7 Factors To Consider When Choosing A Liquid Filtration System

What is industrial liquid filtration system?

Industrial liquid filtration system is a key equipment for removing impurities (such as particles, microorganisms, etc.) in various liquids, which enhances the purity of the liquid through physical interception, adsorption or centrifugal separation to ensure the safety of production equipment and process stability. Its core structure consists of filtration media (such as cartridges, bags), corrosion-resistant housing and differential pressure monitoring system, the choice of materials to adapt to the characteristics of the fluid and the need for precision (0.1 to hundreds of microns).

1. Filtration accuracy and particle characteristics The particle size in industrial fluids directly affects the filtration strategy. According to the GB/T 26114-2024 standard, particles are classified by micron (μm) (Table 1) and need to be matched with different filtration technologies:

2. 100μm: Coarse filters (e.g. basket filters) intercept grit, rust.

3. 1-100μm: Deep filters (e.g. bag filters) are suitable for chemical cooling water.

4. <1μm: Membrane filtration (e.g. PTFE cartridges) is used for pharmaceutical aseptic processes with an accuracy of 0.1μm.

Corrosion and temperature resistance

1. Strong acids/alkalis: Titanium alloy or 316L stainless steel cartridge (30% higher corrosion resistance).

2. High-temperature oils (≤600°C): Ceramic membrane or metal sintered cartridges (Witcher VZTF series).

3. Food-grade liquids: FDA-approved PE/PTFE material (to avoid the risk of leaching).

Filtration quality and performance

1. Filtration precision and efficiency Filtration precision is the core indicator of filtration quality, which is divided into nominal precision (e.g. 90% particle retention) and absolute precision (100% retention of particles of specific sizes). (100% retention of particles of a specific size). For example, oil filters can be as low as 0.1 micron (PTFE membrane) or as high as 500 microns (polypropylene monofilament mesh). Filtration efficiency is calculated by the change in the number of particles before and after filtration, with high efficiency filters achieving efficiencies of up to 99.99% (e.g. PTFE coated media). Material characteristics (such as pore structure uniformity, surface adsorption capacity) directly affect the accuracy and efficiency, such as nanofiber materials through ultra-fine pores to enhance the ability to retain micron-sized particles.

2. Pressure drop and flow characteristics Pressure drop reflects the resistance of the fluid passing through the filter, which directly affects the energy consumption and stability of the system. Ideal differential pressure should be controlled in a reasonable range (e.g. self-cleaning filter pressure drop ≤ 0.1MPa). The flow rate needs to match the process requirements, for example, large flow rate scenarios (50m³/h) need to choose parallel equipment or high processing capacity models. Research shows that too high a flow rate will reduce the filtration accuracy, while too low a flow rate will increase the cost of time, the need to balance the flow rate and efficiency through an intelligent control system.

3. Pollution holding capacity and material durability Dirt-holding capacity refers to the total amount of impurities (in grams or milligrams) that can be retained by the filter before the pressure drop exceeds the limit, and high dirt-holding designs (e.g., deep-filter media) can reduce the frequency of replacement. Material resistance to corrosion, abrasion and temperature (e.g. 316L stainless steel for strong corrosion, PTFE for high temperature of 280°C) is the key to ensure long-term stable operation. For example, polyester fiber in 130 ℃ below the stable performance, and high-temperature environment requires the use of ceramic or silicon carbide material.

4. Operating parameters and dynamic adaptability Filtration performance is affected by dynamic factors, such as changes in porosity due to clogging of particles, complexity of the fluid composition (oil or high viscosity requires the selection of activated carbon or multi-stage filtration). Intelligent systems monitor the differential pressure and flow rate in real time through sensors, and automatically adjust the cleaning cycle (e.g., self-cleaning filters) or switch the multi-stage filtration stage (coarse + fine filtration) to cope with fluctuations in working conditions. For example, the paper industry needs to select stainless steel scraper design according to the impurity load to avoid clogging.

Filtration quality and performance

1. Filtration precision and efficiency
   Filtration precision is the core indicator of filtration quality, which is divided into nominal precision (90% particle retention rate) and absolute precision (100% retention of particles of a specific size). For example, oil filters range from 0.1 micron (PTFE membrane) to 500 micron (polypropylene monofilament mesh) to meet the needs of different scenarios. Filtration efficiency is calculated by the change in the number of particles before and after retention, and the efficiency of high-efficiency cartridges (e.g., nanofiber materials) can reach 99.99%. Precision and efficiency are significantly affected by the material's pore uniformity and surface adsorption ability, such as ceramic cartridges to enhance the ability to intercept micro-particles through nanometer-sized pores.

