Hello all,
a customer complained one of our vibrating-table machines was not working. These are reactive machines - i.e. two-degree-of-freedom systems - where the vibrating table is the second DOF and sits on springs (circular steel bars). The bars are attached to a structure (first DOF) where...
Hi,
We’re going to attempt to locate a suspected fracture in a large cast iron machine part. The part is a shallow, hollow cylinder with vertical axis, about 400 mm tall and 1500 mm in diameter. To access the inner part of the cylinder there are a number of inspection doors about 120 mm día in...
Hi all,
because space constraints we are considering to drive six 4 kW, 400 V identical 10-pole, PM AC, sensorless motors with only one VFD. The applied torque on each of the six motors is NOT the same and varies with time.
I understand the logic that the VFD will fail to determine the...
Greetings,
We must assess the noise attenuation of a sound enclosure designed to contain a 135 dBA noise source with a reduction of 50 dB. The noise source is not yet active and won't be until late September, but an assessment of the noise enclosure is necessary for payment purposes.
A...
Hi all,
is there a way to use a 3-phase inductance to start an AC motor?
The whole picture: the motor is in reality a 110 kW asynchronous 3-phase generator (400 V, delta connected, 50 Hz), moved by an internal combustion engine. Because the generator is SO massive it tolls the engine starter...
Hi!
Which one of the following two intake manifold conditions will lead to better efficiency, on a spark-ignited engine? Can someone say what is the ballpark efficiency increase between the best and worst condition?
A) 1.5 bar(a) pressure and 100ºC
B) 1.5 bar(a) pressure and 50ºC
Both...
Hi all,
we have to build an enclosure to attenuate an SPL of 137 dBA @ 6 ft, coming from a high-temp supersonic nozzle.
A double-walled enclosure with all due precautions and acoustic tricks should provide the 55 dBA attenuation, but we need to reach 60 dBA attenuation and I'm especially...
Hi all!
We're running an 8.0L turbocharged engine on wood gas to drive a stationary electric generator, rated 100 kW.
Wood gas composition is essentially:
20% H2
20% CO
5% CH4
55% N2
We are experiencing loud "clanking" noises coming from the engine when we approach rated power, the conditions...
Hi all,
We're getting a much lower power factor than anticipated on a 100 kW asynchronous generator intended for 100% power export to the grid. It is connected via a dedicated line that serves only this generator and it's auxiliary systems (about 5 kW worth of 3 phase motors).
This is a follow...
Hello all,
A 100 kW DC motor has been moved from its original place (anchored to the floor) on board a centrifuge which now is mounted on air springs and vibrates.
The motor runs at 1000 rpm the transmission lowers the load speed to 330 RPM. RMS vibration velocity is 1.4 in/s. The motor is not...
Hi all,
we are starting up a 100 kW power plant meant to export 100% power to the grid. The plant consists of an internal combustion engine driving an asynchronous (induction) generator. The generator has a rated power factor of 0,85.
After a short test (50% rated power, about 10 minutes), the...
Hello All,
A couple of gensets will be operated at a constant load for 1500 hours a year on a 16h/day scheme. Engines are GM industrial powertrain Vortec 5.7L (350 cu.in), 8.1L (496 cu.in) and 8.1LT (496 cu.in, turbocharged), fired with Natural Gas and load is about 80%, 65% and 75% of standby...
Hello all,
I'm trying to assess vibration attenuation spectrum of a flexible suspension for an automated punching machine.
My instrumental setup is made of two accelerometers, one mounted on the machine and the other one on the floor nearby the machine. The excitation comes from the machine...
Hello everybody!
I'm looking for some good book(s) on muffler and silencer design. I'm interested in dissipative, reactive and hybrid silencers for gases ranging from air to combustion exausts.
Is there any "famous" title everybody working in this field should have over his favorite shelf...
