roll press presentation hydraulik

Hydraulic control ROLCOX of the rolls

1

Fixed Roller

Movable Roller

Left Right

Hydraulic oil tankPump HD 1 M 01

Next

HD1 V 3/4 Prop. valve right

HD1 V 1/2 Prop. valve left

HD1 V 08 Emergency valve

HD1 V 09Pressure decrease valve left

( one way valve )

HD1 V 10Pressure decrease valve right

( one way valve )

HD1 V 07 Retraction cylinder valve

HD1 M 01 Hydraulic pump

HD1 V 06 Bypass valve right

HD1 V 05 Bypass valve left

Left Right

Retraction cylinder

Fixed Roller

Retraction cylinder

Hydraulic oil tank

Movable Roller

Press cylinder

V 08

V 07

Pump HD 1 M 01

V 06V 05

V 09 V 10

2

Next

Next

Next

Next

Next

Next

Next

Next

Next

V 1/2 V 3/4

+ Bearing dist. = 0 mm

RP - Frame

Gap sensor Limit switch

Press cylinder

Fixed Bearing

3 Roller dist. = 10 mm fix

Gap = 10 mm

Movable Bearing

Next

Retraction cylinder

NextNextNextNext

measured by

Distance block

This is the point where the bearing distance is 0.For the gap measuring this point is 4 m Amp.The bearing blocks are fixed in a way that therollers can never touch each other physically

Fixed Roller

Movable Roller

Left Right

Distance pieces

Movble

Roller

Fixed Roller

Left Right

Distance between the bearings used as lowerlimit for the pressure control.If distance is less pressure control will bedeactivated.

Roller distance 10mm = Gap 10 mm

Roller distance 10 mm + Bearing dist. 15 mm = Gap 25 mm

Gap = 10 mm

Set points 4

0 mm ( Bearing distance )L 0mm

GAP > L min Pressure control ONnormal operation

L min 15 mm ( Bearing distance )

Next

Movable Roller

Next

Next

Next

GAP < L min Pressure control OFF

Next

Gap = 25 mm

L min

Movable

Roller

Fixed RollerLeft Right

Gap = 35 mm

Movable

Roller


Gap = 45 mm

L2Parameter set in the PLC. Set only once.Range from 5.0 to 30.0 mmActual set point 25 mm( Set point for material feeding )

Roller distance 10 mm

Set points

L min

+ L2 + 10 Bearing dist. 35 mm

5

Next

= Gap 35 mm+ L2 Bearing dist. 25 mm

Next

L2+ 10 mmUntil this value the rollers are pushed back during start up the main motors.

= Gap 45 mm

Roller distance 10 mm

Next

Next

Movable

Roller


Gap = 65 mm maximum

Roller distance 10 mm + Bearing dist. > 55 mm = Gap > 65 mm

Limit switchMaximum distance allowed between the bearings. ( 65 mm Gap )Determined by a mechanical switch.Over 65 mm gap the roller press willstop with max. gap alarm.

Set points6

Normal operation

Movable

Roller

Next

Next

Ok.

L2

L min

+ 10 mmMovable

Roller

Movable

Roller

Movble

Roller

V 09

V 07

Hydraulic oil tank

Pump HD 1 M 01

Press cylinder

After reaching of L2 + 10 mm, the main drives will be started one by one.

7Start RP group

At every start the emergency valve is energizedto close the hydraulic circuit.

The movable roller will be moved by the retraction cylinders to L2 + 10 mm = 45 mm

To release the oil of the main cylinders the bypass valves and the pressure decrease valves are energized (opened).This will occur with standing rollers.

Next

V 06V 06 V 07V 07

Next

NextNext

Next

V 08

Movable

Roller

Left

Fixed Roller Right

Gap = 45 mm

Next

Next

L min

L2+ 10 mm

V 11

V 3/4

V 10

V 1/2

V 09

V 06V 06 V 07V 07

V 3/4V 1/2

V 07V 07V 07V 06V 06V 06V 06V 05

V 10

Valve closedValve open

Next

V 08

Start RP group

Retraction cylinders are drawn back by springs.

