Belt Bucket Elevator Design 5i6940

By N.Saravanan, Grinding Technology Department, FLSmidth Pvt Ltd., Chennai.

Purpose of bucket elevators * Bucket elevators are used to lift bulk material from one are a reliable and well-proven piece of equipment. * Bucket elevators are an ideal solution for vertical

height to another. They

transportation of bulk materials.

* Bucket elevators operate by using an endless belt or chain on which rectangular buckets are mounted. This belt or chain revolves between a top and bottom pulley and the buckets move with it. * At the bottom, the buckets pick up product fed into the elevator boot and at the top the product is discharged as the bucket turns downward over head pulley. * Along with each type of elevator, different styles of buckets have been developed which better suit the elevator or the materials to be handled.

Types of bucket elevators Centrifugal discharge elevator (CE) : This is the most commonly used type with bucket mounted on belt or chain for handling of free flowing or small particle. Continuous discharge elevators (CO) :

This type pf elevators are used for handling large lumps and material that cannot be handled by centrifugal discharge. The slow speed and gentle method of loading & discharging is the main feature. Positive discharge elevators (PO) : This is similar to centrifugal type except the bucket are end mounted with two strands of chain. Bucket speed is slower and suitable for light, aerated, sticky materials.

BELT BUCKET ELEVATOR INTRODUCION Bucket elevator belts and conveyor belts have different requirements. 



For elevator service, you need to calculate the strength of the belt needed to the weight of the bucket and the material being conveyed. In addition, you need to calculate the strength needed to handle the available horsepower. This is easy to accomplish. Since the weight of the buckets is essentially the same on both sides of the leg, the weight of the material is the difference.

Standard Elevator Bucket Punching 

The type, size, weight, capacity, spacing, and projection of the buckets are critical factors in determining the correct belt for carrying the load and holding the buckets. The number, size and location of the bolts are also important.

Important advantages of belt bucket over chain bucket elevators * Lower wear and tear * Quiet operation * Higher specific conveying capacity * Lower power consumption * Most suitable for handling cement, raw meal, coal etc

TECHNICAL SPECIFICATION Equipment Material to be handled Bulk density Material Temperature Capacity (Design) C/C Distance Belt Belt strength Belt speed Bucket size

: Belt Bucket elevator : Raw meal : 0.8 to 0.9 T/M3 : Max. 120 0 C : 350 T/hr : 68.570 Mtrs : Steel Chord Belt 1050 mm width : 2000 kp/cm : 1.66 m/sec. : 900*335*5

TECHNICAL SPECIFICATION

Belt size Breaking Load Working load Belt strength Safety factor Bucket quantity Distance between two buckets Head and Tail pulley Dia Installed motor Casing size

: 1050 mm W * 141.50 M lg. : 185.800 KP : 15.500 KP : 2000 KP/CM : 12 : 306 : 460 mm : 1250 mm : 110 KW : 1310 W *2450 Box 780

TECHNICAL SPECIFICATION

BOLT SIZE

Torque

M 20 * 1.5

64 Nm/Bolt

M 24 * 2

1000 Nm/Bolt

M 30 * 2

2200 Nm/Bolt

DRIVES Auxiliary drive

: Geared motor- Greaves make GM 095, 5.5 KW, 56 output RPM with spiral Jaw coupling Make : MARK AEC

Safety Device

: Belt sway switch 220 V, 400 mA Electronic speed regulator

Painting

: 2 coats of primer after Sand blasting and 1 coat of final finish synthetic enamel paint by spray painting.

Material of construction Buckets

: 5 mm thick plate

– IS:2062

Head Casing

: 10 mm thick plate

- IS:2062

Boot Casing

: 16 mm thick plate

- IS:2062

Intermediate Casing : 5 mm thick plate

- IS:2062

SPARE PARTS LIST S.No

Item

Qty per assly

01

Buckets

306 Nos

02

Head shaft Bearing

2 Nos

03

Boot shaft Bearing

2 Nos

04

Belt

1 Length

05

Clamping device

1 Set

06

Bucket fixing bolt

2142 Nos

07

Tension Device Assly/ Bearing Bush

2 Nos

CONSTRUCTION DETAILS * Head casing * Lower head section * Head shaft assembly * Boot casing * Boot shaft assembly * special steel chord belt * Belt guide rollers * Buckets * Safety devices * Intermediate casing * Main drive ( Bevel Helical Gear box & Fluid coupling ) * Auxiliary drive * Maintenance platforms * Flanged inlet opening * Flanged dust collecting point at head casing

Erection The following * Storage at site * Safety * Preparation at site * Workmanship * Foundation checking * Guide frames erection * Fastening the side frame to the platform * Drive unit tied into elevator casing * Mounting of elevator belt * Mounting the buckets

