A REPORT ON INDUSTRIAL TRAINING

ONCS2/ACID PLANT

AT

(BIRLLA CELLULOSIC, KHARANCH)(Training duration: 2 JUNE to 16 JUNE 2014)

PREPARED BY: UNDER GUIDENCE OF MANISH A. SADHU ALPESH PATEL

DEPARTMENT OF ELECTRICAL ENGINEERING

SHRI SAD VIDHYA MANDAL INSTITUTE OF TECHNOLOGY

BHARUCH

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ACKNOWLEDGMENT I express my sincere gratitude to Birla Cellulosic (Unit of Grasim Industries Ltd.) for giving me the opportunity to get training in the CS2/ACID PLANT.I would like to express heartfelt to all the members of the faculty concerned who have extended their support and guidance to me and help us to gain technical knowledge. I am thankful to Mr. Bhattnagar for allowing me to undergo training at this Company. I am also thankfull to Ms. Kritika Goswami of the Training Centre of Birla Cellulosic for facilitating our training at Company. I would like to that Mr. Alpesh Patel (Engineer) and Mr. Giriraj (Technacian) of CS2/ACID Plant for their valuable guidance.I would also like to thank my college Shri Sad Vidya Mandal Institute & Technology, Bharuch for providing me the opportunity to undergo training at Birla Cellulosic

Manish A. Sadhu

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PREFACE

Theory of any subject is important but without its practical knowledge it becomes useless particularly the technical student. A technical student cannot become a perfect engineer or technologist without practical understanding of the branch. Hence, this training provides golden opportunity for all technical students. The principle objective of this training in the plant is to get details about power generation, relay protection and many other processes which are carried out in the industries. Another attractive feature is to learn industrial management and discipline which is equally important in life.

Manish A. Sadhu

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ENVIRONMENT POLICY AT Birla Cellulosic:We at Birla Cellulosic are committed for

Integration of Occupstional Health, Safety, Environment, Quality, and Production. Delivering Quality products to meet the requirements of Customers through

continuous Improvement & following highest Standards. Resource conservation through reduction of all types of emissions & waste

generation by continuous improvement. Safety & Health of all Stakeholders by continuous improvement in Occupational

Health & Safety systems. Meeting all applicable statutory & regulatory requirements. Facilitating learning & development of our Employees. Actively participating in the development of surrounding Community.

SAFETY POLICY AT Birla Cellulosic:Birla Cellulosic is committed to adhere with highest standards of safety and make it as integral part of our all business activities.We will make continuous progress towards the vision of Zero Accident and Injury.

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INDEX

CONTENTS PAGE NO.

1. Birla Cellulosic at a glance 62. Introduction of transformer 83. Classification of transformer 104. Transformer name plate specification 145. Construction of a transformer 156. Transformer Cooling Methods 197. Losses of transformer 238. Induction motor 249. Construction Of Induction Motor 2510. Table of parts & function of I.M. 2711. variable frequency drive 28

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Birla Cellulosic AT A GLANCEBirla Cellulose is the Aditya Birla Group's umbrella brand for its range of cellulosic fibers. It comprises versatile sub-brands; Birla Viscose, Birla Viscose Plus, Birla Modal, and Birla Excel. These brands offer a wide range of functional benefits such as soft feel, high moisture absorbency, bio degradability and comfort to the wearer. These fibers have multiple applications including apparel, home textiles, dress material, knitwear, non-woven etc.

Fiber is one of the oldest businesses of the Aditya Birla Group that commenced in 1954. Birla Cellulose is a world leader in viscose staple fiber (VSF). Its production is spread across six countries, viz. Canada, Thailand, India, Indonesia, China and Laos. The Group independently fulfills India's entire VSF requirements.

With a strong focus on Research and Development (R&D), the Group's R&D initiatives span the entire value chain.

World leader in VSF Commenced operation in 1954 Fully integrated operations in Viscose starting from forest through pulp, fiber, yarn

and garment Captive energy resources Geographically well-spread manufacturing locations Diversified product range Global marketing network In-house R&D facility for fibers In-house Application Development Centre Patented heavy metal free environment friendly processes

Vision and values

To be the world leader in man-made cellulosic fiber.

The company believes in value-creation for all its stakeholders, through innovative research and development initiatives which in-turn develop the market for man-made cellulosic fibers.

Companies and units - An integrated outlook

Birla Cellulose is growing by leaps and bounds through both organic and inorganic route. The efforts towards integration and self sufficiency are as follows:

Backward integration into pulp and plantation Captive power plant at all locations

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In house manufacturing of all major chemicals and auxiliaries used in VSF manufacturing.

