Pulp and Paper Production at the Highest Level. with Electrohydraulic Drive Technology from Rexroth

Pulp and Paper Production at the Highest Level. With Electrohydraulic Drive Technology from Rexroth.

Intelligent, Accurate, Robust and Reliable From Raw Material to Fine Paper

The production of pulp and paper Paper and pulp manufacture places slightest problem can have far- is such a demanding process that exceptionally high demands on reaching consequences. A crack in only highly qualified specialists the drive technology. In order to the paper web or a drive malfunc- working on high-quality automa- ensure smooth interplay between tion would inevitably result in an ted systems are able to undertake the high forces generated here, the emergency shutdown of the com- these tasks successfully. Rexroth highest level of robustness and plete system, necessitating a restart, is setting standards in this field absolute precision are demanded which is costly. The technology worldwide: Wherever drives and simultaneously of machines and used must offer maximum preci- controls are concerned – and if systems. system performance is to be maxi- mized – engineers and operators Paper webs of over ten meters in are opting for the intelligence, pre- width, production speeds of up to cision, reliability and longevity of two thousand meters per minute – Rexroth electrohydraulic systems. and that’s around the clock – under such conditions even the Applications Center for the Paper Industry 4

• Optimization through simulation technology • Innovative electrohydraulic drive systems

Chemical Pulp Production 8 sion, dynamics and reliability at all times if such time- and cost-inten- • Digester – Hydrostatic mixed blade drive sive downtimes are to be avoided. with pump, transmission and hydraulic The specialized electrohydraulic motors solutions from Rexroth meet these • Pressure defusers – Specific control requirements – both in the produc- blocks and hydraulic cylinders for screen tion process and at the finishing control stage – and to the highest level. • Dewatering presses – Modular hydrostatic drive systems for dewatering drums

Mechanical Pulp Production 12

• Refiners – Dynamic positioning and pressure-controlled cylinder drives for refiner disc control

Paper Production 14

• Paper calenders – Synchronous and pressure-controlled cylinder drives for roller adjustment as well as deflection compensation of the calender rollers • Paper winders, slitter winder – Position and pressure-controlled cylinder drives for rider roll, press rollers and clamping functions

Paper Finishing 20

• Coaters – High dynamic response synchronous and force-controlled cylinder drives for the splice roll • Paper winder – Compact solutions for position- and force control of press rollers in winders

Modernization / Service 23 4 Applications Center Paper Industry

Rexroth Applications Center Paper Industry: Your Specialist for Branch Solutions

Rexroth has set up the Applications Center Paper Industry to develop the best possible results in precision, economy and longevity of production systems. Specialized knowledge of industrial hydraulics, many years of experience in this branch and extensive process com- petence are all combined here – often in direct, close contact with the users from the industry – to develop highly specialized, individual system solutions. Customer-specific solutions With its Applications Center Paper Industry, Rexroth offers its partners in this sector the assurance of benefitting from the support of the complete Bosch Rexroth international know-how at all times. Whether this relates to engineering and construction of production systems for optimization of factory configurations or efficient modernization measures – you can always be sure that branch-specific features, individual requirements and local prevai- ling conditions will be taken fully into consideration.

Machine control

PLC

Fieldbus/Drive bus

Frequency Digital axis converter controller

Rexroth Rexroth

BTA BTA

Rexroth Rexroth Rexroth

Servo motor Control valve Integrated digital axis controller Eliminating problems before Electrohydraulics: The best of they occur both worlds Rexroth develops customized There is virtually no other branch solutions based on a worldwide of industry where the particular unique, proven product spectrum. advantages of electrohydraulic With the aid of modern simulation drives really come to the fore, as in software the complete, actual the paper industry. Highly complex production process can be dis- pressure, force and synchronism played, tested and optimized in control, which are particularly detail as early as the planning and characteristic of papermaking development phase of a system. machines, represent a technical This reduces commissioning time challenge and demand intelligently to a minimum and guarantees designed electrohydraulic drives. maximum efficiency of the whole system right from the start. In its systems Rexroth combines the unique technical advantages of electronic and hydraulic components, offering solutions that promise a maximum degree of economy and high product quality to customers with high specifica- tions. Systems with control cabinet electronics and also integrated axis controllers with intelligence at the valve are setting standards right across the branch with respect to precision, dynamic and control accuracy – and standardized inter- faces permit easy integration of the hydraulic-specific motion control into the control architecture. Applications Center Paper Industry

