[WilgerIndustries]

I've gotten quite a few questions through posts or PMs on how to best select tips.

Even though the guide shows for wilger tips, even if you are Teejet/ABJ/etc supporter, you can still use tip-wizard to help you either pick tips or double check what kind of tips you'd picked with your dealer (or neighbors for that matter).

As Wilger has 4 different series of tips based on droplet size/drift control, you can think of them as a sliding scale of drift reduction:
ER series (Finest) - No drift control - Similar to Teejet XR tips
SR series (Fine w/ drift reduction) - First level of drift controlled tips
MR series (Coarse w/ Drift reduction) - Similar to ABJ tips
DR series (Coarsest) - Similar to AIXR tips

Definitely let me know if you have any feedback or any other questions you'd want to ask or even if you wanted to double check a tip selection choice to see if it might make sense.

By Don's request, I'll probably add a 'For Further Reading' page in a little bit to talk about how things like Pinpoint will work and how to adjust your spraying to accommodate and get the best use of it. I plan to make up one for dual-tip application as well.

Heck, even if you guys wanted to provide different chemicals and rates that your chemical reps spec for you and want to see them added to the guide, I can definitely do that as well. Generally, even if the rates change for the chemicals, usually the ideal droplet size will remain the same.

Without further adieu, the guide is available for download. The forums only allow pdfs of 19.5kb or smaller, so I had to just leave a link to my dropbox:

TipWizard.pdf


Let me know if you have any questions,

 

[Nitro 1]

WilgerIndustries I am interested in your take on nozzle fan angle as in straight down or facing back or facing forward (not twin jet just single). Have you done any testing with these different angles ? In your opinion what gives the best coverage and why ?

 

[WilgerIndustries]

WilgerIndustries I am interested in your take on nozzle fan angle as in straight down or facing back or facing forward (not twin jet just single). Have you done any testing with these different angles ? In your opinion what gives the best coverage and why ?

Great question.

Honestly, at this point in time, not much 'objective' testing has been done in more controlled settings. First because of the time/cost end of things.

Its easy to test it in a lab and say 'there are X more droplets due to having the flow split up, which means X better coverage'. The harder part is testing it to actually see the active effects of the change in spray.

When it means you are spraying fungicide or even in-crop, what the effect WITHIN the canopy is the harder question to test objectively. Of course we'd follow through with having groups of farmers in different areas testing the dual angle and straight down methods, but its difficult to base a decision on whether it truly is better one way or the other.

To start off, splitting up the flow of a large tip to achieve smaller droplets does work. It means more meaningful droplets (provided they are sized correctly), so there is an immediate PRO for splitting up flow. This benefit is gained through both dual direction and straight down dual tips.

As soon as you start to ignore that initial benefit and try look further into which is better (dual angle or dual straight down), it becomes more vague. Given the speed of the sprayers and the speed of the spray going down, its very hard to physically track the differences between the two while in the field.

All in all, guys are really liking the dual tip and dual direction for higher flow or very coverage sensitive applications, but no hard evidence which is better and by how much better.

Long story short, we are starting a three year test for exactly your question. Its being funded by most of the industry tip/nozzle manufacturers as well as the gov of Canada. Its going to be three years, as they will be doing in-lab testing and then in-field testing. It takes so long as they'd need to do their initial tests and develop the methods to test, and then try test in the crop for a lot more information that you can get in a lab (i.e. how many droplets are within the canopy or unde leaves, etc).

My general feelings are positive toward the use of the technology though. Other than the risk of more drift (as you are spraying from two flat fan orifices versus one), there aren't too many risks to it. In my mind, you'll get better efficacy and coverage with either the dual angled tips or the dual 'straight' down options. As far as the difference between the two, we will have to wait and see for a little bit.

 

[Nitro 1]

I was actualy just wanting your input on a single fan not twin but i guess the three year trial will cover a single fan also.

 

[WilgerIndustries]

Ah gotcha. I re-read your post and it was pretty clear. Sorry about that. Haha.

I hear that question a fair bit, as guys will essentially try rotating their booms both directions a few degrees (usually up to 6 degrees) forward or backward.

BACKWARDS: The justification to rotating the boom backwards is to cut down on wind shear, so that hopefully less droplets/drift will be taken off in the wind.

