[Virtual Presenter] The dryer is a critical piece of equipment in our process, responsible for drying raw materials to the desired moisture level. The filter media, or FM, plays a crucial role in this process, ensuring that the dried material meets the required specifications. The silo and furnace, or FU, store raw materials and provide necessary heat for the drying process. A metal detector detects any metal particles in the raw materials, which could potentially cause damage to the equipment. Explosion vents are installed to prevent explosions from occurring within the dryer. Filter bags capture any dust or particles generated during the drying process. The deaeration system removes air from the system, preventing oxidation and corrosion. The manhole is kept closed to prevent accidental opening, which could lead to contamination or damage. Air velocity is monitored to ensure it remains within the acceptable range. Finally, rework, testing, and labeling systems are in place to ensure the dried material meets the required standards.. 

Scene 1

[Audio] Proper grounding and earthing of equipment and vessels are essential to prevent ignition sources. Eliminating static electricity sparks and electrical arcs through various measures is crucial. Regular maintenance and reporting of equipment failures can also help prevent mechanical contacts that could ignite a fire. Furthermore, installing metal detectors or divertors between the dryer and mill can significantly reduce the risk of ignition sources. By implementing these measures, we can minimize the likelihood of a dust fire or explosion occurring within the process equipment.. 

Scene 2

Prevent : Dust Fire/Explosion – Inside process equipment (operating - Eg: silo, dryer, mill)

Ignition Source
Confinement
Fuel (Combustible dust)
Air
Dust Explosion
Pentagon
Dispersion

Dust confined in vessel Hatch must be kept always closed during operation  Pressure can be safely released by explosion doors  System designed to pneumatically transfer powder with negative pressure – in event of sealing failure, will not blow out and create a dangerous dust cloud in workplace

Prevent ignition source Static electricity spark / electrical arc – proper grounding/earthing of equipment & vessel Mechanical contact of moving parts – proper maintenance and reporting of equipment failures Metal detector/divertor between dryer and mill

Limit amount of fuel Dryer high high level interlock

[Audio] The risk of fire and explosion inside process equipment, such as silos, dryers, and mills, can be prevented by reducing the amount of fresh air being fed to the fire. This can be achieved by stopping the FM, which prevents the feeding of more oxygen to the fire. An automatic and manually activated steam valve can also cut off the oxygen supply to the fire. Additionally, stopping the feeding of fuel to the fire by stopping the suction of FM, limiting the amount of fuel available, and segregating the process using the rotary valve are essential measures. Discharge to the dryer should also be stopped, either manually or through an interlock trigger. Containing the fire or smoldering material inside the equipment is crucial, and under no circumstances should anyone attempt to release burning or smoldering material into the workplace. Following all safety procedures and protocols is vital to ensure safety.. 

Scene 3

Respond : Dust Fire/Explosion – Inside process equipment (operating) [Eg: silo, dryer, mill]

Reduce fresh air being feed to fire Stop FM -> prevent feeding of more oxygen to fire Automatic & manually activated steam valve to dryer to cutoff oxygen to fire

Contained inside equipment Do not attempt to release burning or smoldering material from equipment into workplace

Stop feeding of fuel to fire Stop suction FM ->  prevent feeding of more fuel to fire Stop discharge to dryer – manually or by interlock trigger RX discharge XV Stop Rotary valve -> segregate into sub-process and limits amount of fuel

[Audio] To prevent ignition sources during rework, it is essential to ensure proper grounding and earthing of big bags and equipment. Limiting the rate of discharge from big bags reduces the accumulation of static charges. Fresh, warm, or hot powder should not be discharged into equipment, as this can lead to the buildup of static charges. No incompatible work, such as hotwork, should be performed near the rework area. When restarting the dryer operation, the bag discharge must be stopped and the hatch of the hopper must be closed. By following these measures, ignition sources can be effectively prevented, minimizing the risk of dust fires and explosions during rework.. 

