I run a small crop spraying business. I'm trying to automate the chemical mixing process. I have a 7' x 14' trailer and a 255-gallon water tank. The current system I have I use one pump to pump water from the IBC tote to a 60 gallon cone bottom inductor tank, pour chemical into graduates to make a 30 gallon batch, then pour into the tank. Then I have another pump to either recirculate the mixture or to send it out to my sprayer.
I have this idea for a system with hoppers that I can pour chemical into and then I input how much chem per gallon, like 8fl oz of chem per 2gallon of water, and then it pumps the solution & the water into the inductor. The goal is basically to always have exactly 10 gallons of mixed chemical ready to pump out at any time. Takes around 8 minutes for me to spray 10 gallons, so it can mix in the mean time
I have an idea for two approaches, both would likely require a programmable logic controller of some sort.
1. Have variable rate peristaltic pumps pumping solution out of the hoppers and out of the tote.
2. Have cheap pumps connected to the hoppers but use flowmeters and solenoid valves to shut off the flow once the transfer volume has been met. One issue here is wouldn't that deadhead the pump?
Peristaltic is the way to go with steppers mounted on it for control, but 2 would also work if you need high volume and not that high precision. But the solenoids are redundant, you can just switch the motor off and calibrate the dead zone in the pipe. Dead-head is not an issue for cheapo small pumps when you do it for a couple seconds though.
But if you need ~250ml per 8 minutes, peristaltic with nema17 steppers should be able to do that.
I'd go with ESP32 for control, cheap as shit and easy to even integrate with a mobile app or anything else for control, can do OTA updates as well. Everything arduino works with esp32 as well, at worst with level shifting (since esp32 is 3.3v logic, but this shouldn't matter in this case).
Thanks for the advice, I kind of figured that the peristaltic pumps would be the most ideal. Any suggestions on where I can find peristaltic pumps that work well with those nema17 steppers you mentioned? Or do you think it's more practical to retrofit an existing pump? Either way, not sure where to find the right spec pumps.
Also, you mentioned using an ESP32 for control. Sounds interesting, but I'm not super familiar with setting those up. Got any pointers or resources to help me figure out how to configure an ESP32 system?
Thanks again for your help
Aliexpress has everything you might need in hardware. If you don't know shit about electronics, this is still going to be an uphill battle. The easiest way to program and use an esp32 is through esp-home, which is a front/integration for Home Assistant home automation, which is again a pretty big can of worms to open, so the simpler and second best alternative is just to go with the Arduino IDE and arduino libraries. Youtube is full of various tutorials for this, "how to use esp32 with arduino ide", search something like that.
If you're interested in home automation shit then HAss might be worth looking into, too, but you should know the basics of programming microcontrollers anyway.
Definitely weak on the basics of programming micro-controllers, but I'm willing to brute force to achieve this task. So if I'm understanding correctly, use the arduino IDE to program the ESP32 with like total steps for the individual motors? Maybe? It looks like It would go Pump > Driver > ESP32? Then interface with ESP32 with a mobile app perhaps.
I was thinking get 3 of these pumps, two for moving water
Kamoer 3700ml/min KK25-ODM DIY High Flow Peristaltic Pump 24V
Then get maybe 4 or 5 of these
Kamoer 400-1300ml/min KKDD High Flow Peristaltic Pump 24V DC Motor Dosing Pump
And run those for my chemical additives. Do the whole thing in 24v too. How does it know how many steps to run for a goal volume transfused?
Example situation
2gallons/acre
6fl oz of fungicide per acre, so 3oz per gallon
How do I determine the volume of each step?
Thanks for your help, I really appreciate the knowledge you have already shared.
More ESP32>driver>motor, and yeah, use the arduino IDE to program the esp.
>KK25-ODM
If that's the $300 motor then you are vastly overpaying here. For water just use a simple cheapo pump of any kind and calibrate it either by time or with a flow sensor, I'm assuming you don't need high precision.
The smaller pumps are probably fine, but there are <$20 ones like https://www.aliexpress.com/item/1005004240331933.html which would probably be fine for fricking around, you can always upgrade to the fancier one if the thing actually works.
Buy a bunch of DRV8825 drivers, they're cheap and decent, you'll probably frick up one or two in the process, driver boards, either like https://www.aliexpress.com/item/1005003166428228.html or grbl cnc shield and connect the esp with wires.
Steppers work on a wide voltage range, about 10-30V at least, it's more of a question of what the driver can accept. I'd recommend sticking to 12V since this is a low power project, not much benefit from 24V.
>How does it know how many steps to run for a goal volume transfused?
You measure it when setting up the device, it's going to be consistent. Do 100 steps, measure, do 500 steps, measure, do 5000 steps, measure, calculate the average. Same with the regular pump for water, except that will be detected pulses from the flow sensor, rather than steps.
https://www.aliexpress.com/item/1005003748611606.html flow sensor can be like this, hall effect so nothing in contact with the water inside.
How many different chemicals do you spray regularly? I'm currently building a spray rig for my farm but i mix 250-500 gallons of spray at a time and just spray it all out before switching chemicals. I can see how it would suck to spray small quantities and switch all the time...
So I do corn wheat and beans, so sometimes it's either just fungicide and water or sometimes its fungicide + water + foliar fertilizer and sometimes it's fungicide, fertilizer, drift moronant, and water. which gets to be a pain in the ass, especially if you're making a 30 gallon mix and the foliar fertilizer is like 1-2pints per acre.
In the future I plan on having one tote water, one tote foliar fertilizer, but we'll see. The farmers provide me the chem, typically in 2.5gal jugs so I'm thinking just 5 gallon hoppers would be sublime.
Here you go. At a going rate of $200/hr for a skilled engineer, you now owe me 50 bucks.
Schizo?
Yes. But you still owe me $50 you deadbeat
What kind of pump are you using OP? My current spray skid is a 6.5hp engine running a triple plunger diaphragm pump. Probably overkill but i got the pump for free because it needed some serious rebuilding.
New spray rig will have a new triple plunger diaphragm pump and I am going to try one of those little 3-4 hp diesel engines on it...
I just run two of these I got on Amazon off of a honda generator
VEVOR Shallow Well Pump, 1.5 HP 115V, 1200 GPH
One goes from the IBC tote of water into the conical tank, and then the other draws from the bottom of the conical tank and takes it out to the sprayer or it recirculates in the tank
Here's my future spray rig... booms and a bunch of unnecessary stuff have been removed already in preparation of fixing it up how I want it to be. Was able to salvage a bunch of cylinders, square tubing, and other good steel, and bolts and fittings so far.