Questions tagged [steam]
54 questions
24
votes
9 answers
Why use steam instead of just hot air?
As I understand, a steam machine needs a pressurised gas to work. This can be compressed air but it used to be steam. Energy was provided to the steam engine by heating up water. I don't understand why it used water as the pressurised gas could have…
Manu H
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20
votes
6 answers
Why did steam locomotives not transfer power by cogwheels?
Modern cars use cogwheel to transfer power from the engine to the wheels.
Steam locomotives used some kind of bars (sorry, I'm not a native speaker) to transfer the power to the wheels.
Why did the engineers not use cogwheels?
Would steam…
J. Doe
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12
votes
5 answers
Why is using steam to rotate a turbine more efficient?
For example i have an exhaust pipe with very hot air from burning biofuel, and i have a turbine at the end of the exhaust that rotates and generates electricity.
Why is it more efficient to use the heat to boil water then use the steam produced to…
Mohdak
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11
votes
4 answers
Preventing condensate backup at startup with orifice (venturi) steam traps on medium pressure batch process mains?
I am working with 1" medium pressure steam mains (45 psig) for a batch process. Time between batches is usually short (to the order of minutes) but depending on the day the delay can be hours, and even longer over weekends or holidays.
We recently…
jmac
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10
votes
1 answer
Steam sterilization of whey in a bioreactor
I'm trying to design a bioreactor to produce citric acid with whey and Aspergillus Niger.
The first step in the process would be to put whey into the reactor with some dextrose (approx. 10%). Then, this solution should be sterilized, and I was…
Pepe Mandioca
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9
votes
3 answers
How in Rankine cycle the turbine generates more power than the pump takes?
In Rankine cycle there's the boiler where water gets boiled into overheated steam. On input there's a pump that delivers more water, and on output there's a turbine that picks up the energy of the compressed steam.
The steam pressure is roughly…
SF.
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7
votes
4 answers
Why do steam and diesel engines have differing cylinder configurations?
Consider a fixed steam engine, such as in a Lancashire cotton mill or pumping in a Cornish mine. Then consider a fixed diesel engine such as a large generator or ship's engine.
Why does the steam engine have one or two large cylinders with long…
Paul Uszak
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6
votes
1 answer
How to protect a pressure gauge from condensation in a vacuum steam boiler?
Pressure gauges are protected from steam condensation in a regular boiler by using a siphon where steam condenses and prevents steam from going further up to the gauge.
However in a vacuum steam boiler when the boiler is re pressurized after use the…
Manu de Hanoi
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6
votes
2 answers
Pipe seized to inaccessible coupling - how to attach a new pipe?
A friend of mine that doesn't use the internet much runs a commercial laundry. They use an old 'Manlove Tullis' laundry calendar (c. 1980) that looks like this:
(click to enlarge photos)
Essentially, it is a machine with 3 rollers (2 visible in…
Danny Beckett
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4
votes
1 answer
How can I fit a DN16 flange to a DN10 flanged pipe?
One of the valves on my 3 bar line just failed. Without it, our production has ground to a stop and we can't operate until we get a replacement (which we have already ordered). In order to make a deadline, I am trying to find a way to use a…
jmac
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4
votes
1 answer
How many blades for a steam turbine?
I am building a very simple turbine that runs on steam. I want to make it as simple as possible, thus avoiding impulse and reaction turbines.
I want to design the turbine to fit in an exhaust pipe (about 15cm diameter) so that steam would rotate it,…
Mohdak
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3
votes
1 answer
What is the name of the part that allows a steam wand to have a moveable joint?
On espresso machines, there is some kind of pipe joint which allows the steam wand to move while maintaining its seal. What is this component called?
caleb
- 133
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3
votes
1 answer
estimating the surface area of a steam coil immersed in a tank
I've been tasked to design a steam coil that will be immersed into a tank in order to maintain the fluid temperature above 25C (but not to exceed 40C), and I need to calculate its surface area & length. The fluid is a highly viscous oil additive and…
dnc123
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3
votes
1 answer
Is Vapor Compression Distillation inherently more efficient than a thermal-only boiler-condensor?
I'm having a hard time understanding the benefits of VCD (like Slingshot) over a conventional boiler in terms of volume of condensate produced per unit of energy input. I've found quite a few resources explaining (in too much detail for me to fully…
Rhubarb_Tau
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2
votes
1 answer
Calculating the Fraction of Steam in a Mixture
I have a stream ($10,000$ $m^3/d$) of inert gas and steam. The temperature of the stream is $195$ $^oC$, and the absolute pressure is $1455$ $kPa$.
I am trying to find the amount of steam that can be present in the system. I can assume $100\%$…
quanticks
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