In house engineering division that caters to new project implementation

The range of offerings by Birla Cellulose are as below:

Fibre:

Parameters Details

Denier 0.8 – 12

Cut length 32mm to 44mm (upto 2 denier)

Cut length 32mm to 44mm (above 2 denier)

Variants availableBright bleached, dull, semi dull, grasi nep, grasi rib, SpunShades, anti-

bacterial, chlorine-free, grasi sorb (hollow - flat)

Birla Viscose

Birla Viscose Plus

Birla Cellulose blends Benefits of blending with Birla Cellulose

Denier 1.2 to 1.5

Cut length 32 mm to 51 mm

Birla Modal

Birla Cellulose blends Benefits of blending with Birla Cellulose

Denier 0.9 - 1.5

Cut length 32 mm to 51 mm

Birla Excel

Birla Cellulose blends Benefits of blending with Birla Cellulose

Denier 1.2 - 1.5

Cut length 32 mm to 51 mm

 Chemicals

Sodium sulphate - Anhydrous

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Sulphuric Acid Carbon Di Sulphide

Introduction of transformer

Principle:Transformer is a static device of apparatus by means of which electrical power in once circuit is transformer into electrical power of the same frequency in other circuit. It can rise or lower voltage but with a corresponding decreasing of increasing current. There is a mutual induction in transformer between two circuits by common flux. Coil are separated electrically, but magnetically coupled.Transformer is a device that:1. Transfer electrical power from one circuit to another.2. It does so without change of frequency.3. It accomplish this by electromagnetic induction and4. Where the two electric circuit are in mutual inductive influence ofeach other.

General requirement:Transformer shall be of core type, 2 or 3 windings , 3-phase, oil immersed, having a dual rating whenever specified by natural and forced air cooling and shall be suitable for outdoor/indoor installation as per specification.Overloads:It shall be possible to operate the transformer satisfactorily upto overloads of 150% of rated value in confirmation with the loading guide specified in IS:6600. There shall be no limitation imposed by bushing, tap changers, auxiliary equipment to meet this requirement.Power and rated temperature rise:The temperature rise specified shall not be exceeded when the transformer is operated continuously at the rated power of each cooling classification at the design ambient temperature.

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Insulation level:The insulation shall withstand the rated lightning impulse voltage and power frequency withstand voltage.Mutual inductance of transformer:

EMF equation:E1=4.44 F N1 AVoltage transformation ratio (k) :It is the ratio of secondary voltage to primary voltage or it is the ratio secondary turns to primary turns of transformer.Voltage transformation ratio= k = V2/V1For step-up transformer voltage transformation ratio k > 1.For step-down transformation voltage transformation ratio k < 1.

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Equivalent circuit:Physical limitation of practical transformer is brought together as equivalent circuit model built around lossless transformer. Power loss in the winding depends onR1 andR2.L1 andL2 are leakage reactance.

Classification of transformerTransformer are classified according to their construction, supply voltage, cooling system, application etc,1. according to phase3 phase transformer1 phase transformer

2. according to cooling system.Dry typeWet type

3. according to construction.Core typeShell typeSpiral type

4. according to application.Instrument transformer

1. Current transformer

2. Potential transformerPower transformerAuto transformer

1-phase transformerTo overcome losses, the electricity from a generator is passed through a step-up transformer, which increase the voltage. Throughout the distribution system, the voltages are changed using step-down transformers to voltage suitable to the application at industry and home.

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3-phase transformer3-phase transformer are used throughout industry to change value of 3-phase power is the most common way in which power is produced.Normally transformer has two winding primary and secondary.There windings made of enameled copper. There windings are suitably put on the limbs of transformer cores. The transformer core is made of silicon steel stamping which are varnishes coated. The small transformer are air cooled but the higher capacity transformer are dipped in the oil tank for cooling purposeDry type transformerDry type transformers are cooled by air naturally or by fan.They are used up to 5000KV.Wet type transformerThis types of transformer are widely used as power transformer in power substation.This type of transformer use transformer oil for cooling.

Core type transformerThree core type transformers consist of a magnetic frame with two cores that is upper yoke and bottom yoke.The core is sometime called limb. A circular winding or coils are used in Core type transformer.

In core type Transformer size of limb is of L-size and reverted L-size.

Core type transformer has two limbs it has longer mean length of iron core & shorter mean length of coil turn .In the core type transformer the LV coil is wound next to the core and HV coil is wound on the LV coil after the insulation layer.

