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Safety At and Around Shredding Plants


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Title: Safety At and Around Shredding Plants

Safety At and Around Shredding Plants
  • April 2013
  • Scott Newell
  • Chairman CEO
  • The Shredder Company, LLC
  • Newell Recycling Co. of El Paso

(No Transcript)
  • To watch a shredder in action the first time can
    be a frightening experience. I have shared the
    experience with a number of people over the past
    fifty years and each time I look at the machine
    through their eyes I see it as being a large
    noisy, dangerous looking, and sounding machine.
  • However, we all soon get jaded to the effects of
    the shredder and after having been around one for
    15 minutes it starts looking like a tame animal
    and we are no longer frightened by it. Sometimes
    we even get to the point where we take the
    machine and it's safe operation for granted and
    we forget to pay sufficient attention to the safe
    operation of that equipment.
  • After all, we think, the machine has been in
    operation for a number of years and no one has
    ever been hurt there. I must confess that even as
    manufacturers it is easy to become complacent.
    Every day it seems that we are faced with more
    pressing problems than the problems of safety,
    especially since the safety-type problems do not
    appear gradually.
  • They come upon us with a great rush in some
    catastrophic type of an event. One does not have
    to be a fortune teller to be able to look into
    the future and see that if pieces of scrap steel
    are bouncing out of the shredder and are falling
    around in the scrap yard, that someone could be
    injured. And, yet, because no one has been
    injured we do not take sufficient steps to
    prevent the possibility of that occurrence.

  • The fact that all of you are here today gives
    evidence that you are concerned with the safe
    operation of your shredding equipment. I believe
    that by following some thought-out practices and
    procedures, we can all operate much more safely
    than we have in the past and I believe that this
    will bring benefits not only to us but to our
    employees and customer alike.
  • There will be a number of areas of concern that
    will be discussed. Included are
  • Explosions,
  • Flying pieces of steel,
  • Electrical safety problems,
  • The guarding of conveyors, sprockets, chains,
    gearboxes, and other moving pieces such as the
  • Safety equipment for operating personnel and
    safety practice for maintenance personnel
  • Adequate warnings and signs necessary in order to
    keep people out of areas that should remain
    personnel-free and to warn people of danger.
  • None of these things will make it certain that we
    will never have another accident around the
    shredder but if these recommendations are
    followed there certainly will be a dramatic
    decrease in the possibility of accidents and a
    dramatic decrease of the incidence of injury to

  • An explosion is certainly the most noticeable
    event that can happen around a shredding plant.
    There can be tremendous noise, plume of flame,
    clouds of smoke, and general disarray. Once
    again, there is a problem for those of us who are
    around shredding plants. I can remember one
    situation during the start up of a new shredding
    plant, when there was a explosion. I had
    automatically dropped to the floor of the control
    tower. When I stood up again, within about two or
    three seconds and looked around the plant, I
    could see the employees still running away from
    the machine. Since they had never seen an
    explosion before they did not know what was going
    to follow next. They thought that, perhaps
    another explosion would follow.
  • Contrast that to the same plant two years later
    when I was at the plant site and there was an
    explosion, this time no one panicked, no one
    moved away very far, each man went to his
    assigned position and repaired an explosion panel
    and the machine was running again within 15
  • The danger of this is that people (including
    managers) tend to get used to these small
    explosions and to accept them as an everyday
    ordinary course of events, type of thing. The
    problem of this is that by accepting them as
    normal we sometimes get lax in the prevention of
    these explosions and someday a much larger
    explosion than has ever occurred may take place
    and in that event it is possible to have
    personnel injury or damage to the equipment.

  • It has been my observation that in some plants
    where they have had a series of small explosions
    with no damage, that the personnel become more
    increasingly careless and then one day they have
    a large explosion which scares everyone and then
    inspections are tightened up, procedures are
    followed more carefully, for a while, until
    people forget again just how bad that explosion
    was. I see it as the responsibility of management
    to continually impress upon people the danger of
    explosions and the need for those explosions
  • Obviously, the best cure for an explosion is to
    prevent that explosion and to prevent that
    explosion means that the explosive material must
    not be introduced into the shredding machine.
  • It must be eliminated from the feed stock before
    it gets to the shredder. Such items as gas tanks,
    propane bottles, paint thinner cans, and various
    other containerized explosive-type material have
    all been put into shredders with resultant
    explosions and sometimes damage.
  • It is important for each plant to teach
    inspectors how to find and eliminate the above
    materials before they get to the pile from which
    the shredder is being fed.

