Furnace Charging

7/25/2019 Furnace Charging

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FURNACE CHARGING AREA ELECTRICAL AND AUTOMATION

By Md. AJMAL



Description of C!r"in"

Con#eyor • The charging conveyor w

ill receive billetsfrom the billet skids and advance them oneat a time to the walking beam furnace.

• A loading/discard mechanism is locatedopposite the skids.

• There is a disappearing stopper positioned atthe furnace end of the charging conveyor

and end of the Roller table group-1.• A weigh station is included so that billets can

be weighed prior to entering the furnace.



Conveyor

The conveyor consists of 24 cylindrical rollersdivided into four groups as follows!

• "roup #1$RT%&-'( - ) rollers covering the billetskids.

• "roup #'$RT%&-*( - + rollers afterdisappearing stopper.

• "roup #*$RT%&-,( - + rollers.

•

"roup #,$RT%&-)( - rollers.



ntroduction of &illet kid

• A set of billet separating skids is used to separateand align groups of cold billets deposited on theskids by an overhead crane with magnets.

• &illets are placed on the single-level 0at skids bya crane.

• kids have capacity for *, 1+)mm s2uarebillets.

• &illets are delivered singly by the skids to thefurnace charging conveyor.



• kids are arranged perpendicular to the furnacecharging tables so that billets are advanced acrossthe level of the skids to the tables

• A %isappearing stopper $when raised( holds thebillets until it is clear to deposit onto the furnacecharging table.

• The separating skids consist of a series of 3veparallel 3ed skids with 3ve interposedreciprocating skids. The movable skids are driven from an eccentric

shaft causing a walking-beam action as the

movable skids raise above the surface of the 3edskids advance the billets and then move down to aposition below the 3ed skids.



Roller %rives

• The conveyor rollers are each individually driven byvariable speed gear motors rated ).) k4 15' Rollrpm * phase shaft mounted. The motors are s2uirrelcage induction type. There are , 6667 variablefre2uency inverters one for each roller group.

•

8ontrol is 6667 reversing. The conveyor normallyoperates in the forward direction only. The reversecapability is provided for operator convenience.Reversing can be used to return billets from thefurnace to the discard table.All motors in a group operate in unison therefore group

control is used. 9owever each motor will haveindividual overload protection. :ach group will havespeed ramps to control acceleration and deceleration tostop.



%rive• The eccentric shaft is driven through a )5!1 speed

reducer by an industrial-type 1+5 k4 *;rpm.

8ontrol•

8ontrol for drive motor is full 6667 with overcurrent and under voltage protection and withad<ustable time limit acceleration.



&illet =oader / %iscard

• The loader / discard table is located beside thecharging conveyor on the opposite side of theconveyor from the billet skid. The mechanism has twopurposes one is to load the billet onto the furnacecharging roller table. The other is to discard the billet.

The loader / discard arrangement consists of ,traversing buggies which operate in unison. Thereis a pivoting nose$Arm( piece on each buggy. 4henthe buggy is fully retracted $towards the billet

skids( the nose piece is hydraulically lifted behindthebillet. 4hen the buggies retract they can retractto one of two positions. The 3rst position pulls



• billet to the furnace charging conveyor. the otherposition pulls the billet o> of the conveyor rollersand onto the discard table. There is storage spaceon the table for several billets. &illets areremoved from the discard table by an overheadmagnet crane.



?%:@ 7 :=:8TR8A=%:68:.