Scene 4

Prevent : Dust Fire/Explosion– During rework

Dust confined in vessel –  Stop bag discharge, hatch of hopper must be closed before re-start of dryer operation

Prevent ignition source [enforcement] Static electricity spark / electrical arc – proper grounding/earthing of big bags & equipment Limit rate of discharge from big bags (fast particle movement – high accumulation of static charges)  Strictly no discharging of fresh warm/hot powder into equipment (fresh powder – possess static charges)  Ensure no incompatible work (such as hotwork) near rework area

Prevent dispersion into workplace –  FM must be turn on during when discharging bags into hopper

[Audio] Prevent ignition sources such as static electricity sparks or electrical arcs by ensuring proper grounding and earthing of equipment and vessels. Minimize dispersion by immediately stopping equipment when there's a risk of explosion, using vacuum systems instead of compressed air to remove dust, and keeping operating vessel hatches closed. Minimize dust accumulation through daily housekeeping and thorough cleaning during annual shutdowns. Avoid hot work near process openings and ensure proper maintenance and reporting of equipment failures to prevent mechanical contacts that could ignite combustible dust.. 

Scene 5

Dust Fire/Explosion– Outside of process equipment (flash fire)

Prevent ignition source Static electricity spark / electrical arc – proper grounding/earthing of equipment & vessel  Hot work near process openings (sparks into process or material out from process) [PTW, RA] Mechanical contact of moving parts – proper maintenance and reporting of equipment failures

Minimise dust accumulation in workplace –  Daily housekeeping During annual shutdown - thorough housekeeping to remove dust from difficult to reach areas (secondary dust explosion prevention)

Minimise dispersion –  Immediately stop equipment – blow out of dust due to plugging or suction failure Use vacuum system to remove dust from workplace, do not use compress air to blow Keep operating vessel hatch closed – to prevent explosion in vessel leading to dispersion of dust inside building

[Audio] The dryer temperature interlocks prevent overheating of the dryer. When the temperature reaches 70°C, the PLC sends an alarm and requires operator intervention. At 75°C, the PLC also sends an alarm but closes the RX discharge valve and steam purge line. In extreme cases where the temperature exceeds 100°C, the PLC opens the fire extinguishing steam purge valve.. 

Scene 6

HH: PLC -> Alarm + Close RX discharge valve + steam purge line  L : PLC -> Discharge allowed Dryer




 LSH LSHH LSL TC
 H: PLC -> Alarm Operator intervention

[Audio] The temperature interlocks in this dryer system ensure that operators are alerted when the temperature exceeds a certain threshold. At 70 degrees Celsius, the system triggers an alarm, requiring immediate operator intervention. As the temperature rises further to 75 degrees Celsius, the system takes additional action, closing the RX discharge valve and opening the steam purge line. This is a critical safety measure to prevent any potential damage or harm.. 

Scene 7

70oC –> PLC : alarm, operator intervention

75oC –> PLC: Alarm + Close RX discharge valve + steam purge line

100oC –> PLC: Fire extinguish steam purge valve open

[Audio] The temperature and level interlocks in the dryer guarantee secure functioning. Upon reaching 75 degrees Celsius, the PLC triggers an alert and shuts down the RX discharge valve and steam purge line, thereby preventing any potential risks. At 100 degrees Celsius, the PLC activates the fire extinguishing steam purge valve. The level interlocks also significantly contribute to maintaining safety. Whenever the level drops beneath the minimum threshold, the PLC issues an alert and demands operator involvement, thus ensuring the dryer operates within a secure range.. 

Scene 8

[Audio] The final step in our safety measures is the dryer hatch open interlock system, which ensures that the dryer remains shut until it is safe to open it. Once opened, the fan stops immediately, and the hatch can only be unlocked after a 60-second delay, preventing any accidental opening of the hatch, which could lead to a release of hot materials. The dryer latch remains open until the mixer stop and discharge stop signals are received, and finally, the CCR PLC allows the hatch to be opened once all necessary conditions have been met.. 

