# Questions tagged [air]

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### Calculating total annual quantity of CO, particulate matter, NOx and SOx

I am working on something, for that i need to calculate total annual quantities of CO, particulate matter, NOx and SOx for stationary sources. meters are not installed on emission sources. Can anyone ...
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### I am using a bag house filter to filter particulates in cement industry. suggest an economical combined technology to filter the gases as well

I have designed the baghouse filter but I don't know what device should I install in combination with the baghouse such that it filters the toxic gases too. I saw a lot of technologies but the cost is ...
64 views

### Theory of rotationally symmetric air cushion vehicle

I am trying to develop a theory for this situation: A small blown-up balloon is attached to the center of a compact disc; you let it float as the balloon discharges. Simplifying assumptions: ...
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### Dimples on a golf ball, dimpling on the Mythbusters car, and the terminology used common to both

This post is strategic. I have an answer to the Mythbusters dimpled car question which was asked elsewhere on SE, but since I have a 1 reputation score at the moment and cannot post its answer, ...
1 vote
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### Why carbon water filter can build air pressure inside (before installation)?

Today I got a new refrigerator carbon water filter (this). Before installing, out of curiosity, I dripped a bit tap water into the filter’s outlet to see if water could flow in and out. Obviously it ...
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### What causes water to always drip from an electric furnace when its turned on?

I made an electric furnace as a university project. It can heat up air inside up to 1000 degrees Celsius. It's not fully sealed so some air can escape from small gaps. Not sure if this would cause a ...
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1 vote
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### Properties of air and gas mixture

While studying a heat exchanger, I have encountered a hydrogen rich fluid stream (enters at 90° Celsius and exits at 120° Celsius) which has composition given in the following form: Air Humidity/Fluid ...
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1 vote
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### Optimized water droplet formation

What is the best way to "shatter" a water drop falling purely under gravity if the objective is to break it into as many droplets and as fine (smallest diameter) as possible? Should the ...
237 views

### Heating pump/refrigerator - calculate efficiency

I'm wondering how I can calculate the overall thermal efficiency of my heating/refrigerator pump. Actually I have this AC/heating pump unit from Samsung (P/N: AR09TXFYBWKNEE). I've placed a power ...
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### Can air currents be used to keep dust from settling on solar panels?

I've been trying to build products to start my own solar company. A common issue with solar panels is dust accumulation, which reduces the already low efficiency even further. I've been working on ...
57 views

### How can I calculate the requirements of a fan to obtain a defined airflow after a HEPA filter?

I would like to understand how can I calculate the requirements of a fan in the following scenario. I want to obtain some airflow (m^3/h or CFM)after a HEPA filter. I have found some specification ...
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1 vote
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### What's the most efficient air compressor to reliably deliver up to 15 litres per second at 10 bar? [closed]

Suppose I wanted to continuously supply up to 15 litres of air per second, compressed to 10 bar - what would be the most efficient type of compressor, i.e. the type requiring the least energy input in ...
2k views

### How do suction cups work?

These are suction-mounting hooks. I want to visualize and understand how do they stick on walls. After these hooks stick on wall. Like we compressed them. How? Since gases are compressible up to a ...
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1 vote
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### Air Conditioner for an Acrobat Plane

What kind of Freon air conditioner would work upside down? Or somehow make it cut off and start working again when upright? I have a small cabin so it can be electrically driven. I know they have an ...
179 views

### How to attach a metal rod to an air cylinder?

I have signed up for an engineering class, and the first project is purely mechanical. I've never done mechanical work, so this is quite interesting to me. I have come up with the following project - ...
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1 vote
58 views

### Is this an isenthalpic process?

My professor told us that If we spray water in dry air the process is on an Isenthalpic line of the Mollier diagram. Is it always true? if yes, can you explain me why?
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### Best Fan position for maximum airflow in a Vent

I need to add a simple ventilation duct to my room. The purpose is to draw stale air from the room to the outside. Is it better to place the fan at the intake (position 1) or at the output end (...
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### What is the most efficient way to heat air?

