Hydraulics Operation_Coal_Mill.pdf

31-Oct-14 1Process and operation – LOESCHE Vertical Roller Mill - Type Coal and Raw material

COAL MILL HYDRAULICS, RAW MLL LUBRICATION

SYSTEM & SWING DEVICE OPERATION

Illustration

Hydraulic cabinet HSLM


Bladder accumulator

Main assembly groups

Hydraulic system HSLM : N2 accumulators

Illustration


Connecting pipeline to HSLM


Hydraulic system HSLM : ring pipeline



Hydraulic system HSLM - function

Illustration

The rollers crush the grinding material through their own

weight and additionally applied hydraulic pressing force.

The pressing force of the rollers on the grinding material is

generated by the hydro-pneumatic spring assembly system.

Coal mill:

A stop buffer on the rocker arm

prevents the tires from coming

into direct contact with the

grinding plates.



Hydraulic system HSLM - Spring stiffness

2

34

1

p1

A

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

20,0 40,0 60,0 80,0 100,0 120,0

p2

[bar]

[kN

/mm

]

0,0

000538

cw

f

Pressure bladder accumulator

Cwf Spring stiffness of the

roller

p1 Charging pressure of the

hydraulic accumulator

p2 Operating pressure

A Operating range

Spring s

tiffnes

p1max = 0.8 * p2min

p1min = 0.25 * p2max



Coal: Hydraulic system HSLM - function

• counter

pressure

• operating

pressure

• flow direction

Ball valve 5.4



Coal: Hydraulic system HSLM – hydraulic scheme

Position “0“ dead

Postion “I“ live

Position “I (a,b)“ live

* Temporary

Function table Pump

motorClosure device Solenoid control valves

Mill in operationStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Open Closed 0 0 0 0

7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Increase operating

pressureRunning

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Open Closed b 0 0 0

7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Reduce operating

pressureStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Open Closed 0 I 0 0

7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Raising rollersRunning

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Open Closed a 0 0 0

7.5

0

7.3

I*

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Keep rollers in

top positionStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10


7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Lowering rollersStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Open Closed 0 0 I 0

7.5

I

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Increase

counterpressureStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Open Closed 0 0 0 I

7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Reduce

counterpressureStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10


7.5

I

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Function table Pump


Partial flow

filterRunning

5.3 5.4 5.5 7.1 7.2 7.6 7.10


7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction

• partial flow filter







* Temporary

Service Pump


Nitrogen pressure

test in accumulatorStop

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Open Open Open 0 0 0 0

7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction







* Temporary

Service Pump


Keep rollers in

top position for

service

Stop

5.3 5.4 5.5 7.1 7.2 7.6 7.10

Closed Closed Closed 0 0 0 0

7.5

0

7.3

0

• counter

pressure

• operating

pressure

• flow direction


The roller lubrication system HSMS is an oil

circulating system and consists of:

Hydraulic cabinet HSMS

Connecting pipeline

LM lubrication line

The roller lubrication system HSMS serves to:

lubricate the rollers

Hydraulic cabinet HSMS


RM mill: Roller lubrication system HSMS – structure and function

Illustration


lubrication hydraulic cabinet

connecting pipeline from the

hydraulic cabinet to the roller

roller with bearings to be

lubricated


RM mill: Roller lubrication system HSMS - structure


the grinding rollers are lubricated by

the oil circulation system. The HSMS

hydraulic cabinet grinding roller

lubrication forms the oil supply

system.

ensures a stable oil level in the roller

and a continuous lubrication of the

roller bearings to keep the oil

temperature stable.


RM mill: Roller lubrication system HSMS - function



RM mill: Roller lubrication system HSMS - interlocks

Interlocks

a certain oil temperature in the tank is required to start the system

starting the lubrication pumps after 30 minutes grinding operation

stopping the pumps 1 hour after mill stop

(to avoid the overheating of the bearings)



Swinging device - structure

Illustration

Drawing

The swinging device consists of:

Hydraulic cylinder

HSAV pump unit



Swinging device – HSAV Pump unit

HSAV Pump unit

Illustration



Swinging device - function

1

2

4

A B

5

6

3

00054

0

1 Grinding roller, swung out 4 Hydraulic cabinet, HSAV

2 Hydraulic cylinder 5 Pedestal

3 Joint seating 6 Grinding roller, swung in

Illustration

The swinging device serves to:

swing out the rollers

Hydraulics Operation_Coal_Mill.pdf

Documents

Transcript of Hydraulics Operation_Coal_Mill.pdf