Quartz Sand Filter Activity Carbon Filter Feed Water Pump Reduce Impurity Water Pre-treatment Equipment

Product description

1、 Core equipment composition and functions
1. Quartz Sand Filter
Function: Through the physical interception effect of quartz sand filter material, large particle impurities such as suspended solids, sediment, rust, colloids, etc. in the raw water are removed, and the turbidity of the water is reduced (usually from 20NTU to below 5NTU), providing a clean water source for subsequent treatment.
Structure and principle:
The cylindrical tank is filled with quartz sand (particle size 0.5-1.2mm), with the upper layer of fine sand intercepting fine impurities and the lower layer of coarse sand supporting the filter layer.
Filtration stage: The raw water passes through the filter layer from top to bottom, and impurities are intercepted; Backwash stage: The water flow backwashs the filter material in reverse to remove impurities (backwash intensity 15-20L/(m ² · s), lasting 5-10 minutes).
Key parameters: filtration flow rate of 5-10m/h, design pressure of 0.2-0.6MPa, suitable for raw water with turbidity ≤ 20NTU.
2. Activated Carbon Filter
Function: Utilizing the adsorption properties of activated carbon, remove residual chlorine, organic compounds (such as phenols and pesticides), pigments, and odors from water, and reduce TOC (total organic carbon), protecting subsequent reverse osmosis (RO) membranes or ion exchange resins from oxidative damage.
Structure and principle:
The tank is filled with coconut shell or coal based activated carbon (specific surface area ≥ 1000m ²/g), and pollutants are removed through physical adsorption (microporous capture) and chemical adsorption (surface functional group reaction).
The adsorption efficiency for residual chlorine is greater than 99%, and the adsorption capacity for organic matter can reach 100-150mg/g.
Maintenance points: Activated carbon needs to be replaced once a year or restored to its adsorption capacity through regeneration equipment.
3. Feed Water Pump
Function: Provide power for the water pretreatment system, transport raw water from the water source to subsequent treatment units (such as sand filters, activated carbon filters), and meet the pressure requirements of subsequent processes such as reverse osmosis (such as RO systems requiring 0.8-1.5MPa pressure).
Type and selection:
Commonly used centrifugal pumps, available in stainless steel (corrosion-resistant) or cast iron (economical) materials;
The flow rate is designed based on the system’s water production capacity (for example, when producing 10m ³/h of water, the pump flow rate needs to be ≥ 12m ³/h), and the head needs to overcome pipeline resistance and equipment pressure loss.
4. Other auxiliary equipment (pre-treatment components to reduce impurities)
Precision filter (security filter):
The filtration accuracy is 5 μ m, intercepting small particles and colloids remaining after sand filtration/carbon filtration, protecting the RO membrane from physical damage, and the filter replacement cycle is 1-3 months.
Dosing device:
Add coagulants (such as PAC) or scale inhibitors (such as CP118) to enhance impurity removal efficiency or prevent scaling (such as calcium and magnesium ions in high hardness water).
Softening device (optional):
Remove calcium and magnesium ions through ion exchange resin, reduce water hardness (such as from 300mg/L to below 5mg/L), and prevent RO membrane fouling.

2、 System Process and Working Principle
1. Typical preprocessing process
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Raw water → feed pump → quartz sand filter (to remove large particles) → activated carbon filter (to remove residual chlorine/organic matter) → precision filter (5 μ m) → subsequent treatment (such as RO, ion exchange)
2. Linkage mechanism
Water supply pump control:
Interlock with the liquid level of the raw water tank (start at low liquid level, stop at high liquid level) to avoid damaging the pump body due to idling.
Variable frequency control (optional): Automatically adjust the speed according to the pressure requirements of the subsequent processing unit, saving energy and reducing consumption.
Automatic operation of filtering equipment:
The sand filter and activated carbon filter ensure stable filtration effect through pressure differential sensors or timed backwash triggering.
During backwashing, the feed pump needs to maintain a certain pressure (about 0.3MPa) to ensure the strength of the backwashing water flow.
3、 Application scenarios
1. Industrial water treatment
Reverse osmosis pretreatment:
The preparation of high-purity water in the electronics, pharmaceutical, and chemical industries involves sand filtration, activated carbon, and precision filtration to remove impurities and meet the RO inlet requirements (SDI ≤ 5, residual chlorine ≤ 0.1mg/L).
Circulating cooling water system:
Remove suspended solids and organic matter, reduce heat exchanger scaling and microbial growth, and extend equipment lifespan.
Pre treatment of boiler water:
Cooperate with softening devices to remove hardness and suspended solids, preventing boiler scaling and corrosion.
2. Civil and commercial water purification
Direct drinking water system in residential areas:
Sand filtration and activated carbon remove sediment, rust, residual chlorine, and odors from raw water, producing drinking water that meets the GB 5749 standard.
Commercial water purification equipment:
Centralized water supply in schools, hospitals, and other places can improve water quality through pre-treatment and reduce the cost of replacing filter cartridges in the future.
3. Special water quality treatment
Groundwater removal of iron and manganese:
The quartz sand filter is filled with manganese sand and combined with aeration technology to remove iron and manganese ions (Fe ²+, Mn ²+), suitable for scenarios where the iron content in groundwater is greater than 0.3mg/L.
High residual chlorine water source treatment:
Increase the loading capacity or extend the residence time of activated carbon filters to ensure thorough removal of residual chlorine (such as swimming pool return water purification).

