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1. Drive Motor
Drive motor horsepower is determined based on process load requirements to achieve
desired velocity gradient value, plus drive efficiencies, frictional losses and a safety
factor. All drive motors include severe duty features. Insulation upgrades can be
provided when using variable frequency drives.
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2. Variable Speed Device
Variable speed capabilities allow optimization of the flocculation process. A
mechanical variable speed device, as pictured, provides up to a 5:1 speed ratio
using a traction disc design. A variable frequency drive (VFD) can be supplied which
provides up to a 10:1 speed adjustment, infinitely adjustable in that range. VFD duty
motors are required and supplied for this service.
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3. Gear Reducer
Gear reducer selection is based on reduction ratio required to achieve desired
paddle tip speed as well as input horsepower required to achieve process requirements. The
preferred gearing design is Helical Bevel. All reducers are provided with
severe duty features, which include wash down ability.
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4. Chain & Sprocket Power
Transfer
Rotational movement is transferred from the gear reducer output shaft to the
flocculator line shaft through a chain and sprocket arrangement. A direct couple
arrangement can be provided when a dry well, of sufficient size, is available. Shear pin
mechanisms, for over-torque protection, can be supplied for either arrangement.
The chain and sprocket arrangement can provide up to 4:1 additional speed ratio.
Non-metallic or metallic (steel or stainless steel) chain can be provided based on the
process load and chain tension. Steel sprocket hubs with replaceable UHMW-PE teeth is
standard. The chain can run wet, in the basin or in a dry well. A chain tensioner is
supplied if required. The direct couple arrangement does not provide additional reduction
but eliminates chain and sprocket maintenance.
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5. Stuffing Box
A stuffing box is required when utilizing a dry well with either a chain and sprocket or
direct couple drive arrangement. The stuffing box stops water leakage where the
flocculator line shaft penetrates a basin wall. The Jim Myers & Sons, Inc. stuffing
box utilizes a centering/shoulder bushing, lantern ring and rope packing. Grease
lubrication is recommended to optimize the stuffing box performance. The stuffing box can
be housed in a wall sleeve using link seals to stop water flow and center the stuffing
box. This arrangement allows the entire stuffing box to be removed for maintenance
if required.
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6. Flocculator Line Shafting
Line shafting can be provided as solid bar shafts or pipe shafts with solid bar spool
shafts at bearing points. Solid bar and pipe shafts can be provided in various grades of
carbon steel or stainless steel. Solid bar and pipe shaft diameters selected are based on
process loads, input horsepower, stress and deflection. Carbon steel shafts are provided
with an NSF approved paint system.
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7. Shaft Connections
Solid bar shaft connections are made with compression couplings at required locations.
Pipe shaft connections are made with ANSI flange connections, typically on either side of
a bearing location.
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8. Bearings
Shaft bearings are supplied and sized based on the required shaft diameter. Split bearing
design is required for shaft removal. Adjustable bearing base plates are required to
achieve proper bearing alignment.
Split cylindrical roller bearings can be supplied and provide self-aligning
characteristics, contaminant protection of internals using triple labyrinth seals, and
long service life. Grease lubrication is required by means of a packed grease cavity or
grease lines. Cooper split cylindrical bearings are standard.
Split journal bearings can be supplied and provided with UHMW-PE, bronze or Ryertex
liners. Journal bearings are typically water lubricated during wet operation but may
require lubrication during dry operation.
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9. Paddle Reel Assemblies
Paddle reel assemblies are designed based on specific job requirements. Quantity of reels,
geometry of each reel and paddleboard size is determined based on process
requirements. Paddle arms are painted carbon steel or stainless steel. Paddle
blades are fiberglass as a standard. Blade widths vary based on process requirements.
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