SOLID STATE DRIVES APPLICATIONS

B.PRAKASH,DEEE.,

PAPER MILL

Deinking plant Pulp Mill Board Machine Paper machine Finishing House & Dispatch

PAPER PLANT

DEINKING PLANT

• Deinking is the industrial process of removing ink from paper fibers of recycled paper to make deinked pulp.

• Deinking plant is mainly used for removing various another material(impurities) and to refine the pulp to fresh material supplied to machine.

• There are two types of deinking plant 1. Voith deinking plant.2. Lamort deinking plant.

DEINKING PLANT

PULP PROCESS

A pulp mill is a manufacturing facility that converts wood chips or other plant fibre source into a thick fibre board which can be shipped to a paper mill for further processing.

PULP MILL

PAPER MACHINE

• It is the machine which is used for making a paper by rolling process.

• All the process are similar as in board machine.

• This machine yields three types of papers 1. Board Machine2. News Paper3. Writing Paper

PAPER MACHINE

BOARD MACHINE

It is a machine in which we make board paper by rolling process

Raw material transfer from shorting conveyors to pulper and other devices used for removing the impurities and various particles as plastic pin,pebels etc to the final towers.

Then the slush transfer to the machine where work’s is in progress for making of paper.

BOARD MACHINE

FINISHING HOUSE & DISPATCH

• In the finishing house the paper reel is transfer from machine to revinder where the cutting reel size by the knives.

• Then it transfer to the cutter machine where the sheet cutting of paper reel as required size

• Then binding of sheets is done and then dispatches.

• It is the paper processes that occur after the complete of papermaking operations, including calendaring, slitting, rewinding, sheeting, trimming, sorting, etc., prior to shipment from the facility.

FINISHING HOUSE & DISPATCH

1. RADIAL DRILLING MACHINE2. SHAPER MACHINE3. LATHE MACHINE4. MILLING MACHINE 5. CNC GRINDING MACHINE (ROLL GRINDING

MACHINE)6. RADIAL DRILLING MACHINE

MECHANICAL WORKSHOP

i. SYNCHRONOUS MOTORii. INDUCTION MOTORS

SELECTION OF MOTOR

for choosing induction or synchronous motors for industrial applications such as paper mill

 The sizes are 1,000 to 3,000 HP, and the voltage is 2.4-kV.

The mill is served by a 33 MVA 115/12.47-kV transformer, and the expansion will require the installation of a second 33 MVA transformer and second 12.47-kV bus.  

Cont……..

LOW SPEED AND HIGH H.P POWER FACTOR CONSTANT SPEED EFFICIENCY

WHY SYNCHRONOUS MOTORS ?

If we consider a 1000 HP, 8 Poles motor working 24 Hrs, 7 days a week:

Typical average efficiencies and then kWH consumptions in one year are: 

Induction Motor (EFF =93.8);   kWH= (1000 * .746 / 0.938 )*365*24 =  6,966,908

Synch.  @0.8 PF (EFF=94.2);  kWH= (1000*.746/0.942)*365*24 =6,937,325

SYNCHRONOUS MOTOR VS INDUCTION MOTOR

Synch.  @1.0PF (EFF=95.1); kWH= (1000*.746/0.951)*365*24 =6,871,672

Assuming energy cost $0.05 dollars per kWH, the yearly electric bill becomes:

Induction ----------  $348,345Synch @ .8PF-------$346,866Synch @1PF -------$343,583

CONTD……

synchronous motor drive

Wound field motor (a)cylindrical rotor wound field motor (b) salient pole rotor wound field motor Permanent magnet motor Synchronous reluctance motor Hysteresis motor

Classifications of synchronous motor

Modes of adjustable frequency control (i) Open loop volts/HZ control (or) separate cotrolled

(or) true synchronous mode (ii)self-controlled mode

Adjustable frequency control

Block diagram

open loop volts/Hz speed control characteristics

 

Supply Frequency to the synchronous motor is controlled from the inverter which receives its firing pulses from a frequency controlled oscillator.

The machine will exhibits conventional behavior. Up to base speed the motor operates at constant

torque and above base speed are obtained by clamping the voltage at rated voltage. Frequency can be increased and the motor operates in flux weakening region

Control can modify the angle between the flux

phasors

Because of self-control, machine does not show any

stability or hunting problem of traditional

synchronous machine

The transient response is fast – similar to dc machine

The rotor inertia is smaller than dc machine with high

energy magnet

Self control mode

Block diagram

Commutation of the converter feeding the motor is controlled through the rotor position information from a shaft encoder.

Under over excitation the motor voltages can be employed to commutate the thyristors at the inverter. Now the inverter becomes simple. But at low speeds commutation assistance is required.

Rotor position is sensed and the firing signals to the devices are synchronized to the motor position.

For every 600 rotation of the rotor a new device in the sequence is fired

Closed loop control

VSI fed Synchronous Motor drive

VSI FED DRIVE CSI FED DRIVE

Different schemes of synchronous motor drive

PWM INVERTER FED DRIVE

SQUARE WAVE INVERTER

CSI fed Synchronous Motor drive

Cycloconverter fed Synchronous Motor drive

A Synchronous motor in self controlled mode is called “commutator less Dc motor”.

commutator less Dc motor