Hello,
Have some problems with a roots blower. Twelve inch gears, 762 mm long bi-lobes. Horizontal gas flow.
Operating with a 80% hydrogen mixture.
Inlet about 0,6 barg / 30 deg C
Outlet about 1 barg / <70 deg C
Machine max. allowable speed as per the OEM is 1800 rpm.
The blower is driven by...
Hello,
I came across something that I believe is a bearing load diagram, if not please correct me:
How shall I read it and can someone explain the meaning of the numbers pointing in different directions?
Hello,
If you have a range of various models of roots blowers, what is the path to be able to predict sound level at various operating points for each machine in the range?
Is full testing and noise measuring of each rpm and pressure point the only way to go or is it possible to determine the...
Hello,
Over the years, I have participated in a number of tenders for the supply of rotating machinery to various EPC contractors pretty much all over the world.
Nowadays, machinery noise level seems more important than ever. I guess mainly due to more stringent regulatory requirements pushing...
The importance of a correct K/gamma-value for you inlet gas when selecting a compressor is of the utmost importance as you can read here http://www.jmcampbell.com/tip-of-the-month/2009/05/the-sensitivity-of-k-values-on-compressor-performance/
Hence the question how to navigate this jungle and...
Hello,
We are regularly buying standard catalogue shell and tube coolers. It is a range of 13 coolers with the smallest one at about 50 kg (DN40 flanges) and the biggest one at about 1000 kg (DN300 flanges).
The problem is that the vendor doesn't share the design/selection software. Hence I am...
Hello,
Typically I use HYSYS or ChemCAD to find out the condensation temperature of my gas mixture at a certain pressure. Information that I need to know this when working with compressors and trying to understand the importance of a KO drum and how to design it.
However, I have been building...
Hello,
Working on the design of a compressor casing in material grade EN-GJS-400-18-LT as per EN 1563:2018. Ultimately I want the compressor casing to fulfill PED, ASME code and API 619 requirements.
The material selection origins from API 619 that suggest that this material may be selected...
Hello,
I am looking to make rotors in accordance with API 619.
As per guiding table F.1 in Annex F, they are suggesting the following materials to choose from:
Shaft
Material Specification Oil-Flooded, Dry-Screw Form °C Min. °C Max. °F Min. °F Max.
Ductile iron JIS G 5502 FCD700 OF...
Hello,
I recently procured a PD blower with 2-lobe rotors. Part of the agreement, the vendor provided a blower data sheet. When I study the data sheet I see that they provide the POLAR MOMENT OF INERTIA (WR2): 29 LB-FT2 for the blower.
What does POLAR MOMENT OF INERTIA (WR2): 29 LB-FT2 mean...
Hello,
When designing PD blower packages there is always a returning document deliverable that disturb me a little bit:
"Civil and Foundation Drawing with total weight, anchor bolt location dynamic forces and moments"
The disturbing part is the dynamic forces and moments as it seems like none...
Hello,
Every now and then I am forced to specify procurement details for PSVs and its piping hook-up in gas service.
Is there some simple purpose built software I can use to check sizing, inlet and outlet pressure drops?
For example, I many times got into the trap with my PED notified body...
Hello,
I am trying to find information and design guidance for lobe rotor with a step top/tip. Google is not my friend on this subject.
If I understand correctly a step can be added to any lobe rotor profile, correct? The step should match with the waist of the casing as indicated by the below...
I am looking for a fundamental explanation on how the pressure distribution happens and works in a 2-stage roots blower setup.
I am familiar with blowers and fully accept and understand the following working principle given by CAGI about the functionality:
If we look at this example:
My...
Hello,
I have an old roots blower selection software, issued some 20 years ago. The manufacturer no longer exists which means that the support of the software has stopped since some 15 years back.
The input values are:
Flow rate in m3/h or Nm3/h or kg/h or fixed rpm
Inlet pressure
Inlet...
Hello,
I am working for a compressor manufacturer. For the last couple of projects delivering various gas compression systems I have been struggling to find the ultimate lifting facility (lugs, padeye etc.) for transportation and installation of our skids.
The best engineering just looks...
Hello,
I am working in a compressor selection software and I have to enter the heat capacity ratio (K-value or Cp/Cv value) of my inlet gas stream to proceed with the selection. How can I get the Cp/Cv value for my inlet gas stream in ChemCAD 7?
The molecular weight and Cp value is given in...
Hello,
Trying to setup our latest project in ChemCAD and part of the process is a pygas absorption scrub column, which is a new piece of equipment for me. Never worked with absorption type scrubbers before.
If I've understood correctly the scrub column is a typical scrubber with an internal...
Hello,
I need to blanket the oil covers on a compressor with nitrogen. The nitrogen is delivered to the skid in a 1" pipe at a pressure of 6 barg. The pressure shall be reduced to 1,4 barg. My intention is to put a piping to tubing adapter and continue with tubing lines within the skid.
My...
Gents,
I am getting crazy trying to understand if my IO signals are active or passive.
I have a new IO list template that require us to fill if our signals are active or passive.
To make it more confusing, we received and example of the list that I believe is incorrectly filled which is...
