BOILER CONTROLS &BOILER CONTROLS & …

1 Your Logo HereBOILER CONTROLS & BOILER CONTROLS &HereBOILER CONTROLS & BOILER CONTROLS & INSTRUMENTATIONINSTRUMENTATIONPRESENTED ATPRESENTED ATPRESENTED AT PRESENTED AT M/S. MAGADI SODA COMPANY , M/S. MAGADI SODA COMPANY , MAGADI KENYAMAGADI KENYAMAGADI , KENYAMAGADI , KENYA24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED11 MAJOR CLOSED LOOP CONTROLS IN BOILERMAJOR CLOSED LOOP CONTROLS IN BOILER DRUM LEVEL CONTROLDRUM LEVEL CONTROL PUMP ONPUMP ON--OFF CONTROL ( USED ON OFF CONTROL ( USED ON ((PACKAGED SATURATED STEAM BOILERS)PACKAGED SATURATED STEAM BOILERS) SINGLE ELEMENT DRUM LEVEL CONTROL SINGLE ELEMENT DRUM LEVEL CONTROL ( USED IN SMALL & PACKAGE BOILERS WITH ( USED IN SMALL & PACKAGE BOILERS WITH ECONOMISERS OPERATING AT LOW ECONOMISERS OPERATING AT LOW PRESSURE)PRESSURE)PRESSURE)PRESSURE) THREE ELEMENT DRUM LEVEL CONTROL ( THREE ELEMENT DRUM LEVEL CONTROL ( USED IN HIGH PRESSURE LARGE CAPACITYUSED IN HIGH PRESSURE LARGE CAPACITYUSED IN HIGH PRESSURE LARGE CAPACITY USED IN HIGH PRESSURE LARGE CAPACITY BOILERS )BOILERS )24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED2224/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED33 SINGLE ELEMENT DRUM LEVEL CONTROLSINGLE ELEMENT DRUM LEVEL CONTROL IN A SINGLE ELEMENT CONTROL , THE IN A SINGLE ELEMENT CONTROL , THE LEVEL TRANSMITTER ON THE STEAM LEVEL TRANSMITTER ON THE STEAM DRUM WILL TRANSMIT THE LEVEL DRUM WILL TRANSMIT THE LEVEL SIGNAL TO THE CONTROLLER.

2 LEVEL SIGNAL TO THE CONTROLLER. LEVEL CONTROLLER COMPARES THIS SIGNALCONTROLLER COMPARES THIS SIGNALCONTROLLER COMPARES THIS SIGNAL CONTROLLER COMPARES THIS SIGNAL WITH THE SET POINT AND SENDS AN WITH THE SET POINT AND SENDS AN OUTPUT SIGNAL TO THE FEED WATEROUTPUT SIGNAL TO THE FEED WATEROUTPUT SIGNAL TO THE FEED WATER OUTPUT SIGNAL TO THE FEED WATER CONTROL VALVE TO OPEN OR CLOSE CONTROL VALVE TO OPEN OR CLOSE TO INCREASE OR DECREASE THE FEEDTO INCREASE OR DECREASE THE FEEDTO INCREASE OR DECREASE THE FEED TO INCREASE OR DECREASE THE FEED WATER FLOW TO THE FLOW TO THE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED44 SINGLE ELEMENT DRUM LEVEL CONTROLSINGLE ELEMENT DRUM LEVEL CONTROL24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED55 WHY THREE ELEMENT CONTROL ?WHY THREE ELEMENT CONTROL ? IN HIGH PRESSURE BOILERS , WHEN THE IN HIGH PRESSURE BOILERS , WHEN THE ,,STEAM DEMAND OF THE BOILER INCREASES STEAM DEMAND OF THE BOILER INCREASES SUDDENLY , THE WITHDRAWAL OF STEAM SUDDENLY , THE WITHDRAWAL OF STEAM FROM THE STEAM DRUM WILL BE HIGHERFROM THE STEAM DRUM WILL BE HIGHERFROM THE STEAM DRUM WILL BE HIGHER FROM THE STEAM DRUM WILL BE HIGHER THAN THE STEAM GENERATION AS THAN THE STEAM GENERATION AS COMBUSTION CONTROL WILL TAKE SOME COMBUSTION CONTROL WILL TAKE SOME TIME TO REACT AND INCREASE THE FUEL TIME TO REACT AND INCREASE THE FUEL HEAT INPUT TO THE WILL HEAT INPUT TO THE WILL RESULT IN DRUM PRESSURE FALLINGRESULT IN DRUM PRESSURE FALLINGRESULT IN DRUM PRESSURE FALLING RESULT IN DRUM PRESSURE FALLING TEMPORARILY.