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Shell typeIn case of Shell type Transformer consist of a magnetic frame with a central limb and two side cores, completing the path of Magnetic flux. In this case primary and secondary winding are placed in between the limb is known as Shell type transformer. Shell type transformer has three limbs it has shorter mean length of iron core & longer mean length of coil turn. In the Shell type transformers the LV & HV windings are sandwiched between each other. It is defined as the transformer in which the magnetic circuit continuously surround the circuit. It is used in the transmission of multiple high and low voltages. It'sWindings can be partitioned in to groups.

Instruments transformerInstrument transformers are used for measuring voltage and current in electrical power systems, and for power system protection and control. Where a voltage or current is too large to be conveniently used by an instrument, it can be scaled down to a standardized low value.Instrument transformers isolate measurement, protection and control circuitry from the high currents or voltages present on the circuits being measured or controlled. A current transformer is a transformer designed to provide a current in its secondary coil proportional to the current flowing in its primary coil. Voltage transformers (VTs), also referred to as "potential transformers"(PTs), are designed to have an accurately known transformation ratio in both magnitude and phase, over a range of measuring circuit impedances. A voltage transformer is intended to present a negligible load to the supply being measured. The low secondary voltage allows protective relay equipment and measuring instruments to be operated at a lower voltage. Both current and voltage instrument transformers are designed to have predictable characteristics on overloads. Proper operation of overcorrect protective requires that current transformers provide a predictable transformation ratio even during a short-circuit.

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Auto transformerIn an autotransformer portions of the same winding act as both the primary and secondary. The winding has at least three taps where electrical connections are made. An autotransformer can be smaller, lighter and cheaper than a standard dual-winding transformer however the autotransformer does not provide electrical isolation. Autotransformers are often used to step up or down between voltages in the 110-117-120 volt range and voltages in the 220-230-240 volt range, e.g., to output either 110 or 120V (with taps) from 230V input, allowing equipment from a 100 or 120V region to be used in a 230V region.

.

A variable autotransformer is made by exposing part of the winding coils and making the secondary connection through a sliding brush, giving a variable turns ratio. Such a device is often referred to by the trademark name Variac

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Transformer name plate specificationKVA 2085VOLTS H.V. = 11000

L.V. = 433AMPERES H.V. = 109.4

L.V. = 2780.1PHASE H.V. = 3

L.V. = 3TYPE OF COOLING ONAN (oil natural air natural)FREQUENCY 50 HzIMPEDANCE VOLTS 6.78%CONNECTION SYMBOLS DYn11CORE AND WINDINGS 3200 KgWEIGHT OF OIL 1120 KgTOTAL WEIGHT 6200 KgOIL 1280 Literes

Construction of a transformer:Transformer tank (oil tank):The whole assembly of large size transformer is placed in a sheet metal tank. The heat generated at the core and windings should be removed efficiently in order to avoid the insulation deterioration, the moisture should not be allowed into the insulation.

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This objective the built up transformer in a closed tank filled with no inflammable insulating oil.Conservator:When the oil temperature increases, it expands and the air will be expelled out from the conservator. Whereas when the oil cools, it contacts and the outside the air get sucked inside the conservator.

The outside air which has being the moisture content. When such an air comes in contact with oil, oil will absorbed moisture content and losses its insulating properties.

Breather:Air goes in or out through the breather, To reduce the moisture content of this air some drying agent such as silica gel or calcium chloride is used.

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Buccholz relay:There is a pipe connecting the tank and conservator. On this pipe a protective device called Buccholz Relay is mounted. When the transformer is about to be faulty and draws large currents, the oil becomes very hot and decomposers.

This process different types of gases are liberated. The buccholz relay get operated by these gases and gives alarm to operator. If fault continues then the relay will trip off the main circuit breaker to protect the transformer.Explosion vent (pressure release valve):When the transformer becomes faulty, the oil will get decomposed. If the gas pressure reaches a certain level then the explosion vent will burst to release the pressure.

Windings:The conducting material used for the windings depends upon the application, but in all cases the individual turns must be electrically insulated from each other to ensure that the current travels throughout every turn large power transformers use multiple stranded conductors as well. Transformer windings are wound rectangular, cable, paper insulated, copper wires.

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Suitable mechanical strength of the winding is provided by firm pricing by means of suitable plates, located in the top yoke bars.Transformer Bussing:Transformer bushing is the input and output part of the transformers. Output side of bushing is covered with porcelain insulation corner. These bushing can be dividing in to two parts.1) HT Bushings Normally input side of the transformer windings are known as HT bushing. Those bushing are periodically checked and clean the bushing remove the dust on porcelain part may reduce creeping part.2) LT Bushings Normally output side of the transformer endings are known as LT Bussing.

Radiator:Radiator is used for transformer oil cooling purpose.

