How to save the most money? Looking for a solution?
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The process now includes an underground storage tank. The process does not require accurate knowledge of the liquid level, but it is important that the tank neither runs empty nor gets flooded; preventing damage to the pump is sufficient. Float balls or level switches can be used for measuring the liquid level. How should the control circuit be designed?
In our case, a level switch is used; the signal is fed into the DCS to enable interlocking with the start/stop of the pump.
A float level switch can generate high and low signals.
A float level switch generates two alarm signals, which are used for interlocking with the pump: the pump stops when the liquid level is low and starts when the level is high. The function of the pump is to draw the medium from an underground storage tank and deliver it to another location.
Float level switch: The float level switch operates using magnetism, has no mechanical connections, and is simple and reliable in operation. When the floating ball switch is actuated by the floating element of the medium being measured, the element drives the main body to move; simultaneously, the magnet at the other end of the element affects the magnet on the actuation lever of the switch. Technical advantages of float level switches: Float switches do not contain components such as bellows, springs, and seals that can cause failures. Instead, a straight float is used to drive the magnet inside the switch, and the simple lever of the float switch causes the switch to act instantly. The float’s cant angle is limited to prevent it from becoming vertical. A float level switch is a level controller with a simple structure, easy to use, and safe and reliable. It is faster than ordinary mechanical switches and has a longer service life ； Compared to electronic switches, it also features strong resistance to load surges, and a single unit can enable multi-point control. It is widely used in various industries. Working principle: The magnetic float of the float level switch moves up or down as the liquid level changes, causing the reed switch chip at a predetermined position within the sensor’s detection tube to activate, thereby generating a signal that switches the contacts on or off. One or more reed switches are installed inside a sealed, non-magnetic tube; this tube is then passed through one or more floating balls that are hollow and contain ring magnets inside. The rise or fall of the liquid causes the floating balls to move up and down as well, which in turn causes the reed switches in the non-magnetic tube to either close or open, thereby generating a switch signal
Thank you all! How to design a control loop?
I think the level switch is cheaper than a float switch; the key in this solution lies in making that choice, as the circuit principles are more or less the same. It’s just a matter of choosing the gauge to be used on site.
Use a three-electrode level switch; connect the normally closed contact for low-level alarm to the electrical circuit of the pump, and connect the normally open contact for high-level alarm to a bell.