Pipe Leaks (Pulp and paper industry)

[iqbalnaq]

Hi,
We are having leak problems with our caustic slurry lines. Slurry is white liquor (sodium hyroxide, sodium sulphate, sodium carbonate and sodium sulphide) and calcium carbonate. Temp is 200F (dont know the pressure but not very high). Flow rate is 92gpm in 4" ss304l line.
The problem is mostly where the elbows are (Slurry is flowing from 2nd to 1t floor and we have two lr elbows connecting vertical pipes with a horizontal pipe and then it flows into a tank).
Any material recommendation. We think it is mostly erosion that is causing leaks and not corrosion as we should see leaks all over the pipe.

 

[Latexman]

How many years did the elbows last?

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[LittleInch]

Have you tried searching this site for answers. Try "slurry elbow" , "slurry erosion".

Can find gems like this

http://www.eng-tips.com/viewthread.cfm?qid=340801

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Artisi]

Think you assumption is pretty well on the mark, "erosion" --Can you change to long radius bends, this may help a little with the erosion problem.


It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[LittleInch]

Normally these issues revolve around angle of impact, velocity and materials. Things to consider:

Radius of elbow as Artisi quite righly points out
Diameter of elbow - velocity effects are sometimes power related so expand to say double the size before the elbow then reduce back down again afterwards.
Internal lining - ceramic, tungsten carbide, PE and rubber have all been used to reduce erosion effects on slurry lines.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Artisi]

Expanding and then contracting to accommodate an increased diameter bend / elbow could make the situation worse due to introducing turbulent flow in an area already having problems. Investigating high temp. elastomer lining of long radius bends could be the best option.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[emdfranz]

Hi iqbalnaq!

I would like to ask what is the material you are using during these problem.
franz