Millmate Roll Force Systems

Reliable, long-term solutions foryour roll force measurement

Introduction

The Millmate Roll Force load cells act asintegral parts of the mill stand. The rock-solid Pressductor® load cell design in combi-nation with the intelligent, reliable commu-nication functions are crucial keys to true rollforce measurement.

The Millmate Roll Force System consistsof a Millmate Controller (MC 400) and twoload cells with matching units. The various

types and the wide load range of MillmateRoll Force load cells cover practically all con-ceivable roll force measurement applications.

The ABB equipment is easy to install andoperate. We offer installation support as wellas long-term after sales supply and support.Due to ABB’s long experience in the rollingmill industry, we can offer outstanding appli-cation know-how in this particular field.

A measurement technology offering high accuracy is a prerequisite today for modern rolling mills. The constant striving to

achieve optimum process quality and the highest possible productivity is the essential goal of modern production units.

Rolled products are called upon to meet ever stricter demands, and as a consequence so is rolling mill equipment.

A truly measured roll force is crucial in achieving correct roll gap settings, true force distribution from operator

side to drive side of your mill and supervision of the backup bearings and roll eccentricity.

The Millmate Roll Force System incorporates all these essential features.

2

System overviewBuilding blocks and net-work for ABB's ForceMeasurement Systems inrolling mills.

Plant network

Local area network

Fieldbus

Internet

ABB’s Pressductor® Technologyand the Measurement Principle

ABB’s Millmate Roll Force load cells arebased on the well-known Pressductor® princi-ple patented in 1954, the magneto-elasticeffect, according to which the magnetic prop-erties of steel are influenced by mechanicalforces acting on it.

In the transducer body there are fourholes. Two coils at right angles to each otherare wound through these holes. One winding(the primary) is supplied with an alternatingcurrent; the other winding (the secondary)acts as a measurement winding. Since the twowindings are at right angles to each other,there is no magnetic coupling between themas long as there is no load on the transducerbody.

If the transducer body is loaded (as shownin the figure), the field pattern changes. Thepermeability of the steel is reduced in the

direction of the force and increases in thedirection at right angles. The result is achange in the symmetry of the magnetic flux,so that some of the flux induces a voltage inthe secondary winding. The induced voltageis proportional to the load.

Right from the beginning of the Pressductor era a transducer based on thismeasurement principle turned out to be perfect for the rolling mill environment.

The key factors are:• No compression of the transducer is needed

to achieve a reliable signal corresponding tothe applied force.

• An overload capacity of up to 700% isachieved by utilizing only a small part of theelasticity of steel.

• The standard load cell consists of 1,500transducers, always ensuring a true rollforce measurement, even if the load isunevenly distributed.

• Signal-to-noise level is higher than that ofother techniques due to the high signal out-put from the transducer.The rock-solid design of the Pressductor

load cells fulfils these key factors and will assureyou many years of accurate measurements inyour rolling mill.

Unloaded Loaded

The measurement principleis based on the magneto-elastic effect, according towhich the magnetic proper-ties of a material are influ-enced by mechanical stress.The transducer is magnet-ized via the primary coil. Avoltage proportional to theapplied force is induced inthe secondary coil.

700% of nominal loadThe highest permissible single loading without mechanicaldamage to the load cell.300% of nominal loadThe highest permissible load without permanent change ofdata.

3

700% ofnominal load

300% ofnominal load

Nominal load

4

System Building Blocks:Building Blocksfor ABB's Force Measurement Systems in Rolling Mills

Your selection of load cells, control units and optionsABB’s Roll Force Systems offer a comprehensiveselection of building block combinations ofload cells, control units and options coveringyour needs for accurate and reliable roll forcemeasurement in your rolling mill.

You choose from the Millmate Roll Forceload cells coming in three different versions:Circular, Rectangular and Annular. The mostcommon installation application for the cir-cular version is under the mill screw. The rec-tangular version is normally installed underthe lower back-up roll bearing. The annularversion is installed between the mill nut andthe mill stand.

The choice of control unit is made in thelight of system requirements and according toyour communication needs. Choose the bestbuilding blocks for your mill. We offer you thesuperior force measurement systems.

Mill responsible: How do I keep upwith my competitors?

