What is Spray: Definition and 53 Discussions

I have a kid who wants to do a report on aerosols. As I understand, we have researched that for pepper spray devices liquid CO2 is used as a propellant, but we can't find out how they calculate the concentration. Is there a place we can find the right formulas needed?

As our family drove along the highway, one of my 3 college boys started commenting about the water towers we were seeing. We started a deep discussion about how water towers work and that led to a fascinating discussion about water supply in skyscrapers that are clearly taller than your average...

Hi all Another random, kinda open-ended question here. Sorry for that. I found myself reading about atomizing nozzles in oil burners, and got curious about the physics of atomized sprays. I didn't have much luck researching this on my own, so I'm turning to you all. It was the kind of situation...

Hi all, I have a positive displacement (diaphragm) pump that I am looking to use to supply spray nozzles. The pump has a max pressure rating of 69 bar at 30.6 L/min (1450 rpm). I however want my nozzles to spray at 15 bar pressure and from the nozzle performance data sheet that equates to 0.68...

Hello. I want to make a own refillable aerosol spray can, but I don’t know really how to do it. I’ve seen quite a few videos/tutorials on youtube where people attach a bicycle valve with epoxy to a spray can and use compressed air to pressurize it. But I want the gas to be...

Is it possible to pressurize a spray can with gunpowder or something similar, in order to make a reliable spray can with high pressure? I’m asking this question because a small amount of gunpowder generates a huge amount of propelling gasses when ignited. I need to make a compact spray can...

Hello. Ordinary pepper sprays on the market are cans pressurized with propane, butane etc., that propells the liquid pepper through a spray nozzle. So I thought, would it be possible to make a pyrotechnic composition that act as pepper spray? Either that the burning powder itself act as a...

I looked up misting nozzle design, but the results I found referred to two types of industrial misting nozzles which don't match up to what a spray bottle looks like at all. I tried looking up design elements of spray bottle nozzles specifically, but all I found were details on how the pump...

Hi there, I noticed that when I release the cap it moves forward slightly (away from me) which I attribute to the surface being not level and my hand applying a small force. However, the cap will roll backwards afterwards (towards me). What is causing the cap to roll back and forth? It...

My name is Stetson, I am an Agricultural Pilot. AKA crop duster. I am looking for some help to answer a few questions to improve the efficiency, productivity, and safety of my profession. I fly an aircraft 6-10 feet above the canopy of a crop and apply various crop protection products. My...

I just have read about a new kind hybrid diesel-steam engine where water has been injected inside an internal combustion engine to improve efficiency. The basic principle behind the process is that water will soak up a large section of heat generated by burning the fuel and will turn into steam...

Do different sized bicycle wheel spray differently? I was asked this question recently and have got myself confused with an answer. To expand on the question a little, when riding through mud at the same speed, which would spray the mud further, a 26 inch wheel or a 29 inch wheel? My thought...

Hi, ok another strange question: how does this work: <link to video deleted> or what exactly is the science behind it? I saw it on BBC and they told something like "the low density of the gas is a result of the radioactive decay" i don´t get it. maybe someone could explain.

The water looks transparent, but when the water hit the stone, it looks as if it turns white? Why?

Homework Statement How far will water shoot from a hole in a pipe knowing the pipe pressure, hole size, and exit liquid velocity and flow rate. It is assumed that the hole is located such that the water is sprayed at a 45 deg angle from the horizontal. Homework Equations Basic projectile...

Hello all, my name is Mike and I'm looking to see if it is possible to keep a paraffin wax liquid inside an aerosol can. Then when sprayed out the wax turns to a solid film. Any help will be appreciated. Thank you for your time-Mike

Say you use a water mist spray bottle against a egg smell, do the water molecules crash into the scent molecules and bring them down? What about if the water has mixed into it essential oil? How does the spray interact and affect the scent molecules? Does a air freshener that you can buy in the...

Hi. First post so I hope I have the correct thread location. I am reverse engineering a 40+ year old vertical slide carburettor design i.e. the venturi is horizontal. The current spray nozzle protudes vertically into the airflow but is straight sided and flat across the exit. Option 1...

Hey, I am attempting to figure out the optimal nozzle placement for an evaporative cooling tower. Now, calculating the theoretical coverage of each nozzle is obviously not a problem since I know the spray angle of the nozzles. However, since the water is injected at a much higher speed than...

to keep it simple, I will explain what I basically need. Imagine a rectangular Plastic brick. With 10 small holes on the bottom that would release fluid. There is a cap on the top of the rectangle box that the fluid will be poured into. And a press style button on the side of the rectangle to...

Good day guys, aside solution concentration and depositing time, what are the factors affecting the size of the ZnO thin films deposited by spray pyrolysis. Also please include the articles or links for citation thanks!

Sorry if this is the wrong forum to ask. I have a fine spray application where I need ~140 psi but only .3CFM. I'm trying not to buy a regular air compressor (money wasted on unneeded CFM) and am looking at tire inflators, but very few of them have CFM ratings. Any suggestions?

Hello, I was wondering if someone knew what product/chemical could turn the clear Dettol antibacterial spray fluorescent yellow. I sprayed some Dettol onto a bit of kitchen towel and wiped my tap with it and the Dettol on the kitchen towel instantly turned fluorescent yellow. I tried it again...

Hello fellows, i would like to ask if you might know any spray with metal elements which can be visible in X-rays. I want to use it as coating in objects. Does any common gold or plat spray be used? Thank you!