Tap position switch Oil temperature gauge Winding temperature gauge MOG(magnetic oil level gauge) Primary side terminal box Secondary side terminal box

Transformer Cooling Methods:Air cooling For Dry Type Transformers:Air natural Type (A.N.)

Air Forced type (A.F.)

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Cooling For Oil Immersed Transformers: Oil Natural Air Natural Type (O.N.A.N) Oil Natural Air Forced Type (O.N.A.F.) Oil Forced Air Natural Type (O.F.A.N.) Oil Forced Air Forced Type (O.F.A.F.)

Oil immersed Water Cooling:Oil Natural Water Forced (O.N.W.F.)Oil Forced Water Forced (O.F.W.F.)

Air Natural Transformer Cooling:This type of Transformer Cooling method applies to dry type transformer of small rating. The surrounding air in the vicinity of the transformer is used for cooling. Small transformers below 25kVA and be readily cooled by air natural cooling. However air natural cooling is also used for large dry type transformers. Cooling takes place by convection air currents.

Air Forced Transformer Cooling:This type of cooling is provided for dry type transformers. The air is forced on to the tank surface to increase the rate of heat dissipation. The fans are switched on when the temperature of the winding increases above permissible level.

Oil Natural Air Natural Transformer Cooling:This type of Transformer cooling is widely used for oil filled transformers up to about 30MVA. In Natural cooling, the oil in the tans gets heated due to the heat generated in the core and windings. The hot Oil flows upward and the cold Oil comes down according to the principle of convection. The oil flows in the transformer tank by the principle of natural convection hence this type of cooling is called Oil Natural Cooling. Heat is transferred from core and transformer windings to the oil and the heated oil is cooled by the natural air.Cooling area is increased by providing the cooling tubes.

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Oil natural Air Forced Transformer Cooling:In this method, air fans are mounted near the Transformer and the forced air is directed on to the cooling tubes to increase the rate of cooling. The fans are provided with automatic starting. When the temperature of the oil and windings increases above a permissible value the thermostats switch on cooling fans.This happens during heavy load condition and during higher ambient temperatures. In higher rating transformers where the heat dissipationis difficult this type of cooling is used. Fans are used to forced and air blast on radiators. Forced air cooling increases the heat dissipation rate. In this type of cooling oil circulates by natural convection and the blast of air is directed towards the better heat dissipation rate.

Oil Forced Air Forced Transformer Cooling:

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Transformers above 60 MVA employ a combination of Forced Oil and Forced Air Cooling. Oil Natural Air Forced type of cooling is not adequate to remove the heat caused by the losses which is approximately equal to 1% of the transformer rating (0.6MW). In case of Forced Oil and Forced air cooling system a separate cooler is mounted away from the transformer tank. This cooler is connected to the transformer with pipes at the bottom and the top. The oil is circulated from the transformer to the cooler through the pump. The cooler is provided with the fans which blast air on the cooling tubes. This type of cooling is provided for the higher rating transformers available at the Substations and Power Stations.

Oil Forced Water Forced Transformer Cooling:This type of cooling system needs a heat exchanger in which the heat of the transformer oil is given to the cooling water. The cooling water is taken away and cooled in separate coolers. The oil is forced through the heat exchanger. The oil pump pumps the oil from transformer to the heat exchanger though the top pipes. Oil from the heat exchanger is pumped back to the transformer through the bottom pipe. This type of cooling is provided for very large transformers which have ratings of some hundreds of MVA (Generating Transformer will have very high rating and rating equal to the rating of the generator). This type of transformers is used in large substations and power plants.

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Transformer connection:Star-starStar-deltaDelta-starDelta-delta

Star-star connection:

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Star-delta:

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Losses of transformer:1) Copper losses:These losses occur in both the primary and secondary windings due to their ohmic resistance. These can be determined by short-circuit test. It is clear that copper losses vary as the square of load current Thus if copper losses are 400 W at a load current of 10 A, then they will be(1/2)2 400 = 100 W at a load current of 5A.It may be noted that in a transformer, copper losses account for about90% of the total losses.

2) Iron losses:These consist of hysteresis and eddy current losses and occur in the transformer core due to the alternating flux. These can be determined by open-circuit test. Both hysteresis and eddy current losses depend upon (i) maximum flux density Bm in the core and (ii) supply frequency f. Since transformers are connected to constant-frequency, constant voltages supply both f and Bmare constant. Hence, core or iron losses are practically the same at all loads. The hysteresis loss can be minimized by using steel of high silicon content whereas eddy current loss can be reduced by using core of thin laminations.3) Hysteresis losses:The area enclosed by the hysteresis loop of a material represents the hysteresis loss. Hence special magnetic materials should be used in order to reduce the hysteresis loss. Materials such as silicon steel have hysteresis loops with very small area. Hence such materials are preferred for the construction of core. Commercially such steel is called as lohys, means low hysteresis materials. The hysteresis loss is frequency dependent.