Pulp and Paper Production

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr, Germany Tel.: +49(0)9352/18-0

RE 09957/10.07-CD

AG th xro Re sch Bo 007 ght 2 ©Copyri

The DVD “Pulp and Paper Production by Rexroth” contains: • Corporate film • Application examples • Paper animation • Information • Contacts • HYVOS Simulation Program 8 A4CSG A2FM GMH speeds. at low even rotation, accurate with combined accuracy, high-speed permits transmission hydrostatic for the translation tuned fectly Aper- operation. long-term stable permits element method, finite the to built drive, planetary Rexroth The Pump. Piston Axial A4CSG the and drive planetary GMH coupled Motor Piston with Axial A2FLM the –comprising system drive abranch-specific developed has Rexroth for production pulp requirements exceptional For these element its in method element finite The drives. electrohydraulic Rexroth of features typical –all life service along and effectiveness of degree ahigh with drives the of control precision and maintenance low- powerful, technology: sophisticated extremely an demands process production chemical The motion. constant and temperatures high at pressure, high under solutions alkaline strong of aid the with particles wood digesting chemically involves process This technology. drive the on demands particular places pulp of production The Prevail Naturally Where Basic Forces Chemical Pulp Production: pulp production pulp chemical of sequence Process Wood chips Damper High pressure Impregnator

r r Digester

r r Pressure defuser Atmospheric washer Pulp Dewatering press Naturally Prevail Where Basic Forces Chemical Pulp Production: Wood chips Damper High pressure Wood chips Damper High pressure Impregnator Impregnator

r r

r r Digester Digester r r

r r Pressure defuser Pressure defuser Atmospheric washer Atmospheric washer Pulp Dewatering press hydrostatic transmission hydrostatic Pulp Dewatering press combination as a as combination Pump-motor Pump-motor Chemical Pulp Production Pulp Chemical low service life costs. life low service and outlay maintenance minimal of form a the in off pays clearly it –and appreciate really industry the in users many that properties are These temperatures. extreme and pressures high chemicals, aggressive dirt, moisture, as such influences environmental harmful to resistant it particularly makes This complete system. the and components of the both method, construction robust profile, closed the in lies Rexroth from concept drive electrohydraulic the of features outstanding ofOne the conditions harshest the even under form top In 10

Chemical Pulp Production: Precision plus Stability

Whether slow and smooth yet with powerful rotations, or whether accurate and highly dynamic linear motion – Rexroth technology can perform both in the extraction of raw materials: the longest service life of systems and components despite immense loading and simulta- neous sensitive open and closed loop controllability.

Long service life for series In order to guarantee stable oper- production ation with these extreme loadings Both for the mixing blades in pulp over a long period, Rexroth places digesters and the rotating drums particular emphasis on a long in dewatering presses, drives that service life when designing the operate slowly and with very high drives. r r r r torques are required for even dis- tribution and for pre-dehydrating the raw material.

Digester

Dewatering press Chemical Pulp Production 11

Pressure defuser

Optimized pressure defuser In order to ensure that the washing process in the pressure defuser achieves the best possible results, precision movement of the screen is of great importance. The Rexroth drive system developed especially to this purpose permits accurate control of these cyclical move- ments. Special components such as the CYDI cylinder and pressure- compensated FESE proportional throttle valves, as well as a control F[t] F[t] manifoldblock directly on the cylinder, control the immense dynamic forces continuously and with maximum precision.

CON With the help of special Rexroth LCD63DR50E software, the behavior of the new m complete pressure defuser system x is displayed at a very early stage. A4VSO CON

This makes clear any potential Load = f(x) improvements in the accuracy of the movement. Simulation model of a pressure defuser 12

Mechanical Pulp Production: Performance Advantage for Refiner

As in all other system components, the The production of high quality For safety reasons the servo valve refiner also contains proven Rexroth com- wood fibers made from wood chips can be aligned to support swift ponents for maximum efficiency: Reliability in a thermo-mechanical process opening of the refiner nip in the and precision are the most important cri- requires precision control and event of an emergency. teria with refiner disc control as far as safe monitoring of the pressing force process sequences are concerned; preci- between the refiner discs and the Secure position monitoring sion electrohydraulic control systems gaps in between. In combination with the HNC100, increase productivity and guarantee trouble- the proven digital axis controller, free operation. Secure force control the choice can be made between In order to guarantee a safe, re- force and position control with liable production process and swift flexible changeover. This enables opening of the nip in the event of optimum setting of the refining an emergency, the Rexroth system process to produce a high quality offers the 4WSE2EM, a high-dyna- wood pulp. mic response, two-stage servo valve with mechanical feedback and integrated valve electronics.