ABB representative: You don't have tolook around anymore, ABB can help you.

Mill responsible: I need to increasethe productivity in my mill.

ABB representative: We have longexperience and solid know-how of

rolling mill applications.

Mill responsible: I want to avoiddamaging the mill stand and alsoimprove the thickness tolerances.ABB representative: You need a

reliable roll force measurement system.

Mill responsible: Today I already havea roll force measurement system, a

simple one, but I don't really rely on it.ABB representative: We understandyour problem and we have a solution

you can trust.

Mill responsible: I also need thisequipment to communicate with the

rest of my mill.ABB representative: MC 400 adaptsseamlessly to your specific application.

Mill responsible: This sounds toogood to be true.

ABB representative: Just pick andchoose from our selection guide.

5

First Selection of System Building Blocks:Load Cells

The heavy-duty Millmate Roll Force loadcells have high-stability components encasedin a protective stainless steel box providingthe built-in calibration and temperature com-pensation of the load cell.

Due to its low impedance and high outputsignal power the Millmate Roll Force load cellhas an extremely low sensitivity to insulationdefects and maintains its measuring accuracydown to a 10 kΩ insulation level.

The load cell output signal is calibrated forfull interchangeability between load cells of thesame type and size. The various types and thewide load range cover practically all conceivableroll force measurement applications.

Circular load cells PFVL 141CThe circular load cells are machined from aquadratic core. Shrunk-on stainless steel ringsprotect the load cell windings and underlyingcomponents.

There is a choice of core diameters in mul-tiples of 30 mm, giving 23 different standardsizes for forces between 1.6 to 60 MN.

Rectangular load cells PFVL 141VThe load cell can be adapted to the requireddimensions, and the length is chosen as a multi-ple of 30 mm. For load cells longer than 900mm, the chosen length must be a multiple of60 mm. The width is chosen as a multiple of30 mm. Stainless steel side-bars protect the loadcell windings and underlying components.

This load cell type is available in standardsizes from 0.63 to 56 MN.

Annular load cells PFVL 141RThe annular load cell consists of stainlesssteel laminations wound on an annular stain-less steel core, after which an outer stainlesssteel ring is shrunk on to the load cell to pro-tect the load cell windings and underlyingcomponents.

Standard sizes of annular load cells are avail-able from 2 to 28 MN. Load cells with otherdimensions can be manufactured to order.

ABB offers a complete range of roll force load cells.

Load cellInstallation arrangements

1. Under the mill screwFor installation under the mill screw, the loadcell can be combined with thrust bearingsand pressure plates into a package movablyattached to the mill screw; this makes for eas-ier roll changing. This arrangement givesgood force distribution, simple, inexpensiveinstallation and easy servicing. In addition,there is no need to machine any surfaces onthe roll stand. However, this arrangementdoes take up space in the roll window.

2. Under the lower back-up roll bearingThere must be a sufficiently large flat surfaceon the lower part of the roll stand to allowthe installation of the load cell under thelower back-up roll bearing. This arrangementhas the advantage that there is no need to payparticular attention to the load cell duringroll changing.

See also our offer regarding Load CellPackages on the next page.

1

2

ABB has many years of experience of install-ing load cells in all types of rolling mill.

To achieve the best possible measurementresults, certain basic rules must be observedduring the installation of the load cell:• The entire force must pass through the

load cell.• The force must be measured as close to the

source of the force (the roll gap) as possible.• The load cells must be protected to the

greatest possible extent from high bending,lateral and torsional forces.

There are currently three types of load cellin the product range:1. Load cells for installation under the mill screw2. Load cells for installation under the lower

back-up roll bearing3. Load cells for installation between the mill

nut and the mill stand

Application hintLoad cells can beinstalled in severaldifferent ways, butthe preferredarrangement, fromboth the economicaland technical pointsof view, is usually toinstall the load cellunder the mill screw.

6

3

3. Annular load cell between the mill nut and the mill standThis variant makes measurement possible even if the space under the millscrew and under the lower back-up roll bearing is insufficient. Thisarrangement also has the advantage that there is no need to pay particularattention to the load cell during roll changing, and it is well protected.

Load Cell PackagesWhen the load cell is positioned under thelower back-up roll bearing, which is the mostexposed position, we can offer a prestressedpackage with lower pressure plate, load celland upper pressure plate.

