Draglines & Clamshell in Construction of Materials
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Transcript of Draglines & Clamshell in Construction of Materials
DRAGLINES(GẦU DÂY)
I. OPERATION & EMPLOYMENT
DRAGLINE IS A VERSATILE MACHINE
6MAIN COMPONENTS
DRAGLINE BUCKET
DRAGLINE BUCKET
EMPLOYMENT
DOES NOT HAVE THE POSITIVE DIGGING ACTION OR LATERAL CONTROL
EASY OCCUR SPILLAGE
DRAGLINE LOADING IS GREATER THAN EACH OTHERS
MAXIMUM BUCKET SIZE DEPENDS ON MACHINE POWER, BOOM LENGTH,
MATERIAL WEIGHT.
PRODUCTION ESTIMATING
USING TABLE TO ESTIMATE DRAGLINE PRODUCTION
TABLE 3.7:IDEAL OUTPUT
OF THE DRAGLINE
TABLE 3.8:OPTIMUM
DEPTH OF CUTFOR SHORT
BOOM
TABLE 3.9:SWING-DEPTH
FACTORFOR
DRAGLINE
EXPECTED PRODUCTION = IDEAL OUTPUT X SWING-DEPTH FACTOR X EFFICIENCY
EXAMPLE 3.4
JOB MANAGEMENT
MINIMUM SWING ANGLEMAXIMUM PRODUCTION IN
SHOVEL OPERATION
LIGHTEST BUCKET SHOULD BE USED
INCREASEING THE ALLOWABLE BUCKET SIZE
& REDUCE CYCLE TIME
JOB MANAGEMENT
-The most efficient digging area is located within 15 degree forward and back of a vertical line
CLAMSHELLS(MÁY ĐÀO GẦU NGOẠM)
CLAMSHELLS ARE
COMMONLY USED FOR
EXCAVATING VERTICAL
SHAFTS AND FOOTINGS
UNLOADING BULK
MATERIALS FROM RAIL CARS AND
SHIPSMOVING
BULK MATERIAL
FROM STOCKPILES
TO BINS,HOPPE
RS
OPERATION & EMPLOYMENT
2 bucket halves are forced
together by action of sheaves
Closing line is released
The counterweights cause the bucket
halves to open as the bucket is held by the
holding line
Bucket penetration depends on
bucket weight - Light
- Medium- Heavy
- With and with out teeth
ORANGE PEEL BUCKET
-ROCK PLACEMENT
-UNDER WATER
EXCAVATION
PRODUCTION ESTIMATINGUSE EQUATION 2-1
PRODUCTION = VOLUME PER CYCLE X CYCLES PER HOUR
EXAMPLE 3-5
SOLUTION OF EXAMPLE 3.5
JOB MANAGEMENT
• Continue operation
Have clamshell loading chart
• Limit load to 80% of the safe lifting capacity
• Limit to 90% for crawler-mounted equipment
Clamshell loading chart is
NOT avaiable
JOB MANAGEMENTTest maybe
necessary to determine the size
of bucket
Cycle time is reduced by
organizing the job
Keep the machine level to avoid
swinging uphill or downhill