Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Dear Ralf Weiser,
I have once used an air to air cooler for an Aerzen VM337 compressor with a cement unloader.(Although not in North America)
The cooler was custom manufactured.
Between the compressor and the cooler arrangement, there were, of course, the silencers and approx 4 m of piping and hoses.
The cooler performed well.
If you are worried about pressure pulsations, you can always use a pulsation damper and a tank, to eliminate compressor pulsation.
For blowers, use the airsil type.
take care
teus ■
Teus
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Hi Teus,
I think I can account for proper pulsation dampening and noise abatement once I have found a capable vendor who has the technical expertise to specify what their product's limitations are. So far we have found only one air-to-air cooler manufacturer called Xchanger, that provided us with coolers, but also seems to lack the technical expertise. That is why they unfortunately do not provide a warranty in conjunction with PD machines - they seem not sure of themselves. Therefore I am looking for another resource to tap into. AKG of America used to have a great line of air-to-air coolers, but they no longer sell direct to OEM accounts, and dealing through resellers has been a constant issue.
Could you think of any other vendors?
Thanks! ■
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Hi Ralf,
The maunfacturer in 1998 was "Bugge Apparatenbouw" in The Netherlands.
If you call Aerzen Benelux in Duiven The Netherlans, they can certainly help you to get in contact.
best regards
Teus ■
Teus
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Dear Sir,
You are requested to elaborate lobe pass frequency.
Regards
Sachin Kr. Arora ■
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Hello,
lobe pass frequency on positive displacment rotary lobe or helical screw blowers and compressors is the frequency of the rotor lobes passing by the exhaust port. It is also sometimes called pulsation frequency.
For conventional two lobe blowers this is calculated as follows:
Main rotor input speed times the total number of rotor lobes (both rotors combined. Here it would be
Main Rotor RPM x 4 = lobe pass frequency.
For conventional three lobe blowers this is calculated as follows:
Main rotor input speed times the total number of rotor lobes (both rotors combined. Here ti would be
Main Rotor RPM x 4 = lobe pass frequency.
For helical screw machines there is usually a different lobe count per rotor. Here the formula is simply Main RPM times number of Main Rotor lobes = lobe pass frequency (or Secondary Rotor x number of Secondary Rotor lobes = lobe pass frequency -it is the same frequency).
Does this help? ■
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Dear Sachin,
Nowadays a modern blower (Roots type) consists of 2 parallel rotors with each 3 matching lobes.
(The lobes can be compared with the teeth of a teeth gear)
The space between the housing and a lobe chamber is at a certain moment connected through the inlet with a low pressure environment (vacuum or atmospheric)
After some rotation a chamber is separated from the surroundings after the inlet is closed and the outlet is not yet open.. This chamber has the pressure of the inlet piping..
After some more rotation, this chamber is connected to the pressure side of the system (atmospheric or over pressure)
At that moment, air flows back from the system, which is under higher pressure than the chamber, until the chamber and outlet piping have the same pressure.
(AIR FLOWING BACK)
Then, by further rotation of the rotors, the air is positively displaced out of the narrowing chamber into the outlet piping.
(AIR FLOWING FORWARD)
The air is flowing back and forth, each time a lobe passes the outlet.
This flowing back and forth is the definition of sound and sound is pulsating air(periodically pressure changes)
Example: 3 lobes at 2000 rpm # 3*2000/60 = 100 Hz
By smoothening the pressure equalization between the piping and the chamber, these pulses are made less energetic. (Aerzen Airsil system)
Screw compressors with internal compression have the same phenomena, but less at the designed internal compression pressure.
A blower is not just a rotation piece of iron, it is technology.
Ask Mr Ralf Weiser for the real story.
have nice day
Teus ■
Teus
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Thanks Sir Teus and Mr Ralf Weiser for the valuable information but what is this real story?
Regards
Sachin ■
Re: Air Cooled After And Inter Coolers For Pd Blowers And Compr…
Hi Sachin,
This is an interesting question. if I read between your lines correctly, you are probably asking me why I am looking for vendors.
Simply put we do occasionally get into situations when our sub component vendors do not provide us with a warranty when they do not feel competend that their equipment will be able to endure pulsation and noise. When that happens our customers expect us to provide a warranty anyway - that can get expensive.
Is this what you were asking for? ■
Air cooled after and inter coolers for PD blowers and compressors
Hello,
does anyone have good experience in North America with air to air coolers for PD blowers and compressors?
The pressure ranges from 0-15 and 0-50PSI with temperatures ranging from 200-480 degrees F. Flows can range from 100 to 8000scfm. Key challenge is usually finding a company that has experience with the problems that can arise due to noise and pulsation caused by the lobe pass frequency. ■