  • A more difficult and more dangerous item are the
    explosives, like plastic explosives, dynamite and
    similar items.
  • The most damage ever done to a shredding mill, of
    which I am aware, was caused by a half-case of
    dynamite that was left in an old automobile that
    a contractor was using as a storage shed and
    which was later stolen. This car was flattened
    and taken to a shredder and when the material was
    processed it caused an explosion that lifted the
    mill housing apart. This type of material is very
    difficult to detect and is very dangerous when it
    causes an explosion in a shredding mill.
  • It is a very rare explosion indeed that causes
    damage to the mill housing.
  • There was never a more appropriate place to apply
    the old adage that "an ounce of prevention is
    worth a pound of cure" than in the elimination of
    potentially explosive materials from being
    introduced into a shredder.
  • No matter how good the inspection systems are,
    there seems to be the possibility that some
    material will eventually get into a shredder that
    will cause explosions. If that fact is
    acknowledged, then it becomes important for us as
    manufacturers and processors to design our
    equipment and to operate that equipment in such a
    way that potential explosions will cause minimum
    damage and will give maximum protection to the
    personnel operating that equipment.

What happens in an explosion
  • In order to understand what must be done to
    prevent explosion damage, it is necessary, I
    believe, to try to understand something about
    what happens in an explosion. At this point I
    should make it clear that I am not speaking as an
    export in the dynamics of explosions, I have
    however, observed many explosions and have
    discussed this matter with a number of people who
    are qualified by virtue of their study of
  • It seems that when explosive material is
    introduced into the shredder, and for the purpose
    of this illustration let's assume that a gasoline
    tank with some liquid fuel is introduced into the
    shredder, as that gasoline tank passes the anvil
    or cutting edge as it goes into the machine, the
    gas tank is ripped open and the fuel vaporizes
    and becomes a potentially explosive vapor present
    in the shredder.
  • As we all know, there are tremendous sparks
    caused by friction where the hammers are hitting
    pieces of scrap inside of the shredder at all
    times. It seems a miracle to me that every fuel
    introduction does not cause a tremendous
    explosion. It has been my experience, however,
    that not every single time does an explosion take
  • This leads me to believe that the proper amount
    of fuel and air must exist in order to sustain
    that explosion.
  • This is one of the things that I believe is
    improved by the use of a Smart Water System (SWS)
    that puts water into the shredder with compressed
    air in proportion to how much scrap is
    beingshredded at any one time.

  • The SWS puts water into the shredder which keeps
    things cooler but it also creates a creates a
    steam that displaces oxygen and from long
    experience we know for certain that the SWS
    reduces the incident and the severity of
  • It is my unproven theory that in the absence of a
    SWS explosions from combustible fuel are
    reinforced by finely dispersed organic pieces of
    cloth from upholstery, seats, and etc. It is my
    thought that the SWS water injection removes many
    of those particles and allows them to exit the
    shredder with the shredded scrap. This material
    is then separated from the magnetic material by
    magnetic separation and by air separators that
    are located away from the shredder. As a
    consequence, the severity of any explosion is
    dramatically reduced.
  • Another advantage of the SWS as compared to the
    older system of removal of air from the shredder
    by an fan and cyclone and perhaps scrubber or bag
    house, is that if the small particles are not
    entrained in the air stream, those same particles
    do not have to be removed by extensive further
  • In jurisdictions where it is still required to
    remove the steam from the shredder instead of
    venting to atmosphere, we find that by moving
    much less air from the shredder we are able to
    reduce the size of the equipment and at the same
    time we can be much cleaner with the particulate
    matter that is eventually released to atmosphere.
    We have been able to meet less than 20 ppm of
    particulate matter and we believe that it is
    possible to reach a goal of 10 ppm of particulate
    matter by use of the SWS along with the air
    system from the shredder.