The safe and compact Load Cell Packagesecures easy and correct installation. Youincrease the possibility of accurate measure,and can count on a longer lifetime and lowermaintenance costs.

7

Step-by-step assembly ofour prestressed

Load Cell Package.

8

Selection Load Cells:Circular

Circularload cellsMeasurementrange 1.6 - 60 MNPFVL 141C

Nominal ID OD Max. cableload (MN) (mm) (mm) length (m)1.6 150 210 252.5 180 240 243.1 210 270 234.0 240 290 225.0 270 320 216.3 300 350 208.0 330 380 1910 360 410 1812.5 390 440 1714 420 470 1616 450 500 1618 480 530 1520 510 560 1522 540 590 1425 570 620 1328 600 650 1231 630 710 1135 660 740 1040 720 800 845 750 830 850 780 860 651.5 810 890 660 810 890 6

Select as follows:• Determine the load for which the load

cell is to be used and choose from thetable the next higher value in the standardrange.

Standard sizes and cable lengthsLoad cells are manufactured in the standardrange as below: OD

ID

74

ExampleNominal load 20 MN perload cell. Select 20 MNload cell, dimensionOD=560 mm,ID=510 mm

PFVL 141C, 20 MN.

When ordering, pleasestate:• type designation• nominal load

9

Selection Load Cells:Rectangular

Nominal load and cable lengthsNominal load Max. cable length(MN) (m)0.63 250.80 251.0 251.25 251.6 252.0 252.5 243.1 234.0 225.0 216.3 208.0 1910 1812.5 1714 1616 1618 1520 1522 1425 1328 1231 1135 1040 845 850 656 6

Width (W) mmLength (L) mm

Select as follows:• Determine the load for which the load

cell is to be used and choose from thetable the next higher value in the standardrange.

• Determine either the width or length ofthe load cell and calculate the otherdimension using the following formula:L x W x 0.0001 = F

L = load cell length in mmW= load cell width in mmF = nominal load of load cell in MN

(taken from the standard series in thetable)

The width and length are rounded up to thenext higher value in the table.

74

L

40

45

W

40

ExampleWith a nominal load of 14 MN and a width of370 mm the length will be390 mm (rounded up from378 mm).

PFVL 141V, 14 MN,L=390 mmW=370 mm

When ordering, pleasestate:• type designation• nominal load• width and length

120150180210240270300330360390420450

480510540570600630660690720750780810

840870900960102010801140120012601320

70100130160190220250280310340370400

430460490520550580610

Rectangularload cellsMeasurementrange 0.63 - 56 MNPFVL 141V

10

Selection Load Cells:Annular

Nominal D1 D2 D3 D4 Max. cableload (MN) (mm) (mm) (mm) (mm) length (m)2 100 130 200 240 752.5 100 130 210 250 723.1 200 230 300 340 694 225 255 340 380 665 255 285 380 410 636.3 285 315 420 450 608.0 320 350 470 500 5710 355 385 525 555 1811.2 375 405 550 580 1712.5 400 430 590 620 1714 420 450 620 650 1616 450 480 660 690 1618 480 510 700 730 1520 505 535 735 765 1522.4 535 565 775 805 1425 565 595 820 850 1328 595 625 865 895 12

Standard sizes and cable lengths

Select as follows:• Determine the load for which the load

cell is to be used and choose from thetable the next higher value in the standardrange. We can customize load cells if astandard load cell is not suitable for a par-ticular application.

• To calculate the load F for non-standardload cells

F=(D32 π4 -D2

2 π4 ) × 0.0001 MN.

For even smaller forces than 2 MN, we alsohave the annular load cell QGPR 102/104 inthe range 0.1 – 1.6 MN.

Other dimensions on request

D1

D2

D3

D4

74

L

ExamplePFVL 141R, 10 MN,D2=385 mm, D3=525 mm.