TA A P B TB

4WSE2EM Mechanical Pulp Production 13

Wood pulp removal Chip infeed

M Rexroth

I p Refiner disc nip monitoring I p

4WSE2EM

PLC HNC100

Fieldbus 14

Paper Production: Perfect Solu- tions for Perfect Surfaces

Precision linear force control Opening and closing – spot on As the paper proceeds through the When closing the calender, the calender between the individual lowest roller, together with the pairs of rollers, the calender gener- other mechanically coupled rollers, ates the required paper thickness are controlled using two hydraulic and surface quality by means of cylinders and the associated open pressure and temperature. For the loop control via synchronous and linear force control of the upper alternating force control. The roller as well as the opening and calender is opened in synchronous closing of the calender, Rexroth operation. uses closed loop controlled hydraulic drive systems. Dynamic The functional control is effected proportional valves Type IAC-P here via an HNC 100 2-axis NC control the required force in each control system. In addition to the individual hydraulic cylinder. The extensive controller structures the linear force required is flexibly HNC also has both a synchronous adapted during the production and a pressure controller. This process via the integrated fieldbus enables it to switch over smoothly interface. between the control modes.

Shine and smoothness on the paper, The WRPEH dynamic control combined with consistent paper thickness valves control the synchronous – these are the decisive criteria when operation with high precision setting up the calender. In order to achieve during the closing operation, as the best results here, precision in force well as alternately the force of both control is required as well as swift opening cylinder axes. of the nips in the event of an emergency.

HNC100-3X Paper Production 15

Fieldbus

IAC-P IAC-P

PLC

Fieldbus

Rexroth Rexroth

Axis 1 Axis 2

HNC 100

p I I p

4WRPEH 4WRPEH 16

Paper Production: Deflection Compensation for Uniform Paper Quality

From continual measurements of Drive-integrated safety technology the paper thickness the machine A fail-safe setting of the valve control can generate individual piston allows the fastest possible pressure command values for every speed for opening the nip – for single segment of the calender example if the web cracks. This is roller. These command values are effected either by switching off the transmitted to the axis controller supply voltage or by removing the either by analog means or via a release signal, causing a spring to fieldbus system. push the valve piston into setting A – T. The large cross-sectional The nip is closed via the flow opening thus created means that control function of the integrated the zone cylinders can be rapidly axis controller. All zone cylinders exhausted. travel at the same fast speed fol- lowing the flow command value. On contact with the roller the axis controller electronics (Rexroth IAC-P) switch automatically into pressure control mode.

Precision and differentiated closed loop The pressure control command Problem of calender control of the nip using zone-wise deflec- values are set individually for each deflection and solution tion-compensated calender rollers is zone cylinder, thus permitting pre- indispensable if uniform paper properties cision control of the force profile are to be achieved – an essential criterion across the complete nip. for paper quality.

Ideal roller

Actual roller

Compensated roller Paper Production 17

A-A

Paper web Papierbahn

Zone 1

Solid steel roller

Calender roller as rotating hollow roller A

Pressure port Zone 1

Fieldbus

PLC

IAC-P

Pressure control for Zone 1 18

Paper Production: Smooth Reeling Thanks to Flexible Press Roller Adjustment

Press roller adjustment Clamping of the cores Low-friction hydraulic cylinders Secure clamping of the individual with control valves Type 4WRPEH cores for the reeling process is are used both sides for the press achieved through electrohydraulic roller. As the winding process control of the core chuck. The begins the HNC 100 2-axis NC- clamping cycle for this is pro- control undertakes the task of grammed in the HNC 100 with positioning the roll onto the tube NC sentences. One position- and via synchronous control and then one pressure controller switch over switches smoothly into force con- smoothly from one control mode trol. The increasing diameter of to the other, when either closing or the paper roll increases the roller opening the core chuck. weight – the contact force therefore needs to be reduced continually Control valves Type 4WREE6 with to the same extent. The diameter- integrated valve electronics reduce dependent force command values the wiring required. are transmitted ﬂ exibly from the master PLC via ﬁ eldbus to the HNC 100.

