8 replies to this topic

[Andree]

Hello,
Could somebody advise me, what type of level gauge system for control of interface level is suitable/recommended for liquid/liquid separator (my liquids are: diesel fuel and water)? Please, advise me your confidential companies which offer such devices (preferably in the West-Europe market, but it is not essential).
Regards,
Andrzej

[pleckner]

Have you tried to search the Internet? Google "Level gauge".

[Andree]

Sure, this is first I have done... I found many instruments, but no one was clearly described as suitable for liquid/liquid interface. In the discussions different opinions can be found. I would like to get a feedback from people who probably are/were in touch with such an instrument at operation - this would be the best confirmation of the device suitability for given application.
Regards,
Andrzej

[wnovaes]

Dear Andree,

You may try a displacer level transmitter. I experienced use these kind of level transmitter for water + glycerin solution and vegetable oil interface measurements. Bellow follows a manufacture reference.

http://www.foxboro.c...cy/buoyancy.htm

Yours faithfully,
WSN.

[Ravin]

Andrzej,

Guided Wave Radar is the best instrument I found for interface level control. It can measure and control interface and overall liquid level as well. Try to locate a supplier of this instrment in your area. If you need, I can send you some links of suppliers in North America.

Thanx,

Ravin

[Zauberberg]

Hello Andrzej,

Try to contact one of these:

http://www.agarcorp.com/detectors.html
http://www.tracerco....erfacegauge.htm

Agar is the leading manufacturer in this area (multiphase level control), as far as I know. You can check their references.

Best of luck,

[Andree]

Following my question releated to level gauge, I would like to ask about automatic drainage from coalescer: what parts are necessary?
1. Suitable level gauge (btw. thank you to Zauberberg for advise of manufacturers)
2. Drain valve: what type is recommended?
3. Electrical motor for valve operation (steering based on signal from level gauge to a controller)

I just wonder how the mode of draining is designed. In my opinion (it is my guess only) the valve should be closed until the interface level reaches upper level and then opens to drain collected water. But the draining should not be complete, but to some level (let's say 20% on the whole level range) to prevent draining of continuous phase liquid.
Is it OK? And how it is in your sites?

And one more issue: what if there is no water at the bottom (no interface)? Is it possible to program the system that "no interface = drain valve closed" (for example at start up)?

I will appreciate your comments, opinions and sharing with experience.
And sorry for confusion if something is not sufficiently clarified. I have no practical issue related to operation - I just work on design of complete coalescer system with instrumentation and process control.

Regards,
Andrzej

[Art Montemayor]

Andree:

Zauberberg has given you some great advice and comments. The best one directed you to recommended suppliers of interphase level controllers. Another supplier that has been in this business probably longer than most is Fisher Controls and their web page, http://www.emersonpr...s/tour/fmi.html, will guide you to how you can apply such a level control – complete with a control valve.

By now, you should have followed Zauber’s advice and have found out how you can apply hardware to achieve what you are looking for in the field instrument. We don’t know what system, supplier, or scheme you have selected so we can’t make any further comments. Your selected or preferred supplier can give you all the pertinent and required information to successfully control an inter-phase liquid. If you can’t get that kind of service from a supplier, you are talking to the wrong people and you should look for another.

There are many ways you can control an inter-phase level. You know all the scope and basic data, so you control the decision. As long as we don’t know exactly what you are doing, we can’t make any important, specific comments. We don’t know if:

• You have a continuous or batch process;
• You want to maintain the inter-phase at a set, determined point 100% of the time;
• You desire to drain your liquid continuously or intermittently;
• You are based on electronic instrumentation or you have pneumatic.
• Plus a lot of other basic data…….

Therefore, you should decide together with your selected supplier.

[Andree]

Thank you for guidance. On the Fisher's website I found also Valve Positioners, which is needed for automatic operation of coalescer (when coupled with level controller/transmitter).
The mode of operation of my coalescer is continuous, but I just wonder if intermittent draining is more effective - I found this in one article and wonder if this is a standard operation mode for most designs or for that one only. The information about existing designs, at your facilities, could be of an advise, this is why I asked about it
The instrumentation, digital or pneumatic, is an open question - I design equipment and based on quotation I will need to offer coalescer unit with instrumentation suitable for customer requirements. However, Fisher offers both and the issue seems to be resolved with this supplier.
I will appreciate greatly any further comments.
Regards,
Andrzej