After L2 will be reached in pre bin the shut off Gate will be openedto release material flow to the rollers.

8

Next

L2 Gap = 35 mm

In case if during moving back the movable roller an oil pressure is measured of more than 40 bar ( normal < 40 bar ), the start willbe interrupted by an alarm signal. Fault has to be acknowledged at the roller press after checking.

Possible causes: Material between the rollers.Disturbance in the hydraulic circuit. Roller can not move free.

After bearing distance is on both sides L2 the roller press group will be released and feeding of the pre bin can be started.

Next

Next

Movble

Roller

V 09

Hydraulic oil tank

Pump HD 1 M 01

Press cylinder

V 06V 06 V 07V 07V 08

Movable

Roller

Left

Fixed Roller Right

Gap = 45 mm

V 10

V 3/4V 1/2

V 07V 07V 07V 07V 06V 06V 06V 06

V 11

After this the movable roller will be pushed back to L2 by the main cylinders from 45 mm to 35 mm.This happens with running rollers.

V 07

Next

V 06V 05 V 07V 06

V 10V 09

V 1/2 V 3/4V 1/2 V 3/4

Gap = 35 mm

Pump stops and valves will be closed.

V 3/4V 1/2 V 3/4V 1/2

V 08

V 07

V 06V 05

Press cylinder

Left RightFixed Roller

The proportional valves will increase pressure to themain cylinders up until the set point.Hydraulic pump start.

9

Hydraulic oil tank

Pump HD 1 M 01

Next

Start Pressure controlAfter the start program is ready the pressure control will start automatically.

After opening of the shut off gate there will get material between the rollers.

Next

Movable Roller

Next

V 10V 09

Pressure controlBy the intake behaviour of the running rollerscombined with the pressure of the column ( gap )

of material on the rollers the material flow willtend to press the rollers apart.

Hydraulic oil tank

V 3/4V 1/2

V 07

Pump HD 1 M 01

V 08 V 06V 05

Left Right

Press cylinder

Movable Roller

Fixed Roller

When the hydraulic reaches the value set point-tolerance the proportional valves will be closed and the pump will stop.

10

Pres.Set point

At this value the material counter pressure and the cylinder pressure will be on balance.

- 10 bar

+ 10 bar

V 1/2 V 3/4

Next

Next

V 10V 09

AccumulatorGas ( N2 ) Pressure = 90 bar100 bar

135 bar125 bar115 bar

Set point 125 bar

Hydraulic oil tank

V 3/4V 1/2

V 07

Pump HD 1 M 01

V 08 V 06V 05


Press cylinder

Movable Roller

90bar

Start up< 90 bar

Pressure controlPressure variations with in tolerance will becompensated by the N2 accumulators.

11

V 1/2 V 3/4

100bar Next

125 bar

Next

V 10V 09

Note: This can happen at both sides at the same time but alsoon one of both sides, depending of pressure measurement onthis side.

V 3/4V 1/2

V 10

V 07

Hydraulic oil tank

Pump HT 1 M 01

V 08 V 06V 05


12

They will remain open until the set point operation pressure + tolerance is reached. After this the valves will be closed.

Pressure controlWhen the hydraulic exceeds the pressure (value) set point + tolerance the proportional valves will open and the pressure decrease valves will be opened (energized).


4 m Amp

Characteristics of proportional valves.

100 %

100%

12 m Amp0 %

Proportion valvepressure increase

20 m Amp

Proportion valvepressure decreaseSet point

30 %

30 %

8 m Amp

V 3/4

Next

Press cylinder

Movable Roller

Next

Next

V 11V 10V 09

Pressure controlWhen the hydraulic gets beneath the pressure (value)set point – tolerance the proportional valves will beopened and the pump will start.

V 3/4V 1/2

V 07

Hydraulic oil tank

Pump HD 1 M 01

V 08 V 06V 05

V 09 V 10


Press cylinder

Movable Roller

13

This will remain so until set point operation pressure – tolerancehas been reached. After this the valves will close again and pump will stopped.

