.
- Any blinding reduces screen capacity example
losing 10 of the screen openings due to blinding
or pegging decreases the screen capacity by 10.
33Relative Open Area Comparisons On A 6x20
Screen Box.
Flex-Mat 3 D or T Open Area
Polyurethane Open Area
Flex-Mat 3 S Open Area
Total Area Of Screen Box
Woven Wire 20 Blinded Open Area
Woven Wire Open Area
34Relative Open Area Comparisons
35Flex-Mat 3 Benefits
- ? If Flex-Mat 3 provides your customer with a
25 increase in open area over his standard woven
wire, it effectively converts his 6x16 screen
box into a 6x20 screen box. - Talk about eliminating screening bottlenecks!
36Stubborn As A Mule
- But your customer never has a blinding or
pegging problem and he never needs to increase
his capacity or tons per hour????
37Flex-Mat 3 can reduce the amount of dollars
spent on screen media.
- Flex-Mat 3 can provide 3 to 5 times the wear
life of traditional woven wire. - Our dealers have numerous customers who ran their
initial order of Flex-Mat for more than 2 years. -
- ?The initial higher investment will more than be
offset by the added wear life and labor costs
that would have been spent to change woven wire
screen cloth more frequently.
38Which Flex-Mat 3 To Specify?
39Flex-Mat D
- The most commonly sold Flex-Mat 3, 67 in 2005.
- ?Provides an accurate passing product to meet
gradation specifications. - ?Replaces square opening woven wire.
- ?Now available in openings of 3/64 up to 4.
40Flex-Mat S
- ?The second most commonly sold Flex-Mat 3,21
in 2005. - ? Use where you need to remove a large amount of
fines. - ? Use to replace slotted wire(not harp wire or
piano wire). - ? Retained material will be clean, quality
stone. - ? Passing material will have some oversize, but
less than long slot cloth. - ? Available in openings of 3/64 to 2.
41Flex-Mat T Heavy-Duty Applications
- ? Use in high-impact areas or where you have
heavy bed depth. - ? Rule of thumb 25 of material is 4 or 5
times the opening. - ? Straight wire is larger diameter and does not
stretch. - ? Do not sell just because customer asks for it,
or it looks like what the customer used
previously. - ? Available in openings of 5/16 to 2.
42Flex-Mat T Fine Screening
- ?Use for fine screening applications.
- ?Available in openings of .015 to 1/4.
43LFM
- Major Wires solution to a better Harp or piano
wire. - Longer wear life of 3 to 4 times longer no
moveable metal crossing. - Wire size can be customized to meet each
application, whereas producers are limited to two
sizes with Harp piano wire.
44- Flex-Mat 3, providing solutions to your
customers screening problems.
45