E.Glycol WATER CONTENT
E.Glycol WATER CONTENT
(OP)
Hello my friends,
I would like to know what is the best or the latest technolgy device or method to meter the water content of the Ethylene Glycol after regeneration.
I´ll appreciate your help !!
I would like to know what is the best or the latest technolgy device or method to meter the water content of the Ethylene Glycol after regeneration.
I´ll appreciate your help !!





RE: E.Glycol WATER CONTENT
JMW
www.ViscoAnalyser.com
RE: E.Glycol WATER CONTENT
Do you have any recommendation ?
RE: E.Glycol WATER CONTENT
The solutions I am familiar with are based on measuring the density of the solution using vibrating elemenyt density meters.
These can be tube or fork style and can include those coriolis mass flow meters with a decent density measurement and suitable software.
The density variation with concentration allows for very good resolution.
The instrument measures the density and the temperature.
Using a suitable referral algorythm the density at a reference temperature is determined.
The simplest approach is to then assume the relationship between the concentration and base density is linear. This is fine if you are interested in a specific concentration as the assumption will be most accurate at this value.
The alternative approach is to use a calculation where the %mass of water in glycol is then found using the density of pure water and pure glycol.
If the range of concentrations is quite wide and the errors in these simple approaches are significant, the relationship between concentration and base density can be modelled using suitable equations. With some manufacturers these equations are available as standard.
In water glycol diluation schemes that do not involve recirculation e.g. de-icing fluids for aircraft, there is no entrained air problem. In pharmaceutical refirgeration plant, and similar, there may be a problem with entrained air due to the nature of the installation. If there is air in the water/ethylene glycol then the choices are more limited and some loss of accuracy will be incurred using vibrating element technologies e.g. the Mobrey Entrained Gas Amplifier version of the 7845 tube density meter.
You might investigate the ultrasonic density meters as an option though care would be required if there is entrained air.
Tube density meters can measure to within 0.1-0.2kg/m3 and fork types to 1.0kg/m3.
You may find some typical examples of this type of measurement by following the web link below (in the signature).
Manufacturers to consider:
PEEK (Thermo Electron); Emerson Micromotion; Mobrey (now another Emerson company); Khrone for vibrating element systems.
For ultrasonics, Cannongate, SensoTech Gmbh.
For ethylene glycol/water data visit www.houghtonchemical.com
To decide the best solution, determine what accuracy you require and wif you are making a tank measurement or a pipeline measurement.
JMW
www.ViscoAnalyser.com
RE: E.Glycol WATER CONTENT
My Best Regards !!
Happy New Year !!!
RE: E.Glycol WATER CONTENT
Regards
Stonecold
RE: E.Glycol WATER CONTENT
There are two options available, reflection and transmission devices.
Can't say offhand what the differences are but these can also be added to the list of possible devices.
Transmission instruments from Katronic, reflection devices are far more common and suppliers can easily be found e.g. K-Patents.
With all devices, be sure there really are no bubbles.
JMW
www.ViscoAnalyser.com
RE: E.Glycol WATER CONTENT
RE: E.Glycol WATER CONTENT
All the best for each one of you !!!
RE: E.Glycol WATER CONTENT
For EG/water content measurement, most common and accurate is refractive index measurement. This is possible with refractometer installed in the small side stream, very accurate, with temperature compensation. Here can be mentioned that refractive index is very temperature dependent and instrument must be temperature compensated.
Refractive index and density are bot nonliner functions of temperature.
Preconditions are: glycol must be clean without turbidity-presents of particles and/or air bubbles.
If you using glycol from the sump of the distillation column this turbidity is always present and this kind of measurement is not possible. Please describe your process with more details.
RE: E.Glycol WATER CONTENT
We´re pumping from the EG surge tank that is located downstream of the column reboiler.
So you think that we must to install a kind of filter to avoid the turbidity, before the installation of the refractometer ?
Any recommendation will be appreciated
My best regards
RE: E.Glycol WATER CONTENT
http://www.kpatents.com/
A recent installation revealed that the refractive index process head needed an option to keep it from filming over due to a very small percentagle (0.3%) of additives in the solution.
Works well.
RE: E.Glycol WATER CONTENT
(http://www.flexim.com/america/refracto_basics.php)
Coating is a common problem for refractometers and to be investigated in this case.
Vibrating element density meters have a successful history with ethylene glycol solutions: PEEK and Mobrey both having success with single pass systems where there are no entrained gases
e.g. blending/ concentration control for aircraft de-icing,
But in pharmaceutical plant, where it is recirculated through the refrigeration plant and the concentration managed (to compensate for dilution due to steam/condensate leakage across valves at the reactor jackets when they swithc from heating to quenching the reaction) there is often significant aeration in the hot well and here the Mobrey vibrating tube EGA (Entrained Gas Amplifier)instrument is used.
This can handle up to 100% air and is used for such fluids as coffee excracts where 50% CO2 may be included prior to spray drying (to proivde the granulated texture).
As Smiro also suggests, temperature is a factor for refractometers and vibrating element transmitters; two influences to be considered:
1. the effect of temperature on the measurement which in the vibrating element densitometer is the effect of Youngs Modulus and which is factory calibrated
2. the effect on the density of the fluid. Usually the instrument will include alogoythms to convert between the density at the measurement temperature to the density at a reference temperature. Once this last is known then the concentration can be determined. The algorythm requires a knowledge of the temperature density relationship Vs concentration for the fluid. (see the Houghton Chemicals link above).
JMW
www.ViscoAnalyser.com