high pressure grinding roll 1112

7/24/2019 High Pressure Grinding Roll 1112

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HIGH PRESSURE GRINDING ROLL

HPGR) MACHINE CONTROL METHODS

Michael Uliana

Technical Sales Manager

2012 WMEA San Antonio Meeting and Technical Symposium

San Antonio, TX, November 16, 2012


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Page 2< Confidential to TMEIC Corporation>

Who is TMEIC?

TOSHIB

Since 1896MITSUBISHI ELECTRIC

Since 1921

Industrial Systems

TOSHIBA MITSUBISHI-ELECTRIC

INSUSTRIAL SYSTEMS CORP.

Industrial Systems

TMA Electric Corporation

Since 1999

Since 2003

Power

Electronics

Motor Motor

Power

Electronics

TMEIC Corp.

Roanoke, VA, USA

Houston, TX, USA


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Presentation/Paper outline

HPGR Machine Design

Control Methods

Conclusion


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What is an HPGR Machine?

A

R1 R2

P

Material is crushed between two independently driven rolls

Hydraulic pressure is applied to maintain a specified gap

An autogenous layer forms on the rolls to protect the roll

surface


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HPGR Machine Design

Maintaining the same roll tangential velocity is important:

Helps maintain the autogenous layer

Minimizes roll wear

Increases uptime

R1 R2


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Industries using this technology:

Cement (very common, mostly fixed speed)

Mining (becoming more common, variable speed)

Why?

Potential energy savings v/s other grinding methods

Roll life becoming longer

HPGR Machine Design (cont.)


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Control Concerns:

When starting the mill, no connection between the rolls

How do you maintain speed?

While running, rolls are essentially connected by orebeing crushed

How do you share load?

Rolls are not absolutely identical and can wear atdifferent rates.

How do you keep the tangential velocity the same?

HPGR Machine Design (cont.)


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Potential Control Solutions

1. Independent Speed Regulators

2. Torque Regulation

3. Master-Follower Arrangement


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Independent Speed Regulation

A

R1 R2

P

M2M1 Drive 2Drive 1

Speed

Reference


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Independent Speed Regulation

Benefits:

Speed control during startup

Concerns:

Load sharing

Tangential Velocity


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Torque Regulation

A

R1 R2

P

M2M1Drive 2

Drive 1

Torque

Reference


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Torque Regulation

Benefits:

Even Load sharing

Concerns:

Speed control

How is the torque reference generated?


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MasterFollower Arrangement

A

R1 R2

P

M2M1

Drive 2

(Follower)Drive 1

(Master)

Speed

Reference Torque Reference


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The master drive operates as a speed regulator

The follower drive operates as a torque follower


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Benefits:

Even Load sharing

Good at maintaining tangential velocity

Utilizes a speed reference


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Sequencing: Uses different control schemes for

startup and operation.

1. Mill starts up with both drives in speed regulation


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2. Drives monitors torque and shifts to master-follower

mode when the load threshold is met


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Additional Functionality: OR Regulator

Monitors actual drive speed v/s the speedreference.

If measured speed diverges from reference speed

the follower drive will shift back to speed regulate


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Additional Functionality: Master Drive Selection

Either drive can be designated as the master

Selector switch on Drive #1 cabinet used in this

example


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Master Drive Designation


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After analyzing various control methods for HPGR

machines we determined an effective way to control the

system is via a Master-Follower arrangement

Conclusions


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Page 22< Confidential to TMEIC Corporation>

TMEIC Drive Line


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Customer Success, Every

Project Every Time!

Questions?

high pressure grinding roll 1112

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