Re: Conveying Issues After Shot Peening
Dear ,
If all the other parameters of the installation are the same as before the shot peened pipe was mounted, your suggestion is plausible. Remains the physical reason why.
Suppose that the pipeline resistance increases, then the pressure should also increase at the same feeding rate.
In your case the capacity dropped.
At what pressure is the installation running now ??????
How is the pipeline fed ? If the feeding is mechanical, then a drop in capacity is not likely.
Have you done some maintenance on other parts of the installation that could have influenced the capacity?
A calculation before the modification, based on the operational parameters and a calculation, based on the new operational parameters, could reveil the cause.
Has the amount of angle hair forming changed?
Pneumatic conveying, although a simple principle, is more than just looking at capacity.
success
teus ■
Teus
Re: Conveying Issues After Shot Peening
The line is fed by a rotary valve. Usually our limitation is our extruder rate.
The current line pressure is 80 Kpa, the high pressure trip point is 83. Typically this pressure was around 75 to 77 kpa.
Nothing else was changed on this system other than some of the piping which was mostly horizontal. Only about 6 m of vertical pipe was changed.
The amount of streamers are less, but I would expect that when rates are lower. ■
Re: Conveying Issues After Shot Peening
Dear matt,
46 tons/hr at 76 kPa corresponds with 76/46 = 1.652 kPa/(ton/hr)
41 tons/hr at 80 kPa corresponds with 80/41 = 1.951 kPa/(ton/hr)
Assuming nothing else has changed , then it seems that the product resistance of the pipe line has increased.
But, maybe the rotary valve is functioning on the higher pressure not as good as on the lower pressure, increasing the solid loading ratio, which in its turn increases the pressure drop.
A more in depth and accurate investigation is now required.
Is the compressor blowing off air?
Is the rotary valve leaking more air?
The reduction in angel hair indicates lower product resistance or at least a lower velocity.
The 2 mentioned calculations might give some indications where to focus on.
Pressure drop measurements along the pipeline can show where the pressure drop is generated. (should correlate with the calculations)
Have a nice day
teus ■
Teus
Conveying Issues after Shot Peening
We've recently replaced some transfer lines with shot peened ones and we've experienced a significant reduction in transfer rates.
We transfer low density polyethylene pellets normally at a rate of about 46 metric tons per hour. Since the transfer lines were peened our rates are maxing out about 41.
Could the peening be causing this? ■