  • If an air system is connected to the shredder, it
    is important to put the proper explosion relief
    panels on the equipment so that in the event of
    explosion (which we know will happen), it is
    important to release the pressure wave into
    atmosphere at a pressure that is less than the
    tearing strength for the duct work, cyclones,
    fans, scrubbers or bag houses. Hopefully, the
    explosion will be released to the atmosphere
    straight up at low enough pressure wave values so
    that no one is hurt and damage to equipment will
    be minimized.
  • When an explosion occurs, there is a very rapid
    oxidation of the fuel and a release of energy.
    This energy travels in a pressure wave and as the
    pressure wave takes place in an uncontained
    atmosphere it dissipates rather quickly.
  • However, if that pressure wave is inside of a
    contained area, the pressure builds up until it
    has built up as far as it can or until the
    pressure wave has sufficient strength to rupture
    the vessel that it is enclosed in. If the
    enclosing vessel has ductwork or a cyclone then
    the cyclone may rip apart with great force and
    pieces of steel can be thrown away from the area.
    It is important that the explosion panels release
    the pressure wave before the pressure wave has
    sufficient time to build up to the point of the
    tearing strength of the steel.
  • A formula has been developed that seems to work,
    and that is that there should be one square foot
    of explosion panel for every ten cubic feet of
    enclosed volume and that explosion panel must
    release at three pounds per square inch.

  • You may be interested to know how this formula
    was developed.
  • At first, we put explosion panels only on the
    mill section and then we had an explosion that
    destroyed a cyclone.
  • It occurred to us that if we put some explosion
    panels on the cyclone that perhaps the pressure
    would go away and leave the cyclone alone so we
    added panels to the cyclone.
  • This seemed to take care of the next few
    explosions without a problem and we were
    congratulating ourselves on having solved that
  • Then we had a large explosions and again the
    cyclones were damaged. It only seems natural to
    us then that we should put further explosion
    panels on that system.
  • About that time we contacted a University
    professor who did some calculations and assured
    us that one square foot for each 30 enclosed
    cubic feet would probably do the job so we did
    some calculations and put one square foot for
    every twenty cubic contained feet but we did not
    put an explosion panel that released at a low
    enough pressure.

  • After the next series of explosions and further
    conversation with the theoreticians it was
    decided that we needed an explosion pressure wave
    release system that released at a lower PSI and
    that we needed more explosion panels.
  • At the present time, we have found that one
    square foot for every ten cubic feet with that
    explosion panel releasing at 3PSI seems to
    eliminate almost all damage from explosions.
  • It is important to place all of the explosion
    panels so that they release upward and away from
    any area where personnel might be located.
  • If all of the above precautions work correctly
    then the chance of the equipment suffering damage
    will be relatively minor. This is very important
    because when the equipment is not damaged and
    when the explosion forces are vented upward into
    the atmosphere the chances of personnel being
    injured are minimized and this is, after all, our
    major consideration.
  • Every-thing else is replaceable except that human
    being who could be injured in this type of an
    event. The most important thing to remember
    regarding explosions is that the personal safety
    of our employees and our customers is paramount

  • To that end, we must be diligent in the
    inspection of the material that is introduced
    into the shredder and then we must see that the
    shredder has proper explosion relief venting and
    that our people are properly trained to stay out
    of high risk area. While the machine is operating
    there are a number of areas that should be listed
    as being "off limits".
  • Specifically, the area on the discharge side of
    the shredder must be personnel free at all times
    the shredder is operating.
  • The other area of major concern is the area of
    cyclones and scrubber. In the event of an
    explosion it is always possible for some piece of
    steel or other material to fall as the result of
    the explosion and of course there is the
    explosion wave or the pressure wave that can
    cause damage to a person.
  • The control tower as it normally sits looks down
    into the feeding area of the machine. In the
    event of an explosion there is generally a
    pressure wave that comes back up the feeding area
    and affects the control tower. The control tower
    should be built very sturdily and should have
    bullet proof glass such as LEXAN installed as
    windows in that control tower. Those windows must
    be installed securely so that they do not come
    out and injure people in the control tower.
  • A growing number of shredder plants are being
    operated remotely with the use of cameras and
    screens and we will not be surprised if this
    trend continues and gains strength. It is not
    only for the safety of the operator but for more
    efficient use of personnel time and energy.
    Modern shredders are operating more automatically
    all of the time.

