Filter with sand for water treatment
Filter with sand Function:
Trap organics,suspended solid,colloidal solid,microorganisms in water.
Remove nitrogen and phosphorus
Reduce COD(Chemical Oxygen Demand) in water
Filter with sand Working Principle:
Continuous sand filter is widely used in many fields,especially for drinking water,industrial process water,sewage and industrial waste water purification. It is a kind of continuous filter,combined flocculent,settling,filtering together.For tertiary filtration of reclaimed water, the gravity sand filter offers advanced treatment:efficiently remove suspended and colloidal solid, oil,iron and manganese oxide,and kill the bacterial,algae,virus in water.
Route of water: Raw water enter into inlet pipe(1)feed into sand filter(2)and water distributor(3) into sand bed(4),
Raw water will be purified when passing through the sand bed.The filtrate flow out from(5).
Route of Sand: when the water flow upward,sand bed move downward continuously.The dirty sand was drawn from the bottom of sand bed,and begin to wash the dirty sand,return the clean sand back to the top of sand bed(7)
Route of Air: Circulation of sand is based on “gas principle”,compressed air will push the mixture of sand and water into the center pipe(8),and move upward.Suspended solid and sand separated by strong friction.Reject water pour out (9).Sand falling down in sand washer,amount of sand in air lifting pipe is decided by the amount of compressed air.
Sand Washer: The washer(10)with its well-designed hydraulic features is positioned around the airlift pipeline.
The
sand particles
fall through the
washer,
where they are finally washed by a small amount of clean filtrate,flowing
through the washer counter currently.The filtrate flow is generated by a difference in discharge level between the
filtrate(11) and the wash water(9)
Appearance of Filter with sand
Video of demonstration in youtube:
https://www.youtube.com/watch?v=KKuc_yWvc48
Control Manners of Filter with sand
Automatic control manner: include electric control and Air control.
Electrical control cabinet:start up, operation,alarm and other functions.During normal operation, the electrical
control cabinet make it
continuous flushing; when running abnormal, the warning signal will be transmitted to the
control box, then the program will be issued
a directive to stop filtering.
Air control cabinet: control the compressed air passing through the solenoid valve and feed into the air flow
meter. The pressure switch
is set to detect the inlet pressure of the solenoid valve, so that when the compressed
air pressure is lower than the set value, the
pressure switch and the alarm starts, while stopping the supply of
compressed air. Further, when the pressure control valve or solenoid
valve fails, itwill alarm and stop the supply
of compressed air.
Characteristics of Filter with sand
High Efficiency: Work online 24 hours,no need stop to backwash
Low operating cost:No need the high flow and high lift backwash pump,and it can be programmed to control
intermittent wash sand
control mode, greatly reducing operating costs.
Low maintenance cost: without any moving parts, low failure rate during operation and low maintenance costs.
Low one-time investment: no coagulation tank, clarify pool and other facilities, filters, high utilization
Lower requirements on inlet water quality: long time bear SS: 150mg / L.
Can withstand short
time SS:250mg / L.
Low Head Loss: Due to the single-stage filter,we clean the sand timely, head loss will be reduced to 0.5m
Efficient Filtration, Stable outlet water quality: Due to the timely clean filter can ensure stable and efficient filtration,
no water quality
cyclical fluctuations.
Easy for expansion: Unit operating mode can be adjusted according to changes in water quality and quantity of
filters, easy to renovate
and expansion of existing facilities.
Filter with sand Application:
Appliedto the town water supply, water plants, municipal wastewater treatment, industrial wastewater treatment,
recycling
cooling water treatment, process water treatment, seawater purification, algae laden water filtration.
Active sand filter Manner of feeding compressed air
External circulation Internal circulation
External Circulation :Air compressor push the sand-water mixture into sand washer by compressed air through
an external tube
Internal Circulation: compressed air flow from the bottom of the device,push sand water mixture
into the sand washer,which locates
in the central.
Filter with sand Parameter
Surface load in the unit time per filter surface impurities trapped, units:mgSS / m2h.
Recommended active sand filter surface load values are as follows:
Continuous sand filter can withstand a higher load than the value of the surface in a short time.
Filtering area can be determined by the largest surface area of the filter load and raw water quality and quantity.
For security, the actual
selection should be slightly larger than the calculated value of the filter area.
Work flow rate can be calculated by the raw water flow and filters the wash service area. Note that when the
flow rate rises to a
certain level, the biological flocculation experience disintegration or dissolution of the filter
or filters will produce flow phenomenon. In
the modeling work should ensure that the filter flow rates below this
evel.
Temperature factors should also be considered, in the low-temperature region,the sand depth is generally
greater than 2 meters.
Under normal operating conditions, the activity of continuous sand filter can ensures the following effects:
SS<5mg/l(dose flocculant)
<10mg/l(without flocculant)
BOD removal:0.3~0.6mg/mgSS
COD removal:.8~1.6mg/mgSS
Color: <5 degrees
Turbidity: <0.3NTU
Algae removal rate close to 100%
Table of Active sand filter
Verified Supplier - Changzhou Peide Water Treatment Equipment Co.,Ltd
Bussiness Type: Manufacturer 
