V filter

VType filter tankIt is a deep bed filtration tank equipped with a fixed biofilm reaction function, which is a deep treatment unit that integrates biological denitrification and filtration functions. Its flexible design can choose to operate the filter separately or in denitrification operation process, and has excellent removal of solid suspended solids and effluentTSS＜5mg/LWhen the nitrogen content in the raw water is high, the bypass carbon source system is activated to display excellent nitrogen displacement function, and the total nitrogen in the effluent is less than3~5mg/L.

1、 Working principle

VType filter is a form of fast filter because its inlet tank shape isVNamed after the shape of the character, it is also known as a uniform particle filter (which uses homogeneous filter material, i.e. uniform particle size filter material) or a six valve filter (which has six main valves on various pipelines). We pass throughVType filter can observe the operation of sewage in various channels. Can understandVThe structure and principle of a filter tank. By observing the filtration process, backwashing process, and masteringVThe working principle and operation method of the filter tank.

1Filtering process: The water to be filtered flows from the main inlet channel through the inlet valve and square hole, overflows through the weir, and then enters the side hole along the water to be filteredVType groove, with evenly distributed water distribution holes at the bottom of the groove andVThe shaped weir enters the filter tank. The filtered water filtered by the homogeneous filter layer flows into the bottom space through the long stem filter head, and enters the steam water distribution pipe channel through the square hole. It then flows into the clean water tank through the water seal well, outlet weir, and clean water channel in the pipe gallery.

2Backwash process: Close the inlet valve, but a portion of the incoming water still flows into the filter through the normally open square holes on both sidesVOne side of the groove flows towards the drainage channel, forming a surface cleaning. Then open the drainage valve to discharge the pool surface water from the drainage tank until the water level of the filter tank meetsVThe top of the groove is flat. The backwashing process often uses three steps: air flushing, simultaneous backwashing with soda water, and water flushing.

Open the intake valve and activate the air supply equipment. The air flows evenly into the bottom of the filter through the small holes in the upper part of the steam and water distribution channel, and is sprayed out by the long handled filter head. The impurities on the surface of the filter material are washed off and suspended in the water, which is then flushed into the drainage tank by the surface cleaning water.

Simultaneous backwashing of soda water starts the flushing water pump at the same time as air flushing, opens the flushing water valve, and the backwash water also enters the soda water distribution channel. Air and water flow into the bottom distribution area of the filter through small holes and square holes respectively, and evenly enter the filter through the long stem filter head. The filter material is further flushed, and surface scanning continues. Stop the air flushing, rinse separately with water, continue the surface scanning, and finally flush all impurities in the water into the drainage tank.

2、 Process characteristics

VThe type filter consists of a filter medium (filter layer), a support layer, a water and air distribution system, an effluent collection system, a central control system, and a bypass carbon source system.

1High reliability:

When a carbon source is added, the high-quality implantation conditions of high-strength crushed ceramic particle homogeneous filter material enable effective surface microbial biofilm formation, ultimately converting nitrate nitrogen into nitrogen gas and achieving nitrogen removal function.

As the denitrification deep bed filter operates, the biofilm continuously thickens, ages, and suspended solids are constantly intercepted, which increases the filtration head. Regular backwashing is required to update the biofilm and clean the filter material to restore biochemical and filtration functions. As it is a downflow gravity filtration, there is no residual biofilm in the effluent.

2Filter material: Denitrification deep bed filter material, mainly achieving dual functions of turbidity removal and biofilm denitrification. High strength ceramic particle crushing homogeneous filter material

3Raw material: Bentonite, solves the problem of surface glazing, improves its surface hydrophilicity, enhances the auxiliary function of biofilm, starts the mold quickly, and has high film hanging efficiency (the same as imported Norwegian filter material)

4Surface roughness and porosity: provide a good environment for implantation and bacterial growth

5Strong biochemical stability: good corrosion resistance, not easily corroded by acid and alkali

6Strength: High mechanical strength, friction resistance, and flushing resistance

7Particle size range: deep bed1.8mThe above choices2.0~4.0mmFlexible and scientific selection can be made based on water quality conditions and filter depth1.2~2.0mmas well as0.9~1.2mmWait for homogeneous filter media of different ranges.

8Carbon source feeding system: bypass link, can be flexibly started or exceeded.

9Backwash:

When suspended solids are continuously intercepted, biofilm thickening, aging, increased head loss, and decreased biochemical function, backwashing is necessary.

Backwashing is a key step in restoring the cleanliness of the filter material and the uniform renewal of the biofilm, as well as improving the biochemical capacity of the filter. Accurate backwashing intensity controls the flow state of the filter layer, preventing complete fluidization of the filter bed while maintaining a slightly expanded state of the filter material, avoiding grading problems caused by homogeneous filter material, and saving backwashing water.

3、 Technical advantages

1Multifunctional: Denitrification deep bed filter with multiple uses, synchronized removalTN(Add carbon source)SS(Downflow gravity filtration)TPThe three water quality indicators are stable and meet the standards, and the operation is reliable. After treatment by denitrification deep bed filter, the effluentTSSReachable3mg/LAnd below (usually5-10mg/L),TPReachable0.3mg/LAnd below (usually0.5mg/L）, TNReachable3mg/L.