When ordering, pleasestate:• type designation• nominal load• D2 and D3

Annularload cellsMeasurementrange 2 - 28 MNPFVL 141R

11

Load cellsdata and definitions

Signal

Fnom

Signal

Fnom

Signal

Fnom

HysteresisSensitivitydrift

Zero pointdrift

Linearitydeviation

Nominal load (Fnom) is the load for whichthe load cell is dimensioned and calibrated,i.e., the sum of the stationary load and themaximum measured load in the measuringdirection.Accuracy class is defined as the maximumdeviation and is expressed as a percentage ofthe sensitivity at nominal load. Thisincludes linearity deviation, hysteresis andrepeatability error.Linearity deviation is the maximum devi-ation from a straight line drawn betweenthe output values of zero and nominal load,related to the nominal load.Hysteresis is the maximum deviation of theoutput signal at the same load during acycle from zero to nominal load and back to

zero, related to the sensitivity at nominalload. The hysteresis is proportional to thecycle.Repeatability error is defined as the maxi-mum deviation between repeated readingsunder identical conditions. It is expressed asa percentage of the sensitivity at a nominalload.Compression is the total reduction in theheight of the load cell when the load isincreased from zero to nominal load.Zero point drift is defined as the drift inthe output signal when there is no load onthe load cell.Sensitivity drift is defined as the drift in theoutput signal at nominal load, excluding thezero point drift.

Accuracy class % of Fnom ±0.5Linearity deviation % of Fnom ≤±0.5Hysteresis % of Fnom ≤0.2Repeatability error % of Fnom ≤±0.1Compression (mm at Fnom) 0.05Calibration error 0.1%

Compensated for min. error +20 – +80°CZero point drift ≤±0.01%/°CSensitivity drift ≤±0.01%/°C

Working temperature range* -10 – +90°CStorage temperature range -40 – +90°C*) Max. permitted short-term temp. +110°C

12

Second Selection of System Building Blocks:Control Unit

Millmate Controller 400The control unit supplies theload cells with power, processesthe signals from the load cellsand communicates them toother systems. Communicationcan take place via digitalinputs/outputs, analog out-puts, RS-232, RS-485 and, asan option, via a high-speedfieldbus.

The control unit can beoperated using the MillmateOperator Unit 400, exter-nal units via a serial inter-face or digital inputs. Set-up and commissioning areeasy due to the user-friendly interface.

Measured values aredisplayed on the operatorunit, connected to ana-log outputs or transmit-ted via a serial interfaceto external displays orother external units.

Basic building blocksThe building blocks required for a basic rollforce system are:

Two Pressductor load cellsOne Millmate Controller 400One Millmate excitation unitTwo Matching units

FeaturesMillmate Controller 400 has been designedto offer a lot of functionalities and at thesame time a high degree of user-friendliness.

MC 400 covers most mechanical arrange-ments. This means the user only has to fol-low the step-by-step instructions in order toset up the controller and to obtain correctroll force measurement.

Some examples of the built-in functionalities:• Predefined standard measurement modes• Built-in load cell tables• Filter times from 1 up to 500 ms• Easily configurable analog/digital

inputs/outputs• Level detectors• Unit selection (N, kN, MN, kp, t, lb, T)• Self-diagnostic test system including

transducer test

13

Data for Control unit with Excitation unitDimensions: (H × W × D)

Two pieces 380 × 235 × 90 mmWeight: 5 kg + 7.4 kgProtection class: IP 20Mains voltage: 85 – 264 VPower consumption: 650 VAOperating temperature: 0 to + 70 °CStorage temperature: -40 to + 70 °CAnalog outputs:

Voltage 0 – 10 V Current 0 – 20 mA

4 – 20 mAinsulated as groups

Step response 1 ms (0 – 90%)Digital inputs: 0/+24 V

insulated 4 + 4Digital outputs: 0/+24 V

insulated 4 + 4

External connections:• Excitation current to the load cells• 2 analog inputs for load cell signals• 4 analog outputs, voltage or current • 8 digital inputs for control signals• 8 digital outputs• +24 V supply for external units, max. 0.5 A• Ethernet connection

Service and multiple control units• 2 serial interfaces of type RS-232 for

external displays, control, etc.• 1 serial interface of type RS-485 for exter-

nal display• High-speed fieldbus (optional)

Load cells requiring different types ofexcitation cannot be mixed in the same con-trol unit. Analog/digital inputs and outputsare galvanically insulated as groups.