Operational procedure The following check points should be reviewed before initial operation. * Head and boot shafts must be parallel to each other and pulleys in line * Casing plumb to within given tolerances * All bolts ing sections properly tightened * Reducer filled with oil to proper level * Correct motor rotation * Tighten all bucket moving bolts * All lateral s in place and secured * Bearing lubrication * Guards should be provided * Inspection door should be closed * Check for interlocking controls & safety controls

Initial operation Particular attention should be directed to the following * Loud or unusual noise * Excess vibration * Bearing overheating * Drive unit overheating

MAJOR COMPONENTS MAINTENANCE CHECK LIST S.No 01

Item

Check point

Frequency

DRIVE UNITS Motor Gear Box

Lubricants, Heatup Lubricants, Heatup

Coupling

Alignment & Tightness of bolts

Geared motor

Lubricants, Heatup

Level switch

Electrical function

As per Manufactures Manuals

MAJOR COMPONENTS MAINTENANCE CHECK LIST S.No 02

Item

Check point

Frequency

Head casing Baffle plate

Wear out Position/ Fit out condition

Pillow Block in Head Shaft Assembly

Grease in bearing

Monthly

Every 3 months

General cleaning & Every 2 years Check for worn out of parts & replace if Required. Shaft assembly

Check for worn out Every 2 months parts

MAJOR COMPONENTS MAINTENANCE CHECK LIST

S.No

Item

Check point

Frequency

03

Take up

Tension in screw rods

Every 3 months

04

Inspection hole at boot casing

Material Weekly once accumulation during break down Foreign material in feed.

MAJOR COMPONENTS MAINTENANCE CHECK LIST S.No

05

Item

STUFFING BOX

Check point

Inspection of packing for wear & tear

Frequency

Monthly

Tightness of glands screws 06

BELT & BUCKETS

Tightness of Bolts & Nuts on Buckets

First 100 hours of operation

Inspection of belt for damage Every 3 months Inspection of bolts & tightness & completeness Deformed and damaged buckets to be replaced

MAJOR COMPONENTS MAINTENANCE CHECK LIST S.No

Item

07

Clamping Device

Check point

Tightness of bolts with torque wrench

Frequency

After 50 hours of operation After another 2 weeks After another 6 weeks After another 3 months

LUBRICATION CHART S.No

Lubrication point

Lubricant Specification or make of lubricant Grease

Qty

Frequency

Method of application

Servogem 2 of Indian oil

20 Gms

800 hours/ By Grease as and when Gun/ By required hand

01

Antifriction bearings in Plummer block

02

Motor

Grease

Servogem 3

20 Gms

Every year 10000 running hours

Grease Gun

03

Gear box

Lubricati ng oil

Servomesh SP 320 of Indian oil

100 Ltrs

6 Months

By pouring through oil plug

04

Fluid coupling

Lubricati ng oil

05

Geared motor

Lubricati ng oil

As per Manufacture’s Manuals

Troubleshooting Please see the “ Troubleshooting.doc “ file for various troubleshooting methods. This file is given along with Belt bucket elevators presentation

OPERATION OF BELT BUCKET ELEVATORS

HEAD PULLEY & BOOT CAGE Head pulley

Boot cage

BELT BUCKET ELEVATOR’S DRIVE

INCHING DEVICE This is normally a low speed geared motor. It permits low speed drive for inching and turning of large size and high speed bucket elevators in case of maintenance, inspection and test run

Jaw clutch

BELT & BUCKETS

TENSIONING DEVICE

BELTS & BELT ING METHODS

Bucket on belt attachment

Various types of Buckets ts

BUCKET SIZE & PUNCH STYLE

BUCKET SIZE & PUNCH STYLE

BUCKET SIZE & PUNCH STYLE

BUCKET SIZE & PUNCH STYLE

Advantages of Fluidomat Fluid Couplings: 

Wear-free power transmission because of absence of mechanical connection between the input and output elements.



No-load start-up of motor irrespective of machine load. Motor peak torque utilized for machine acceleration.



Motor selection to operating HP rather than starting loads. Saving on energy cost and capital cost.



Simple control of maximum or limiting torque by easy variation of oil filling.



Added protection for motor and driven machine by limiting torque to a predetermined safe value.



Automatic unloading of prime mover in case of any sustained overload, by blowing-off of fusible plug on coupling, thus draining out oil.

Advantages of Fluidomat Fluid Couplings: * Automatic synchronization and load sharing in case of multi-motor drives * Effective dampening of shocks, load fluctuations and torsional vibrations. Helpful in improving the drive duty conditions in machines subjected to shock loads, frequent load changes, startups and reversals.

* Smooth and controlled acceleration of driven machines. Important for machines such as conveyors, wire drawing and textile machines. * Step less speed variation in wide range obtained in scoop type fluid couplings. * Continuous clutching and declutching of large drives obtained from SC type couplings. * Economy on machine and drive designs. * Energy saving