The force between roll and rider roll must be kept constant to ensure even winding in the paper roll – by precision, sensitive force control of the press roll. Axis 2

HHNC100NC 0 Press roll

adjustment Rexroth 44WRLE16W LE16 4W4WRPEH6EH6 Axis 1

Press roll I p Axis 2

I p Paper Production 19

Weight compensation of the Rexroth developed the IAC-P for core chucks this speciﬁ c task. In Q-operating To prevent overloading during the mode it drives the cylinder propor-

paper reeling operation, the intrin- tionally to the adjustable Q-com-

x r o t h

e x r o t h

sic weight of the core chucks is mand value. On selecting operating

x r o t h

e x r o t hydraulically compensated. To this mode p it regulates the required h purpose the low-friction cylinders, compensation pressure. which drive these during the roll change operation, are pressurized The integrated digital pressure

Rexroth

R r ex ot in compensation mode so as to controller and the pressure sensor h virtually correspond to the intrin- make the IAC-P unique for its sic weight of the chucks. type. The p- and Q-command values can be speciﬁ ed as 4 – 20 mA-signal or via the ﬁ eldbus.

In slitter winders the paper is cut length- Axis 1 wise to the customer’s requirements and wound onto transportable rolls. This is Fieldbusus IAC-PIAC P PLC effected by means of two drum rollers, for which Rexroth offers a comparable, complete drive concept with hydraulic press Weight compensation Core chuck roll adjustment, core clamping and weight compensation of the core chucks.

Axis 2 Rexroth

4WREE66 Axis 1

Paper rolls HNC100 Rexroth

p I

Core clamping Axis 2 Axis 1 20

Paper Finishing: For Greater Precision and Reliability – The “Flying Splice”

The “flying splice” from the end of the old paper web to the beginning of the new one – and this is at full web speed – constitutes a major challenge for the drive and control technology in coating machines. By using Rexroth solutions this process runs smoothly with precision, repetitive accuracy and reliability.

If the old paper web is separated, without excess force the specified An innovative electrohydraulic then a press roller has to join it to force in both cylinders is precisely system of dynamic adjusting el- the new web using adhesive strips. adjusted. In less than one second ements, combined with intelligent The task of the electrohydraulics of after start of the motion both closed loop control technology co- the press roller here is as follows: roller drives must dynamically re- ordinated with the hydraulics, is the roll is brought into contact turn the roller to prevent the paper proving its outstanding perform- with the paper roll in synchron- web from fulling and thus damag- ance capability in new machines, isation control and on contact and ing the paper. as well as in conversion projects, by a marked improvement in the quality and reliability of the process. 1. Splice before contact Unwound 1. New paper roll For the machine builder there is, paper roll VWeb = 1200 m/min over and above this, the possibility Splice with of combining standardized prod- double adhesive strip ucts with customer-specific soft- Diameter approx. 2500 mm Splicer Mass approx. 40 t ware. In this way the benefits of 2. Splice on contact standard solutions in the hardware are combined with the protection VWeb = 1200 m/min of customer-specific know-how.

New paper roll Unwound paper roll “Old paper web” “New” paper roll

3. Splice after contact 2.

Knife 3.

VWeb = 1200 m/min Paper Finishing 21

PLC

Fieldbus

Axis 1 Axis 2

Rexroth Rexroth HNC100 I I p p S S

I I p p

4WRSE6 4WRSE6 22 Paper Finishing

Paper Finishing: The Art of Reeling

The paper is placed onto the reel by specified by the master control. means of the press roller. During The pressure differential in the the reeling process the reel pulls cylinder chambers and the area As it is essential when reeling to prevent back, with the paper web wound ratio of the cylinders have to be the paper web from going askew, or bubbles on, while the press roller presses taken into account here. The IAC- or creases forming and allowing air to be the web, applying the specified R axis controllers are operated trapped in the rolls at the infeed, one of the force with two parallel cylinders. both as pressure controllers and as most important processes in the roller is By using IAC-R axis controllers dynamic proportional directional the control of the drum. the linear force between press control valves. Depending on the roller and paper roll is regulated command value from the mas- precisely to the command value ter control, it can be determined during the process which needs to be activated – pressure control or position control with pressure PLC reduction. When changing the paper rolls it is necessary to do a press roll run with synchronous monitoring.

Communication of the IAC-R with the master control is effected via a standardized fieldbus interface. I I This permits easy integration into p IAC-R IAC-R p the system and an exchange of command and actual values.

