Re: Conveying Pipeline For Bed Material
Dear Siva Prasad,
Probably the material velocities are high.
Calculate the product velocities using the compressor FAD and the measured pressures.
If the calculated air velocities are high compared to the mean suspension velocities of the particles, there might be an opportunity to reduce the air flow.
That would increase the pressure drop.
Near the flange joints, it is creating more problem.
Properly align the flanges and take care of smooth flange transitions.
Solving the problem starts with evaluating the installation and its design.
Best regards
Teus ■
Teus
Re: Conveying Pipeline For Bed Material
Originally Posted by Siva Prasad
Dear Sir,
Greetings of the day,
In my plant, we are having dense phase pneumatic conveying system for APH material (Air Pre Heater) outlet material i.e., Bulk density of : 900 Kg/m3 with average particle size of 150 to 250 microns and iron percentage of 3-4 %. Capacity of 2.4 T/H ,Conveying distance of 100 mtrs.
Actually we are using 3" pipe line, It is creating more hammering in the pipe line and Wear and tear is also very high. Near the flange joints, it is creating more problem.
Kindly suggest, what is the size of the pipe line, i have to use and for decreasing the wear and tear - what i have to do?
Kindly give your valuable suggessions for solving the problem.
With regards,
Siva Prasad.K
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Dear Siva Prasad,
In dense phase conveying, pipe line hammering, and wear and tear problems are generally caused by wide variations in conveying pressures and the resulting high thrust loads on pipe bends. What kind of pressure control system do you have? With this system, can you control these variations within a range of +/- 1% or less? In addition to these problems, do you have any shaking of the pipe line?
Regards,
Amrit Agarwal
PNEUMATIC CONVEYING CONSULTING
EMAIL: polypcc@aol.com ■
Re: Conveying Pipeline For Bed Material
2.4 tph can easily be handled in a 3" pipe at 100m. It looks like you are using too much air.
If you give details of the conveying system and operating parameters further advice can be given. ■
About The Wear Resistance
Originally Posted by Siva PrasadDear Sir,
Greetings of the day,
In my plant, we are having dense phase pneumatic conveying system for APH material (Air Pre Heater) outlet material i.e., Bulk density of : 900 Kg/m3 with average particle size of 150 to 250 microns and iron percentage of 3-4 %. Capacity of 2.4 T/H ,Conveying distance of 100 mtrs.
Actually we are using 3" pipe line, It is creating more hammering in the pipe line and Wear and tear is also very high. Near the flange joints, it is creating more problem.
Kindly suggest, what is the size of the pipe line, i have to use and for decreasing the wear and tear - what i have to do?
Kindly give your valuable suggessions for solving the problem.
With regards,
Siva Prasad.K
Dear friend,
As you mentioned it has a very serious abrasion ,so how do you handle this kind of problem ,i wonder. ■
Re: Conveying Pipeline For Bed Material
Originally Posted by Teus TuinenburgProbably the material velocities are high.
Calculate the product velocities using the compressor FAD and the measured pressures.
If the calculated air velocities are high compared to the mean suspension velocities of the particles, there might be an opportunity to reduce the air flow.
That would increase the pressure drop.
Properly align the flanges and take care of smooth flange transitions.
Solving the problem starts with evaluating the installation and its design.
Best regards
Teus
Dear Mr.Teus,
Thank you very much for the advice, We will implement the same the solution ■
Re: Conveying Pipeline For Bed Material
Originally Posted by Amrit AgarwalDear Siva Prasad,
In dense phase conveying, pipe line hammering, and wear and tear problems are generally caused by wide variations in conveying pressures and the resulting high thrust loads on pipe bends. What kind of pressure control system do you have? With this system, can you control these variations within a range of +/- 1% or less? In addition to these problems, do you have any shaking of the pipe line?
Regards,
Amrit Agarwal
PNEUMATIC CONVEYING CONSULTING
EMAIL: polypcc@aol.com
Dear Sir,
We are not having any major pressure control system, We are giving 4 bar pressure air through "Orifice Plate", The system is supplied by Macawber BK.
Shaking will occur when that respective pipe line U clamps are loosen or broken stage only.
Please suggest any modification to be done for the existing system.
With regards,
Siva Prasad.K ■
Re: Conveying Pipeline For Bed Material
Originally Posted by MantooIf you give details of the conveying system and operating parameters further advice can be given.
Dear Sir,
Thank you for the response,
Our Pneumatic conveying system details are:
BOiler Capacity: 150 TPH
Collection point: APH
No. of collection points: 2
Number of systems : 1 ( 1 master vessel + 1 Slave Vessel)
Particle size: 57 % - near about 10 microns
43 % - less than 10 microns
PARTICLE TYPE: MEDIUM FINE
Capacity of the System : 2.8 Tons/ hr
Conveying pipe line size: 3 "
Air line size: 1 1/2"
pressure supply: 4 bar
Coneveying distance : 100 mtrs.