Proposed locations for explosion panels
This is what the SWS looks like inside of the
shredder. This reduces the number of explosions
and reduces the severity of explosions.
  • All shredders about which I know anything, have
    the possibility to emit pieces of steel scrap
    back out of the feeding device. You will note
    that I have used the term flying pieces. If you
    have ever been in a court room with a plaintiff
    attorney asking if you were responsible for the
    creation of the shrapnel that injured his
    client you might understand my desire to properly
    characterize the scrap as flying pieces.
  • It seems logical that an opening into a shredding
    mill large enough to let an automobile into the
    shredder also has an opening large enough to let
    a small piece of steel scrap be propelled out of
    the machine.
  • We all know that this can happen but all too
    often we fail to check the continuation. If a
    piece of steel scrap can ricochet out of the
    machine and fail in the scrap yard or on our
    neighbor's property, it stands to reason that
    someone could be hurt by that piece of steel
    scrap. That piece of scrap can by heavy or light,
    it can be twisting or it can be just falling.
  • A check of continuations will show each of us
    that the possibility of extensive damage is very
    real and this problem must be addressed by all of

Modern Shredders have enclosures
  • Sims Adams Plant at Terminal Island

  • TISCO, in Taiyuan, China, worlds largest
    stainless steel producer with 3 Million tons of
    Stainless and 7 Million tons of carbon Steel.
    This is a 10,000 hp shredder with the shredder
    itself inside of a room to control sound,
    emissions and flying pieces.
  • Note that the operators control room is just
    outside of the building.

Safety shield over feeding device
  • Grossman Iron and Metal

  • Note that the shield extends down to very close
    to the DFR feed area.

Newell Savannah shield being installed about 5
years ago.
Drawing showing shield between the shredder and
feeding system.
ADELCA, Quito, Ecuador. Note the rubber curtains
to deflect flying pieces from USO area.
Photo showing proper handrails, kick boards,
shielding around head and tail pulleys . At
ADELCAs steel mill in Quito

Drive shaft guard to reduce consequential damage
in case of failure.
  • The exact mechanics of how that piece of steel
    scrap comes out of the machine are not known, but
    it seems that the hammers traveling at about
    15,000 feet per minute can impart a sufficient
    velocity to a piece of steel scrap so that it can
    possible ricochet once, twice, perhaps even three
    times and still leave the machine with some
    amount of velocity.
  • Certainly not a very high percentage of pieces
    ever leave the machine in this matter but when
    you are handling millions of pieces a day, a
    statistically very small percentage can amount
    to a large number of pieces.
  • In order to combat this problem a number of
    deflectors and operating techniques have been
    designed that minimize the possibility of those
    pieces coming out of the machine.
  • First of all, the operator is instructed to keep
    the feed roller in the down position as much as
    possible and to keep scrap material in the
    feeding device. We have all seen what happens
    when the feed roller is lifted high when the
    machine is processing material, when there is no
    material in the feeding device a large number of
    pieces can ricochet from the feed opening,
    therefore, it is important for the operator to
    keep the feeding device low and to keep scrap
    material in the feed hopper.
  • Modern shredder that are being operated by a
    Smart Shredding System (SSS) made by us or by
    other manufacturers, keep the feeding device low
    and in contact with incoming scrap at all times
    because the SSS only raises the feeding system
    when there is a requirement caused by an increase
    of pressure to the hydraulic system. This only
    happens when scrap is under the roller so this
    minimizes the flying piece problem.

  • Normally, this will prevent any pieces from
    emerging, however, sometimes it is possible for a
    piece to ricochet off of the anvil or the feeding
    area and bounce straight up. Therefore, a shield
    is designed to fit between the shredding mill and
    feed roller. This shield must be kept in good
    repair so that it will deflect upward ricocheting
  • No matter how well the shields and deflectors and
    enclosures are designed, it might be possible for
    piece of flying material to get out of the
    shredder and the enclosures and to land in the
    area adjacent to the shredder or behind the
    shredder, therefore it is important to maintain a
    personnel free area around the equipment during
  • The entire scrapyard should be a hardhat area so
    that if the safety precautions fail the chance
    for a serious accident will be minimized.

Unshreddable Items
  • We have already discussed the importance of not
    introducing into the shredder any explosion
    producing material and now we should discuss the
    other items that should not be put into the
    shredder for fear of causing damage and injury.
  • All shredders operators know the damage that can
    be caused by an unshreddable piece going into the
  • Normally, we do not consider this to be a safety
    problem in terms of damage to people but it
    should be realized that a very real danger does
    exist when an unshreddable piece goes into the
  • No one knows the extent of damage that can be
    caused. But we know that a driveshaft could
    possibly break or there could be other structural
  • It is a fact that while we do not know exactly
    what can happen we do know that it is certainly
    possible for someone to be hurt. Massive
    unshreddables should be kept out of the shredder
    for all kinds of reasons.