The press roller drive design permits extremely smooth and tautly Paper web Paper roll wound paper rolls with diameters of more than 3,500 millimeters and masses of up to 150 tons. Rexroth Modernization/Service 23

Modernization: Better Than Ever Before

In addition to service and mainten- Existing machines and systems The performance spectrum can ance of existing systems Rexroth with their obsolete drive technol- range from service and mainten- also offers modernization and ogy are frequently no longer able ance of existing systems right conversion based on its own cur- to match today’s requirements, yet through to the conversion of rent, extensive branch know-how, they are capable of performance electrohydraulic drives and their combined with state-of-the-art enhancement. Modernizing the control systems. The reference technology. drive and control technology list below gives some examples of makes the machines more produc- conversion projects undertaken by tive and economic. Rexroth in recent years.

Rexroth references for modernization projects

Country Customer Project Belgium Burgo Ardennes Splice roll drive Germany MD Albbruck Calender sensomat drive Germany MD Albbruck Calender control, S-roller and additional pressure Finland UPM Jämsänkoski Super-calender drive Finland UPM Lappeeranta Coating machine drive Finland Stora Enso Varkaus Unwinder tensioning system Finland UPM Walki Special calender drive USA International Paper Roller transport drive USA International Paper Calender roller drive USA International Paper Wet press system USA BBA Nonwovens Calender roller drive 24 Modernization/Service

Service: As Much as You Like!

Condition Monitoring Modular and made-to-measure – obtained from a single source, Machine data is received, trans- from one-off service through to with a single point of contact. mitted and evaluated via Trended, complete package This can range from one-off jobs, the special data capture and evalu- Anyone wishing to manufacture such as servicing, maintenance or ation system from Rexroth. This economically must be sure that the repair jobs, customized modular means that servicing and mainten- machines and systems are always combined services, such as cus- ance work is condition-oriented operating optimally. Only this tomer-specific repair and spare and is only undertaken when way can productivity be exploited part concepts, right through to required. By using current status to the maximum and downtimes complete packages with a service information available online to reduced. With Rexroth all the station situated on your own machines and drives, the service technical services required are premises. life can be utilized to the maximum without breakdowns result- ing in unplanned downtime.

Trended

System & Trended GSM data transmission Alarm via SMS sensory technology

GSM data transmission

Rexroth Server User

World Wide Web Intelligent Hydraulics in New Dimensions

Whether it’s a case of raising or Rexroth is the ideal partner if you The Drive & Control Company Electric lowering loads smoothly, under- want to develop highly efficient Rexroth is unique. No other Drives and taking linear or rotational move- machines and production facilities brand on the world market can Controls ments, achieving even acceleration – from the first point of contact offer its customers all drive and or accurate positioning, maintain- right through to commissioning control technologies, both on a Hydraulics ing preset speeds, transmitting and across the complete life cycle. specialized and integrated power or linking motion sequences Teams operating worldwide will basis. We are considered to be Linear – in fact, wherever economical take on the complete project design the worldwide benchmark when Motion and power is required, this is where work of your systems, even produc- it comes to drives, controls and Assembly hydraulics comes into its own. ing a turnkey solution if required. motion. Our technological Technologies leadership is continually setting Rexroth is technology and market Whether it’s competent support us new challenges, with approxi- Pneumatics leader in industrial hydraulics with on the telephone, urgent repairs or mately 30,000 employees in an extensive product program and supply of spare parts, or a callout more than 80 countries around Service proven applications know-how. by one of our engineers – which- the world. This is possible thanks With the widest selection of hydrau- ever service you require, experi- to an infrastructure designed lic products in the world, Rexroth enced personnel and a worldwide with partnership and customer will provide you with standard service network will guarantee proximity in mind. products, application-orientated that the problem is swiftly solved. systems and customized solutions As a company Bosch Rexroth of the highest quality. Furthermore, Using hydraulic drive and control can look back on more than 200 with the aid of the latest micro- technology from Rexroth will years of tradition. As a wholly electronics, Rexroth has made help you become more competitive owned subsidiary of Robert hydraulics even more powerful than ever. Bosch GmbH, we are part of a than ever. globally operating technology group. All this is both our drive and our commitment. And it is unique – just like Bosch Rexroth. The Drive & Control Company. Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr, Germany Phone: +49(0)9352/18-0 Fax: +49(0)9352/18-1638 [email protected] www.boschrexroth.com

Printed in Germany RE 09957/10.07