Water Coolled Fixed Grate Steam Boiler
PT. INDIRA DWI PARTNER
- INITIAL ADMINISTRATION PROCEDURE
- BOILER PREPARATION
- Burn to the fuel chamber (furnace ) by changing the switch switch feeding screw in the MANUAL position , until the furnace is filled with +/- 0.5 m³. After filling, turn the selector switch feeding screw in the AUTO position .
Warning: Hoper boilers must always be filled with fuel, refueling into the furnace is set automatically adjusting steam usage to the process. If the Hoper is not filled with fuel it allows the smoke from the Furnace to come out of the Hoper through a screw.
- START REFILLING BOILER
- Re-check boiler water level and amount of fuel in the furnace.
- Desired pressure boiler settings for modulating RWF controls
How to set RWF 55 (CONTROLLER)
- Turn on the fuel in the boiler furnace. Use combustible material to help start ignition (if needed, flush fuel with enough oil).
- Wait a few moments to make sure the fuel has been burned, turn the selector switch on the FD Fan , ID Fan and Feeding Screw on the on position . (make sure all switches / selector are ON).
- Make sure the RWF Control is in the Manual mode position (Press the ESC button for 5 seconds until the HAND indicator is on the monitor) then enter the manual operation load value of 10%.
- Manually set Feeding Screw (adjust the amount of fuel needed) so that it doesn’t overload until the pressure of the Boiler is pressurized (1 -2 Barg) or the temperature furnace indicator reaches 400-600 degrees Celsius.
- After the Boiler is ready, the Feeding Screw is set in the Auto position, then the Controller (RWF) can be operated Auto (Press ESC for 5 seconds until the HAND indicator does not turn on).
Description: – Under Manual Control (RFW) conditions the FD Fan and Feeding Screw will operate constantly according to the Controller (RWF) manual setting. This means that the amount of fuel put into the furnace is only limited to the RWF manual set point value.
- Under Control (RWF), the AUTO system will work modulating. This means that the amount of fuel put into the furnace follows the Boiler Pressure Point. If the pressure has reached the setpoint then the Fuel is entered only to keep the boiler pressure at the pressure setpoint.
- Because the boiler pressure is still 0 Barg, the boiler will automatically work at a maximum load (load 100%). before the pressure set point is reached the boiler load will decrease according to the use of steam.
- If the use of steam in the process is less than the steam produced, the boiler pressure will continue to rise and when the pressure exceeds the setpoint pressure the boiler will automatically shut down.
- INSTRUCTIONS AT THE OPERATION
- SOME THINGS YOU MUST NOTICE
- Carefully open the valve cover, not to open and close the valve suddenly. Give special attention when opening and closing the steam channel.
- The boiler operator has the main duty to pay attention to water level and pressure. If there is a lack of water or excessive pressure, SOON OFF THE BOILER IMMEDIATELY
- Blowdown Air Boilers as needed, the settling crust will reduce efficiency and will cause overheating of the boiler.
- Popping Safety valve periodically (Minimum 1 Month), but do not be done when high pressure.
- Fill Hoper regularly and measurably.
Things that will happen if the Hoper is not filled properly
- The boiler pressure is unstable because feeding screws sometimes do not carry fuel normally.
- Smoke comes out of the Hoper through feeding screw and the fuel will burn from the furnace.
- The operator fills the fuel to the hopper in a hurry, so it can damage the sling Bucket elevator and Limit switch.
- BOILER SYSTEM
- WATER SYSTEM
- Safety Water Level
Safety water level still follows the existing system which consists of:
- LAH: High Alarm Level, Alarm, BFW OFF
- LAL: Low Alarm Level, Alarm
- LALL: Low Low Alarm Level, Alarm, ID FAN, FD FAN and SCREW OFF
- Feed Pump
The pump On / Off is set from the water level
- PRESSURE SYSTEM
- Pressure Transmiter (PT)
It functions to read the pressure that is on the Boiler and sends it in the form of a signal (4-20 mA) to control FD Fan and Feeding Screw (Modulating).
- Pressure Switch
The Pressure Switch functions as safety pressure. If there is over prssure, the FD FAN and FEEDING SCREW OFF.
- Pressure Indicator (PI)
This pressure indicator or pressure gauge serves to determine the pressure on the boiler.
- Safety Valve
Serves to remove pressure over the boiler according to the safety valve settings.
- Blow Down Valve
To remove sediment water in the boiler. The goal is to reduce the content of water crust.
- GLASS LEVEL
Level Glass functions to know the water level manually.
- Electrical Brake out
If there is a complete power failure (no power) for a long time, turn off all breaker panels. If it starts, start again according to the initial ignition procedure.
- Emergency shut down / Emergency stop
Emergency shut down can be done depending on emergency conditions, Press Emergency Boiler button if emergency shut down is needed for certain boilers.
- BOILER CARE (MAINTENANCE)
- ELEVATOR BUCKET AND FEEDING SCREW
Give lubricants in the form of Grease / Grease on Rolling Buckets Elevator regularly. Keep clean on the Wheel / Rolling Rail. Make sure Bucket Elevators can go up and down easily.
Operate the Bucket Elevator slowly and be careful not to break the sling and damage the Wheel / rolling Bucket elevator.
Warning: The limit switches on bucket elevators are only in addition to the safety of charging Hoper. If the operator is not careful, the limit switch will be quickly damaged.
Check the fuel that is inserted into the Bucket Elevator, if it is carried by hard objects such as stone, iron, wood, etc., it will damage the Feeding Screw.
Check the combustion chamber / furnace. Clean the crust of the remaining combustion in the furnace when the boiler is not operated, do not let the crystallization occur (the fuel does not burn out) because it can clog the vent.
Make sure the air supply from FD Fan must match the fuel requirements that are inserted into the furnace. If there is a blockage in the vent / pores of the furnace, the combustion is incomplete and wastage of fuel occurs.
- MOTOR AND BLOWER
- Ensure cleanliness around the Motor and Blower. Perform preventive maintenance by maintaining the condition of moving equipment such as bearings, shafts, impeller blower screw feeders etc.
- Check the oil in the Gear Box regularly, make sure the oil is well maintained and filled.
- Perform lubrication like other equipment standards, so that moving equipment does not rust and wear.
- Check the Amper motor regularly (min. 1 week) so that motor damage can be predicted early.
- Always pay attention to the change of sound of the blower and the heat of the motor as a sign of abnormalities in the motor and blower.
- WASTE TEMPERATURE
In solid fuels such as shells, coal, wood and others, combustion will cause residual carbon or soot that is likely to close the outer side of the furnace pipe and the inside of the pipe boiler So if dirty it will cause the exhaust gas temperature to rise.
Every increase in exhaust gas is 20 degrees, fuel efficiency will decrease by 1%. Therefore recording the exhaust gas temperature will make it easier to control the condition of carbon impurities in the furnace and boiler.
If left unchecked, the boiler capacity will go down, to avoid cleaning at least once every 6 months.