Process flow and equipment selection for hotel swimming pool water treatment systems
I am Daniel Wang, a water supply and drainage specialist. The hotel swimming pool water treatment system is a key element in enhancing the guest experience and ensuring water quality safety and operational compliance. Its design must strictly follow the relevant requirements of the Water Quality Standards for Swimming Pools (CJ/T 244-2016) and Section 3.9 of the Standard for Design of Building Water Supply and Drainage (GB 50015-2019). Improper system design may lead to water quality deterioration, excessive energy consumption, or frequent equipment failures, affecting the hotel's reputation and economic benefits. The following, based on years of engineering experience, explains the process flow and equipment selection in detail.
Process Flow
A standard swimming pool water treatment system usually adopts a closed-loop process of "circulation filtration + disinfection + heating":
1. Circulation and Make-up Water: Water is drawn by the circulation pump from the pool return inlet (usually located at the bottom of the pool wall), while fresh water is supplemented by the make-up water system (including liquid level control) to ensure water balance. According to Article 3.9.5 of GB 50015-2019, the circulation period should preferably be 4-6 hours (hotel pools often adopt 4 hours).
2. Pre-filtration: Water first passes through a hair collector (or basket strainer) to remove hair and debris, protecting downstream equipment.
3. Filtration: Quartz sand filters (commonly used) or diatomaceous earth filters are used to remove suspended solids and particulate matter. According to the standard, the filtration rate should preferably be 15-25m/h, and the filter layer thickness 0.8-1.2m.
4. Disinfection: Primary disinfection uses chlorine-based disinfectants (such as sodium hypochlorite solution or chlorine tablets), with auxiliary ultraviolet or ozone disinfection, ensuring a residual chlorine level of 0.3-1.0mg/L (Article 5.2 of CJ/T 244-2016).
5. Heating: Heating is achieved through plate heat exchangers or heat pumps to maintain a water temperature of 26-28℃ (commonly used for hotel pools).
6. pH Adjustment: Sodium carbonate or hydrochloric acid is dosed to maintain a pH value of 7.2-7.8.
7. Water Quality Monitoring: Online monitoring of parameters such as residual chlorine, pH, and turbidity, with automatic control of chemical dosing.
Key Points for Equipment Selection
- Circulation Pumps: Select cast iron or stainless steel pumps. The head is calculated according to system resistance (usually 15-25m), and the flow rate is selected according to the circulation flow rate (≈ pool volume/circulation period). Variable frequency control is recommended for energy saving and noise reduction (low noise is required in hotel environments).
- Filters: Vertical quartz sand filters are recommended, equipped with multiport valves or electric valves for easy backwashing. According to the pool volume, select a diameter of 1.2-2.4m; the filtration area must meet the filtration rate requirements. Case: A five-star hotel pool (400m³) selected two filters with a diameter of 1.8m, operating in parallel, with a backwash cycle of 48 hours.
- Disinfection Equipment: Primary disinfection uses a sodium hypochlorite dosing system (with storage tank and metering pump), with auxiliary ultraviolet sterilizers (flow rate matched to circulation rate). Avoid using ozone (may leave irritating odors and affect guests).
- Heating Equipment: Hotels often use boiler waste heat or air-source heat pumps. Case: A resort hotel in Sanya used plate heat exchangers (heat exchange area calculated based on a water temperature rise of 5℃ over 4 hours), connected to the primary side of the boiler, achieving energy savings and reliability.
- Chemical Dosing System: Metering pumps are used for pH adjustment and disinfectant dosing, equipped with online analyzers (such as Hach or E+H brands) to achieve automatic control.
- Control System: PLC control cabinet integrating circulation, backwashing, dosing, and heating logic, with remote monitoring functions (convenient for hotel engineering department operation and maintenance).
Practical Engineering Case
An international brand hotel (Shenzhen, pool volume 500m³) originally used traditional sand filtration + chlorine disinfection, and frequently experienced filter media hardening and excessive residual chlorine during operation. I recommended retrofitting as follows: variable frequency circulation pumps (noise reduction and energy saving), upgrading sand filters to high-speed filtration (filtration rate 20m/h), adding auxiliary ultraviolet disinfection, and introducing online monitoring with automatic dosing. After the retrofit, water quality met standards and operation and maintenance costs were reduced by 30%.
Summary
The hotel swimming pool water treatment system should take "circulation filtration as the core, disinfection as the safeguard, and heating as the auxiliary." Equipment selection should match the pool scale, water quality requirements, and hotel operational characteristics, with emphasis on energy saving, low noise, and automation. The above are reference opinions. The actual project situation still needs to be further comprehensively evaluated and implemented in combination with specific working conditions, site conditions, and other factors.