Guided Wave Radar in Agitated Tank
Guided Wave Radar in Agitated Tank
(OP)
Hello,
For an upcoming tank design I would like to use a guided wave radar as the level transmitter. The radar probe is to be 16mm, 108" long, and made of 316SS. I need to determine whether this will be sturdy enough to withstand turbence created by the agitator. The tank is 108" diameter, the agitator is 37" diameter, and the probe will be 12" from the wall of the tank, leaving about 22" between the tip of the agiatator blade and the probe. The agitator has 3 blades and the design speed is 84 RPM. The media will be a mixture of liquids with SG~1.3. I do not have prior experience with guided wave radars, but I would like to use one in this situation due to potential foaming in the tank. It has been a while since fluid dynamics and I haven't been able to find any reasonable equations pertaining to this problem. Thanks for your time.
Best,
Danny B.
For an upcoming tank design I would like to use a guided wave radar as the level transmitter. The radar probe is to be 16mm, 108" long, and made of 316SS. I need to determine whether this will be sturdy enough to withstand turbence created by the agitator. The tank is 108" diameter, the agitator is 37" diameter, and the probe will be 12" from the wall of the tank, leaving about 22" between the tip of the agiatator blade and the probe. The agitator has 3 blades and the design speed is 84 RPM. The media will be a mixture of liquids with SG~1.3. I do not have prior experience with guided wave radars, but I would like to use one in this situation due to potential foaming in the tank. It has been a while since fluid dynamics and I haven't been able to find any reasonable equations pertaining to this problem. Thanks for your time.
Best,
Danny B.





RE: Guided Wave Radar in Agitated Tank
Have you thought about using guided radar with wire ropes?- They're secured to the bottom of the tank and are a variation on the rods- bit harder to remove for cleaning though!
Cheers.
RE: Guided Wave Radar in Agitated Tank
RE: Guided Wave Radar in Agitated Tank
RE: Guided Wave Radar in Agitated Tank
RE: Guided Wave Radar in Agitated Tank
Why the choice of guided radar, why not use hydrostatic pressure measurement. If density variation is an issue use a two piont measurement system where you look at a differential head over a known height, this infers the density. If the tank haas variable head pressure then a third sensor is required for compensating the tank vapour space pressure.
Mark Hutton
RE: Guided Wave Radar in Agitated Tank
I've had a radar probe working with up to 20mm of scale on it- but the signal begins to lose energy as it passes up and down the rod and the real level becomes harder to detect.
If your looking at cleaning regularly and scale is a problem- stay away from the cable type- the coupling at the bottom will scale up and give you problems when you remove it.
Suggest you talk to the manufacturers as per above- don't forget to ask about unguided radar probes- they can punch their signal through foam as well and you will have less of scaling issue. I've used Vega and Endress and Hauser and have been happy with both.
Cheers.
RE: Guided Wave Radar in Agitated Tank
ItDepends/pleckner: I will be in contact with the E+H rep. Unfortunately I am limited to using Siemens or E+H.
HEC: Would all the sensors be on one 'probe stick' or would I have to introduce 2-3 entire instruments to the tank? Also what are your thoughts on how H/P would handle foaming?
Best,
Danny B.
RE: Guided Wave Radar in Agitated Tank
Is the tank sealed, does the tank contents density change appreciably? If the answer to both these is No, then only one hydrostatic pressure taping point is required. For changing density two are required (bottom and known height) for sealed (variable pressure in vapour space) and constant density two are required (bottom and head space). If both sealed tank and variable density the three pressure taping points are required. These would generally be a diaphragm seal inside a 4" flange. as the foam is not very dense it would not register as part of the tank contents. is this a problem?
Cheers
Mark Hutton
RE: Guided Wave Radar in Agitated Tank
We have another type of radar that it's working principle is a magnetic float level. This has a flaoting device in a tube that when the level changes, there are some small metal cylinders (not in contact with the product that roll and show a different colour and you can see immediately which is the level that you are working with. In our case this level is from Krohne.
RE: Guided Wave Radar in Agitated Tank
RE: Guided Wave Radar in Agitated Tank
Mark Hutton