Hydraulic control ROLCOX of the rolls
1
Fixed Roller
Movable Roller
Left Right
Hydraulic oil tankPump HD 1 M 01
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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
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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
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Retraction cylinder
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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 )
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Movable Roller
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GAP < L min Pressure control OFF
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Gap = 25 mm
L min
Movable
Roller
Fixed RollerLeft Right
Gap = 35 mm
Movable
Roller
Fixed RollerLeft Right
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
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= Gap 35 mm+ L2 Bearing dist. 25 mm
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L2+ 10 mmUntil this value the rollers are pushed back during start up the main motors.
= Gap 45 mm
Roller distance 10 mm
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Movable
Roller
Fixed RollerLeft Right
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
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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.
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V 06V 06 V 07V 07
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V 08
Movable
Roller
Left
Fixed Roller Right
Gap = 45 mm
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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
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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.
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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.
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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
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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.
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Hydraulic oil tank
Pump HD 1 M 01
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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.
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Movable Roller
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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.
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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
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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
Left RightFixed Roller
Press cylinder
Movable Roller
90bar
Start up< 90 bar
Pressure controlPressure variations with in tolerance will becompensated by the N2 accumulators.
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V 1/2 V 3/4
100bar Next
125 bar
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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
Fixed RollerLeft Right
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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).
135 bar125 bar115 bar
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
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Press cylinder
Movable Roller
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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
Fixed RollerLeft Right
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.
135 bar125 bar115 bar
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
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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
Left RightFixed Roller
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.
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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
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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
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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
Left RightFixed Roller
L(r)L(l)
Presscilinder
Movble
Roller
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Gap correctionand Pressure Control
Press cylinder
Movable Roller
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V 11V 10V 10V 09
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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
Left RightFixed Roller
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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
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V 11V 10V 10V 09
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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
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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.
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The Pressure decrease valves will close, the proportional valves will close,and the emergency valve will open.
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V 10
V 3/4
V 10V 09
Roller pressDosing Gate
min. Pos.
open
Open theDosing Gate
Dosing Gate in
Movable Roller
Fixed Roller
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close
RP - Bin Slide Gate.
opened
max. Pos.
Dosing Gate
Last
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