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4) Eddy current loss:Due to the time varying flux, there is some induced emf in the transformer core. This induced emf causes some current to floe through the core body.Thesecurrents are knows as the eddy currents.Eddy current loss = (eddy current loss)2* rThe eddy current losses are minimized by using the laminated core.

Efficiency: Efficiency =

outputinput

=output

output+cu loss+iron loss

Voltage regulation:• Loading changes the output voltage of a transformer. Transformer regulation is the measure of such a deviation.

V no-load =RMS voltage across the load terminals without load.V load = RMS voltage across the load terminals with a specified.

INDUCTION MOTORGeneral principle:As a general rule, conversion of electrical power into mechanical power takes place in the rotating part of an electric motor.In a.c. motors, the rotor does not receive electric power by conduction but by induction in exactly the same way as the secondary of a 2- winding transformer receives its power from the primary. That is why such motors are known as induction motor. In fact, an induction motor can be treated as a rotating transformer; one in which primary winding is stationary but the secondary is free to rotate.

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CONSTRUCTION OF INDUCTION MOTOR:There are two main parts of induction motor.1) Stator 2) Rotor

1) Stator:As the name suggests, it is a stationary part of motor. This part is made of silicon stampings. The stampings are slotted.

When complete stator is assembled; the through slots are formed on the inner side of the stator. The slots may be open type, semi open type or closed type. In these slots, a 3-phase winding is accommodated. This winding may be star or delta connected. The three ends of this windings are brought out into the terminal box where 3- phase a.c. supply can be connected.

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2) Rotor:There are two types of induction motors depending upon the construction of the rotor.a) Squirrel cage type b) wound rotor type

a) Squirrel cage type rotor:This is the simplest and most rugged construction. The rotor consists of a cylindrical laminated core with skewed rotor slots.The rotor conductors which are thick copper bars, are placed in these slots and are brazed of welded to and rings. Thus, the rotor conductors are permanently short-circuited. Therefore it is not possible to add any external resistance in the rotor circuit.

The rotor body is made of silicon steel stampings. The construction of the rotor looks like a cage of squirrel and hence called as squirrel cage type motor.

b) Wound type rotor:In this type of induction motor, the rotor is wound for the same number of poles as that on the stator. The rotor is made up of laminations with slots on the outer periphery in which a 3-phase rotor winding is placed. The three phase are starred internally. The remaining three terminals are brought out and connected to the slip-rings mounted on the shaft.The slip-rings are made up of copper or phosphorus bronze and there are three brushes

resting on them. External connections to additional resistances are done at the brushes.When running under normal conditions, the slip-rings are short-circuited by a metal collar which is pushed along the shaft and the brushes are lifted from the slip-rings to reduce the frictional losses and wear.As a regular 3-phase winding is used for rotor, this type of is called as phase wound rotor type.

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Table of parts & function of IM

PART FUNCTIONStator frame Supports the core, protects inner parts.Stator core Houses stator winding.Stator winding Produces rotating magnetic field.Rotor core Houses rotor winding.Rotor winding To produce rotor current.Cooling fan For air circulationSlip rings Connects resistance to rotor circuit via brushes.Brushes To provide connection between resistance and

slip-rings.Shaft Supports rotor.

Induction motor name plate specification

3 phase ,50 hzKW 45HP 60V 415 ± 10%

CLASS BRPM 1475

A 80.13DUTY S1

4.9KGM 2

AMB 50°CMTG B3

IP 55FRAME D250 S

IP: ingress protection rating.it is used to the environmental protection of electrical equipment.

AMB: ambient temperature.

MTG: mounting

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Variable Frequency DriveA Variable Frequency Drive (VFD) is a system for controlling the rotational speed of AC

electric motor by controlling the frequency of the electric power supplied to the motor.A VFD converts input power to a new frequency in two stages: the rectifier stage and the

inverter stage.The conversion process incorporates three functions.Stages Of VFDRectifier stageInverter StageControl System

3ø

Rectifier dc bus bar inverter 3 phase I.M

Application of VFD:

Constant Torque applications Steel mills machines, Paper machines (winder,tension reels, mill stands) Cement mills, rubber mills, mixers, crushers sConveyors Cranes and elevators cars

Variable Torque applications Centrifugal pumps Centrifugal fans Compressors

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