Abs As A Pneumatic Pipe Lining Material
Acrylonitrile Butadiene Styrene is approxiamtely 200% less wear resistant than a low carbon steel. ■
Re: Abs Pipe For Abrasive Material
ABS might have good abrasive wear properties but you are dealing with erosive wear in pneumatic conveying pipe lines and polymer matrix is very poor against erosive wear.
As far as 25 m/s conveying velocity is concerned it is not to high for this system. You should be looking into ceramic lined bends etc ■
Re: Abs Pipe For Abrasive Material
Not sure about ABS.
Can you reduce the velocity (probably not)?
Consider abrasive slurries - what about ceramic lined pipes (coal slurry etc):
http://www.ludowici.com.au/
Et al
Have seen rubber lined pipes / impellers for wear (petroleum, probably wont do it any good).
What about re running the pipe (avoid bends - probably not possible). Or the use of bends that rely on material accumulation to minimise wear (material wears against deposited other material, instead of the pipe / liner etc).
Regards,
Lyle ■
Advantages & Disadvantages Of Abs Pipe For Abrasive Wear
Is there anyone else that can provide informative suggestions in regards to my query? I am quite eager to discover if any blends of ABS material are suitable or not for pneumatic conveying of abrasives from other's experience.
Lyle Brown, thank you for your comments. Yes, ceramic coatings and other surface treatments are being investigated as part of the feasibility study. We expect that any harder materials that are either in pipe form or applied to coat or line the internal wearing surfaces would require a more costly commitment than installing plastic piping such as a particular ABS material.
Rubber linings may not be suitable for this particular application in my opinion. Reduction of velocity and straightening of the conveying path are not possible.
Mantoo, thank you for your comments. I am not convinced that "polymer matrix is very poor against erosive wear". In the Oil & Gas installations I have designed we utilised HDPE for below ground Gas pipelines instead of steel where coal fines caused premature wear when a certain erosional velocity was exceeded. It was discovered that HDPE has a very low coefficient of wear in this mode of erosion for below ground installations. Perhaps other plastic material blends would resist abrasion quite well. Is it possible that there are a specific blend of polymer matrix that would suit the description I initially posted? The mechanism of wear failure may be due to a combination of abrasion and erosion rather than one or the other.
My curiosities at this point in time is as follows:
1) Has anyone had any experience with using ABS pipe for the purpose of lean phase pneumatic conveying abrasive materials in a dry airstream?
2) If so, what advantages and disadvantages were experienced by the specific installation?
3) Did the ABS pipe provide a cost effective solution for design, operation, installation and periodic maintenance? ■
Re: Abs Pipe For Abrasive Material
Did an installation using ABS across the roof of a building outside in Canada. Customer wanted to "save money & time" by using ABS outside instead of running steel inside below the roof. Temperature -20 to +35 C. Material was expanded vermiculite but rock dust component was noticeable and it wore out airlocks & blower rotors pretty good.
Had to redo the ABS joints 1-2 times every year or they would suck air. I think we concluded that black ABS in the sun has a much different expansion rate than steel. Later it was replaced with grey PVC & I think it performed better. Don't recall if any fittings ever wore out because the maintenance guys did that work themselves & didn't contract it out. ■
Re: Abs Pipe For Abrasive Material
Oh yes I forgot to mention that plastic pipe is bad for static & sparks. Watched my electrician with one hand on the pipe, take a spark in the backside with a gap of about 2" to a steel handrail. He stood up straight real quick & never did it again. Not sure how effectivelyyou could ground out that kindof charge. ■
Pipe Wear Problem
Bends need replacement frequently. That is common with normal bends. You can consider using STAG diverter bends. These will extend life of bends. You can get more info from:
http://www.stag.net/fileadmin/dateie...gpot80165.pdf ■
Re: Abs Pipe For Abrasive Material
Mr. Kielczewski:
As Mantoo points out, ceramics provide superior wear performance. It is true that ABS pipes are significantly cheaper that steel pipes with ceramic coatings. However, the indicator to compare one solution to another is the cost per ton processed.
This include not only the cost of the material being replaced but hand labour involved and production reduction due to constant shutdowns.
Ceramic liners can provide years of protection.
Corrosion Engineering manufactures ceramic liners for such applications. If you're in Australia, our partner Imatech (
href="http://www.imatech.com.au" target="blank">www.imatech.com.au) could help solve your problems. The picture attached depicts a particular application.
Feel free to contact us for more information.
Regards,
Attachments
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Advantages & Disadvantages Of Abs Pipe For Pneumatic Conveying …
Thank you all for providing your input with regards to this query.