2Reliability:TNControl technology: Due to the fragility of the pre-treatment process in most domestic sewage treatment plants, when the effluent quality fluctuates greatly, the filter tank canTNThe stable compliance has played a supervisory role and can cope with increasingly strict long-term requirementsTNThe emission standards, no biofilm residue in the effluent, and stable and reliable water quality reflect reliability.

3Economy: Process flexibility: SummerTNIf the standard can be met and the process operating conditions can be easily changed during operation, the denitrification deep bed filter can be flexibly converted into a deep bed filter without starting the carbon source feeding system, adapting to seasonal changes, saving operating costs, and having good economic efficiency.

4Low investment cost: The submerged inlet weir and nitrogen drive technology of the denitrification filter ensure that the filter has minimal carbon source consumption and energy consumption.

5Vulnerable and consumable parts: The denitrification deep bed filter is maintenance free and has no vulnerable or consumable parts.

4、 Equipment operation and maintenance

（1） TheVType filter operation

1Adjust the outlet valve(purge valve)Opening,Keep the water level of the filter on the surface of the filter material1.0+0.5mabout.

2, every2hCheck the effluent of the filter once(filtered water)Turbidity, residual chlorinepHValue.

3Regularly check the filter for algae in summer,Yes No“Mud ball”Or appear“Mud blanket”Phenomenon.

4If the opening of the outlet valve is adjusted to the fully open position,The water level of the filter is still rising,Or out of water(filtered water)When turbidity or head loss exceeds the set value,Or the filter has been running continuously24~48h(Or the time determined based on the actual operation of the filter tank),The filter tank needs to be backwashed.

（2） Backwash of filter tank

1Before backwashing,It must be confirmed that the compressed air pressure is above the specified pressure before proceeding.

2The backwashing process involves a mixture of air flushing and water flushing—Water flushing(surface sweep washing)Three consecutive stages. During backwashing operation,Follow the backwash operation procedures.

3Slowly close the inlet gate of the filter to be flushed,Slowly open the filter outlet valve(purge valve),Until the fully open position. Wait until the water level drops to0.5~0.6mtime,Close the filter outlet valve(purge valve),Open the drainage valve of the filter tank.

4Open the air flushing valve of the filter to be flushed,Close the exhaust valve of the filter.

5Open the safety valve of the blower,Close the exhaust valve,Start the blower. When the blower is fully turned on,After normal operation,Open the air outlet valve,Close the safety valve,Supply air to the duct,Get ready to charge.

6Open the safety valve of another blower,Close the exhaust valve,Start the blower. After normal operation,Open the air outlet valve,Close the safety valve,Continue to supply air to the duct,Perform an air shock.

7Arriving at the set time,End of gas shock phase,Open the safety valve of the blower,Close the exhaust valve,Suspend the operation1A blower. Entering the stage of water and air mixing:

（1）Open the filter water flushing valve and the first1The outlet valve of the backwash pump.

（2）After reaching the set time,Open it2The safety valve of the air blower,Close the exhaust valve,Suspend the operation2A blower. Mix air and water for flushing.

（3）Close the air flushing valve of the filter tank,Open the exhaust valve of the filter tank,Entering the water flushing and surface scanning stage, the air water mixed flushing stage ends.

（4）Open the2After the backwash water pump reaches normal operation,Open it2Taiwan backwash pump outlet valve,Perform water flushing.

（5）After reaching the set time,Open the inlet gate of the filter tank,At this point, the water flushing phase has ended,Enter the water flushing and surface scanning stage.

（6）1minafter,Close the water flushing valve of the filter tank,Close the outlet valve of the backwash pump,Stop two backwash pumps.

（7）Close the drainage gate of the filter tank,Open the filter outlet valve(purge valve).

（8）Turn the conversion switch from“hand movement”switch to“Automatic operation”Location.

（3） Filter shutdown

1The shutdown of the filter should be arranged as much as possible after completing a backwash process.

2Slowly close the inlet valve of the filter to be shut down. Slowly close the outlet valve,Wait for the water level in the pool to drop below the drainage channel,Fully close the outlet valve(purge valve),If the filter tank is under maintenance,Close the outlet valve when the water level drops below the drainage channel,Simultaneously open the vent valve,Drain the remaining water from the pool.

3Filter shutdown8hthe above,The remaining water in the filter tank must be emptied.

4Make a good record of the shutdown.

5The filter should maintain continuous operation,Long term prohibition“Storage pool”.

（4）Sand replenishment for filter tank

1If sand leakage occurs during the operation of the filter tank, the cause should be identified and sand should be replenished in a timely manner.

2The thickness of the filter material layer after sand replenishment in the filter should be greater than the design thickness,But it should be less than10cm.

More aboutVType filter tankFor relevant information, please follow the company website（www.sdmzjscl.com）！