Pump required for pesticide spraying drone

Projects General Guidance
1

Helllo,
I am working on a pesticide spraying drone. I am looking for a pump which can spray water as a starting point.
I have tried different pumps like this.

But the problem I am facing is that once they start and there is water in the water carrying tube even after stopping the pump the water still keeps running out if the water storage tank is higher than the water carrying tube.

I am looking for a pump that can stop the water flow through a closing valve that it might have.
Please suggest specific pumps with links.

2

What kind of volume/output are you needing ?

How far must the spray penetrate ?

Sounds heavy for a battery operated drone :thinking: .

3

I could never get the link you supplied to give me anything. But I see it is a submersible pump. I hope you are not planning to run a submersible pump in a pesticide solution. Quickly eat away the metal.

You have found a siphon and managed to make it work. You can stop the siphon by opening a vent to the air at the high point of the water carrying tube when you want to stop the siphon. A tee connection with a small floating ball will stop the vent with pressure and gravity will open it back up with no pressure.

Or you can use a self-priming pump and keep it out side of and above the the water container.

4

Weight is the big issue here !! Have you done some sums on power required to lift your liquid load

Not only hard to lift weight , but there are restrictions on large unmanned Vehicles.

5

That looks like an impeller pump: sort of like a fan for water. A diaphragm pump or a piston pump would also have the same problem because the inlet and outlet valves would both allow siphoning. I think you need a "Rotary Positive Displacement Pump" which moves 'chunks' of fluid when turning and blocks siphoning when stopped. One good choice would be a paristaltic pump.

6

Two things come to mind:
a) Pressurize the pesticide tank with compressed air and use a solenoid valve to control the spray.
b) Pressurize the pesticide tank with an air pump and once the pump is shut off (and pressure back to atmospheric), flow will stop.

1 Like
7

That would be a sensible solution. You would need to produce quite large droplets however as otherwise the spray would just disperse.

8

I was thinking about something very similar recently for destroying wasp nests because we currently have an active one in our roof space.
I came across this video Hornet nest drone predator obliterates 11 nests in a day - YouTube which shows something similar, but using inflamable liquid (which would not be appropriate in my application) instead of insecticide. However, the principles will be the same. Unfortunately there are no construction details

9

Use a gear pump...

10

Don’t bother with a pump. You need all kinds of things to make it work and it is heavy. Used compressed gas and you can refill when the liquid is empty. Then all you need is a solenoid valve for the sprayer. This is how manual sprayers work. You will be able to pick up the bits in any hardware store and if you really want multiple runs before recharging then get an old sodastream machine.

11

and just what kind of container does any compressed gas come in.....??? Yup heavy duty

12

You don’t need a heavy duty container. You are not scuba diving!! It can be stored in anything from a carbonated drinks bottle to a carbon fibre donut depending on the needs of the project. For a pump you need to carry the heavy pump, the heavy batteries to run it and the heavy plumbing and control mechanisms. In a compressed gas system you can simply use the container your liquid is stored in to contain some pressurised air and a small solenoid valve.
Buy a garden sprayer from your local diy store!

13

It occurs to me that simply hovering the drone next to the nest may be very effective. :grin:

1 Like
14

hmmm. Where did I see that idea before? :slight_smile:

15

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