I'm now determined to experiment with various design applications to evaluate possible alternative pneumatic conveying pipe materials by means of a test rig to draw comparisons and some conclusions.
The experimental tests are expected to exhibit different results with material behaviour in relation to air speed, product abrasiveness, wear performance, and other measureable factors.
Kindest regards
Mark Kielczewski ■
Alternative To Ceramic Lining Pipe Wear
I see I am a little late on this post, but what the heck. I will give you the scenario of an application at one of my customer's locations, and see if this may apply to you. My customer unloads railcars with bulk pneumatics, the piping to the termination point only had 3ea 6" 90 degree elbows in the line. The had previously used a specific wear resistant elbow with a cavity for the product to build against itself, and therefore not wear out the elbow. A sister company had replaced the elbows with larger diameter sweeps, and increased the unloading speeed by about 30%. The problem now was that the sweep elbows were wearing at about the rate you have listed, every six weeks. The product is a fine sand / talc like material, very abrasive. We replaced the bubble backed (sharp 90 degree bend), elbows with 48" radius sweep elbows, lined with a fusion weld high nickel based alloy. The alloy is designed to be applied in a low profile, as to not increase the friction, it has a Rockwell C of 60+. About 10 times harder than steel piping. Despite a application thickness of only about 1/32" of an inch, the lining works well for this sliding abrasion application. This did increase the flow as predicted, the elbows have now been in service for 16 months and still performing well. We were able to accomplish this at a much better price point compared to the ceramic coatings. I am in Pittsburgh, Pa.. We have also used HDPE pipe in some mobile applications, and you can really get a jolt from that stuff. The HDPE isn't even an option on the elbows. ■
Advantages & Disadvantages Of Abs Pipe For Pneumatic Conveying …
Thank you RUBBERSPECKTOR for your informative posting in response to my forum query. A late response is better than no response in my opinion. We did find that the operators were "blowing" material through the piping network 3x faster than the necessary transfer rate initially specified for the designed application. We measured ~55 m/s (~180 fps); It was designed for ~20 m/s (~65 fps). The reason given for this was to meet demand upstream with minimal capital cost. The problem then was a combination of abrasive and erosive wear. It was also discovered that the material being transferred was non-homogenous with highly abrasive contaminants. Those main factors were identified as the main problem and no amount of magical piping made from "unobtanium" would have worked. The long radius bends were made of a very hard steel alloy commonly known as "Bisalloy" and have good wear resistance properties.
On the other hand, I'm still gathering results on my home made test rig for various materials of piping and transfer products on what is now coined as "the almost cheap" set up. Some neighbours don't like me very much due to the noise and clatter when things go bang. On the other hand, I'm having a ball and am learning a great deal. You are quite correct in that HDPE generates intense static sparks. I have grounded my testing system with wetted rope to a water pipe and now handle some plastic piping with insulated gloves for good reason. Adelaide, South Australia.
PS Thanks to all that have and will respond to this forum posting. This forum is an excellent medium for learning and is widely appreciated. ■
ABS Pipe for Abrasive Material
Can anyone provide any insight on this topic?
I am undertaking a feasibility study to provide alternatives for a client that currently experiences premature failure of the steel pipeline material used for the pneumatic conveying of abrasive nonhomogenous material at high airstream velocities.
The pneumatic conveyor system currently utilises a screw feeder to feed an aggregate of wood chips, soil, sand and other waste products into a DN200 Sch 80 steel pipe approximately 100 metres in length with several bends and changes in direction.
The pneumatic conveyor is driven by a Rootes blower that provides an airstream velocity of approximately 25 m/s which may be the main factor contributing to the premature material failure of the steel pipe by excessive erosional velocity.
Currently the owner of this equipment requires a maintenance program where the pipe is rotated 120 degrees each 8 week period with complete failure occurring approximately every 6 months. The bends fail approximately every 6 weeks and we have been informed that these have been nitride hardened. Hence, we are investigating the use of alternative materials as a request form the client.
Regardless of this, I would like to know if anyone has any experience or knowledge where ABS pipe has been used for pneumatic conveying.
After extensive investigation, I have not been able to ascertain if ABS has been successfully used to convey abrasive material at high airstream velocities.
Although sources indicate that ABS compounds exist that have good abrasion resistance properties I have discovered that ABS pipe is particularly susceptible to dust induced static electricity that produces pinholes in the material as a result of arc penetration of the material surface. Also, the conveyed material may contain oil and grease based substances in small quantities. I have discovered that certain petroleum products can reduce the integrity of the ABS by depolymerisation and is also highly susceptible to various solvents.
Suggestions for other materials or surface coating that can be substituted or incorporated into the existing design would be appreciated also. ■