Scene 9

Process Overview

Proper grounding and earthing of equipment and vessels are essential to prevent ignition sources. Eliminating static electricity sparks and electrical arcs through various measures is crucial. Regular maintenance and reporting of equipment failures can also help prevent mechanical contacts that could ignite a fire. Furthermore, installing metal detectors or divertors between the dryer and mill can significantly reduce the risk of ignition sources. By implementing these measures, we can minimize the likelihood of a dust fire or explosion occurring within the process equipment.

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The risk of fire and explosion inside process equipment, such as silos, dryers, and mills, can be prevented by reducing the amount of fresh air being fed to the fire. This can be achieved by stopping the FM, which prevents the feeding of more oxygen to the fire. An automatic and manually activated steam valve can also cut off the oxygen supply to the fire. Additionally, stopping the feeding of fuel to the fire by stopping the suction of FM, limiting the amount of fuel available, and segregating the process using the rotary valve are essential measures. Discharge to the dryer should also be stopped, either manually or through an interlock trigger. Containing the fire or smoldering material inside the equipment is crucial, and under no circumstances should anyone attempt to release burning or smoldering material into the workplace. Following all safety procedures and protocols is vital to ensure safety.

To prevent ignition sources during rework, it is essential to ensure proper grounding and earthing of big bags and equipment. Limiting the rate of discharge from big bags reduces the accumulation of static charges. Fresh, warm, or hot powder should not be discharged into equipment, as this can lead to the buildup of static charges. No incompatible work, such as hotwork, should be performed near the rework area. When restarting the dryer operation, the bag discharge must be stopped and the hatch of the hopper must be closed. By following these measures, ignition sources can be effectively prevented, minimizing the risk of dust fires and explosions during rework.

Prevent ignition sources such as static electricity sparks or electrical arcs by ensuring proper grounding and earthing of equipment and vessels. Minimize dispersion by immediately stopping equipment when there's a risk of explosion, using vacuum systems instead of compressed air to remove dust, and keeping operating vessel hatches closed. Minimize dust accumulation through daily housekeeping and thorough cleaning during annual shutdowns. Avoid hot work near process openings and ensure proper maintenance and reporting of equipment failures to prevent mechanical contacts that could ignite combustible dust.

The dryer temperature interlocks prevent overheating of the dryer. When the temperature reaches 70 degrees celsius, the P-L-C sends an alarm and requires operator intervention. At 75 degrees celsius, the P-L-C also sends an alarm but closes the RX discharge valve and steam purge line. In extreme cases where the temperature exceeds 100 degrees celsius, the P-L-C opens the fire extinguishing steam purge valve.

The temperature interlocks in this dryer system ensure that operators are alerted when the temperature exceeds a certain threshold. At 70 degrees Celsius, the system triggers an alarm, requiring immediate operator intervention. As the temperature rises further to 75 degrees Celsius, the system takes additional action, closing the RX discharge valve and opening the steam purge line. This is a critical safety measure to prevent any potential damage or harm.

The temperature and level interlocks in the dryer guarantee secure functioning. Upon reaching 75 degrees Celsius, the P-L-C triggers an alert and shuts down the RX discharge valve and steam purge line, thereby preventing any potential risks. At 100 degrees Celsius, the P-L-C activates the fire extinguishing steam purge valve. The level interlocks also significantly contribute to maintaining safety. Whenever the level drops beneath the minimum threshold, the P-L-C issues an alert and demands operator involvement, thus ensuring the dryer operates within a secure range.

The final step in our safety measures is the dryer hatch open interlock system, which ensures that the dryer remains shut until it is safe to open it. Once opened, the fan stops immediately, and the hatch can only be unlocked after a 60-second delay, preventing any accidental opening of the hatch, which could lead to a release of hot materials. The dryer latch remains open until the mixer stop and discharge stop signals are received, and finally, the CCR PLC allows the hatch to be opened once all necessary conditions have been met.