Technical Standards for Water Treatment Equipment and Filtration Equipment

1. Test Procedure

1.1 In the test, the hydraulic characteristics of the filtration equipment are mainly determined by measuring differential pressure, flow rate, filter media volume, and filter media particle size.

1.2 Differential Pressure Measurement

1.2.1 Differential pressure measurement can reflect the degree of fouling of the filter media bed. The effectiveness of filter backwashing can generally be determined by measuring the pressure drop of the filter media bed before and after backwashing.

1.2.2 Differential pressure measurement uses the measuring devices listed in Chapter 6.

1.3 Flow Rate Measurement

1.3.1 Flow rate measurement can determine the output of the equipment and can also be used to determine the fluid velocity during backwashing, forward washing, and various components of the filter.

1.3.2 Flow rate measurement uses the measuring devices listed in Chapter 6. 1.4 Temperature Measurement

Temperature measurement is to ensure the filter operates under its design conditions. The methods and instruments for temperature measurement are as specified in Chapter 6.

1.5 Measurement of Filter Media Layer Height During Loading

1.5.1 Measuring the filter media layer height is used to confirm the layer height of various sizes of filter media in the filtration equipment.

1.5.2 When measuring the filter media volume, the volume of the container head and the volume occupied by the internal distributor should be considered.

1.6 Measurement of Filter Media Particle Size During Loading

Measuring the particle size of the filter media is used to determine whether the particle size of the filter material meets the design requirements of the equipment.

1.7 Chemical Measurement

Chemical measurement is mainly used to determine the filtration performance of the filtration equipment.

1. 8. The quality of water entering the filter must comply with the requirements of JB/Z 360.

2. Items Requiring Chemical Measurement in Filtration Equipment Performance Tests

2.1 Mechanical Filter Sample Inflow Liquid Outflow Liquid

Measurement Item: Suspended Solids Suspended Solids

2.2 Activated Carbon Filter Sample Inflow Liquid Outflow Liquid

Measurement Item: Oxygen Consumption Oxygen Consumption Chlorine Residual Chlorine

3 Measurement Methods

3.1 Differential Pressure Measurement

3.1.1 Pressure drop in filtration equipment or systems is typically measured using pressure gauges or differential pressure gauges installed along the flow path.

3.1.2 Pressure loss values for a single device or system can be measured using a differential pressure gauge or a pair of matched, calibrated pressure gauges. If a pair of pressure gauges is used, both should ideally be installed at the same height to avoid corrections for different static pressure heads and to facilitate simultaneous reading of inlet and outlet pressures.

3.1.3 The pressure gauge range must be appropriately selected. The maximum range of the pressure gauge should generally be 1.5 to 2 times the indicated average value.

3.1.4 Because flow rate affects the differential pressure value, it is essential to agree before the test whether to use one or several flow rates.

3.1.5 For resistance loss tests, pressure measuring points must be placed on the inlet and outlet pipes of the filter container.

3.2 Flow Measurement

3.2.1 To determine the backwash flow rate, cleaning flow rate, and operating flow rate of the filter equipment, a flow meter can be installed on the inlet pipe of the filter equipment to measure the flow rate.

3.2.2 In small-scale filtration systems, if a flow meter is not installed, water flow can be introduced from the filter equipment outlet into a container agreed upon by all parties involved in the test, used for both mass and volume measurement, to determine the flow rate.

3.3 Temperature Measurement

Temperature measurement can be performed using a liquid-filled glass thermometer.

3.4 Measurement of Filter Media Layer Height

The layer height is calculated by measuring the mass and bulk density of the filter media.

3.5 Measurement of Filter Media Particle Size

3.5.1 Particle size measurement includes the measurement of particle diameter and uniformity coefficient, which can be measured using sieving analysis.

3.5.2 Particle diameter is expressed in the following two ways:

a. Average particle size d 50 – The sieve aperture diameter (usually expressed in mm) through which 50% (by weight) of the filter media can pass.

b. Effective particle size d10 – The sieve aperture diameter (usually expressed in mm) through which 10% (by weight) of the filter media can pass.

3.5.3 The non-uniformity coefficient KB is calculated using the following formula:

KB = d80/d10 Where: d80 – The sieve aperture diameter (usually expressed in mm) through which 80% (by weight) of the filter media can pass.

3.6 Chemical Measurements The collection of water samples entering and exiting the filtration equipment and the determination of various chemical items shall be carried out in accordance with GB 6903~6913 and the former Ministry of Water Resources and Electric Power of the People's Republic of China's "Test Methods for Water and Steam in Thermal Power Plants (1984)".