electromagnetic flowmeter for partially full pipe

[bitengineer]

I am trying to convince a local sewer authority to allow my client to utilize an electromagnetic flowmeter for partially full pipe specifically a Parti-Mag II for process wastewater (vegetable washwater). The Authority uses magmeters but only on sewer mains that are constantly full. Their engineer has no experience with electromagnetic flowmeter for partially full pipes, thus he wants us to utilize weirs or flumes. Do you have any documentation or testimony that can be use to convince their engineer that electromagnetic flowmeter for partially full pipes is a viable metering device?

 

[IRstuff]

Isn't that something that the manufacturer's FAE would be able to answer more authoritatively?

TTFN

FAQ731-376

 

[bitengineer]

Yes, but all manufacturers hype-up their products just ask any of them and they will tell you their product is the best on the market and it will do whatever you asked for...anyway everything I read on magmeters for partial flow shows accuracy of 3% to 5% of the actual flow rate, the processing plant's discharge is approximately .33 mgd. Maybe the authority is worried they will lose revenue or they will miss out on a $10,000 fine if the factory discharges more than allowed. But I don’t believe measuring through weirs or flumes are more actuate. The authority's operators are hands-on people and if there is literature or study’s done on actual operating systems or even other operators’ testimony of using these products would be beneficial.

 

[danw2]

Conventional magmeters by major or minor manufacturers make no claim to measure partially full pipes and specifically state flows are accurate only with a full pipe. However, this ABB model does make a claim to measure a partially full pipe. ABB is not a fly-by-night outfit which I presume has some integrity in its product offering.

I side with IRstuff, asking why can't ABB provide some references for this product? Have you asked them? (or their rep?)

 

[JLSeagull]

Also, try to modify the installation to include a rise after the meter to help maintain the meter segment liquid full.

 

[tsmith62]

I would contact Krohne. They have a partially filled mag meter offering and they have extensive waste water experiance. They will likely have a reference.

 

[Standingback]

The ability of a magflo meter to measure flows in partially filled pipes is heavily dependent on the design of the coils in relationship to the pickup electrodes.

I only have limited experience on actual applications, but believe that the Toshiba make a specific meter for this application that wraps the coils around an armature to distribute the magnetic field in a way that compensates for the partial fill.

http://www.toshiba.com/ind/product_display.jsp?id1=9&id2=91&id3=157

I trust this helps,
Mlv

http://www.coulton.com

 

[glowing]

consider a flapper check valve downstream. This will keep the pipe full.