Vessel Level Control & Flow Sensing

The Problem:

Vessel Level Control & Flow Sensing An aqua cultivation company required a constant flow of water to ensure the best conditions for the produce in the pool. The water in the pool was kept moving using a pump, taking water through the top of the pump and into the bottom of the tank. This flow had to be constant, however the pool lost water due to evaporation and was topped up using mains pressure water which increased and also disturbed the flow. The client also wanted to automate the topping up of the pools to reduce maintenance costs.

The Solution:

To solve these issues a control system had to be devised. Using a T24-PA pulse acquisition module coupled with an axial turbine flow sensor, the flow of water in to the bottom of the pool could be monitored. As the flow rate fluctuated, a T24-AO1 analogue output was used to regulate the pump. Using the 4-20mA PLC input allowed for the client to control the flow of the system.
The level of water was monitored using a T24-RA potentiometer acquisition coupled with a linear potentiometer. One end of the potentiometer was bolted to the top of the pool with the other end attached to a float which moved with the level of the water. The T24-RA output reported the free space in the top of the pool and when this exceeded the lowest limit a T24-RM1 relay module was used to open the actuating valve controlling the input of mains pressure water. As the water was added and the flow increased, the T24-PA reported a rise in flow which in turn caused the T24-AO1 to slow the pump down to account for additional flow. Should an environmentally IP rated enclosure be required all of the wireless input modules were available in protective housing with powering and field terminals.