Analysis of Water Source Characteristics and Demand
1. Comprehensive testing of water quality parameters
Basic indicators such as conductivity, turbidity, calcium and magnesium ion concentration, TDS, and pH value of the raw water need to be tested to clarify the direction of the pretreatment process (such as softening treatment for high hardness water sources);
Special pollutants such as chloride ions, sulfates, and organic compounds require targeted testing and matching with anti pollution or corrosion-resistant membrane components.
2. Confirmation of water production and usage mode
Based on the peak water consumption during production (such as 24-hour operation for continuous production), it is recommended to reserve 20% -30% redundant production capacity for the designed water production;
Example: The ultra pure water system in an electronics factory is designed to produce 200m ³/day and requires a reverse osmosis equipment with a water production capacity of 8.5m ³/h
Equipment parameters and process design
1. Selection criteria for membrane components
Select single-stage or two-stage reverse osmosis according to desalination rate requirements: single-stage is used for ordinary industries (desalination rate ≥ 95%), and two-stage+EDI modules are required for pharmaceutical/electronic industries (desalination rate ≥ 99%);
Membrane specification adaptation: 4040 membrane is suitable for small equipment (1-5m ³/h), 8040 membrane is suitable for medium-sized systems (10-50m ³/h).
2. Pre treatment process design
Basic pretreatment: multi-media filtration (removal of suspended solids)+activated carbon adsorption (removal of residual chlorine)+softening treatment (anti scaling);
Enhanced treatment of highly polluted water sources: ultrafiltration (controlling SDI value<3)+addition of scale inhibitors (reducing the risk of scaling).
3. Post processing system configuration
Pharmaceutical/electronic industry: EDI module (resistivity ≥ 18M Ω· cm)+UV sterilization;
Food industry: Ozone sterilization+terminal security filter (precision 0.2 μ m)
Installation environment and operation and maintenance planning
1. Evaluation of equipment installation conditions
Space layout: A single 10m ³/h equipment takes up approximately 15-20 square meters and requires a reserved 1.5-meter operating channel;
Environmental requirements: Temperature between 4-40 ℃, humidity ≤ 70%, avoid direct sunlight or dust pollution.
2. Calculation of operating costs
Energy consumption accounting: High pressure pumps account for 70% -80% of the total energy consumption of the system, and frequency conversion technology can reduce power consumption by 15% -20%;
Consumable cost: The replacement cycle of reverse osmosis membrane is 2-5 years (accounting for 15% -25% of the total equipment price), and the annual replacement cost of pre-treatment filter element is 5% -10%.
3. Shutdown protection and emergency plan
Short term shutdown (≤ 72 hours): Keep the membrane moist to prevent drying;
Long term shutdown: Inject 1% sodium bisulfite solution and seal for storage to avoid microbial growth
Cost optimization and risk control
1. Whole life cycle cost analysis
Initial investment: 30000 to 100000 yuan/set for single-stage equipment, with a 30% -50% increase in cost for two-stage equipment;
Long term operation and maintenance: The comprehensive cost of low-energy equipment for 5 years is reduced by 20% -35% compared to traditional solutions.
2. Risk prevention measures
Water quality fluctuation risk: Install online monitoring instruments (real-time alarms for conductivity and pH values);
Membrane pollution prevention: Establish a chemical cleaning cycle (3-6 months/time) and a pollution index warning mechanism
summarize
Before selection, it is necessary to clarify the pre-treatment requirements through water quality testing, select membrane components and process combinations based on parameters such as water production and desalination rate, and evaluate the installation environment, operation and maintenance costs, and supplier technical capabilities. For example, when selecting a chemical plant, a softening+anti fouling film solution was used to increase the system recovery rate to 75% and reduce the cost per ton of water by 28%