I'm testing various nozzles with orifice sizes from 5mm to 40mm. The feed water comes from a hopper that is open to atmosphere into a pump. The pump has a flowmeter at the outlet. Then a pipe feeds the pumped water to the nozzle rig. The nozzle is spraying down onto screen filters. In terms of...

I was wondering if an antenna could pick up some sort of signal if it was exposed to a spray of electrons or ions. For instance I have a patch antenna calibrated for 300 MHz. The patch antenna was placed in an environment where it could be getting sprayed by a wave of electrons followed by a...

Consider a water jet that sprays from ground level on flat ground. The jet can spray at any angle $0<\theta<\pi$ along some horizontal axis, that is in one vertical plane. The jet sprays water at a velocity of $v_0$. Ignoring drag, find an equation that describes the boundary between where water...

When a hand spray painting gun is used to paint say metal tanks, about 80% of the paint is lost in the air. This not only leads to a wastage of paint, but also the paint partivles settle on other stuff causing paint spots. What method can be used to reduce this? One is ionizing the tank...

"Ionized water spray bottles" I'm not sure if anyone has seen these products. But, there are several different products out there - you put plain tap water into a spray bottle that has a battery & some "fancy looking" electronic equipment inside, include little LED lights that apparently flash...

Hi, I'm designing a system that spray water into air. I'm wondering how I should go finding out the relationship between the flow rate and distance of travel of the water droplet in air. If I am spraying the water going the same direction as the wind, how much would the velocity of the...

I am asking this question because I am trying to understand what entropy is and I just can't seem to get it clear. Now I think the asnwer is 0.5. The pressure of the can is 30. the Atmospheric pressure is around 15. You divide the pressure in the can by the atmospheric pressure and you...

Hi, What is the charge on a droplet of paint? Im trying to understand what's going on in electrostatic spray painting - specifically at the spray nozzle (this could also be crop spraying too) My understanding so far is that a paint supply is fed into a grounded nozzle. An electrode...

We are looking to produce a spray changes colour when it comes into contact with Carbon Dioxide. Ideally this would be colourless when sprayed, but become a visible "smoke" where carbon dioxide is present. Failing this, we are open to a white "smoke" that changes to coloured where Co2 is...

hello! is there a material that will be sprayed through a tube inside a 3D labyrinthine structure and it will create a skeleton inside that labyrinthe? thanks!

Homework Statement Why must the object that is undergoing electrostatic spray painting be earthed/grounded? 2. The attempt at a solution I understand that during electrostatic spray painting, the paint droplets are positively charged and they are attracted to the negatively charged...

Hi, I'm trying to build an electrostatic spray system. They are commonly used for spraying cars and pesticides onto fields of crop efficiently and easily. The spray is given a negative or positive charge that makes the spray attracted the opositely charged target (car or plant etc), ensuring...

At our recycled paper mill we are planning to install a spray starch system to help with ply-bond . http://www.freeimagehosting.net/t/1h2ie.jpg The basic idea is to feed 14 % starch slurry and recycled water into a centrifugal pump. The diluted slurry then runs through rubber hosing, valves...

Question: In an adibatic Spray cooler, a fine mist of liquid water is used to cool hot air by evaporating all of the water. The liquid flows in at a rate of 90 g/s and 30°C. The input hot air is at 450°C and 900 torr. The dewpoint of the input air is 47°C and the flow rate is 1362 L/s...

i have a red light laser measuring device. the application is to scan automobile head light assemblies for contour and size relative to the CAD model. The mounting lugs and plastic on the back of the assembly is easy to measure, the shiny front is a problem in that it scatters laser light and...

http://www.msnbc.msn.com/id/39516346/ns/us_news-life/ I can't believe this. That man may be at fault for neglecting to pay the $75 fire service fee, but this is plainly inhuman. His animals died in the blaze. Makes you wonder: if there were people still in the house, would they have put...

Like there is pressure in the bottle, and when you push on the lid it releases pressure shooting the spray out of the bottle? Isn't that called diffusion? When pressure moves things around to equal out everything?

Hello, I’m new to this forum, and this may seem elementary, but I can’t be sure of my thinking on the subject, so I’ll post the question here. The question concerns the following. I have two household spray bottles, each of the same size. Each has its hose down nearly to the bottom of...

Spray your tomatoes with Raid?! Check out this old commercial for Raid bug spray; at about the 40 second mark. https://www.youtube.com/watch?v=54mo6VXO17U

I am new to the forum so please go easy on me. I know I may be posting this in the wrong forum but I am a mechanical design engineer so if it doesn't have cogs I am in trouble. I am working on a project in which i have a pump/perfume bottle type of mechanism, I need to calculate how much...

Hi everyone I'm doing a project which looks at the measurement of astha inhaler spray force. The idea is that a spray will be propelled from an inhaller onto a flat plate and the force will be measured using a load cell for example. To get an intial idea of the size of forces, I am trying to...

Hhhhhmmmm... not so sure about this one, they make a pretty big claim: http://www.drfrankspainrelief.com/home.php"

Question: A new disinfectant spray is expected to kill 50% of the known germs in a room, but for health reasons it can only be used once a day. Between spraying, the germs increase by 25%. How many consecutive days of spraying are required to reduce the germs in the room to 10% of the original...

Hello everybody, I'm new here. I'm working with spray driers and I need to know how does the velocity descent affect to the process. Can you help me? I need to know how the variables affect and the consequences. Thank you very much

Why do grocery store owners spray fresh fruits and vegetables with water?

Hello, I was wondering if anyone has ever seen a movie where some people are robbing a bank or art gallery, and they spray something to make the laser beams show. Does anyone know what type of spray could do this? I have tried google, and I didn't know if this is the right place to ask...