In this example on one side.


Characteristics proportional valves.

100 %

100 %

12 m Amp0 %

4 m Amp

Proportion valvepressure increase

20 m Amp

Proportion valvepressure decrease

80 %

80 %

18,4 m Amp

V 3/4

Next

Next

Next

V 10V 09

A certain deviation is due to non homogenate mixture of raw materials (coarse, fine, wet, dry).

Gap (l) Gap (r)=

V 3/4V 1/2

V 07

Hydraulic oil tank

Pump HD 1 M 01

V 08 V 06V 05

V 09


Gap (r)Gap (l)

Gap(l) Gap(r) =- Gap(diff)

Gap(diff) > Gap(diff)toll.

Correction will be done first on the side with the biggergap by pressure increasing.

Correction is permitted until operation pressure + 5 bar.

14

If this value is exceeded the skewing will be corrected.

Gap correctionA deviation in gap width between left and rightin permitted until a preset value.

This will remain so until gap - difference - tolerancehas been reached. Set point 4 mm.

After this the valves will close again and pump will stop.

Presscilinder

Movble

RollerPresscilinder

Movble

RollerPress cylinder

Movable Roller

V 1/2

Next

Next

Next

V 10V 09

V 3/4V 1/2

V 09V 07

Hydraulic oil tank

Pump HD 1 M 01

V 08 V 06V 05

Movble

Roller

Gap (r)

RightFixed Roller

Left

Gap (l)

If skewing is after this correction still not withintolerance limits, at the side with the smallest gap,pressure will be released.

15Gap correction

This will remain so until gap - difference - tolerancehas been reached. Set point 4 mm.

After this the valves will close again.

PresscilinderPress cylinder

Movable Roller

V 3/4

Next

Next

V 11V 10V 09

V 1/2 V 3/4

After this correction pressure control will be reactivated.

If pressure difference between left and right exceeds apreset maximum ( 30 bar ) an alarm will be generated and pressure will be released at both sides.

Gap (diff) < Gap (diff)toll. ( 4 mm )

V 07

Hydraulic oil tank

Pump HD 1 M 01

V 08 V 06V 05

V 1/2 V 3/4


L(r)L(l)

Presscilinder

Movble

Roller

16

Gap correctionand Pressure Control

Press cylinder

Movable Roller

Next

Next

V 11V 10V 10V 09

Next

Current control

By means of to much adjusting of operation pressure or due to changing material properties the electrical load of the main drives can become to high. If this load exceeds a preset maximum the pressure willbe reduced.

V 07

Hydraulic oil tank

Pump HD 1 M 01

V 08 V 06V 05


17

After this the pressure control will be reactivated.

V 1/2V 1/2 V 3/4V 3/4

This will last until the movable roller reaches L2 + 10 mm = 45 mm gapor until the drives get below operation load.

Press cylinder

Movable Roller

Next

V 11V 10V 10V 09

Next

V 10V 11

RP Group stop

The Pressure decrease valves will open, the proportional valves will open,and the emergency valve will open.

Hydraulic oil tank

Pump HD 1 M 01

Left RightFix Roller

18

Press cylinder

Movble

Roller

Fixed Roller

Movable Roller

V 07

V 09 V 06V 05

V 1/2V 1/2 V 3/4

V 08

The rollers will due to material pressure move apart until L2 is reached on both sides or after time limit.Roller press will stop after 30 sec.

At a stop of the roller press (desired or undesired) the RP - slide gate will close and stopped the material feed to the RP.

Next

The Pressure decrease valves will close, the proportional valves will close,and the emergency valve will open.

Next

Next

V 10

V 3/4

V 10V 09

Roller pressDosing Gate

min. Pos.

open

Open theDosing Gate

Dosing Gate in

Movable Roller

Fixed Roller

19

close

RP - Bin Slide Gate.

opened

max. Pos.

Dosing Gate

Last

roll press presentation hydraulik

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