presented by - grainnetequip bucket elevators with a belt alignment monitoring device which will...

Brian Knapp&

Johnny Wheat4BComponentsLimited

PRESENTED BY:

Copyright 2011 © 4B Components Ltd. All Rights Reserved

Combustible Dust (Fuel)

Dispersionof Dust Particles

Ignition Source (Heat)

Confinement of the Dust Cloud

Oxygen in Air (Oxidizer)

YOUR PROBLEM: Grain dust is explosive

YOUR SOLUTION: Remove one of the elements from the dust explosion pentagon


Common Ignition Sources:1. Belt Slip2. Belt Misalignment3. Hot Bearings


If you eliminate these ignition sources then you not only considerably reduce your chance of having an explosion, but you also realize every day values of:

1. Improved Preventative Maintenance2. Smoother Running Equipment3. Longer Service Life for Equipment


YOUR PROBLEM: Belts slipping on the head or drive pulley of amachine is an ignition source

YOUR SOLUTION: Install a speed switch at the tail end of the bucketelevator or conveyor to warn when the belt starts to slip and automatically stop the machine

Senso r

M800 Elite Speed Switch


Standard 1910.272(q)(5)The employer shall equip bucket elevators with a motion detection device which will shut-down the bucket elevator when the belt speed is reduced by no more than 20% of the normal operating speed.


YOUR PROBLEM: Belts misaligning and rubbing against a machine’scasing is an ignition source

YOUR SOLUTION: Install belt misalignment sensors at the drive andtail ends of the bucket elevator to warn when the belt starts to rub and automatically stop the machine

Senso r

Senso r

Touchswitch


Belt Rubbing Through Casing

Standards 1910.272(q)(6)(i) & (q)(6)(ii)Equip bucket elevators with a belt alignment monitoring device which will initiate an alarm to employees when the belt is not tracking properly.


YOUR PROBLEM: Bearings overheating are ignition sources

Sensor

Sensor

ADB Bearing Temperature Sensor


YOUR SOLUTION: Install bearing temperature sensors on all critical bearings such as the drive and tail bearings to warn when a bearing reaches a high temperature and automatically stop the machine

Standard 1910.272(q)(4)(ii)Provide vibration monitoring, temperature monitoring, or other means to monitor the condition of those bearings mounted inside or partially inside the leg casing.


YOUR PROBLEM: Electrical equipment can itself, be an ignitionsource for a grain dust explosion

YOUR SOLUTION: Only install equipment approved / listed andcertified by an NRTL (Nationally Recognized Testing Laboratory)

Class II Division 1 Group G -• For example, inside a bucket elevator or belt conveyor

Class II Division 2 Group G -• For example, outside a bucket elevator or belt conveyor


YOUR PROBLEM: You are not confident that your local electrical service supplier has the experience and knowledge required to

professionally installing a hazard monitoring system

YOUR SOLUTION: 1. Send your electrician to the manufacturers facility for training on the equipment to be installed

2. Have the manufacturer install the system or recommend a suitable installer


YOUR PROBLEM: Operators continue to operate equipment despite hazard monitoring systems indicating that there is a hazardous condition

YOUR SOLUTION: 1. Educate operators on the hazards of grain dust explosions2. Instruct operators of the severe penalties that will be enforced if they do not follow company policy3. Automatically log all alarms and shutdowns so that operators understand that there is a permanent record and they are accountable


YOUR PROBLEM: Equipment does not perform to your expectations

YOUR SOLUTION: 1. Inspect the system and installation2. Commission the system3. Test the system, both initially and periodically4. Train the operators and management on the capabilities, use, maintenance and testing of the system


YOUR PROBLEM: A sensor or control is damaged and the only way to run equipment is by electrically bypassing the hazard monitoring system

YOUR SOLUTION: DO NOT RUN IN BYPASS. Have spare sensors and components available for immediate replacement so that down time is reduced to a minimum

! ! ! WARNING ! ! !


Standard 1910.272 App A

It is imperative that the prearranged schedule of maintenance be adhered to regardless of other facility constraints. The employer should give priority to the maintenance or repair work associated with safety control equipment…

(See Actual Standard For Full Interpretation)


YOUR PROBLEM: 1. OSHA has stepped up its facility inspection and audits in conjunction with their National Emphasis Program (NEP) on dust explosions2. OSHA is finding twice as many violations in relation to the NEP inspections compared with all other types of facilities. One such violation is that bucket elevators and conveyors are not equipped with bearing temperature, belt alignment and underspeed detection monitors

YOUR SOLUTION: 1. Understand the dangers of grain dust, and implement a program of compliance to not only OSHA regulations, but also NFPA and other standards2. Install hazard monitors (as discussed earlier) to help eliminate ignition sources

FINE $


OSHA & NFPA STANDARDS(See Actual Standard For Full Interpretation: OSHA 1910-272, NFPA 61, NFPA 654)

Hazard Requirement

Belt Slip Motion detection device to provide a shutdown and

alarm at 20% reduction in normal belt speed. Also

shutdown of feeding equipment.

Belt Misalignment Belt alignment monitoring devices at head and tail

pulleys, which initiate an alarm.

Bearing Failure Bearing temperature or bearing vibration monitors which

activate and alarm.

Pulley Misalignment Head pulley alignment monitors which activate an alarm.

Plugged Spout Sensors which provide a shutdown and alarm when there

is a plug condition. Also shutdown of feeding equipment.


o NFPA 61 Standard for agricultural and food processing industry (rev. 2008)

o NFPA 68 explosion venting standard (rev. 2007)o NFPA 69 prevention standard (rev. 2008)o NFPA 70 NEC (rev. 2008)o NFPA 77 static electricity (rev. 2007)o NFPA 499 guide to combustible dust area

classifications (rev. 2004)o NFPA 654 standard for general industry (rev. 2006)

NFPA STANDARDS


TYPICAL SENSORS FOR HAZARD MONITORING

Speed & Belt Slippage

Belt Misalignment Bearing Temperature


TYPICAL CONTROLS FOR HAZARD MONITORING

Watchdog™ EliteSingle MachineHazard Monitor

PLC T500 Hotbus™Multi Machine

Hazard Monitor


QUESTIONS?


Belt Misalignment

Hot Bea

rings

Belt Slip

NFPA

OSHA

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