NUMBERS OF ROLLER TABLE MOTORRoller Drive Motors - FC/M1-24

PED’S

1. Pro!"t Dete"tors #t Roller T#$le %ro!& '1 - FC/PED1

2. Pro!"t Dete"tors #t Roller T#$le %ro!& '( - FC/PED2

(. Pro!"t Dete"tors #t No. 2 Sto&&er P)otoele"tri" Dete"tor -FC/PED(

4. Pro!"t Dete"tors #t F!r*#"e E*tr+ - FC/PED4

PRO,MT LMT STC0

Billet Lo#er / Dis"#r Tr#verse Lo# *i"#tio* - FC/PLS

Billet Lo#er / Dis"#r Tr#verse &i"!& *i"#tio* - FC/PLS3

Billet Lo#er / Dis"#r Tr#verse is"#r *i"#tio* - FC/PLS

Billet Lo#er / Dis"#r R#ise Positio* *i"#tio* - FC/PLS5

Billet Lo#er / Dis"#r Lo6er Positio* *i"#tio* - FC/PLS7



PRO,MT LMT STC0Dis#&&e#ri*% Sto& No. 1 Positio* R#ise *i"#tio* - FC/PLS1

Dis#&&e#ri*% Sto& No. 1 Positio* Lo6ere *i"#tio* - FC/PLS2

Dis#&&e#ri*% Sto& No. 2 Positio* R#ise *i"#tio* - FC/PLS(

Dis#&&e#ri*% Sto& No. 2 Positio* Lo6ere *i"#tio* - FC/PLS4

Billet si sto&&er !& i*i"#tio*-PLS

Billet si sto&&er o6* i*i"#tio*-PLS

Pro!"t Dete"tor #t Sis Dis#&&e#ri*% Sto& - FC/LS18 2

ei%) Li9t R#ise Positio* *i"#tio* - FC/PLS1(

ei%) Li9t Lo6ere Positio* *i"#tio* - FC/PLS14

Billet si :otor )o:i*%-PLS

LOAD CELL

ei%)er Lo# "ells - FC/LC1-4

LEN;T0 MEASUREMENT UNT

Billet Le*%t) Me#s!re:e*t - FCRT/BLS1



SOLENOD <AL<ES

Billet Lo#er / Dis"#r Tr#verse Sole*oi <#lve -FC/E<1

Billet Lo#er / Dis"#r R#ise Sole*oi v#lve - FC/E<2

Dis#&&e#ri*% Sto& No. 1 Sole*oi <#lve - FC/E<(

Dis#&&e#ri*% Sto& No. 2 Sole*oi <#lve - FC/E<4

ei%) Li9t Sole*oi <#lve - FC/E<11



%isappearing topper

• There are ' disappearing stoppers in the charging

conveyor. The stopper is intended to take theimpact of billet moving in the forward directiontoward the furnace only.

topper ?o.1 - This is located at the end of

the 3rst Roller table group. t is used to hold billetat the skid section until the roller table is ready toreceive the billet.

topper ?o.' - This is at the furnace entry. t isused to hold billets if the entry table inside thefurnace is occupied. &illet front ends against thisstopper are properly positioned for weighing andmeasuring.



&illet ensors$=BT 4T89(

Two Pro!"t Dete"tors =FC/LS1-2>li:it s6it")es are provided. These detecta billet at the billet skids disappearing

stopper position and will initiate thelowering of the disappearing stopper and aroller table loading cycle. Two%isappearing topper Cosition proimity

switches are indicates the DC position andindicates the %4? position.



&illet ensors

• There are four billet photoelectricsensors $78/C:%1-,( located on thefurnace charging conveyor these are

used to detect whether the tablesare clear to receive a new billet.



&illet ensor at roller table group #1

• Croduct %etectors at Roller %ro!& '1detects whether a billet is on the rollergroup #1 f roller group #1 is occupiedthen the billet skids will not be allowed to

place a billet on the roller table.

&illet ensor at roller table group #*

C:%-' sense the head of the billet and

speed of R==:R TA&=: "RDC getsdown. it will also detect if a billet hasbeen reversed back to roller group #1 fordiscarding.C:%-* is located after the 'nd

motor of Roller table "roup-*.



=A% 8:==

• There are , tension type ei%)er Lo# Cells built

into the lifting mechanism. 4hen the beam is lifted asignal sent from the , load cells to the electronic scaleunit where the weight in Eg is indicated on a digitaldisplay and printed. The indicator is in the furnacecharging pulpit. The printer can be located in an oFce

or clean control room environment. Crinted dataconsists of date time grade heat charge billetnumber and accumulated total. This information isalso passed to the =evel ' system.

•

Accuracy in G of load weight with tare weight lessthan 1555 kg!

• H/- 5.1 G for 1)55 to *555 kg

• H/- 5.'G for )5 to 1)55 kg

• Baimum capacity - *555 kg - Readout in 1 kg

increments



BLLET LEN;T0 MEASUREMENT• Beasurement of billet length is important to allow

correct billet placement in the furnace.• A billet is measured as part of the weighing cycle.

• As the billet is raised the billet is at the same height asthe laser measurement system the laser signal is

monitored this signal is converted into a distancemeasurement $@(.

• The distance between the laser measurement systemand the disappearing stop #1 is known $I(

• The system can then calculate the &illet length! I - @

J K• A small delay should be added to the system to allow

the billet to settle before the laser signal is monitored. This should initially be set to 1 second but be sitead<ustable.



