Training Design of Vertical Roller Mill Polysius Headquarter

Training Design of Vertical Roller Mill Polysius Headquarters Germany Raw material preparation Roller mill RM 6629555 – THALOFA Roller mill RM 6629555 – BAZIFA Schematic movement of material on the grinding table Doublegroove grinding system Roller mill feed shute with preseparation Mill housing Roller pairs

Design of Vertical Roller Mill

Training

Polysius Headquarters / Germany

19 May – 13 June 2008

Raw

material-preparation

Cement- production

Raw Material (Mixture) Raw Meal

THALOFA raw mixture

Hot gas Return air

Exhaust gas

Mixed gas before mill

Roller mill RM 66/29-555 – THALOFA

 High drying capacity

 Grinding, drying and separating in only one unit

 Compact arrangement

 Low energy requirement

 Proven wear protection

 Does not necessarily need

a proper mill building

Roller mill RM 66/29-555 – BAZIFA

 Tie rods & hydraulic system

 Mill main drive & auxiliary drive

 SEPOL Separator

 Water injection

 Roller pair dismounting device

Roller Mill Assemblies

Roller mill RM 66/29-555 – BAZIFA

Capacity: 500 t/h raw material

at 12% R 90µm

Initial moisture content: max 8.0%

External material circuit:

100% of nominal mill output

Mill fan sizing: 1,000,000 m³/h

90 mbar

required 3,762 kW

SEPOL separator 5,550 mm cage diameter

2,900 mm roller diameter with bypass lubrication system for roller bearings

6,850 mm grinding table diameter with quick changeable dam ring arrangement

Required 4,830 kW

Roller mill RM 66/29-555 – THALOFA

Schematic movement of material on the grinding table

table outside inside

Material bed

Movement of grinding roller

Feed Chute

with chute optimised

Feed Chute

Coarse Feed Valve Hot gas

Coarse Feed Valve

Basic data

Maximum moisture content 8 %Construction size 2.000 x 2.000 Diameter of the housing (internal) 2.000 mmLength of the valve (internal) 2.000 mm Overall height with base frame 2.800 mmRotational speed of the vane rotor 5.1 min-1

Total weight 16.200 kg

Heating with hot air requires the following indications

Minimum velocity of the hot air in the valve vmin 18 m/s Minimum hot air volume at Vmin 28.800 m³/h

Nominal width of the supply pipe 800 mm Minimum temperature of the hot air at the valve 200 C Maximum permissible temperature of the hot air 350 C

Coarse Feed Valve

Overload coupling

Type Syntex 50 TD1 Rotex GS48/50 Overload torque set when being

delivered 225 Nm

Wear inside the housing

Wear on top of the sealing strips

Scraper jammed

Coarse Feed Valve

Hot gas

Material

Heated feed chute Feed Chute

Feed Chute

Material flow Feed chute

20°C

259°C max 350°C

261°C Hot gas

Hot gas Material

Feed Chute

Mill housing

Mill doors Mill housing

Mill doors

Rubber sealMill housing

Mill housing

Adjustable nozzle ring

POSITIONS FOR THE NOZZLE RING

Adjustable nozzle ring

Adjustable nozzle ring

Hot gas chanel

Grinding table with grinding track

Nozzle ring

Cross-section with the highest

velocity

Adjustable nozzle

ring segment

Hot gas Adjustment

distance

Feed Chute

Mill housing

Roller pairs

Roller Pair

Roller Pair

Roller Pair

Basic data

Outside diameter of grinding rollers:

2.900 mm

Material of roller tyres:

wear resistant cast iron

Weight of one roller tyre: 16,2 t

Weight of one complete roller pair unit:

107,8 t Setting values for oil temperature:

Alarm 115 C Shutdown 125 C

Maximum wear, measured value „S2“

190 mm

Data for repair work

Dimension „Z“ for pre tensioning of the grinding roller bearings 0.1 mm

(Difference between the dimension „X” and the height of the intermediate ring, see 7.4 Repair)

Roller Pair

Item No relating to the roller pair unit

2.3 Spring type straight pin 25 Roller tyre

9 Inner bearing cover

10 Air chamber cover

11 Radial shaft seal 12.1 Hose pipe for radial shaft seal

Confining air system

PRoller Pair

Confining air systemRoller Pair

Confining air system

viewRoller Pair

Confining airRoller Pair

Confining air system

Roller Pair

Positive air pressure to avoid dust penetration

Oil circulation system

Roller Pair

Roller Pair

Oil circulation system

Filter contamination checked by Delta Pressure

Metal detector to separate particles

of the oil

Roller Pair

Recording of the wear

on the roller tyres

Roller Pair

Maximum wear on roller tyres

To prevent breakage of the roller tyres, the specified maximum limit values

„S2” = 190 mm must not be exceeded (see Section Technical data).