3 THIS LOSS OF PRESSURE TEMPORARILY. THIS LOSS OF PRESSURE WILL RESULT IN THE FORMATION OF STEAM WILL RESULT IN THE FORMATION OF STEAM BUBBLES IN THE DRUM WATER DUE TO THE BUBBLES IN THE DRUM WATER DUE TO THE ENTHAPHY DIFFERENCE BETWEEN THE TWO ENTHAPHY DIFFERENCE BETWEEN THE TWO PRESSURE LEVELSPRESSURE LEVELS24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED66 PRESSURE THREE ELEMENT CONTROL ?WHY THREE ELEMENT CONTROL ?CONTINUEDCONTINUED THIS BUBBLING IN THE DRUM WATER WILL THIS BUBBLING IN THE DRUM WATER WILL RESULT IN THE FOAMING AND INCREASE IN RESULT IN THE FOAMING AND INCREASE IN THE VOLUME LEADING TO THE LEVEL GOINGTHE VOLUME LEADING TO THE LEVEL GOINGTHE VOLUME LEADING TO THE LEVEL GOING THE VOLUME LEADING TO THE LEVEL GOING UP SPURIOUSLY. THE LEVEL TRANSMITTER UP SPURIOUSLY. THE LEVEL TRANSMITTER WILL TRANSMIT THIS INCREASE IN DRUMWILL TRANSMIT THIS INCREASE IN DRUMWILL TRANSMIT THIS INCREASE IN DRUM WILL TRANSMIT THIS INCREASE IN DRUM LEVEL TO THE CONTROLLER LEADING TO LEVEL TO THE CONTROLLER LEADING TO REDUCTION IN FEED WATER FLOW INSTEAD REDUCTION IN FEED WATER FLOW INSTEAD OF INCREASING THE FEED WATER FLOW OF INCREASING THE FEED WATER FLOW DUE TO HIGHER DEAMND ON BOILER .

4 TO DUE TO HIGHER DEAMND ON BOILER . TO AVOID SUCH A WRONG CONTROL 3 ELEMENTAVOID SUCH A WRONG CONTROL 3 ELEMENTAVOID SUCH A WRONG CONTROL 3 ELEMENT AVOID SUCH A WRONG CONTROL 3 ELEMENT DRUM LEVEL CONTROL IS REQUIREDDRUM LEVEL CONTROL IS REQUIRED24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED77 THREE ELEMENT DRUM LEVEL CONTROLTHREE ELEMENT DRUM LEVEL CONTROL IN THIS THE DRUM LEVEL CONTROLLER IN IN THIS THE DRUM LEVEL CONTROLLER IN ADDITION TO RECEIVING THE DRUM LEVEL ADDITION TO RECEIVING THE DRUM LEVEL SIGNAL WILL ALSO RECEIVE THE STEAMSIGNAL WILL ALSO RECEIVE THE STEAMSIGNAL , WILL ALSO RECEIVE THE STEAM SIGNAL , WILL ALSO RECEIVE THE STEAM FLOW AND FEED WATER FLOW FLOW AND FEED WATER FLOW TRANSMITTER SIGNALS. HENCE WHENEVER TRANSMITTER SIGNALS. HENCE WHENEVER THERE IS A DIFFERENCE BETWEEN THETHERE IS A DIFFERENCE BETWEEN THETHERE IS A DIFFERENCE BETWEEN THE THERE IS A DIFFERENCE BETWEEN THE STEAM AND WATER FLOW , THE STEAM AND WATER FLOW , THE CONTROLLER WILL APPLY SUITABLECONTROLLER WILL APPLY SUITABLECONTROLLER WILL APPLY SUITABLE CONTROLLER WILL APPLY SUITABLE CORRECTION TO ITS OUTPUT SIGNAL TO THE CORRECTION TO ITS OUTPUT SIGNAL TO THE FEED CONTROL VALVE.

