Auto Leveller

7/25/2019 Auto Leveller

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A Presentation on

AUTOLEVELLER

Yogesh Sachan

B. Tech Final YearTextile Engineering


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AUTOLEVELLER

Autoleveller is an onlineprocess control device whichkeeps mass variation under

control limit.


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Features of Autoleveller

Lon term Autolevellin! means thevalue of sliver count should not driftwith time.

Relia"ilit#! the autoleveller should "erelia"le from the point of view of itsperformance.

Reproduci"le $ettins. %ide &ontrol Rane.


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Autolevelled v's (on! autolevelled$liver


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)ass variation

*ependin upon the unit lenth thevariation can "e classi+ed as!

Ver# $hort Term ,-m $hort Term -m / -.m )edium Term -.m / -m Lon Term -m ! -0m Ver# Lon Term 1-0m


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Length variation curve

The variation reduces with increase in unit lenthover which the mass is considered.


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Principle of autoleveller2

On the "asis of its workin principle3autoleveller can classi+ed as!

Open Loop

&losed Loop


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Open Loop System:

4n an open loop s#stem the mass sensin islocated near the feed reion of the process. Thesensor enerates a sinal correspondin to theactual value of the parameter to "e controlled.5Linear *ensit#6. The measured sinal iscompared with reference value in order toestimate the deviation from it. 4f the deviation

oes "e#ond a tolerance limit3 the di7erencesinal is ampli+ed and after a necessar# dela# isfed to an actuator3 which in turn suita"l# ad8uststhe desired parameter at the output process.


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Open Loop System

$et value' TReference $inal

4(OUT

)aterial Flow

$ensin Point Process

$tore' *ela#

Actuator

Ampli+er


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Closed Loop System:

4n an closed loop s#stem the mass sensin islocated at the deliver# end and the controllinpoint near the feed end of the process. The

sinal emanatin from the sensin point isinterated or averaed compared with the setreference value. An actuatin sinalproportional to the di7erence sinal is then

enerated. 4t is ampli+ed and fed to anactuator to "rin necessar# chanes in theparameter to "e controlled in the process.


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Closed Loop System

T $et value'

Reference $inal

4(OUT

)aterial Flow

Process $ensin Point

Actuator Ampli+er


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&omparison 9etween Open :&losed loop $#stem

OPE( LOOP &LO$E* LOOP

The total volume of allthe slivers is measured

at the feedin . The ad8ustment is done

"# chanin the draft inmain draftin Field.

9est suited for the short

and medium termvariations

)a# introduce $hortterm Error.

The evenness of thedelivered sliver is

measured at deliver#. The ad8ustments are

made in draftin Field.

9etter for the lon termvariations. *oes not introduce $hort

term Error.


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T#pes of Autoleveller

Lon Term Autoleveller

)edium Term Autoleveller

$hort Term Autoleveller


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Lon Term AutoLeveller

)easurin is performed "# a sensor inthe deliver#


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Lon Term AutoLeveller


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)edium Term AutoLeveller

An optical measurin device detectsrelative variations in the cross!section of the +"er la#er on the mainc#linder over the whole width of thec#linder. The measurin device is"uilt into the protective cover a"ove

the do7er. The device measuresre>ection of infrared liht from the+"ers.


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After comparison with the set

value3 a di7erence sinal isenerated and passed to anelectronic reulatin unit. This

operates via a reulatin driveto ad8ust the infeed speed ofthe card so that the depth ofthe +"er la#er on the mainc#linder is held constant.

&apa"ilit#2 ?m onwards


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)edium Term AutoLeveller


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$hort Term AutoLeveller

A pneumatic sensor senses the slivermass and enerates e@uivalentsinals. These sinals are processedand there after used "# electroniccircuit or micro &omputer to var# thedraft of a draw "o placed in front of

the trumpet.The *raft rane of draw "o lies within

B.-

&apa"ilit#2 B0!B- cm wavelenth


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$hort Term AutoLeveller


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Thank Cou

Auto Leveller

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