Roller Pair

Roller Pair

Recording of the wear on the roller tyres

Roller Pair

Force application to the roller pair units

Force application to the roller pair is determined by the position of the hooks relative to the roller unit axis Experience has shown that shifting the hooks influences the wear pattern on the roller path For this reason, the roller pair units are equipped with adjustable hooks

A wear-measuring inspection of the grinding elements forms the basis for the decision in which

direction to shift the hooks A shift towards the outside (+Y) is necessary when the inner roller path shows more advanced wear A shift towards the centre of the grinding table ( Y) is necessary when the outer roller path shows more advanced wear

The roller pair units are delivered with the hook mounted in „zero position (A)”.

When turning around the roller pair units to spread the wear uniformly over the roller tyres, definitely make sure that the hooks are in the same position relative to the roller unit axis (both in magnitude and direction) as before turning

NOTE

The tie rods are always suspended from the outer hooks (20).

Roller Pair

Force application to the roller pair units

• Roller Pairs are delivered with hooks in the zero position

• Wear inspection of the roller may indicate a need to reverse roller pair 180 degrees

position relative to the roller unit axis.

Permissible shifting of hooks

in +Y direction 100 mm

in Y direction 100 mm

Roller Pair Turning roller pair units around

Remove the roller pair units, turn them around through 180°

outside of the roller mill and re-install them into the roller mill.

When the roller pair units have been turned around,

definitely make sure that the hooks are in the same

position relative to the roller unit axis (both in magnitude

and direction) as before turning.

After installation of the roller pair units, the oil probes must be

re-calibrated and checked for proper functioning.

Roller Pair

Replacement of the roller tire

Lay the roller pair unit horizontally on its side Remove the nuts

from studs (26) and force off the clamping ring (27) by means of

the forcing screws The roller tire can now be lifted off If the

roller tire (25) has got stuck on the roller body (8) and cannot be

pulled off by means of customary fitting tools, the roller tire may

also be sprung off.

In this case proceed as follows:

 Locally heat up the roller tire (25) by means of a welding

torch,

 Then cool the heated areas with water (quenching).

Polysius personnel must be present at the first time.

25

No Work to be performed Frequency Remarks

1 Check oil level in the oil reservoirs for weekly

lubrication of the radial shaft seals

2 Check oil level in the oil circulation weekly

No Work to be performed Frequency Remarks

4 Take an oil sample of the grinding every 6 months check the oil for lubrication

roller lubrication system properties and soiling

5 Check the wear on the roller tyres (25) every 6 months during commissioning

Recording of the wear

6 Check the wear on the guide pins (21) every 3 months the permissible wear is

10 mm

Maintenance - Roller pair

Servicing

No Work to be performed Frequency Remarks

1 Retighten the studs (26) with the every 6 months if the roller tyres are new,

specified tightening torque after 30 to 50,after 250,

Damaged studs have to be replaced after 500 operating hours

2 Retighten the following bolted connections every 6 months at the first start-up and

with the specified tightening torque as per subsequently to every

table in section Repair repair after 30 to 50

- of hook (20) operating hours

- of guide pin (21)

- of outer bearing cover (13)

- of bearing cover plate (14)

- of confining air connection (22) to the roller carrier

3 Turn around roller pair units as required latest all 2 years see Repair

Maintenance - Roller pair

No Work to be performed Frequency Remarks

4 Shift hooks (20) as required see Repair

5 Replace roller tyres (25) as required see Repair

6 Replace guide pins (21)

or rehabilitate by build up welding as required

Maintenance - Roller pair

Fault Cause Rectification

Maintenance - Roller pair

Feed Chute

Mill housing

Roller pairs

Grinding table

Grinding Table

Technical Data:

• Outside Diameter 7.040 mm

• Height 2.500 mm

• Number of table liner segm 8

• Weight of table liners 53.800 kg

• Total weight of the Grinding table 214.800 kg

Grinding Table

6

7 7

8 8

10 10

11

1 Complete surface machined

2 Flatness of surface

3 Contact faces of clamping pieces machined

4 Dimensional check with template

5 Hollow spaces filled with insulation material

6 Sleeve centred

7 Sleeve material

8 Clamping piece secured against turning

9 Clamping piece reinforced

10 Expansion bolt with rolled thread

11 Expansion bolt with heat insulation

Grinding Table

Grinding table insulation

Dam ring heightener

Clamping piece

Lug Wedge element

Table liner segment

Table liner fastening

Grinding Table

Assembly of table liners

• Alignment of the table liner segments on the

grinding table

• Adjustment of equal gaps between segments

• At the inner radius, the table liner segments must be in contact with the limit stops

• The lugs must be in contact on the side which is opposite to the sense of rotation Gaps must be closed with packing plates

• The wedge elements must be ground until they have the right size depending on the toleranced casting dimensions

