how does a bubbler level system work?

Interesting. Thanks. That's another thing I knew nothing about until now.

Simple and elegant.

A constant flow of air is directed into the liquid close to the bottom of the vessel using a pipe. The pressure in the air line is almost identical to the liquid head, ignoring flow losses in the pipe. Therefore a pressure sensor in the air line measures the head of the liquid.

Periodic maintenance is necessary to ensure that the pipe is not blocked.

Simply a bubbler works by blowing air thru a tube (sense line) that is inserted into a tank, it measures the pressure it takes to blow the "bubble" and then correlates that into a depth reading (hydrostatic principle). There is more to it than this brief explanation as you may have guessed.

The site; www.levelcom.net has some in depth information on bubblers and current bubbler technology and applications.

BR

Steve

My Friend, Using air bubbler (static pressure type) to the oil tank will not gives any good read out or control. Air Bubbler can be used only in water tank, reservoir, intake and dam. The components are as follows: *Air compressor, complete with air regulator *DPT *Rotameter *Stainless tubing (SS316) Length is depending on the length required (depth of water), this tubing shall be supported with PVC pipe, with strategic holes around it. We never use this oil tank, due to oil SG and sometimes build up oil residue inside tubing. Eren

Eren:

We have been using Levelcom pulsed air bubblers in diesel, fuel oil and various process related liquids, both food and fuel for over 15 years. The bubblers we use are not continuous flow bubblers but rather a computer driven pulsed bubbler that purges the line and then makes a reading. It has SG input so you can use it for most all oils, H2O, acids, suspensions and many other liquids. A 1.0" to 2.0" down tube set 6" off the tank bottm should take care of any sludge or residue problem. Steve

First bubbler system is preffered for applications wherein you don't want the liquid to be contact with your transmitter sensor/cell (ex. sludge, acid etc.)

In this system, air is purge continously to a dip tube going down the vessel and into the high port of your transmitter. After sometimes, with constant air flow, the pressure inside the tube will be the same as the head pressure of the liquid (hydrostatic pressure). An increase or deacrease in the level of liquid will correspond to an increase and decrease of the back pressure in the tube which is sensed to the high port of the transmitter. Thus, the back pressure experienced in by the cell of your transmitter infers the liquid level of your vessel.

It is then almost the same as a dp principle where you need to know your liquid's density/SG and liquid pressure. But for you to maintain accuracy of level measurement, you need to have a continous monitoring of constant air flow in the system.

Control and Instrumentation,

DINO N. LACSAMANA

Check. www.levelcom.net. Contact info is there also.