Flow measurement of Corrosive liquid with sticky solids

[LuisCuellar00]

Hi.

We have been struggled with a hard application in flow measurement:

S2Cl2/Hexane = very corrosive, its flammable, Solvent, and has little solids that sticks ( Lets say 1 Kg per TON)

We need to dose from Tank to Reactor

Tank = Glass lined 1,000 Gal with agitation
Reactor = Glass lined 2,000 Gal with agitation.
Transfer line is Teflon lined. Dose = 11 kg/min. +/- 1 kg/min

We prepare a mixture of 25% S2Cl2 / 75% Hexane in the tank; the materials are charged trough coriolis transmitters, no problem.
Because our Hexane has traces of humidity, some S2Cl2 reacts forming Sulfur that sticks in Tank walls from bottom to top, Teflon pipes, sightlass, etc. Transfer pipe does not get plugged because it’s a 2” pipe, but needs to be cleaned from time to time.

So, how can one measure flow of a corrosive liquid with sticky solids? Or the level of the tank to measure level change.

So far:
We are working with a ¾ Teflon capilary level gauge but the risk it’s very high and needs to be cleaned frequently.
We had had lots of problems with weighing cells in the past in our site, so it’s no option. Anything else can be put in the negotiating table.
Can coriollis work if solids get stick in tubes?
Radar level could work, but the antenna will get dirty of a layer for shure.
Differential Pressure transmitter: will get dirty with layer.
We tried a diaphragm pump, but leaked trough it because of the solids. Maybe a peristaltic pump?

Any suggestions?
Hope some body can help. Thank you.

PS. Sorry for bad english.

 

[zdas04]

Your English is fine, it is your problem that sucks. You've tried every option that I came up with while reading the problem statement. The radar level option with strict PM's to inspect/clean the antenna seems like the best of a suite of bad options. I don't think that you are going to get decent flow measurement with any instrument I could think of.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[EmmanuelTop]

I'm not familiar with the technology, but if all these problems stem from wet Hexane, did you ever consider drying it? Flow rates seem quite small so I think you can get an adsorbent package for a very decent price - definitely less than than the cost of all this maintenance nightmare and repairs you have been facing. This is the same concept like drying of refrigerants that are supplied to a remote plant site. You just dry the liquid during offloading. Small extra cost for avoiding water ingress in cryogenic process, and all the horror that comes afterwards.

Peristaltic pump generally does a good job with dirty fluids. We have used it in the spent caustic service, and for pumping sour water condensate from the TEG off-gas separator. No issues that I can remember.

Dejan IVANOVIC
Process Engineer, MSChE

 

[georgeverghese]

From feedback I've heard from radar level transmitter vendors, these work well even when the internal radar device is fouled up; also talk to an ultrasonic top mounted LT vendor.

A non intrusive flow sensor is what you need here, I think - try these folks

http://www.flexim.com/en

 

[LuisCuellar00]

Hello again.

EmmanuelTop:
Our hexane has up to 0.01% of Water, do u think an adsorvent can dry it lower? any water in remaining in hexane will react. Do you know anny supplier or literature that I can Check?

georgeverghese:
I have contacted the supplier, I let you know what they think.
And I found a E+H teflon lined Radar level transmitter in our warehouse, if supplier think can work, I will do a change request to try this option.

Thank you guys.
PD. Also peristatic pump was tried 10 years ago, and got plugged frecuently.