Sprayer Looking for a Chemical Injector

[TheFarmerInAdell]

I'm looking to add an in-line chemical injector to my 3 point sprayer. The pump is PTO run, and I have 6 nozzles on it. I typically use the yellow or red nozzles (.2gpm or .4gpm), so the total flow is somewhat low. I don't like having the chemicals in the tank as I want to use it for just about everything. I would like to have just water in the tank and have the the chemicals (herbicides, pesticides, whatever else) be injected into the line just before the nozzles. I'd like to be able to spray the weeds in the hay field, then water the garden with the hand held hose and not worry about residual chemicals in the tank killing my tomatoes. I haven't had any luck finding an injector to fit my needs.

Does anyone have any suggestions?

 

[M59]

TheFarmerinADell,

A nice objective but also one fraught with problems.

The ratio of chemical to water ( diluent ) for many chemicals, particularly insecticides can be very low and depends upon the chemicals original solution strength. I have a few that are 1-2 grams per gallon of water.

At very low flow rates ( the 0.2-0.4 are very low flow ) the calibration of injection rate becomes problematic as very small changes of injected quantity into a very low flow system are actually large swings in the ratio of chemical to diluent ( water ).
You would need peristaltic pump or some other positive displacement pump since gravity feed is highly error prone.

How do you calibrate such a system before each use?

How do you assure chemical isn't flowing into the water while you are not spraying?

What happens to the chemical that has flowed into the water in pipe leading to spray heads before water leaves the spray head and you stop spraying? Does water and chemical flow back into the water holding tank?

To solve some of the above problems, you would have to add the chemical just post the nozzle end into the water as it sprays out. Similar to metal arc spraying in the metal finishing trade or some versions of epoxy layup for boat building where the two reactive epoxy components mix in the spray head but the epoxy sprayers also have method to air blow out residual epoxy components so they don't mix, at time of shutdown, and clog sprayer.

I'm interested to see what solutions are suggested.

 

[Hay Dude]

I'm looking to add an in-line chemical injector to my 3 point sprayer. The pump is PTO run, and I have 6 nozzles on it. I typically use the yellow or red nozzles (.2gpm or .4gpm), so the total flow is somewhat low. I don't like having the chemicals in the tank as I want to use it for just about everything. I would like to have just water in the tank and have the the chemicals (herbicides, pesticides, whatever else) be injected into the line just before the nozzles. I'd like to be able to spray the weeds in the hay field, then water the garden with the hand held hose and not worry about residual chemicals in the tank killing my tomatoes. I haven't had any luck finding an injector to fit my needs.

Does anyone have any suggestions?

Have you contacted Paul B Hardware? They have everything under the sun for sprayers.
Not far from me. Amazing place!

Sprayers & Applicators - Agriculture Supplies

paulbhardware.com

 

[Wagtail]

The first thing that comes to mind is a type of 'venturi' device/system.

 

[K5lwq]

Could you make something like this work? You can put different size tips in to meter how much chemicals you want per gal. This happens to be a air gap version but I should have some older action gap back flow versions. I should have two GPM as well. One of them is 1gal/minute the other would be 4gal/minute.

 

[TheFarmerInAdell]

TheFarmerinADell,

A nice objective but also one fraught with problems.

The ratio of chemical to water ( diluent ) for many chemicals, particularly insecticides can be very low and depends upon the chemicals original solution strength. I have a few that are 1-2 grams per gallon of water.

At very low flow rates ( the 0.2-0.4 are very low flow ) the calibration of injection rate becomes problematic as very small changes of injected quantity into a very low flow system are actually large swings in the ratio of chemical to diluent ( water ).
You would need peristaltic pump or some other positive displacement pump since gravity feed is highly error prone.

How do you calibrate such a system before each use?

How do you assure chemical isn't flowing into the water while you are not spraying?

What happens to the chemical that has flowed into the water in pipe leading to spray heads before water leaves the spray head and you stop spraying? Does water and chemical flow back into the water holding tank?

To solve some of the above problems, you would have to add the chemical just post the nozzle end into the water as it sprays out. Similar to metal arc spraying in the metal finishing trade or some versions of epoxy layup for boat building where the two reactive epoxy components mix in the spray head but the epoxy sprayers also have method to air blow out residual epoxy components so they don't mix, at time of shutdown, and clog sprayer.

I'm interested to see what solutions are suggested.

I use lower flow nozzles so I can cover more ground on a single tank. I use a 150 gallon tank to spray about 4 acres and I mix chemicals based on acreage not based on volume of water. I get a total of 1.2-2.4 total gpm with the nozzles I use. I use a PTO driven roller pump and I would put the injector after the pump and between the pressure relief valve and the nozzles. To stop spraying I turn the PTO off so with no water flowing there should be no chemical flowing. There are pressure activated check valves at the nozzles to prevent siphon dripping and back-feeding.

Have you contacted Paul B Hardware? They have everything under the sun for sprayers.
Not far from me. Amazing place!