Massive unshreddable identified in entry chute
The worlds most highly paid maintenance guy
(George Adams) shows how to safely and correctly
remove that piece. Note he is in safety harness
and is properly clothed with all safety equipment.
  • Unshreddable safely removed!

Massive unshreddable caused serious damage,
including broken bearing housing, bearing and
drive shaft damage.
Broken draw bar and broken yoke bearings on Drive
Shaft. This was a 100,000 massive unshreddable
but it could have been worse. It could have bent
the rotor shaft, which would have made it a
500,000 unshreddable.
Removal of a massive unshreddable after the
10,000 HP shredder, but this time lucky with no
damage, as the piece was removed by operation of
the reject door.
More unshreddables
(No Transcript)
Special Concern for wire rope
  • Something that is not often mentioned but which
    is a serious danger is the processing of wire
    rope in lengths beyond 5 meters.
  • When a length of wire rope or cable of any kind
    is strung out through the incoming scrap and part
    of it gets fed into the shredder, a contact with
    a hammer can accelerate that length of wire rope
    from zero to 15,000 feet per minute instantly.
    This can cause a whip like action of the wire
    rope that can damage the equipment or even worse
    it can cause serious injury or death.
  • In one very sad situation, a wire rope
    accelerated and threw a bar over the top of the
    shredder and the bar hit an employee working on
    the picking conveyor after the magnets. The bar
    went through the protective cage and hit the
    employee in the side of the head and killed him
  • In all of our sales literature, we specify that
    wire rope or cable longer than 5 meters should
    not be processed by shredding.

  • There have been several accidents at shredding
    plants of which I am aware, where improper
    operation of electrical equipment has caused
    serious injury to personnel as well as extensive
    damage to the plant.
  • Electrical equipment should only be operated by
    properly trained personnel and should never be
    patch fixed. If something is wrong it must be
    fixed properly.
  • Operating instructions for starting gear must be
    followed precisely and the operating people need
    to develop a healthy respect for the damage that
    can be caused by electrical failures.
  • The most common serious electrical accident
    involved opening the high voltage starter which
    has 4160 volts while the motor was under load.
    This causes a heavy flashover and damaged the
    equipment and seriously injured the person who
    opened the switch.
  • It has also been my experience that operators
    tend to patch-fix something if it happens during
    the middle of an operating shift, believing they
    can wire around fuses, bypass safety devices
    until the end of the shift. This is very poor
    practice and has led to some extensive damage and
    some personal injury.
  • When there is an electrical problem, it needs to
    be fixed correctly and immediately.

Very dirty filter at electrical controls.
Checking found that dirty air was entering the
electrical room through the cable trench!
  • This is another piece of electrical equipment
    that was being subject to dirt coming into the
    room from the conduit trench.
  • The point to emphasize is that the electrical
    motor room has to have cool clean air at all
  • There are numerous examples of electrical failure
    caused by air filled with fine iron particles
    causing a short circuit and serious problem.

Some examples of what not to do! Open electrical
boxes are bad, bad for safety and bad for
(No Transcript)
Safety and maintenance nightmare!
  • While the equipment that we are going to discuss
    in this section is not as spectacular or as
    obvious as an explosion or flying piece of steel,
    you may be surprised to realize that more
    injuries and more deaths have been caused by
    improper operation of conveyors than any other
    piece of equipment around the shredder.
  • This is an area that has been specifically
    covered by OSHA regulations, but too often these
    regulations are ignored or not followed

Note the chains to prevent entry to an area where
there is rotating equipment. Also note the fire
extinguisher present.
All pinch points at conveyors must be
protected by proper shielding. Also note that
Pancho is wearing hard hat, glasses with side
protection, bright vest and hard toes shoes.
Belts and pulleys must be totally guarded
Belts and pulley covers are requried.
Safety during Maintenance ProceduresPancho
Rojas, Shredder Manager at SAR TI, uses a model
of his shredder to explain to the maintenance
team what they will be doing during a scheduled
procedure. In this photo he is getting the team
ready to change a back wall casting, which is
never easy. The team gather around and go
through the plan step by step before going to the
Please note the removable catwalk which is added
when working inside of the shredder. Please note
the cover for the rotating positioning device on
the end of the rotor.
Hammer Changing
  • It is important to have a safe place to stand
    while connecting a lifting device to the hammers
    and pin protectors that must be held while the
    pin is being withdrawn hydraulically.
  • The rotor needs to be held in position so that
    when some castings are removed from the rotor
    that it will not try to turn because of the out
    of balance situation.