2. Flow characteristics and pressure drop control
   The flow rate needs to match the process demand (e.g. 300m³/h equipment occupies only 6m²), while the pressure drop reflects the fluid resistance, which directly affects the energy consumption. Ideal differential pressure needs to be controlled in a reasonable range (e.g. self-cleaning filter ≤ 0.1MPa), too high a flow rate will reduce the accuracy, too low will increase the cost of time. y-filter balances the flow rate and efficiency in a high-pressure-differential scenario through compact design and automated backwashing (water consumption of only 0.2%). Dynamic parameter tuning strategies (e.g., particle swarm algorithms) optimize real-time matching of flow rate and pressure drop.

3. dirt-holding capacity and material durability
   The dirt-holding capacity refers to the impurity carrying capacity (in grams/milligrams) of the filter element before the pressure drop is exceeded, and the deep filtration media can be replaced less frequently. Materials need to have corrosion resistance (such as 316L stainless steel), high temperature resistance (PTFE resistance 280 ℃) and wear resistance. For example, polyester fiber is stable below 130 ℃, high temperature environment requires ceramic or silicon carbide material. Regenerative design (such as stainless steel cartridge backwash) can extend the service life and reduce maintenance costs.

4. Dynamic adaptability and intelligent control
   Filtration performance needs to adapt to fluctuations in working conditions (e.g., particle clogging, changes in fluid composition). Intelligent system through the sensor to monitor the differential pressure / flow, automatically adjust the cleaning cycle or multi-stage filtration (coarse + fine filtration). For example, the paper industry uses a stainless steel scraper design to cope with fluctuations in impurity loading, and self-cleaning filters are remotely managed via the Internet of Things. Real-time data-driven parameter tuning techniques (e.g., model predictive control) can improve system robustness.

5. Certification standards and environmental suitability
   Filter cartridges need to comply with international standards such as ISO, ASME, and meet industry-specific certifications (e.g., 0.1 micron for sterility in the pharmaceutical industry). Environmental suitability involves temperature range (-40℃~150℃), humidity tolerance (e.g., superhydrophobic surface for moisture resistance) and chemical compatibility (e.g., titanium alloy for strong acid environment). Modular design (e.g., multiple cartridge families) allows for flexible adaptation to diverse scenarios such as chemical and food applications.

Safety and Compliance

a. Safety

1. Data protection

• • Confidentiality: Encryption technology (e.g. AES-256) is used to protect the data from being illegally accessed during transmission and storage, e.g. a relational database uses encrypted storage for sensitive fields.

  • Integrity: Data constraints (primary key, foreign key), transaction management (ACID attributes) and hash checksums are used to ensure data accuracy and consistency and prevent tampering.

  • Availability: Guarantee business continuity through redundant backup, disaster recovery, load balancing and other technologies, such as regular database backup and failover mechanisms.

2. Access control and authentication

• • Privilege management: Role-based (RBAC) or least privilege principle restricts the scope of user access, such as Predix platform through the API gateway to implement fine-grained privilege control.

  • Multi-factor authentication: Combine passwords, biometrics and other technologies to strengthen authentication and reduce the risk of unauthorized access.

3. Technical Protection and Vulnerability Management

• • Network Security: Firewalls, Intrusion Detection Systems (IDS) and SSL/TLS protocols are used to guarantee communication security.

  • Vulnerability Repair: Regularly scan and repair system vulnerabilities, such as the integration of automated vulnerability management tools in DevSecOps.

b. Compliance

Legal and Standards Compliance

• • Regulatory compliance: Comply with GDPR (data privacy), PCI DSS (payment security), HIPAA (healthcare information) and other regulations, for example, the financial industry needs to meet anti-money laundering requirements. Industry norms: Follow ISO 27001 (data privacy), PCI DSS (payment security), HIPAA (healthcare information) and other regulations.

  • Industry compliance: Comply with standards such as ISO 27001 (information security management), NIST 800-53 (security control), and pass third-party audit and certification.

2. Process and System Management

• • Internal policies: Formulate systems such as data classification and grading, access approval, etc. to ensure that business operations meet compliance requirements, such as clear safety clauses in construction contracts.