5 THIS TYPE OF FEED CONTROL VALVE. THIS TYPE OF CONTROL WILL KEEP THE DRUM LEVELCONTROL WILL KEEP THE DRUM LEVELCONTROL WILL KEEP THE DRUM LEVEL CONTROL WILL KEEP THE DRUM LEVEL CONTROL TO FUNCTION CORRECTLY EVEN CONTROL TO FUNCTION CORRECTLY EVEN WHEN THE BOILER LOAD CHANGESWHEN THE BOILER LOAD CHANGES24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED88 OOCGSOOCGS24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED99 FLOW COMPENSATIONSFLOW COMPENSATIONS IN CASE OF FLOW MEASUREMENTS FOR IN CASE OF FLOW MEASUREMENTS FOR COSSS ( SG S )COSSS ( SG S )COMPRESSIBLE FLUIDS ( STEAM , GAS ) , THE COMPRESSIBLE FLUIDS ( STEAM , GAS ) , THE DENSITY WILL CHANGE DUE TO CHANGE IN DENSITY WILL CHANGE DUE TO CHANGE IN PRESSURE AND TEMPERATURE OF THE PRESSURE AND TEMPERATURE OF THE MEDIUM. IN SUCH CASES BOTH THE PRESSURE MEDIUM.

6 IN SUCH CASES BOTH THE PRESSURE AND TEMPERATURE OF THE FLUID ALSO SHALL AND TEMPERATURE OF THE FLUID ALSO SHALL BE MEASURED TO APPLY THE DENSITYBE MEASURED TO APPLY THE DENSITYBE MEASURED TO APPLY THE DENSITY BE MEASURED TO APPLY THE DENSITY CORRECTION FOR THE FLOW MEASUREMENTS. CORRECTION FOR THE FLOW MEASUREMENTS. FOR EXAMPLE IN A THREE ELEMENT DRUM FOR EXAMPLE IN A THREE ELEMENT DRUM LEVEL CONTROL THE CONTROLLER WILL ALSOLEVEL CONTROL THE CONTROLLER WILL ALSOLEVEL CONTROL , THE CONTROLLER WILL ALSO LEVEL CONTROL , THE CONTROLLER WILL ALSO NEED THE STEAM PRESSURE AND NEED THE STEAM PRESSURE AND TEMPERATURE SIGNALS TO CORRECT THE TEMPERATURE SIGNALS TO CORRECT THE STEAM FLOW. WITHOUT THIS THE CONTROL STEAM FLOW. WITHOUT THIS THE CONTROL WILL GO GO THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED1010 SUPER HEATER STEAM TEMPERATURE SUPER HEATER STEAM TEMPERATURE CONTROLCONTROLIN BOILERS WITH HIGH SUPER HEAT IN BOILERS WITH HIGH SUPER HEAT TEMPERATURES IT IS NECESSARY TO PROTECT TEMPERATURES IT IS NECESSARY TO PROTECT THE DOWN STREAM EQUIPMENT LIKE STEAMTHE DOWN STREAM EQUIPMENT LIKE STEAMTHE DOWN STREAM EQUIPMENT LIKE STEAM THE DOWN STREAM EQUIPMENT LIKE STEAM TURBINE FROM LARGE VARIATION IN TURBINE FROM LARGE VARIATION IN TEMPERATURES.