&==:T B:ADR?" ARRA?":B:?T

?,

FURNACE DSAPPEARN;

CENTRE OF LASER

STOPPERMEASUREMENT DE<CE



7DR?A8: 89AR"?" C:RATR 8?TR=4T89:

DSCARD TRA<ERSE BLLET [email protected];N; CON<EER

BA? ADT BA? ADT BA? ADT

MP1 CASTER SDE

R:A%I ?T R:A%I &==:T R:LD:T

MP2 DSCARD TRA<ERSE

R:A%I ?T R:A%I 7R4AR% =A%

%8AR% TC

MP(

R:A%I ?T R:A%I E-STOP

MP4

R:A%I ?T R:A%I SREN



FUR. DSAPP STOP DSCARD ARM

RA: RA:

=4:R =4:R

E;0 SCALE STAC@N; AREA

RA: &==:T

=4:R ADT E%

DSAPP STOP =BEFORE R.T ;ROUP-1> BLLET S@D O;

RA: R:6 74%

=4:R 7.R:6 7.74%

FURNACE C0AR;N; CON<EOR

%R6-"R1 %R6-"R' %R6-"R* %R6-"R, BAT:R

R:6 74% R:6 74% R:6 74% R:6

74% R:6 74%



BLLET S@D MOTOR SPECFCATON

• Cosition drive

• upply voltage ,55 6ac +;5 6ac

• upply fre2uency )59K

•

Rated E4 1+5E4• Rated current ';) Ampere

• Revolution per minute *;

• Cower factor 5.M' cos



BLLET S@D TEC0NCAL SPECFCATON

• Baimum drive tor2ue '5+.)1 ?m

• ?ominal drive tor2ue '5+.)1 ?m

• Baimum drive current ';) Ampere

•peed down time ' sec

• peed up time ' sec

• ynchroniNation set R.C.B '55 RCB



BLLET S@D TEC0NCAL SPECFCATON

• 7ast speed at Auto Bode ,)5

• Banual Oog 7orward ,)5

• Banual Oog reverse -,)5

•low Banual Oog 7orward ')5

• low Banual Oog Reverse -')5

• ?ominal %rive Rated RCB 55

• Baimum %rive Rated RCB )5



ROLLER TABLE MOTOR TEC0NCALSPECFCATON

• ?ominal rated of drive 1)55 RCB• Dpper speed limit 1)55 RCB

• =ower speed limit -1)55 RCB

• Oog forward RCB M55 RCB

• Oog Reverse RCB -M55 RCB

• "ear ratio 1,.5

• topping time from rated speed to Nero ).5sec

• Luick stop time from rated speed to Nero *.5sec



ROLLER TABLE MOTOR TEC0NCALSPECFCATON

Baimum drive current 1).5 Ampere?ominal drive current 1'.5 Ampere

?ominal drive tor2ue 1555.5 ?m

Baimum drive tor2ue 1'55.5 ?m



The se2uence of the loader will be as follows!

• %iscard arm lower $down(.

• Traverse at pick up position $fully towards

billet skids(• &illet at disappearing stopper.

• %isappearing topper lower $%own(.

•

%iscard arm up.• Traverse to charging conveyor.

• %iscard arm lower $down(.



FURNACE C0AR;N; AREA AUTO CONDTON



0M CONTROL



A!to:#ti" Billet Lo#i*%Se!e*"e 9ro: Sis to

Roller Co*ve+or



&illets are advanced up against the stopper $8ycling the&illet kids(.



'. 4hen billet reaches to the last position of the

billet skid two trans-receiver type C:% located atthe edge of skid detects the last position.

C:% for sensing last position of the billet on the

billet skid



*. The stopper of the billet skid gets lower $down(and simultaneously a loading cycle starts.

&illet skid stopper

down



,.%iscard arm gets up and by holding the billet itcome back to the =A% position and place the billetin the centre of Roller table "roup-1.

%iscard armlower



+. C:%-' sense the head of the billet and speed of R==:R TA&=: "RDCgets down.

. &illet reaches to the R==:R TA&=: "RDC-, and before thestopper-' C:%-* is located when C:%-* sense the billetR==:R TA&=: "RDC-, gets o>.

C:% -*



M.topper -' will get down.

topper-' upC=

topper-' downposition

topper-' downC=



;. 4eighing scale will get raise and it will measure the actualweight of the billet before entering to the furnace.

15. 4hen weighing scale will be in raise position that time&illet =ength Beasurement unit measured the length of thebillet.

&illet =ength Beasurementunit



11. 4eighing scale will get down 8C-1 operator accept thelength and weight of the billet then 7urnace entry door will open.

1'. Roller Table "roup-, will get start and it reaches the C:%-,and when billet tail edge leave the C:%-, that time stopper-'will get raise.

C:%-,R:8:6:R

C:%-, TRA?BTT:R

7DR?A8: :?TRI%R



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Furnace Charging

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