Note catwalk and handrails complete with kick
boards. All rotating equipment has been
protected with screens or by other shields.
It is important to identify confined spaces and
to apply the correct safety procedures when
working inside of these areas.
Pinch points are shielded and there are barriers
to prevent employees from getting caught by
conveyor belt and or rollers.
All electrical and hydraulic rooms at SAR plants
are kept in very, very clean condition as a
matter of company policy.
SAR TI have photos on each of the pieces of
hydraulic equipment in the hydraulic room showing
the equipment that each powers. This helps the
employees to properly lock out the equipment
before starting work on that piece.
(No Transcript)
Warning signs and labels help employees to
recognize what they are doing and provides
information and motivation to do it correctly.
(No Transcript)
Safety Alert to warn maintenance people of the
dangers, in this case of very high pressure oil
leaks. This is a photo of someones hand who
simply pointed to a very high oil pressure leak
in a pipe. The oil entered his hand and cause
extensive damage.
  • It may or may not be surprising to you to realize
    that a large percentage of the accidents that
    result in injuries to personnel occur when the
    shredding plant is shut down and maintenance is
    being performed. It is important to be aware of
    the type of problems that can occur and the
    preventive methods that will keep them from
    happening. (photo of SAR model)
  • Some of the things to look for are as follows
  • The electric motor that powers the shredder mill
    itself must be
  • able to be locked out so that there is no chance
    of this motor being started while people are in
    the shredder.
  • All modern shredders are opened for maintenance
    and therefore must have safety blocks to insure
    that the mill will stay open while personnel are
    in the area.
  • It should be remembered that no one should work
    alone at the shredder because of the danger of
    injury due to slipping, dropping something on
    one's self, etc. If a person is alone he may not
    be able to get help.

  • 2.) The rotor should be held in place while it
    is being worked on. While changing hammers the
    rotor becomes unbalanced and if the wrong type of
    safety hold is being used the rotor could turn
    quickly injuring someone.
  • 3.) Changing hammers can be a dangerous
    operation . When the
  • hammer pin is being changed with a hydraulic
    system, there is considerable pressure required
    to move the pin and there is
  • always the danger of something breaking or
    slipping and when
  • there is that amount of pressure available,
    something can fly.
  • Injuries have occurred when changing hammers and
  • requires diligence on the part of the supervisor
    to keep people in an area where is something
    fails it fails to the safe side.
  • When more than one worker is welding, care must
    be taken to avoid
  • flash burns as the welding is being done in a
    close proximity and
  • it is quite often a problem in that one welder
    will catch a flash-
  • burn from a welder working nearby. This problem
    can be solved but, again, it requires diligence
    on the part of the supervisor to keep the men
    properly spaced.

  • 4.) The men should have proper tools for the job
    that they are
  • working on. Injuries have occurred because
    someone tried to do
  • something with a tool that did not fit. He tried
    to improvise, tried
  • to stack pieces on top of each other in order to
    use a hydraulic
  • jack when a jack should have been placed in
    another position. The proper tools should be
    available and should be used.

  • 5.) Extreme caution must be exercised when
    cleaning out ductwork
  • And cyclones. Several people have been injured by
    the failure to
  • Lock out an airlock while working inside a
  • Electrical switches should have the ability to be
    locked in an open position so that there is no
    chance of an accidental equipment start-up.

The following are a series of warnings
appropriate to post at your shredding plant.
Observance of these warnings will make your
shredding plant a safer place.
  • 1. WARNING
  • Exclude from processing all items that can cause
    explosion or fire. Examples are items such as
    gasoline tanks, propane tanks, paint thinner
    cans, and closed containers of any kind.
  • Extreme caution should be exercised in order to
    prevent explosives such as dynamite or plastic
    explosives from ever entering into the shredder.
    It should be noted that the above list is not
    intended to be exhaustive but rather contains
    examples of items to avoid.

  • 2. WARNING
  • Exclude from material to be processed all types
    of massive unshreddable material such as steel
    billets or ingots, heavy steel shafts large
    gears, or large electric rotors.
  • The above list is not intended to be exhaustive
    but rather contains examples of items to avoid.

  • 4. WARNING
  • In order to minimize the danger of pieces of
    materials flying back from the mouth of the
    shredder, the feed roll should be kept as close
    as possible to the feed ramp at all times during
    shredder operations.