Kindly let me know any further details required.
With regards,
Siva Prasad.K ■
Re: Conveying Pipeline For Bed Material
Dear Mr. Siva Prasad.K,
It is not possible to read from your information, how much air is feeding the pneumatic conveying system.
I understand that you are using a sonic choke to control the airflow.
Is there a way to verify the air flow?
Do you also use a venturi eductor?
I modeled the system according to your limited data and found:
80 m horizontal
20 m vertical
5 bends
3”pipe line
Air flow 0.0327 m3/sec
A continuous capacity of 2.8 tons/hr
Air velocity between 6 to 7.5 m/sec
A conveying pressure drop of approx. 1500 mmWC
As Mr Mantoo stated
2.4 tph can easily be handled in a 3" pipe at 100m.
What are the usual conveying pressures?
What is the feeding pressure?
What is the size of the sonic choke orifice?
What is the air feeding condition of the compressor (pressure, temperature)?
Cheers
Teus ■
Teus
Re: Conveying Pipeline For Bed Material
Originally Posted by Teus TuinenburgIt is not possible to read from your information, how much air is feeding the pneumatic conveying system.
I understand that you are using a sonic choke to control the airflow.
Is there a way to verify the air flow?
Do you also use a venturi eductor?
I modeled the system according to your limited data and found:
80 m horizontal
20 m vertical
5 bends
3”pipe line
Air flow 0.0327 m3/sec
A continuous capacity of 2.8 tons/hr
Air velocity between 6 to 7.5 m/sec
A conveying pressure drop of approx. 1500 mmWC
As Mr Mantoo stated
What are the usual conveying pressures?
What is the feeding pressure?
What is the size of the sonic choke orifice?
What is the air feeding condition of the compressor (pressure, temperature)?
Cheers
Teus
Dear Mr.Teus,
There is no equipment to verify the air flow, and we are having Venturi Educator also with 1/2 capacity (1.2 Tons/hr)
60 m horizontal
40 m vertical
5 bends
3”pipe line
What are the usual conveying pressures?
while conveying - back pressure will be around 1 bar to 1.5 bar
What is the feeding pressure?
4 bar pressure
What is the size of the sonic choke orifice?
1 1/2" size is the orifice plate, It consists of 8 holes (Circle) with 5 mm dia hole.
What is the air feeding condition of the compressor (pressure, temperature)?
Sir, Material is free flowing into the vessel with gravity.
Material temperature will be around 100 degree centigrate
Conveying pressure giving to vessel is 4 bar.
Kindly do the needful.
With regards,
Siva Prasad.K ■
Re: Conveying Pipeline For Bed Material
Dear Siva Prasad.K,
I remodeled the pipeline and tried to figure out the airflow through the sonic choke orifices.
With a compressor pressure of 4 bar and 8 holes of 5 mm, the critical airflow will be approx. 8 * 0.0205 =0.164 m3/sec
This value is very strongly depending on the temperature and the pressure.
A calculated conveying pressure (after the eductor) of 0.3 bar is far below the measured 1.0 to 1.5 bar.
Moreover, a conveying pressure of 1.5 bar influences the sonic choke, whereby the airflow reduces.
Calculating an equilibrium situation for an eductor/ venturi combination is almost undoable.
Any fluctuation in feeding rate, airflow, pressures, temperatures causes pressure fluctuations, which in fact are followed by new pressure fluctuations. (pressure feedback response)
If the pressure feedback response (influenced by the system time response constant) is more than 1, the system may run out of control.
Start with feeding the pneumatic conveying system with an exact rate, to minimize the pressure fluctuations from this source.
Investigating the behavior on site under various conditions is now a must.
The supplier of the system, who has to have experience with these systems, should be able to help you further.
Success
Teus ■
Teus
Conveying Pipeline for Bed Material
Selection of Conveying pipe line for Bed material
Dear Sir,
Greetings of the day,
In my plant, we are having dense phase pneumatic conveying system for APH material (Air Pre Heater) outlet material i.e., Bulk density of : 900 Kg/m3 with average particle size of 150 to 250 microns and iron percentage of 3-4 %. Capacity of 2.4 T/H ,Conveying distance of 100 mtrs.
Actually we are using 3" pipe line, It is creating more hammering in the pipe line and Wear and tear is also very high. Near the flange joints, it is creating more problem.
Kindly suggest, what is the size of the pipe line, i have to use and for decreasing the wear and tear - what i have to do?
Kindly give your valuable suggessions for solving the problem.
With regards,
Siva Prasad.K ■