Rainwater Recycling System

Rainwater Filter System at Ground

Recently, we have been working on rainwater recycling projects in Singapore and this is one of the completed project. Increasingly, rainwater recycling systems will be more prevalent around us. These systems help building to save water, by collecting rainwater for non-portable uses. 

The system at the ground floor filters solid particles using a DE filter, this water is then pumped to the roof top collection tank as shown below. To keep the system pressurized, a pressure tank is placed on the ground floor. 

Rainwater Make-up System at Roof

The rainwater supplied from the ground is transferred to this small tank on the right. This water is then supplied to the cooling tower to be used as a coolant. During this process, we would have to control the PUB valve in the cooling tower tank, to ensure rainwater does not backflow into the PUB inlet. 

PLC/HMI Rainwater Recycling System

To keep up with the increasing demand in such systems, we have programmed a new HMI touch screen system to make the system more user friendly. The advantage of such systems is that the user is able to change the water level settings and keep the system dynamic. Instead of using a stationary level electrode sensor, a radar sensor (4-20mA) is used to measure the water level in the rainwater collection tank.

L4 – L1 represents various levels of water level that dictates when the valve opens and pump runs. These levels can be set or changed by the user if needed.