4、 Equipment selection and design points
1. Design parameters of quartz sand filter
Filter layer thickness: 1000-1500mm, with fine particle size at the top and coarse particle size at the bottom (such as 0.5-0.8mm for the upper layer and 0.8-1.2mm for the lower layer).
Backwash parameters:
Water recoil: intensity 15-20L/(m ² · s), time 5-10 minutes;
Air water recoil (optional): Air intensity of 15-20L/(m ² · s)+water intensity of 8-10L/(m ² · s) to enhance the recoil effect.
2. Design parameters of activated carbon filter
Activated carbon particle size: 1.0-2.0mm, bulk density 450-550kg/m ³.
Contact time: 10-20 minutes, ensuring sufficient adsorption of pollutants (e.g. residual chlorine contact time ≥ 5 minutes).
3. Key points for selecting feedwater pumps
Traffic calculation:
The peak flow rate during system water production and backwashing (usually 2-3 times the normal flow rate).
Head calculation:
Equipment resistance (sand filter ≈ 0.1MPa, activated carbon filter ≈ 0.05MPa)+pipeline resistance+subsequent process pressure (such as RO requiring 0.8MPa).
5、 Maintenance and troubleshooting
1. Daily maintenance
Quartz sand filter: Check the loss of filter material every month and replenish quartz sand; Check the turbidity of incoming and outgoing water every quarter to ensure filtration efficiency.
Activated carbon filter: Detect residual chlorine in the effluent every quarter, and replace activated carbon when it exceeds the standard; Acid wash the tank annually (0.1% citric acid) to remove metal oxides from the filter layer.
Water supply pump: Check the vibration of the pump body and bearing temperature (≤ 70 ℃) every week, and replace the lubricating oil every six months; Regularly clean the inlet filter screen to prevent blockage by debris.
2. Common faults and solutions
Possible causes and solutions for the fault phenomenon
The turbidity of the effluent from the sand filter is high, and the filter material is compacted/the backwashing is not thorough, and the filter material is not thoroughly washed/the backwashing parameters are adjusted
Activated carbon filter odor filter material adsorption saturation/sudden increase in organic matter in raw water Replace activated carbon/strengthen front-end dosing
Insufficient pressure in the feed pump, impeller wear/pipeline leakage, impeller replacement/inspection of pipeline sealing
System flow decrease, filter blockage/insufficient water pump power, backwash filter/upgrade water pump
6、 Environmental protection and energy-saving design
Reuse of backwash wastewater:
Collect the backwash wastewater from sand/carbon filtration to the sedimentation tank, and reuse it in the raw water tank after flocculation and sedimentation, reducing water resource waste (reuse rate can reach 50% -70%).
Energy saving water supply pump:
Using a variable frequency centrifugal pump, the flow rate and head are dynamically adjusted according to system requirements, saving 20% -30% energy compared to a fixed frequency pump.
Environmentally friendly filter material:
Select biodegradable filter media (such as bamboo activated carbon) to reduce solid waste pollution.

summarize
The pre-treatment system composed of quartz sand filter, activated carbon filter, and feed pump is the core link in the water treatment process to remove impurities. The synergistic effect of physical interception and chemical adsorption can effectively improve the quality of raw water, laying the foundation for subsequent deep treatment such as RO and ion exchange. In practical applications, it is necessary to flexibly configure auxiliary equipment (such as softening and dosing) according to the quality of raw water (such as turbidity, residual chlorine, hardness), and ensure stable operation of the system through automated control and regular maintenance, achieving the goals of efficient, energy-saving, and environmentally friendly water treatment.