FORWARDS: The justification to rotating the boom forwards is to get better coverage (more smaller droplets) by having the wind shear break up the bigger droplets in your spray. It is thought that the potential loss in driftable content is overcome by the better coverage.

Overall though, with sprayers picking up speed (spraying at 20-22mph), the actual air resistance that the spray is fighting against is going to be doing a lot of the bad stuff whether you rotate forward or backward. If you think about it, by the time the spray is hitting the ground, it may very well be something like 6 feet behind the sprayer. That gives it a lot of time to stray from the pattern and enough wind shear/resistance to break up bigger droplets resulting in more drift (potentially better coverage if not too much drift).

My thoughts are that once you get to higher speeds than like 10mph, the ~6degree rotating would have less impact than we'd think.

Lets say we want to try reduce drift and turn the boom 6 degrees backwards while going 20MPH.
[I couldn't find the study that actually showed what the terminal velocity measure would be at 60PSI, but I recall the spray reached terminal velocity at around 2/3 of the distance to the ground at 24" spray height.]
So, if there is 24" of height from the boom to the ground/target, and 2/3 of the distance (16") is the distance the spray takes to reach the point where the droplets start to slow down from their max speed, it would leave 8" where the droplets are slowing down (of course smaller droplets would have hit their Terminal Velocity a lot sooner).

If we are going 20MPH and and by the time the spray hits terminal velocity, lets say it is going 18MPH (again, made up numbers until I find the test article) and slows down to 7MPH by the time the droplets reach the ground/target. There is so much air resistance due to the speed of travel that I'm sure before a lot of the droplets are going to end up going sideways more than they are going downward. That is going to result in more drift, as by that point, lets say any droplets 100 microns or smaller are already drifting sideways/upwards by the time the spray has traveled half the distance to the ground.

If you could imagine a 'perfect scenario', it would be either having the boom placed low enough that by the time the drops hit terminal velocity, they are pretty much at the crop. This would mean either slowing down so there is less wind resistance, and dropping the boom height so that there is less 'space' for the droplets to go astray from the target. Another option is 'assisting' the droplets by air or other methods to limit the effect of the 'space' between the boom and the crop (like Air booms which would blast air down to the crop so the droplets maintain their speed-up and terminal velocity for longer)

Honestly, its a tough question to answer when no testing is done, but I think there is benefit to adjusting your boom based on your conditions. If you are dealing with low wind conditions, and you generally travel slower (<8MPH), then you might be able to tilt your boom forward and get better coverage. If you are generally in windy conditions that you find most of your droplets are just exploding in the wind prior to even getting anywhere near the crop, maybe its best to adjust the boom backwards a bit.

There's definitely a lot going on with the spray out in the field, and generally it is always a weighing of the PROs vs CONs with no 'absolute' answer.

 

[BrianTee]

Given the patent for spray nozzles was in 1922, you'd think by now more would be known.

 

[WilgerIndustries]

Given the patent for spray nozzles was in 1922, you'd think by now more would be known.

I definitely agree. There is a fair bit of complexity that comes with the chemicals being use that change how the spray is actually sprayed which can make it difficult to change. There is a huge difference in how a very 'soapy' chemical would spray versus a very 'oily' chemical would spray. A flat fan nozzle might be the very best nozzle for an oily chemical, but it might be recommended to have a different style for the soapy chemical.

It gets to the point where there would/should be a tip (or tip style) that is dedicated to each chemicals' application. From the consumer standpoint, I don't think anyone wants to have like 2 tips for each separate chemical to be sprayed (i.e. high wind chem1 tip, ideal conditions chem1 tip, high wind chem2 tip, etc) That is definitely a good way to get the best coverage given the circumstances, but it isn't really feasible for a lot of guys. Most don't want to have even a single tip dedicated to each chemical. Probably everyone has tried to get the 'one tip that can spray everything', but unless the chemicals need the same-ish volumes with the same droplet sizes (or within a small range) then corners are being cut when it comes to trying to get the best application.

All in all, it is tough to really perfect something unless there is a recognized issue with how it is being done right now. In the states, the EPA is cracking down pretty hard for chemical use and application restrictions, so that might even be the catalyst for some new technology or tips.

 

[WilgerIndustries]

It's that time of year, for help picking tips or checking what the tips you got with your used sprayer would be good for, check out Tip Wizard.