  • 3. WARNING
  • Exclude from material to be processed all types
    of long pieces of wire rope and other types of
    long stringy items. Attempts to shred this type
    of material may cause the long pieces to
    accelerate very quickly allowing that long piece
    either to strike someone or to throw some other
    type of scrap material around the scrapyard which
    may strike someone.

  • Despite careful operation particles of scrap
    material may occasionally be ejected back from
    the shredder with sufficient force to cause
    injury to persons or damage to property.
  • Do not operate the shredder while any persons is
    within the designated hardhat area.

  • 6. WARNING
  • The rotor and hammers will continue rotation for
    a full 30 minutes after motor shutdown. All
    precautions observed during the actual shredder
    operation should be observed during this
    additional period.
  • 7. WARNING
  • Do not operate the shredder unless it is certain
    that all deflectors are
  • in proper operating condition in order to prevent
    emissions from the shredder. This includes proper
    operation of the feed roller, checking the
    deflector between the mill housing and the feed
    roller, checking the rubber curtain behind the
    feed roller.

Manager's Check List of Safety Items
  •  The following items should be verified on a
    periodic basis
  • 1. The entire plant should be a hard hat area.
  • 2. During shredder operation the personnel
    free area (adjacent to the shredder and cyclones)
    must be properly observed.
  • 3. Scrap must be inspected for explosive
    material before processing.
  • Inspector must know where to look for fuel tanks
    on different makes of automobiles and must
    exclude from scrap to be processed all types of
    explosive materials.
  • 4. Scrap must be inspected or wire rope, cable
    and other long stringy items and these items must
    be excluded from the shredder.

  • 5. A warning horn should be sounded before
    equipment starts in operation so that personnel
    will know to stand clear.
  • 6. The explosion relief panels should be
    checked to verify that
  • there are sufficient numbers of them and that
    they are working properly.
  • 7. The electric motor room and other
    electrical equiment should be clean and neat and
    all monitoring equipment should be in good
    working order. Personnel should be properly
    trained before being allowed to operate the
    electrical equipment.
  • 8. The drive shaft and rotor should be
    protected so that personnel can not come into
    contact with them while they are rotating.
  • 9. All pinch points at conveyors should be
  • 10. All chains and sprockets and all belts and
    pulleys should be guarded.

  • 11. All machinery should have electrical
    equipment that can be locked out during
    maintenance procedures.
  • 12. All personnel at the shredder should be
    wearing hard hats, safety shoes, gloves and
    proper clothing.
  • Explanation for items checked and NOT OK along
    with corrective action taken
  • WARNING This list is not intended to be
    exhaustive but rather it is intended to be a list
    of the type of things to look for.

  • The following questions are a good reminder and
    the person responsible should ask these often
  • First, note whether or not proper personnel free
    zones are being maintained while the machine is
    in operation.
  • Secondly, note if the appropriate hard hat,
    proper shoes, and eye protection areas being
  • Next, are all moving machinery parts adequately
    protected? This means that all sprockets, all
    belts, sheaves, pulleys should be protected so
    that a man can not get his hand into the moving
    parts. All pinch points on conveyor belts should
    be properly protected to keep someone from
    getting hand or clothing caught in the moving
  • Are all electrical boxes properly closed?
  • Are all areas around those electrical boxes clean
    and free from oil and water?
  • Are there warning signs located appropriately?
  • Do the employees on the scene have the proper
    safety equipment? It seems to be necessary around
    the shredder for all employees to have on a hard
    hat and for them to be wearing eye protection and
    hand gloves.
  • It is also important that loose clothing be
    prohibited and that long hair must be protected
    by being under a cap or by being held back so
    that it cannot become entangled in machinery.

  • There are a great number of things that can go
    wrong at a shredding
  • plant and many of them can cause injury to
    personnel. Efforts to reduce the chances of such
    an occurrence are worthwhile and will certainly
    pay large dividends.
  • Our people must be trained and then motivated to
    make these efforts and then we must go back to
    see that programs for safer operations are
    consistently implemented. It takes great effort
    to keep people from becoming lax. It seems that
    we must all be constantly reminded.
  • I think that it is very important for each of us
    to implement the philosophy and the policy of
  • Safely or not at all

  • This paper will be posted to the downloads
    section of the web site
  • If there are any questions or comments please
  • Scott Newell
  • Chairman CEO
  • The Shredder Company, LLC
  • 1 915 276 3900

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