• The table liner fastenings must be tightened with the specified torque

• Assembly of grinding table insulation

Grinding Table

Adjustable Table Seal Grinding Table

Grinding Table Insulation

Grinding Table

- Dam Ring

- Discharge Ring

Grinding Table

Discharge Ring

Scraper elements

Wear plates

Grinding Table

Discharge Ring

Scraper elements

Grinding Table

Recording of wear on the grinding track

Checking and recording of wear on the

grinding track every 6 months

During the commissioning phase: every 3 months

Grinding Table

• Dam ring adjustment acc

No Work to be performed Frequency Remarks

1 Checking and recording of wear every 6 months During the

on the grinding track (2) commissioning phase:

every 3 months

Maintenance - Grinding table

Servicing

No Work to be performed Frequency Remarks

1 Retighten the expansion bolts (8.1) every 6 months When the table liners

with the specified tightening torque Are new, after 30 - 50,

Damaged expansion bolts have to be after 250, after 500

2 Retighten the following bolted connections every6 months At the first start-up and

with the specified tightening torque acc subsequently to every

to the drawing specification repair after 30 to 50

- of table body (1) with gear unit operating hours

of dam ring heightener (4)

- of cover (5.1)

3 Check the seals in the joints between the every 6 months If necessary, stuff with

table liner segments, dam ring and grinding sealing cord and then

cord

Maintenance - Grinding table

No Work to be performed Frequency Remarks

4 Adapt the dam ring heightener (4) to match as required

the wear progress of the grinding track

5 Replace worn out table liners (2) as required

Maintenance - Grinding table

Tie Rods and Hydraulic

Tie Rods and Hydraulic system

Description of functioning

The force required for grinding the feed material is generated by a hydraulic system.

Two hydraulic cylinders per roller pair ensure that the grinding force is evenly applied

to the rollers, while maintaining the maximum freedom of roller movement.

The hydraulic System permits infinite adjustment of the pressure in order to adapt

the grinding force to actual operating conditions.

When the mill is started up, the hydraulic pressure is lowered in order to reduce the

force applied to the grinding rollers This in turn reduces the starting torque.

Each hydraulic cylinder is connected to a piston accumulator which dampens the

shocks generated by the rollers running over the bed of material.

No Work to be performed Frequency Remarks

1 Check of the hydraulic system for leakage 1 x per shift

2 Check of the filter (25) for dirt 1 x per shift

3 Check of the oil level in the reservoir (1) 1 x per shift

4 Check of the pumps (7.1 and 7.2) for 1 x per shift

abnormal running noises

5 Check of the gas pressure in the piston weekly Depressurise the

accumulators at the pressure gauges of the oil side of thenitrogen filling units (40.1 to 40.4) piston accumulators

No Work to be performed Frequency Remarks

5 Oil sampling and check for ageing and every 26 weeks Max contamination

lubricity by the oil supplier acc to ISO 18/15,

NAS 1638 class 9

6 Functional check of the hydraulic system yearly

7 Maintenance work at the hydraulic According to

9 Recurring check of the piston accumulators in accordance Pressure vessel

by an expert according to the pressure with the national regulations § 10vessel regulations regulations or in accordance

with the nationalregulations

Maintenance - hydraulic tie rods

Fault Cause Rectification

Maintenance - hydraulic tie rods

Fault Cause Rectification

Maintenance - hydraulic tie rods

Fault Cause Rectification

Maintenance - hydraulic tie rods

Main Drive Unit

Main Drive Unit

Main Drive Unit

Location of

acceleration

sensors

1.0 Horizontal driving flange 1.1 Tilting pad thrust bearing

2.0 Coupling 3.0 Main motor 4.0 Overrunning clutch 5.0 Auxiliary gear unit 6.0 Auxiliary motor 7.0 Safeguard

8.0 Oil supply system 9.0 Vibration monitor 10.0 Gear unit bed plate

11.0 Base frame for the

main motor

Standard unit

Main Drive Unit

Technical data Main gear unit

Power output 4.550 kW Output speed 21,16 rpm Input speed 995 rpm Weight 95,2 t Total oil quantity 4.000 l (max 8.000 l) Oil Viscosity CLP OIL ISO VG 320

Main Drive Unit

Set points of the lubrication SystemLubrication oil pressure < 0,7 bar Mill stopOil temperature 60°C AlarmOil temperature 70°C Mill stop

Axial bearingsBearing temperature 70°C AlarmBearing temperature 75°C Mill stop

Lubrication high pressurePressure < 8,0 bar Alarm loaded conditionsPressure < 2,0 bar Alarm unloaded conditions

Filter contaminationDifferential pressure1,75 bar High pressure SystemDifferential pressure3,15 (4,5) bar Circulation System

Main Drive Unit

Separator SEPOL

Drive shaft Mill outlet gas duct Guide vane adjustment Guide vanes

Sepol housing Sepol rotor

Separator SEPOL

upper bearing arrangement guide vane ring

housing guide vanes

rotor

Separator SEPOL

Technical data

Type RMR 555

Diameter of the rotors 5.500 mm Direction of rotor rotation (top view) right Weight of the rotor 23.400 kg

Wear plates in the housing

Eye bolt

Size M 48 Bearing capacity 32.000 kg

Quantities of lubricants for initial filling

Upper bearing 4.500 g Lower bearing 3.000 g

Separating air

Flow rate 870.000 – 1.000.000 m3/h

Separator SEPOL