7 ALSO WITHIN THE BOILER TEMPERATURES. ALSO WITHIN THE BOILER CONTROL RANGE( NORMALLY 60 TO 100 % MCR)CONTROL RANGE( NORMALLY 60 TO 100 % MCR)CONTROL RANGE( NORMALLY 60 TO 100 % MCR), CONTROL RANGE( NORMALLY 60 TO 100 % MCR), THE STEAM TEMPERATURE LEAVING THE THE STEAM TEMPERATURE LEAVING THE BOILER IS REQUIRED TO BE MAINTAINED BOILER IS REQUIRED TO BE MAINTAINED CONSTANT IN MANY APPLICATIONS. IN CONSTANT IN MANY APPLICATIONS. IN INDUSTRIAL BOILERS THE SUPER HEATERS ARE INDUSTRIAL BOILERS THE SUPER HEATERS ARE GENERALLY CONVECTIVE TYPE AND HENCE ITS GENERALLY CONVECTIVE TYPE AND HENCE ITS HEAT ABSORPTION WILL GO DOWN WITH BOILER HEAT ABSORPTION WILL GO DOWN WITH BOILER LOAD AND THUS GAS AND THUS GAS THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED1111 SUPER HEATER STEAM TEMPERATURE SUPER HEATER STEAM TEMPERATURE CONTROLCONTROL--CONTINUEDCONTINUEDCONTRO LCONTROLCONTINUEDCONTINUEDHENCE THE SUPER HEATER WILL BE SIZED TO GIVE HENCE THE SUPER HEATER WILL BE SIZED TO GIVE REQUIRED STEAM TEMPERATURE AT THE MINIMUM REQUIRED STEAM TEMPERATURE AT THE MINIMUM OF THE CONTROL LOAD AND AT FULL LOAD IF NOTOF THE CONTROL LOAD AND AT FULL LOAD IF NOTOF THE CONTROL LOAD AND AT FULL LOAD , IF NOT OF THE CONTROL LOAD AND AT FULL LOAD , IF NOT CONTROLLED ,THE SUPER HEATER OUTLET CONTROLLED.

8 THE SUPER HEATER OUTLET TEMPERATURE WILL BE MUCH HIGHER THAN TEMPERATURE WILL BE MUCH HIGHER THAN REQUIRED HENCE SUPER HEATER STEAMREQUIRED HENCE SUPER HEATER STEAMREQUIRED. HENCE SUPER HEATER STEAM REQUIRED. HENCE SUPER HEATER STEAM TEMPERATURE CONTROL IS REQUIRED TEMPERATURE CONTROL IS REQUIRED ESSENTIALLY. THE SUPER HEATER OUTLET ESSENTIALLY. THE SUPER HEATER OUTLET TEMPERATURE IS SENT TO THE CONTROLLER BYTEMPERATURE IS SENT TO THE CONTROLLER BYTEMPERATURE IS SENT TO THE CONTROLLER BY TEMPERATURE IS SENT TO THE CONTROLLER BY THE TEMPERATURE TRANSMITTER. THE THE TEMPERATURE TRANSMITTER. THE CONTROLLERS COMPARES THE SAME WITH THE SET CONTROLLERS COMPARES THE SAME WITH THE SET POINT AND GIVES A RESULTANT SIGNAL TO THEPOINT AND GIVES A RESULTANT SIGNAL TO THEPOINT AND GIVES A RESULTANT SIGNAL TO THE POINT AND GIVES A RESULTANT SIGNAL TO THE SPARY CONTROL VALVE TO CHANGE THE SPRAY SPARY CONTROL VALVE TO CHANGE THE SPRAY WATER QUANTITY WATER QUANTITY 24/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED121224/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED1313 BALANCED DRAFT CONTROLBALANCED DRAFT CONTROLIN BOILERS PROVIDED WITH BOTH FD AND IDIN BOILERS PROVIDED WITH BOTH FD AND IDIN BOILERS PROVIDED WITH BOTH FD AND ID IN BOILERS PROVIDED WITH BOTH FD AND ID FANS IT IS NECESSARY TO MAINTAIN THE FANS IT IS NECESSARY TO MAINTAIN THE FURNACE DRAFT AT NEAR ZERO PRESSURE.

