Filter Systems

GFK Series Scanning Self-cleaning Filter




Introduction

GFK Series automatic self-cleaning filter is the high performance filter particularly designed for fine water filtration.The superior filtration rating is 15 to 300μm. Highly efficient back-flushing secures normal working even for the turbid raw water.The water flows into the screen inside from the filter inlet, passes the screen and flows out from the outlet.The particles are blocked by the screen mesh. When the filtration pressure drop rises to the preset value, the control system triggers the cleaning sequeces. The back-flushing nozzles driven by the motor moves helically and clean the inner screen surface. After all the screen area is scanned and cleaned by the suction nozzles, one back-flushing cycle is completed. During back-flushing, the filtration goes on and only very low flowrate fluctuation and outlet pressure decrease happens.


Working Principle

The water flows into the screen inside from the filter inlet, gets through the screen and flows out from the outlet. The impurity particles are blocked by the screen mesh. After the accumulation of more particles, the filtration pressure drop rises to preset value (usually 50 Kpa). The control system triggers the cleaning sequences. Open the back-flushing valve A and the auxiliary back-flushing pump. The gear motor drives the reciprocating scanner at the same time. The dual-channel back-flushing tube moves helically and cleans the screen inside with suction nozzles. The differential pressure = outlet pressure - back-flushing outlet A pressure. The outside filtrate reverse flow passes the screen and injects into the group A suction nozzle inside. The impurities and particles on the inner surface are flushed out by the reverse flow and the filter screen filtration capacity is regenerated. After all the screen area is scaned and cleaned by the suction nozzles, one back-flushing cycle is completed. 


Technical Features and Advantadges

Efficient and Uniform Screen Cleaning Performance  

GFK Series self-cleaning filter cleans and regenerates the screen by the suction nozzle scanning back-flushing working principle. Only less than 0.1% minimum filter area will be back-flushed at the same time during cleaning. So the screen can be completely cleaned by the extremely high velocity reverse flow and 100% surface area can be efficiently and uniformly cleaned. The outlet pressure fluctuation is very low and the waste water discharges is less when back-flushing. Some automatic candle type filters have dead conners that cannot be cleaned completed. About 20%-40% of the filter candle end part gets clogged all the time especially if the filtration degree is finer than 100 μm. When filtering the turbid water, automatic candle type filters get clogged quickly and even fail to work.

Contact Suction Nozzles  Closer Cleaner

The spring-loaded contact suction nozzles (Patent Pending) can back-flush fine particles out of the screen inner surface. The suction nozzle moves close to the screen inner surface, which greatly reduces the un-filtered water around the nozzle flowing into the nozzle when back-flushing. Most of the water comes from the filtrate opposite the nozzles. It greatly increases the back-flushing velocity and intensity, correspondingly increases the back-flushing performance and reduces discharged back-washing water waste. Even when filtering the turbid water with the fine screen, the screen can be back-flushed clean completely and the flow rate keeps stable. This kind of back-flushing principle is the most efficient in current water self-cleaning filters and can guarantee the stable operation of water treatment system. We recommend the GFK series self-cleaning filter with non-contact suction nozzles for filtration degree larger than 200μm or water with less impurities. The nozzles keep distance from the screen inner surface and can back-flush out the larger particles, which reduces the pre-filtration requirement.


High Flow Rate, Easy to back-flush, Accurate Apertures 

HyperSEP series is a special 4-layer screen developed for GFK series self-cleaning filters. The liquid flows from inside to outside and passes the protection layer, filtration layer, distribution layer and the reinforcing layer. Four layers are optimized and laminated. The protection and distribution layers are designed with large mesh, and the filter layer is rarely blocked. So the filtration layer area can be 100% used. This kind of optimized structure makes sure that the filtration layer is effectively back-flushed clean. HyperSEP's real effective filtration area is about 40% higher than the effective filtration area of candle type filter elements at the same screen area. HyperSEP filtration degree ranges from 15μm-300μm. The filtration layer is precisely weaved and has extremely accurate filtration apertures. It can efficiently remove the suspended solids, sediments, Zooplanktons and Phytoplanktons, Two material 316L and 904L are available, 316L is suitable for ordinary water resistance requirement while the 904L is for long-term sea water resistance requirement. HyperSEP is applicable to turbid sea water and can filter and be back-flushed normally.



Specification

Standard Design Pressure 0.7/0.8/1.0mPa ( Depending on the filter mode)
Mini. Working Pressure 0.2mPa, 0.16mPa (with auxiliary back-flushing pump)
Flowrate Range 50~3000m³/h
Applicable Liquid Sea Water, Fresh Water, Other Raw Water
Back-flushing Liquid Filtered Clean Water
Filtration Degree 15~300μm
Working Principle Single Filter Continuous Filtration, Automatic Back-flushing
Design Temperature 0-50℃
Back-flushing Cycle Differential Pressure 50kPa and Time
Differential Pressure Instrument Intelligent Differential Pressure Transmitter
Inlet and Outlet Size DN80~DN600
Installation Direction Horizontal or Vertical
Inlet and Outlet Standard ANSI Flange CLASS150 / DIN Flange PN10
Housing Wet Part Material CS/304/316L/2205 Duplex SS/GRP
Filter Screen Material 316L/904L
Internal Parts Material PTFE、POM、316L/2507
Carbon Steel Anticorrosion Rilsan Coating/ Rubber Lining
Sealing Material NBR/EPDM
Back-flushing Valve Pneumatic Butterfly Valve
Facility Supply 380V AC,0.4-0.6MPa Clean and Dry Compressed Air
Custom-made Design Explosion Proof Design Involve Instruments and Control System

Additional Information

Smart Filter Control System

The basic version is based on Siemens LOGO! controller, while the advanced version is based on Siemens PLC S7-200. They run LIVIC proprietary programs, efficiently control the filter and meet various automatic control requirements.
The control system integrates the differential pressure (D.P. for short) mode and time mode. The D.P. indicates impurity accumulation and screen clogging. When it reaches the preset D.P. value under D.P. mode, the cleaning sequences are triggered. The recommended D.P. value is 50kPa. The D.P. mode is the most efficient and widely applicable. The time mode can be set between 0-24 hours. If the D.P. mode fails, the time mode still works as the final safety protection. The preset time shall be close to the average cycle in the D.P. mode.
The control system based on the Siemens S7-200 PLC can be configured into DCS and support Profibus-DP or Modbus communication protocol. The specified ex-proof class design is available. All instruments and control panel meet the ex-proof requirements.

Automatic Vent Valve

Automatic vent valve releases air in the top of filter housing when the water flows into the filter. After the filter is filled full, vent valve closes automatically to ensure the filter work normally. Exhaust sensitivity and sealing of automatic vent valve are significantly better than ordinary vent valves.

Differential Pressure Transmitter

The new generation monocrystal silica intelligent differential pressure transmitter with highly sensitive and reliable features. Long- term stability, 0.1% F.S./Year. It outputs the real time differential pressure, accurately monitors the filtration status and triggers the self-cleaning in time. It can work stably and reliably more than 10 years.


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