  • Risk assessment: Regular compliance risk assessment is conducted to identify potential problems in areas such as data governance and privacy protection.

3. Audit and Supervision

• • Log Audit: Record key operations (e.g. data access, modification) and generate audit reports to support compliance backtracking, e.g. database audit log function.

  • Third-party review: Verify compliance through independent organizations, e.g., Predix platform accepts ISO 27001 certification and third-party security assessments.

Industrial filter operating: Pressure and Flow

A. Pressure parameters

1. Operating pressure range
The pressure adaptability of industrial filters varies by type and scenario, with a common working pressure range of 0.05~30 bar (0.005~3 MPa). Example:

• Precision filter: Pressure is usually 0.05~0.6 MPa (e.g., high-flow precision filter), applicable to low-pressure scenarios.
• Membrane filters (e.g. reverse osmosis, ultrafiltration): need to withstand high pressure, working pressure up to 5~30 bar (0.5~3 MPa).
• Sand filter/activated carbon filter: lower pressure, 0.5~3 bar and 1~2 bar respectively.

2. Pressure drop and material design

• Initial differential pressure: the differential pressure of multi-media filter is usually ≤0.05 MPa, and backwashing is required when the differential pressure in operation exceeds 0.1 MPa.
• Shell material: high-pressure scenarios using stainless steel (such as 316L) or carbon steel lined with rubber to enhance pressure resistance.
• Structure optimization: such as self-cleaning filter through the dome-shaped porous plate or quick-open design to reduce pressure loss and enhance pressure resistance.

B. Flow parameters

1. Flow range and efficiency
The flow rate needs to be adapted to the process demand, and the common range is from 0.05 m³/h to 300 m³/h:

• High-flow precision filter: flow rate up to 20~300 m³/h, suitable for high flow rate scenarios (e.g. chemical and food industries).
• Self-cleaning filter: supports flow rate of 1,000~20,000 L/h and realizes efficient treatment through parallel connection of multiple filter elements or modular design.
• Multi-media filter: the filtering speed is controlled at 8~15 m/h, too high flow rate will lead to a decrease in the dirt-trapping capacity.

2. Flow rate and pressure drop balance

• Flow rate optimization: high flow rate (>15 m/h) is easy to trigger a steep increase in pressure drop, which needs to be dynamically adjusted by intelligent control systems (such as model prediction algorithms).
• Filter cartridge configuration: High-flow folded cartridges reduce differential pressure and increase flow rate by increasing the pore size (>50%) and straight-through structure.

Maintenance and Replacement Costs of Filtration Equipment

1. High cost of consumables
   Filter bags, cartridges and other consumables are the core expenditure of maintenance costs. Ordinary filter bags cost hundreds to thousands of dollars per unit, and high-efficiency filter cartridges are more expensive to replace, and need to be replaced frequently (3 months for primary effect, 6 months for intermediate effect, and 1 year for high-efficiency). The replacement cycle is shortened under bad working conditions, which further increases the cost.

2. Indirect costs can not be ignored
   Filter replacement requires downtime, resulting in production losses. For example, traditional filters need to be cleaned manually every 2 hours of downtime, and the annual loss can reach hundreds of thousands of yuan; self-cleaning or duplex filters can reduce downtime by more than 90%. In addition, the replacement requires professional testing and commissioning, and the cost is comparable to the cost of the filter element.

3. Optimization strategy to reduce costs

   • Optimization of material selection: the use of high-strength materials (such as PTFE, stainless steel filter) to extend the life and reduce the frequency of replacement.

   • Technology upgrading: self-cleaning filter through differential pressure sensing and modular design, reducing 60% of maintenance costs; high-flow cartridge (single-branch flow rate up to 5-10 times the ordinary cartridge) can reduce the number of cartridges and labor costs.

   • Intelligent monitoring: real-time monitoring of differential pressure and flow to avoid excessive maintenance or failure delays.

Conclusion

The maintenance cost of filtration equipment needs to be assessed in multiple dimensions, including consumables, labor, energy consumption and risk. Through intelligent upgrading and precise operation and maintenance, enterprises can achieve a balance between health, compliance and economy. Industrial scenarios suggest prioritizing the use of highly durable filter materials such as stainless steel cartridges , while the civilian sector needs to balance the initial purchase cost and the frequency of filter element replacement.