9 FURNACE DRAFT AT NEAR ZERO PRESSURE. ( BETWEEN ( BETWEEN 5 TO 5 TO 10 MMWC TO PREVENT 10 MMWC TO PREVENT FLAME FROM COMING OUT AND INJURING FLAME FROM COMING OUT AND INJURING OPERATING PERSONNEL ) THIS IS DONE BY THISOPERATING PERSONNEL ) THIS IS DONE BY THISOPERATING PERSONNEL ) THIS IS DONE BY THIS OPERATING PERSONNEL ) THIS IS DONE BY THIS CONTROL. THE FURNACE DRAFT TRANSMITTER CONTROL. THE FURNACE DRAFT TRANSMITTER SENDS THE FURNACE DRAFT SIGNAL TO THE SENDS THE FURNACE DRAFT SIGNAL TO THE CONTROLLER CONTROLLER ON COMPARINGCONTROLLER CONTROLLER ON COMPARINGCONTROLLER. CONTROLLER ON COMPARING CONTROLLER. CONTROLLER ON COMPARING THE SAME WITH THE SET POINT SENDS AN THE SAME WITH THE SET POINT SENDS AN OUTPUT SIGNAL TO THE PNEUMATIC POWER OUTPUT SIGNAL TO THE PNEUMATIC POWER CYLINDER OF THE ID FAN DAMPER TO OPEN ORCYLINDER OF THE ID FAN DAMPER TO OPEN ORCYLINDER OF THE ID FAN DAMPER TO OPEN OR CYLINDER OF THE ID FAN DAMPER TO OPEN OR CLOSE THE SAME AND THUS CONTROLS THE CLOSE THE SAME AND THUS CONTROLS THE FURNACE PRESSURE WITHIN PRESSURE WITHIN THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED141424/06/201024/06/2010 THERMODYNE THERMODYNE TECHNOLOGIES PRIVATE TECHNOLOGIES PRIVATE LIMITEDLIMITED1515 COMBUSTION CONTROLCOMBUSTION CONTROLTHE STEAM DEMAND FROM BOILER VARYTHE STEAM DEMAND FROM BOILER VARYTHE STEAM DEMAND FROM BOILER VARY THE STEAM DEMAND FROM BOILER VARY DEPENDING UPON CHANGE IN PROCESS DEPENDING UPON CHANGE IN PROCESS REQUIREMENT OR POWER REQUIREMENT.

10 THE FUEL REQUIREMENT OR POWER REQUIREMENT. THE FUEL FED TO THE BOILER SHOULD BE CONTROLLED TOFED TO THE BOILER SHOULD BE CONTROLLED TOFED TO THE BOILER SHOULD BE CONTROLLED TO FED TO THE BOILER SHOULD BE CONTROLLED TO GIVE THE NECESSARY QUANTITY OF STEAM. THE GIVE THE NECESSARY QUANTITY OF STEAM. THE STEAM DEMAND INCREASE OR DECREASE WILL BE STEAM DEMAND INCREASE OR DECREASE WILL BE INDICATED BY THE BOILER OUTLET PRESSUREINDICATED BY THE BOILER OUTLET PRESSUREINDICATED BY THE BOILER OUTLET PRESSURE. INDICATED BY THE BOILER OUTLET PRESSURE. HENCE COMBUSTION CONTROL IS ESSENTIALLY A HENCE COMBUSTION CONTROL IS ESSENTIALLY A CONTROL TO KEEP THE BOILER OUTLET PRESSURE CONTROL TO KEEP THE BOILER OUTLET PRESSURE CONSTANT THE STEAM PRESSURE TRANSMITTER INCONSTANT THE STEAM PRESSURE TRANSMITTER INCONSTANT. THE STEAM PRESSURE TRANSMITTER IN CONSTANT. THE STEAM PRESSURE TRANSMITTER IN THE MAIN STEAM LINE SENDS THE SIGNAL TO THE THE MAIN STEAM LINE SENDS THE SIGNAL TO THE CONTROLLER WHICH IN TURN SENDS AN OUTPUT CONTROLLER WHICH IN TURN SENDS AN OUTPUT SIGNAL TO THE FEEDER MOTORS IN THE SOLID FUELSIGNAL TO THE FEEDER MOTORS IN THE SOLID FUELSIGNAL TO THE FEEDER MOTORS IN THE SOLID FUEL SIGNAL TO THE FEEDER MOTORS IN THE SOLID FUEL FIRED BOILERS AND TO THE FUEL CONTROL VALVE FIRED BOILERS AND TO