Re: Tips On Repipe To Insitu Clean A Dilute Pneumatic Line W/ W…
Originally posted by hollerg
Cleanout options
Knife gates and diverter valve above trench level
Full port ball valve with filler
The pneumatic transport line between the continuous dryer
(~ 140 F)and the hoppers, periodically accumulates a build-up and plugs close to the pickup point. The organic salt is very water soluble, but damp powder is adheasive/coheasive. Right now it is disassembled but to speed recovery I would like to avoid that.
I keep thinking about how to do it cheap, but I keep imagining issues, real or not. So I need advice.
Downstream of the dryer pickup fitting are two more entry points. To isolate the 4" tubing, 11 ga (3.5" pipe) from the downstream points I was going to use a full port ball valve. Anyone have one in this size?
What seat material should be specified? UHMWPE? PEEK? ???
Do I need to worry about the water in the cavity behind the ball? IF so what should be done?
As an alternative who makes a compact water proof diversion tube or plug valve? (This line is in a 12" x 14" trench to allow tow motor traffic)
Sorry I missed your thread earlier:
Your situation would work well with a pnuematic "pipeline pig".
You will be able to find a supplier/cleanout pig very easily as they are a very common thing with service all over the world and suppliers/sytem installers all over the continenents-I am unsure about the former soviet republics though but since the pump oil they have pipeline pigs.
My old joke is they put up a real fuss when they get launched screaching and yelling the whole time and they scream bloody murder when they are shot out of the pipe at the end of cleaning.
:^))
What is typically done:
A pig launching valve is welded in place at or very near the beginning of the pipe and at or near the end a recieving valve is installed to remove the pig after cleaning.
A flexible rubber barbell pig is what you need and it is an easy install to clean your delivery line. A scraper pig will only hasten pipe degradation since you are moving organic salts
Just google or yahoo pipeline pigs and you will have a treasure trove of information as they have been used for many years now.
Please forgive me for asking but where are you and what do you produce? Are you in the former soviet union?, I ask because of the port arthur road address you give. ■
Pigging The Transport Line
Thank you lzaharis
Pigging is certainly an idea I had not considered, but the system is only rated for 15 psi.
Do I need a higher pressure and I would pig before the line is plugged?
Right now I have no advance warning of the pluggage. So my solution is reactive.
(Port Arthur Rd is in Beaumont, TX)
Gary ■
Re: Pigging The Transport Line
Originally posted by hollerg
Thank you lzaharis
Pigging is certainly an idea I had not considered, but the system is only rated for 15 psi.
Do I need a higher pressure and I would pig before the line is plugged?
Right now I have no advance warning of the pluggage. So my solution is reactive.
(Port Arthur Rd is in Beaumont, TX)
Gary
Greetings and salutations from my corner of the slowly defrosting "Eastern Wilderness"@1140 feet above mean sea level.
I was not sure if you were near Houston or Port Arthur, Russia on the Pacific coast :^), any way it is a very, very easy fix as low pressure pigging is done under 100 PSI in soap bottling plants.
Pig models can be towed with wire rope or a sewer tape snake or compressed air of course; the folks installing the pigs, launcher and receiver will be the best ones to help show you how to do it best and with which pig model as there are several dozen types.
Pigging could and can be an easy way to clean the pipeline every week or day depending on volume and timing of pigging-a couple of minutes pigging will save you many hours of work and aggravating slowdowns and stoppages.
I would call Halliburton or one of the other locals about your situation and be able to fix it quicky.
A pig launcher and pig receiver and an air pressure source will be fine as the pigs are tight fitting with easy passage with back pressure sealing and pushing the pig.
There are a lot of small pigging firms as well especially in the oil patch.
Mind you you have to get used to a lot of squealing and complaining from the pig or it brothers :^))
So if I may ask?, are you located at United Salt's evaporated brine plant?
lzaharis@lightlink.com ■
Pipe Line Build-Ups
Gary,
These build-ups can also be removed by using crushed ice as your conveying medium. This option may be less costly.
But why don't you solve the build-up problem by eliminating the source of this problem? In most cases the main reason for such build-ups is low conveying velocity. Increase the velocity so that it is comfortably above the saltation velocity.
Regards,
Amrit Agarwal
Consulting Engineer
Pneumatic Conveying Consulting
Email: Polypcc@AOL.com
Ph and Fax: 304 346 5125 ■
Re: Tips On Repipe To Insitu Clean A Dilute Pneumatic Line W/ W…
Amrit
I realize the periodic cleanout is a fix, not a root cause solution. Limitations on layout, and management dicates for return on capital constrain actions that would solve all problems.
My original intent was to ensure the current cleanout (every 2 wks to 2 mo) was performed in a minimal time while preventing mistakes, which ultimately cause other outages.
I do not believe this is a low velocity problem (Froude>22). This dryer and dilute phase conveying system is operating too near where the temperature/composition variance causes the air/solid to gradually then suddenly build-up, obstructing flow.
In this case the root cause is the operating point and product character/composition. The plant is pushing the limits of the drying equipment. Any incremental increase in moisture makes the product coheasive/adheasive (weight gain occurs above 50% RH).
Mitigation would seem to require limiting moisture excursions and minimizing coheasion with a method to recover when murphy intervenes.
I am changing to drier motive air, to lessen the problem, but that does not prevent the plant from pushing themselves to the same operating point by allowing the product moisture content to rise, in an effor to achieve greater production.
To run on the edge as a semicontinous operation is the cost effective solution to higher production, given the constraints. Especially if the fix only requires momentary interuptions. ■
Tips on repipe to insitu clean a dilute pneumatic line w/ water?
Cleanout options
Knife gates and diverter valve above trench level
Full port ball valve with filler
The pneumatic transport line between the continuous dryer
(~ 140 F)and the hoppers, periodically accumulates a build-up and plugs close to the pickup point. The organic salt is very water soluble, but damp powder is adheasive/coheasive. Right now it is disassembled but to speed recovery I would like to avoid that.
I keep thinking about how to do it cheap, but I keep imagining issues, real or not. So I need advice.
Downstream of the dryer pickup fitting are two more entry points. To isolate the 4" tubing, 11 ga (3.5" pipe) from the downstream points I was going to use a full port ball valve. Anyone have one in this size?
What seat material should be specified? UHMWPE? PEEK? ???
Do I need to worry about the water in the cavity behind the ball? IF so what should be done?
As an alternative who makes a compact water proof diversion tube or plug valve? (This line is in a 12" x 14" trench to allow tow motor traffic) ■