Sprayers & Applicators - Agriculture Supplies

paulbhardware.com

I looked around there, but I didn't see anything that would be for injecting the chemicals.

The first thing that comes to mind is a type of 'venturi' device/system.

That's what I've been looking for, but I haven't found one yet. Most venturi devices require a minimum of 2gpm. Depending on my nozzle I am between 1.2gpm and 2.4gpm.

Could you make something like this work? You can put different size tips in to meter how much chemicals you want per gal. This happens to be a air gap version but I should have some older action gap back flow versions. I should have two GPM as well. One of them is 1gal/minute the other would be 4gal/minute.

View attachment 754903

I had to look that up because I had no idea what that was. That seems to be on the right track of what I'm looking for. I'll dig around based on that device and see what I can find. Thanks for the tip!

 

[K5lwq]

I had to look that up because I had no idea what that was. That seems to be on the right track of what I'm looking for. I'll dig around based on that device and see what I can find. Thanks for the tip!

I have some I will send you if you want to try it. Just PM me you address.

 

[TheFarmerInAdell]

I have some I will send you if you want to try it. Just PM me you address.

Thanks! PM sent.

 

[JDW2]

I don't know if this is big enough but it's working action is what you're looking for I think. One tank for water, one tank for chemical and then they mix in the line.

https://www.tractorsupply.com/tsc/product/chapin-97761-the-first-ever-clean-tank-tow-behind-with-boom-97761

 

[TheFarmerInAdell]

I don't know if this is big enough but it's working action is what you're looking for I think. One tank for water, one tank for chemical and then they mix in the line.

https://www.tractorsupply.com/tsc/product/chapin-97761-the-first-ever-clean-tank-tow-behind-with-boom-97761

That's exactly what I'm trying to accomplish. Sometime between last night and this morning that item disappeared. I did find another one that isn't the tow-behind: https://www.tractorsupply.com/tsc/p...-25-gal-atv-mixes-on-exit-97562?cm_vc=-10011#

I went to the Chapin website to do some more digging. After further investigation, it appears that the unit mixes the chemical right before the pump. The way it mixes isn't venturi, but with the low pressure (vacuum) on the inlet side it will draw water and concentrate in. I will need to mix after the pump and pressure relief valve, because the pressure relief valve will flow the mixture back into the tank if I mix before the pump.

 

[TheFarmerInAdell]

You would need peristaltic pump or some other positive displacement pump since gravity feed is highly error prone.

I've used peristaltic (metering) pumps in my designs for work before. I did some brainstorming on this. I'd need to have a pressure switch to activate the pump only when the sprayer pump is running, and it would be beneficial to have some sort of potentiometer to control the speed of the injector pump to dial my ratios in. It could work, but is quite involved. I'll keep that idea just in case I can't find a mixing valve that works for my situation.

There are two major hurdles to using a mixing valve or venturi. One is I have a low flow. The other is I have the same pressure on both sides of the mixing valve. Some mixing valves require a pressure differential, or they create their own pressure differential. I'll have to experiment with the ideas here and come up with a solution (pun intended).

 

[M59]

I've used peristaltic (metering) pumps in my designs for work before. I did some brainstorming on this. I'd need to have a pressure switch to activate the pump only when the sprayer pump is running, and it would be beneficial to have some sort of potentiometer to control the speed of the injector pump to dial my ratios in. It could work, but is quite involved. I'll keep that idea just in case I can't find a mixing valve that works for my situation.

There are two major hurdles to using a mixing valve or venturi. One is I have a low flow. The other is I have the same pressure on both sides of the mixing valve. Some mixing valves require a pressure differential, or they create their own pressure differential. I'll have to experiment with the ideas here and come up with a solution (pun intended).

Have you considered running two tanks ( one contains batch mix and one contains water for watering plants ) on the same trailer or have two separate trailers and tanks since you appear to indicate the hay field is is one location and the garden is in another?

What about having a fixed watering tank in the garden area or running a water line above or underground to the garden area so you eliminate the dual use issue?

Don't know your landscape layout to provide better feedback.

 

[TheFarmerInAdell]

Have you considered running two tanks ( one contains batch mix and one contains water for watering plants ) on the same trailer or have two separate trailers and tanks since you appear to indicate the hay field is is one location and the garden is in another?

What about having a fixed watering tank in the garden area or running a water line above or underground to the garden area so you eliminate the dual use issue?

Don't know your landscape layout to provide better feedback.

It is a 3 point mounted sprayer. The hay field is a not visible from the house. I had considered running a water line from the house to the garden, but it would be quite a task. I would need to bury 200 feet of pipe to get to the main garden area, and another 250 feet of pipe to get to our other garden. Plus we get deep frost here and it would need to be blown out completely every year and/or buried 4-6 feed down.

I had considered building another sprayer, but that would cost significantly more than creating a mixing system for the current sprayer. It would also add to the maintenance and storage of equipment.

