EDI Rectifier Panel

KAT Controls Private Limited

INDUSTRY

KAT Controls has been working & supplying EDI Rectifier panels for Water treatment plant manufactures locally & globally. We have been serving this Industry from the last 15 years with repetitive customers assuring us of our quality and the confidence of our Customers.

OBJECTIVE

Electrodeionization (EDI) is a water treatment technology that utilizes electricity, ion exchange membranes and resin to deionize water and separate dissolved ions (impurities) from water. It differs from other water purification technologies wherein it is done without the use of chemical treatments and is usually a polishing treatment to reverse osmosis (RO). There are also EDI units that are often referred to as continuous electrodeionization (CEDI) since the electric current regenerates the resin mass continuously. CEDI technique can achieve very high purity, with conductivity below 0.1 μS/cm.

PROJECT SCOPE

APPLICATION: Electrolytic (EDI/ EDR /ED & BPED) Technologies

Systems for water treatment, demineralization and desalting .Electrolytic technology uses pressure and electrical current to separate soluble ions from water through a semi permeable material which includes both cationic and anionic membranes. Each cell incorporates specific ion exchange resin between the two types of membranes allowing negative and positive ions to only pass through one of the membranes. DC voltage transfers ions from one solution to another through selective ion exchange membranes.

THEORY

An electrode in an electrochemical cell is referred to as either an anode or a cathode, terms that were coined by Michael Faraday. The anode is defined as the electrode at which electrons leave the cell and oxidation occurs, and the cathode as the electrode at which electrons enter the cell and reduction occurs. Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. A bipolar electrode is an electrode that functions as the anode of one cell and the cathode of another cell. Each cell consists of an electrode and an electrolyte with ions that undergo either oxidation or reduction. An electrolyte is a substance containing free ions that behaves as an electrically conductive medium. Because they generally consist of ions in solution, electrolytes are also known as ionic solutions, but molten electrolytes and solid electrolytes are also possible. They are sometimes referred to in abbreviated jargon as lytes. Water is passed between an anode (positive electrode) and a cathode (negative electrode). Ion-selective membranes allow the positive ions to separate from the water toward the negative electrode and the negative ions toward the positive electrode. High purity deionized water results.

SPECIFICATIONS, PROTECTIONS AND SAFETY INSTRUCTIONS FOR EDI RECTIFIER

  1. INPUT AND OUTPUT RATINGS:
    1. Input 415V/380/V480V±10%,3 phase, 50/60 Hz. Total current rating will be as per no. of stack requirement.
    2. Output 1(for upper stage): 3.5A at 100-500V/550V DC
    3. Output 2(for lower stage): 2.5A at 100-500V/550V DC
    4. Output current: Adjustable from 10 to 100%
    5. Current tripping 110%
    6. Output ripple < 3%
    7. Efficiency min 92%
    8. Model to be specified by supplier
    9. Output short circuit protection

Fast acting DC fuse/DC MCB of proper grade and rating to be provided for each stack.

  1. ENCLOSURE FEATURES
    1. Main enclosure should be indoor ventilated floor mountable IP20/IP55
    2. Size and weight will be provided
    3. Color normally RAL7035 Gray, otherwise customer specified
    4. Provision to move the equipment with fork lift
    5. Cable terminals-on lugs for incoming power supply, DC supply and control signals
    6. Cable entry top/bottom. Cable glands will be provided on request
  1. COOLING/ATMOSPHERE
    1. Rectifier will be forced air cooled to be operated at room temperature 45ºC max
    2. Cool air enters from bottom of the enclosure and warm air exits from top. If cooling system failed and abnormal temp. Occurred, the equipment wills ‘CUT OFF’ by thermostat provided on heatsink
    3. Maximum altitude 1000m above sea level
  1. DUTY CUCLE
    1. Continuous 100%, 24 hours a day,7 days a week
  1. CONTROLS
    1. SCR 6 Pulse, Three phase full wave full controller system
    2. Regulation ±1% for voltage and current
    3. Proper thermostat on heatsink for abnormal temp.
    4. SCR PIV 1600V to protect equipment from input high voltage surges
    5. Adequate heatsink to operate SCR Bridge within specified tolerance. Junction temp. Band specified by SCR manufacturers
  1. STARTING EQUIPMENTS
  1. One main input AC circuit breaker MCB/MCCB to protect the equipment from overload and short circuit
  2. One main AC contactor at Transformer secondary to Cut-off output voltage totally and to switch off the output in case of any fault (over current/over temp.)
  1. RECTIFIER SPECIFICATIONS
    1. SCR heatsink over temperature
    2. Main isolation transformer winding over temperature separate thermostat to be provided for each winding
    3. Semiconductor grade fuse for input to protect the DC unit from short circuit/overload
    4. Surge suppression arrangement for SCR to protect from input voltage surges
    5. DC fuse or DC MCB for each stack to avoid damages because of internal/external short circuit
    6. For any sudden rise of current, the SCR firing shall be removed by enable/disable electronic circuit, to protect the equipment from heavy current surge if any.
    7. Single phasing cum wrong phase sequence with under /over voltage protection to be provided. This will protect the equipment from over/under voltage at input side
  1. MAIN ISOLATION TRANSFORMER
    1. Splice free copper windings
    2. Low flux density of core
    3. 180ºC class F insulation to protect the winding in case of abnormal temp
    4. High temp thermostat to be provided to protect the winding in case of abnormal temp.
    5. Core strip to be earthed to avoid leakage current of transformer
    6. BIL of 2.5kV min
    7. Transformer cooling fan will be provided if transformer is placed in separate enclosure. Protection class will be IP20
  1. METERS/CONTROLS
    1. Digital meters to be provided for incoming AC voltage, DC voltage and DC current at front of the panel
    2. Start/stop push button
    3. Voltage and current limit adjustment pot to be provided separately
    4. External operating provision (PLC Operation) like Start/Stop, set voltage/current can be provided on request.
    5. Selector switch to check individual EDI current can be provided on request
    6. Isolator for output voltage and output current can be provided on request
  1. EARTH FAULT
    1. To protect the equipment from earth fault, supplier shall provide earth fault relay at input side on request only
    2. ‘Negative’ terminal of the DC output voltage should be earthed properly at panel end
  1. TESTING/DOCUMENTS
    1. Instruction manual set with all safety instruction bill of material, recommended spares, operating instruction, electrical diagram single line diagram, specifications etc.
    2. Test report of DC source, panel and isolation transformer
    3. Stickers for safety symbols/instructions/warning to be pasted on equipment to increase the awareness.

KAT Controls Implemented Project

30 Stack EDI Rectifier Panel Exported

Leave a Reply

Your email address will not be published. Required fields are marked *

Scroll to top