I'm currently playing with a school project. My goal here is to heat a stream of air to a significant temperature so I can demonstrate air expansion. I have a cylinder, with a few turbines, turning in ...
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1 vote
139 views

### Will an empty spray can maintain a vacuum?

If I were to remove all the air from a canister of WD40 so that it was a vacuum inside, and reinforced the walls so that it won't collapse in from atmospheric pressure, what would happen when I pull ...
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1 vote
256 views

### Accurate method or instrument to measure density of shaving cream foam or whipped cream foam?

I am currently filling a "standard" stainless steel cup of known volume with foam and then I weigh it. Then I calculate density. This method is pretty messy and I have to be careful about how I fill ...
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1 vote
203 views

### Is it possible to create a compressed/freezed air energy storage solution that also purifies the air of pollutants?

Basically can engineers design a machine where , while we are freezing and compressing the air for energy storage, we can also purify it of pollutants?
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1 vote
117 views

### The physics behind the condensation in tents?

When you compare single wall tent to double wall tent usually you will hear short summary "double wall tent prevents condensation from building up". So in most fair comparison it should work like ...
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### How does indoor temperature factor in when determining ideal relative humidity in a home?

I am having trouble understanding how indoor temperature plays into what a healthy indoor relative humidity level should be. Most sources I have come across searching the topic online provide a range ...
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### How can I establish as much airflow from my house to outdoors as possible?

I live in a small flat with all doors and windows sealed. The temperature outside is moderately cold. I assume the temperature in my flat is hotter because my body and the computer are emitting ...
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35 views

### Do companies recover CO2 and water from the purification step of cryogenic air separation, and how?

In the 3rd step of cryogenic air separation, filtered air is purified to remove water, CO2, and hydrocarbons from the N2-O2-Ar stream. Im interested in knowing what happens with that CO2 and water. ...
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### Equation to calculate flow rate

Assume you have a solid walled sphere with an opening of diameter x. The sphere has volume 0.02 litres and has air at 1.4 bars. What general equation would be appropriate to correctly size the ...
43 views

### Why can't we use air bearings for Hyperloop? Why isn't it feasible?

Why isn't the usage of air bearings for HL feasible?
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### Can I lift 15 tons on air bearings with 0.2 kg air/s?

The air is at 13 kPa and 400 K. I can raise both the supply temperature and the pressure if necessary. No problem with that. I could get 1.7 kg/s for the air bearings, but I have no more air. I ...
34 views

### Is this is a valid estimation for the mass flow required for Hyperloop air-bearings?

In Hyperloop air bearings, the air escapes through the rear cross-sectional area of each ski, you know? Yes, there is a pressure differential, but the air comes out of the skis, crashes into the tube ...
53 views

### Why have some Hyperloop researchers abandoned the air bearings initial idea?

Air bearings are a cheap solution for Hyperloop, unlike the costly magnetic levitation system. I'm consulting some sources and it seems there's enough air in the tube at 100 Pa to feed the air ...
67 views

### Is there an optical technology able to measure the temperature of dry air?

Optical IR sensors are able to measure the surface temperature of solids. But is there a range of the EM spectrum that can accomplish the same for measuring the temperature of nitrox (dry nitrogen, ...
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### Why does the water pressure initially drop then stabilize when pressure testing a valve?

Sometimes the dropping goes on so long(10-15 minutes) that the test is thrown out and the valve is opened and filled with water for a longer period of time. Pressure testers claim that it is because ...
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1 vote
995 views

### How an airlock works?

From wikipedia: Before opening either door, the air pressure of the airlock—the space between the doors—is equalized with that of the environment beyond the next door to open Anyone knows how this ...
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### How can I develope a water loop cooler system sustaining with liquid nitrogen? [closed]

Water will be circulated in the water pipe and liquid nitrogen tanks heat going to cool the water pipe,by the way to the water too. And fan is going to blow this cold air and heat is going to be ...
607 views

### is it possible to use copper coil instead of pads in air cooler [closed]

The pads are used in air coolers to cool the air but make it more humid. Is it possible to use copper / aluminum coils instead of pads to get cold and dry air?
114 views

### Ventilation setup high sleeper night cooling

I have a high sleeper in my room (width 3,70m, length 4,50m, height 3,30m) consisting of one large plane (yellow) and one window (darker grey). The plance leaves about 80cm space to sleep. The door (...
1 vote
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### Relation between airespeed and pushing force

I'd like to know how can I estimate the maximum speed that can be achieved by a "portion of wind" accelerated upward from rest on the surface of a place by pushing forces. So far I've thinking in the ...
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### What's the longest lasting tubing in air?

What's the longest lasting tubing for use in low pressure air systems? I'm looking at building a greenhouse with double or triple layer ETFE panels and the tubing would be run through the metal pipe ...
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### How can I determine pressure leakage in a pneumatic system?

I am an engineer currently designing a system in which the leakage of a hose is tested. The system consists of the following components: An air data system used to generate a pressure inside the hose....
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### How to manufacture parts with complex air channels inside?

I am designing a part that requires multiple air channels with an intricate structure inside. I would like to know if there is any state of the art injection molding technique or other technology that ...
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