Shallow sand filter

Shallow sand filter

Shallow sand filter Instruction of Shallow Medium Filter

Shallow Medium Filter (also with name of FQG system) is a kind of high efficiency filter equipment in cutting down water turbidity, and purifying water. It uses silica sand asits filter medium. Under a certain pressure, the muddy water come through the granular or nongranular silica sand, which can efficiently hold back suspended solids, organisms, colloidal solids, micro-lives, chlorine, odour and heavy metal ions, etc.

It consists of several standard filter tank unit, with unique water distributor and water collector inside.automatic backwash valve can control all system’s backwash process.

Shallow sand filter  Application

Shallow Medium Filter is mainly used in pretreatment in water turbidity removal, water softening, electrodialysis, electrodialysis reversal.
However, it makes function on surface water, under ground water as well. Shallow Medium Filter can also be widely used in fields of electronic power, petrochemical,metallurgy,electroplating, papermaking, textile, pharmacy, soft drinks, living water, industrial water, swimming pool, etc.

Shallow sand filter Features

Shallow media filter can widely used at different application, such as water filtering, cooling water by-pass filtering, waster water treating, etc.

1. Shallow media filter has flexible modules, which can combined under actual flow rate, on-site area. 
It is operated backwash automatically, with time control, differential pressure control. Each filter element start backwash one by one, while no need stop operation in backwash. 
2. With smooth water allocation. High efficiency in backwash, water saving, only 30% water consumption of traditional one. Filter uses ASM filter media, which is easy wash.
3. With unique 48” ball filtering unit, and light weight for the whole system. The normal concrete base can used to place. Easy install, no need any boom equipment.
4. With good anti-corrosion feature. 
5. With lost cost, but long lifetime.
6. Water quality:

   inlet water turbidity <80mg/L, outlet quality reach <20mg/L
   inlet water turbidity <20mg/L, outlet quality reach <5mg/L
7. Flow rate: it can treat 30-500m³/h

Shallow sand filter Internal Structure 
Filter structure: main part includes filter tank, water distributor, water collector, hand hole and support base, etc.
Filter tank: it gives enough space for water distributor and collector. Each water collector has 55 water caps, which reforms a internal recycle flow when backwash, no sand leak.
Water distributor: it makes sure water flow smoothly on the padding sand media.
water collector: with 55 unique mushroom shape water caps makes sure water pressure in a balance. It can reforms a internal recycle flow when back wash, no sand leak. 
Hand hole: There have a up and down hand holes, which is easy for installing and replacing water distributor and collector. Meanwhile, the upper hand hole, which is easy for inspecting and adding silica.And down hand hole, which is easy for clear and repair. 
Support base: it is assemble, it can adjust in according to on-site situation. 

Model	Inlet diameter(mm)	Outlet diameter(mm)	Picture	Material
PD-58P	100	100		Plastic

Shallow sand filter Silica sand

Silica sand: mined from silica bed. After milling, it becomes into irregular angular shape. When mixed with concrete, it has a good adhesion, which can increase slurry strength. 
Sea silica: with smooth outside, and even grind and with salty.

Silica sand

Shallow sand filter Operation

Filtration Process

-  The contaminated water enters the tank through the inlet manifold, transitioning to the 3-way valve and into the top inlet of each tank

-  The two-stage deflector creates a uniform distribution for laminar flow across the media bed while avoiding channeling of the media bed

-  Particulate is trapped and retained within the media bed resulting in clean process water flowing out through the stainless steel wedge wire underdrain, to the outlet of each filter tank and to the outlet manifold for end use

Backwash Process

-  Backwash sequence is initiated by either elapsed time of the controller or pressure differential between the inlet and outlet manifolds

-  Water or air pressure opens the 3-way valve causing the reverse flow of a portion of filtered water up through the stainless steel underdrain to hydraulically and uniformly lift the media bed

-  The use of a hydraulically balanced underdrain in conjunction with a gravel pack creates a proper and uniform lift of the media bed while avoiding a turbulent backwash

-  Entrapped particulates are released during the backwash event, exhausted through the backwash manifold and routed to a convenient location

-  One tank at a time is backwashed while continuing to process water for use until the entire system is clean

-  Once completed with the backwash, filtration continues until the next backwash event.

Shallow sand filter Control manner

Peide Backwash control valve is started by water pressure or an external power source.
Peide backwash control valve is composed of solenoid valve, hydraulic relay valve actuator or three-way valve.
Peide filter backwash control valve outlet normally open, drain valve normally closed.
Each outlet is sealed by its own independent sealing seat, but they are controlled by the same stem of seal diaphragm.
Valve is a complete, interactive set. When one outlet is turned on, the other outlet is in a closed state,
So backwash valve can be operated in two modes:

Technical and performance Parameters