The Arlat CF chain and flight sludge collector equipment is designed to be mounted
into rectangular tanks and is suited for Primary and/or Secondary clarifiers as well as water
plant settling tanks. The action of the flights is to scrape the sludge, which settles to the
bottom, to one end where it is collected and transferred to the digesters. The returning
flights travel along the surface of the tank skimming all the scum, which floats, into an Arlat
scum trough or some other removal device.
The Arlat design utilizes non-metallic 720 series chain and sprockets to reduce weight and
cost while providing a reliable and long lasting installation. The scraper flight material is
FRP, fibreglass reinforced plastic, to reduce weight to make installation and maintenance
easier. All flights are connected to the 720 series chain by means of the integrated
connector plate, F26 or F28 depending on the flight size required.
The 720 drive sprockets are keyed to the head shaft which rotates in cast iron wall
bearings fitted with UHMW inserts. UHMW is chosen for its long life, economical price and
to remove the need for greasing bearings that can lead to grease and oils entering the
water stream. The 720 idler sprockets are mounted to stationary shafts utilizing idler
sleeves to reduce the chain drag and required drive torque.
The 78 series bull sprocket is keyed to the head shaft in order to properly transmit the drive
torque to the collector system. The 78 series drive sprockets come in a variety of
configurations; using shear pins with or without trip cams, jaw clutches can be used to
allow a single drive to power two collector units while still offering the ability to segregate a
single tank for maintenance or service.
A variety of options are available to best fit your application:
· Stainless Steel chain is available for severe sludge blanket loading
· Scraper flights are available in a heavy duty profile
· Scraper flights are available in extruded Aluminum
· 2 or 3 shaft configurations are available for non-scum collecting systems or for
DAF tanks
· Full PLC control panels are available that can offer;
o Sprocket monitoring
o Flight monitoring
o Sludge blanket monitoring
o Speed control for the C&F drive system
o Torque monitoring
Technical Information:
· 720 series non-metallic Chain
o Chain material - Glass Filled Nylon
o Pin material - Acetal
o 6” Pitch
o 6000 lb Average Ultimate strength
o 1.4 lbs per foot
· 715 series SS chain (direct replacement for the 720 non-metallic chain)
o Chain material - 403 Stainless Steel
o Pin material - 403 Stainless Steel
o 6” Pitch
o 33,000 lb Average Ultimate strength
o 3.9 lbs per foot
· 78 series non-metallic Chain
o Chain material - Acetal
o Pin material 403 Stainless Steel
o 2.6” Pitch
o 5000 lb Average Ultimate strength
o 1.4 lbs per foot
