R614-6-9. Filters and Centrifuges

A. Filters-General.

1. The necessary protective equipment shall be supplied and used, to protect employees from chemically harmful, hot or irritating materials.

2. Most filtration equipment is dependent on vacuum and/or pressure operation. Therefore, hazards produced by such vacuum or pressure shall be recognized and precautions and training given commensurate with such hazards.

3. Covers, ventilating hoods, feed chutes or other auxiliary equipment located overhead or suspended above the workers shall be adequately secured by recognized engineering standards and shall be inspected frequently to assure that corrosion wear or any other factor has not deteriorated the suspension system, making it unsafe.

4. When hoods or covers are movable and raised (suspended) so that workers must work under them, positive blocking or supports sufficient to support the load must be in place before the employee commences work under the hood or cover.

5. Floors, walkways, ramps, stairs, or other such equipment shall be adequate for the work performed and they shall have handrailings. Where the materials handled cause floors to become slick, anti-skid surfaces shall be provided.

6. When it is necessary to handle heavy components (in excess of 100 lbs) as a regular part of the operation, a hoist shall be provided. In some cases, depending on the lifting position of the employee, a hoist may be necessary when the components weigh less than 100 lbs.

7. Any filter which is activated by pressure shall be equipped with a pressure gauge installed so as to indicate the pressure within the functional mechanism of the filter.

8. All electrical gear installed in connection with filtration must be grounded. Switch gear should be waterproof or installed above or away from the filtration area. All switch gear shall be properly identified.

9. Sumps or other floor openings shall be protected by covers or railings or other satisfactory barricades.

B. Plate and Frame Filters.

1. The filter shall be fitted for the maximum pressure which can be delivered by the feed pump.

2. Plates and frames shall be properly fitted and dressed so as to reduce leakage to a minimum.

3. Provisions shall be established to control leakage from squirting from the filter into the work area. A full cover is recommended.

4. The handles on plates and frames shall be securely attached. When wooden plates and frames are used, the handles shall be inspected and maintained so as to prevent their pulling out while being handled. Plates and frames with loose handles shall not be installed when reassembling a filter.

5. Spigots, when used, shall be adequately maintained.

6. When the filter cake is dropped into an agitator, hopper, extender chute, or tank, a grizzly or other effective means shall be provided to protect the employee from getting caught or falling into such equipment.

7. Hydraulic closers shall be fitted for the pressure encountered. Adequate blocks or other satisfactory method shall be provided so that the hydraulic pressure can be relieved during the operating cycle of the filter.

8. When a bar is used to tighten the filter, a hand guard or block or other satisfactory means shall be provided on the handle to protect the hands of the operator from being mashed against the floor or other contact surface.

C. Drum filters.

1. Driving machinery shall be guarded or totally enclosed.

2. Agitator drive arms shall be arranged or shall be guarded so that the employee is protected at scissor or pinch points.

3. Air lancing of the feed bath or air agitation shall be controlled. Goggles or face shields shall be worn when using an air lance.

4. Repulper agitators shall be protected by grizzly or other means so that hands or feet cannot come in contact with the blades.

5. Filters shall be maintained or a cover shall be provided so that the blow cannot pass through holes in the blanket in such a manner as to endanger workers. This shall be interpreted as meaning hazardous chemicals or hot solutions.

6. Belt discharges shall be guarded so that the nip points are enclosed or otherwise protected.

7. Employees shall not enter the inside of a drum until it is established that a safe atmosphere exists. A fan or other source of breathable air shall be supplied to insure an adequate oxygen supply inside the drum. An employee shall be available outside the drum in case of emergency.

D. Disc or Leaf Filters.

1. Driving mechanisms shall be adequately guarded or enclosed.

2. Adequate footing shall be provided when changing sectors, retainers or rods.

3. The filter shall be fitted for the vacuum and pressures encountered.

4. Disposal of filter cake shall meet the provisions outlined in R614-6-9.B.6.

5. If conveyor discharge is used, the conveyors shall meet the standards set forth in R614-5-2.

E. Pressure filters-Horizontal and Vertical tank type.

1. Pressure filter tanks shall be constructed under the standards established for unfired pressure vessels.

2. The filter shall be fitted for the pressures encountered.

3. All seal gaskets shall be maintained so as to preclude leakage.

4. Closure mechanisms shall be positive so as to prevent any possibility of the tank opening while under pressure.

5. Hinged lever type of closures shall be so arranged that when the handle passes center, when opening the filter, that the operator is protected from the thrust on the handle or it is reduced to a safe force which can be easily controlled.

6. Individual screw type closures shall all be in place and tightened so as to receive strain uniformly around the circumference of the tank before the filter is placed in operation.

7. No pressure tank type filter shall be opened until all pressure has been relieved and is open to atmosphere.

8. Filter media shall be cleaned in a safe manner. Due caution shall be exercised when using steam, hot water or compressed air.

F. Pan, Tray and Belt Filters.

1. The applicable provisions for all above-mentioned filters shall be followed.

2. The slurry feed shall be so controlled to prevent splashing onto the operator.

G. Vacuum and filtrate pumps and lines.

1. All drives shall be enclosed or guarded.

2. Lines shall be adequately identified.

3. When valves are installed in lines, they shall be accessible from floors, ladders or platforms provided, or shall have extension handles to the working area.

H. Filter aids and reagents.

1. Operators shall be knowledgeable concerning any additives used and the reaction which may be hazardous.

2. Chemicals which may be poisonous or severely ittiating shall have such warnings posted along with procedure concerning their use and instructions in case of hazardous exposure.

3. The storage and handling of any chemicals used shall be in conformance with the Manufacturing Chemists Association data sheet concerning the material.

4. Steam and hot solutions or slurries shall be identified and where practical shall have the lines insulated in areas where employees may contact them.

I. Centrifuges.

1. The housing of all centrifuges shall be electrically grounded.

2. Operators of centrifuges shall be trained concerning the hazards of the operation.

3. Each centrifuge shall be equipped with an interlocking device that will prevent the cover from being opened while the machine is in operation or under power.

4. When the cover is bolted, the interlock will not be necessary, but a positive procedure of lockout and tagging shall be enforced.

5. Each centrifuge shall be adequately anchored and shall be equipped with a vibration cutout device. This must be maintained operable at all times. This requirement may be waived when the centrifuge has a full-time attendant.