Right now we have a water tank at the garden and we are watering with buckets. I considered a solar pump, but again it can become cost prohibitive. There have been many times where it would have been nice to have pressurized clean water a long way away from the house, which is kind of a push to go to an injection system.

 

[M59]

It is a 3 point mounted sprayer. The hay field is a not visible from the house. I had considered running a water line from the house to the garden, but it would be quite a task. I would need to bury 200 feet of pipe to get to the main garden area, and another 250 feet of pipe to get to our other garden. Plus we get deep frost here and it would need to be blown out completely every year and/or buried 4-6 feed down.

I had considered building another sprayer, but that would cost significantly more than creating a mixing system for the current sprayer. It would also add to the maintenance and storage of equipment.

Right now we have a water tank at the garden and we are watering with buckets. I considered a solar pump, but again it can become cost prohibitive. There have been many times where it would have been nice to have pressurized clean water a long way away from the house, which is kind of a push to go to an injection system.

What about a temp water line such as some connected garden hoses across the ground to the water storage tank or tanks. Roll them up for the winter. This is cheap and cheerful solution unless you mow or drive over them and /or you have rodents that like to chew. I found about 1/4 mile of 1 inch abs going to a garden from mountain springs on my property. Great idea but rodents liked to sharpen their teeth on them.

Lowes for $25/ 100 feet.

 

[TheFarmerInAdell]

What about a temp water line such as some connected garden hoses across the ground to the water storage tank or tanks. Roll them up for the winter. This is cheap and cheerful solution unless you mow or drive over them and /or you have rodents that like to chew. I found about 1/4 mile of 1 inch abs going to a garden from mountain springs on my property. Great idea but rodents liked to sharpen their teeth on them.

Lowes for $25/ 100 feet.

I tried that. Unfortunately I would have to roll it up every time I mow. And the "light duty" hoses only last one season from my experience. Plus we have rodents. The garage cat (because she insists on staying in the garage instead of the barn...) keeps the population low, but it seems like they still get at anything they can.

 

[mapper]

Have you checked out the Mazzei injector website?
They have a large selection of venturing type injectors and a calculator to figure out the proper size for your application.

 

[M59]

I've used peristaltic (metering) pumps in my designs for work before. I did some brainstorming on this. I'd need to have a pressure switch to activate the pump only when the sprayer pump is running, and it would be beneficial to have some sort of potentiometer to control the speed of the injector pump to dial my ratios in. It could work, but is quite involved. I'll keep that idea just in case I can't find a mixing valve that works for my situation.

There are two major hurdles to using a mixing valve or venturi. One is I have a low flow. The other is I have the same pressure on both sides of the mixing valve. Some mixing valves require a pressure differential, or they create their own pressure differential. I'll have to experiment with the ideas here and come up with a solution (pun intended).

Just ran across this in another TBN thread. A 2 tank spray system similar to what you are interested in.

Chapin 97361: 15-gallon Mixes On Exit (M.O.E.) 12V, 2.5 GPM Pump ATV Spot Sprayer

Stop wasting water, chemical concentrate and time with Mixes on Exit, the clean tank spraying system from Chapin. Separate water and concentrate tanks mean no more messy and wasteful premixing of chemicals – and your water stays clean!

chapinmfg.com

Perhaps something to buy or school up on how it works and make your own.

 

[TheFarmerInAdell]

Have you checked out the Mazzei injector website?
They have a large selection of venturing type injectors and a calculator to figure out the proper size for your application.

Apparently you need to register and have an account to use the calculator. I've kind of given up on venturi devices as most need at least 2gpm.

 

[TheFarmerInAdell]

Just ran across this in another TBN thread. A 2 tank spray system similar to what you are interested in.

Chapin 97361: 15-gallon Mixes On Exit (M.O.E.) 12V, 2.5 GPM Pump ATV Spot Sprayer

Stop wasting water, chemical concentrate and time with Mixes on Exit, the clean tank spraying system from Chapin. Separate water and concentrate tanks mean no more messy and wasteful premixing of chemicals – and your water stays clean!

chapinmfg.com

Perhaps something to buy or school up on how it works and make your own.

That was already suggested here. The issue I discovered when looking into it is it mixes before the pump using the suction to draw in the chemical along with the water. I cannot use that because I have a PTO driven pump and a pressure relief valve that circulates back to the tank. It would pump the mixture into the tank defeating the purpose of what I'm trying to accomplish.

 

[jigs_n_fixtures]

Magnet(s) on the pto drive or the pump, to trigger pulse injectors, running on what ever voltage your tractor has. Adjust injector pulse length to fine tune the injection volume

Expensive but effective: A chemical metering pump similar to an LMI MiltonRoy, which pulses in response to an exterior signal, and a signal generating flow meter. I think you can get the plastic Indian versions of a water meter with pulse output reasonably priced on Amazon. I bought three of them a couple of years back because they were about20% the cost of a good bronze meter.