Scour-Pak® Gravity Filter
Graver’s Scour-Pak® is a heavy-duty, self-cleaning gravity depth filter that uses vigorous air scour followed by backwash. The Scour-Pak filter successfully incorporates the economic advantages of roughing filtration followed by polishing, with air scour. All flow flow control and operating components necessary for automatic operation are built into a central, factory-assembled control center, which can be installed in square or rectangular filter compartments.
Typical Applications
- Clarifier Effluent Polishing
- Cooling Tower Sidestream Filtration
- Reverse Osmosis Pretreatment
- Iron & Manganese Removal
- Direct Filtration With or Without In-Line Coagulation
Scour-Pak® Advantages
- Heavy duty (high turbidity influent) filtration capability because of the depth filtration. Handles high turbidity loads and difficult particles
- The media stays clean even with sticky particles because of the vigorous air scour preceding the backwash using the unique AWS strainers
- It can be operated at substantially higher than normal flow rates on moderately turbid waters
- Air scour also substantially reduces the volume of water required to clean the filter
- The compact, central control column conserves building space. It also reduces installation costs since it is shipped factory assembled
- The key design features have been proven by more than thirty years of use
- Substantial cost savings are possible because the filters provide their own backwash water, thus eliminating all of the equipment needed for a conventional gravity filter backwash
How it Works
Filtering: Water enters at the inlet flow trough where the inlet flow is hydraulically split among all compartments. It flows down through the filter bed into the false bottom of the filter and then into a common weir compartment, preceeding a clearwell. Flow continues until a pre-determined pressure drop builds up across the bed in one compartment. This compartment then automatically ends the service cycle and begins the cleaning cycle. The length of the service cycle depends on the quantity and nature of the turbidity in the water being filtered.
Draindown and Air Scour: During drain down, the water level in the cell is dropped to prevent loss of media during air scour. This is done by closing influent valve A and outlet valve W, and opening the draindown valve U and the backflush outlet valve C. When the correct level is reached, the air scour timer starts and the blower delivers air to the plenum chamber under the strainer plate through an air distributor and then through air metering tubes into the filter bed. The patented Partilok strainers produce a vigorous scrubbing action which loosens all dirt from the filter media. No water is used during this operation. After a suitable period of air scour, normally five minutes but adjustable, the air scour step ends.
Backwashing: The filter is normally backwashed with water provided by the other cells remaining in service. The necessary head is achieved by the
effluent head weir, while the flow rate is set by means of an adjustable
stop on cell isolation valve W. The bed is expanded by the upflowing
water, which carries the dirt already loosened by the air scour to
waste. The quantity of backflush water needed to clean the bed effectively
is substantially reduced because of the prior air scour. The quantity of backflush water used is adjustable. This step completes the cleaning
cycle and the filter is automatically returned to service by closing the
backflush outlet valve and opening the influent valve.
Scour-Pak® Gravity Filter
Graver’s Scour-Pak® is a heavy-duty, self-cleaning gravity depth filter that uses vigorous air scour followed by backwash. The Scour-Pak filter successfully incorporates the economic advantages of roughing filtration followed by polishing, with air scour. All flow flow control and operating components necessary for automatic operation are built into a central, factory-assembled control center, which can be installed in square or rectangular filter compartments.
Typical Applications
- Clarifier Effluent Polishing
- Cooling Tower Sidestream Filtration
- Reverse Osmosis Pretreatment
- Iron & Manganese Removal
- Direct Filtration With or Without In-Line Coagulation
Scour-Pak® Advantages
- Heavy duty (high turbidity influent) filtration capability because of the depth filtration. Handles high turbidity loads and difficult particles
- The media stays clean even with sticky particles because of the vigorous air scour preceding the backwash using the unique AWS strainers
- It can be operated at substantially higher than normal flow rates on moderately turbid waters
- Air scour also substantially reduces the volume of water required to clean the filter
- The compact, central control column conserves building space. It also reduces installation costs since it is shipped factory assembled
- The key design features have been proven by more than thirty years of use
- Substantial cost savings are possible because the filters provide their own backwash water, thus eliminating all of the equipment needed for a conventional gravity filter backwash
How it Works
Filtering: Water enters at the inlet flow trough where the inlet flow is hydraulically split among all compartments. It flows down through the filter bed into the false bottom of the filter and then into a common weir compartment, preceeding a clearwell. Flow continues until a pre-determined pressure drop builds up across the bed in one compartment. This compartment then automatically ends the service cycle and begins the cleaning cycle. The length of the service cycle depends on the quantity and nature of the turbidity in the water being filtered.
Draindown and Air Scour: During drain down, the water level in the cell is dropped to prevent loss of media during air scour. This is done by closing influent valve A and outlet valve W, and opening the draindown valve U and the backflush outlet valve C. When the correct level is reached, the air scour timer starts and the blower delivers air to the plenum chamber under the strainer plate through an air distributor and then through air metering tubes into the filter bed. The patented Partilok strainers produce a vigorous scrubbing action which loosens all dirt from the filter media. No water is used during this operation. After a suitable period of air scour, normally five minutes but adjustable, the air scour step ends.
Backwashing: The filter is normally backwashed with water provided by the other cells remaining in service. The necessary head is achieved by the
effluent head weir, while the flow rate is set by means of an adjustable
stop on cell isolation valve W. The bed is expanded by the upflowing
water, which carries the dirt already loosened by the air scour to
waste. The quantity of backflush water needed to clean the bed effectively
is substantially reduced because of the prior air scour. The quantity of backflush water used is adjustable. This step completes the cleaning
cycle and the filter is automatically returned to service by closing the
backflush outlet valve and opening the influent valve.