The PROFIBUS optionAs an option the control unit can be equippedwith PROFIBUS – a vendor-independent,open-communication standard for auto-mation in manufacturing and process control.The Profibus interface in the MC 400 isupdated with a new complete set of measuringvalues every 0.3 millisecond.

High-speed fieldbus option

Matching unit PFVO 142/143Each load cell requires one matching unit,which is interchangeable between load cells. Itcan be located up to 25 m away from the rele-vant load cell (depending on the nominal load).Dimensions (H × W × D) 300 × 200 × 120 mm, IP65,weight 8 kg.

14

Millmate Operator Unit 400The Millmate Operator Unit 400 providescommunication with the control unit and isdesigned for panel mounting.

The operator unit(s) and control unit(s)are interconnected on a common network.This common network can be a separate net-work for measuring objects or it can be partof a local area network (LAN).

The communication on the network is inaccordance with the IEEE 802.3 standard anduses the TCP/IP protocol.

The operator unit is supplied with 24 V DC from either the control unit or viaother power sources.

Insulation amplifier PXUB 201The insulation amplifier can be used whenimproved electrical insulation is required.Supply voltage +24 V (20-253 V)Current consumption 10 mA+external loadSignal range Input 0 - +5 V

0 - ±10 VOutput 0 - ±10 V

0 - ±20/4 - +20 mARated insulation voltage 600 V (basic)

Relay board PFVK 128Fitted with four relays with one changeoverfunction per relay. The board is supplied with24 V DC.Power consumption 20 mA/relayContact data AC: 8 A at 250 V

DC: 1.2 A at 48 V0.2 A at 220 V

Dimensions (H × W × D) 160 × 235 × 60 mm, IP 65from the front when mounted on a panel acc. to IEC 529,EN 60-529, IP 20 in all other directions acc. to IEC 529,EN 60-529, weight 1.3 kg

Third Selection of System Building Blocks:Options

15

Wall CabinetOne MC 400 with an excitation unit can beinstalled in the dust- and hose-proof wallcabinet. The operator unit can be mountedon the door.Dimensions (H × W × D) 600 × 600 × 200 mm, IP65,weight 21 kg.

Floor CabinetThe MNS floor cabinet is available in twoprotection classes. One is ventilated and com-plies with IEC 529 protection class IP 21.The other has no ventilation and complieswith IEC 529 protection class IP 54.Dimensions (H ×W × D) 2,225 × 740 × 656 mm, weight 150 - 200 kg.

We have local representatives in:Argentina Buenos Aires, Australia Melbourne, Austria Vienna, Bahrain Manama, Benelux Luxembourg,Brazil São Paulo, Canada Montreal, Chile Santiago, China Beijing, Denmark Odense, Finland Helsinki,France Décines, Germany Düsseldorf, India Bangalore, Indonesia Jakarta, Italy Milan, Japan Tokyo,Korea Seoul, Malaysia Kuala Lumpur, Mexico Guadalajara, South Africa Johannesburg, Spain Bilbao,Taiwan Kaohsiung, Thailand Bangkok, United Kingdom Manchester, USA Brewster N.Y., Venezuela Caracas

3BS

E02

8041

R00

01

ABB Automation Technology Products ABForce MeasurementS-721 59 Västerås, SwedenPhone: +46 21 34 20 00Fax: +46 21 34 00 05Internet: www.abb.com/pressductor

ABB is a global leader in power and automation technologies thatenable utility and industry customers to improve performance whilelowering environmental impact. ABB has some 155,000 employees inmore than 100 countries.

ABB Automation Technology Products is the global market leader inautomation technology. We provide products, software and services forthe automation and optimization of discrete, process and batch manu-facturing operations. Key technologies include measurement and con-trol, instrumentation, process analysis, drives and motors, power elec-tronics, robots and low-voltage products, all geared toward one commonIndustrial IT architecture for real-time automation and informationsolutions throughout a business.

ABB Force Measurement is a business unit within ABB AutomationTechnology Products. It provides equipment for accurate, reliable meas-urement and control in a broad range of applications from steelmakingto paper converting industries.

Rep

ro:

Kon

takt

Rep

ro A

B,

Väs

terå

s –

Prin

t: Tr

yckp

rodu

ktio

n A

B,

Väs

terå

s 20

02-0

5