If you read this site, you know we’re fans of recirculating booms. We love them for three reasons:
- They save money and waste by recovering spray back to the tank during priming and rinsing
- They make boom cleaning easier by eliminating boom-ends
- Most require individual nozzle shutoff, which makes for better sectional control
If you’re new to the concept of recirculating booms, read more here.
Until recently, these booms were only available on sprayers imported from outside North America (Horsch, Amazone, Agrifac to mention three), or via France’s Pommier booms that have been available as retrofits for many years. In 2018, Agco introduced their Liquid Logic system on the Rogator line, becoming the first North American manufacturer to offer a recirculating boom at the factory. Pattison Liquid also offers Recirculating booms as standard equipment on their Connect Sniper pull-type sprayer.
In the meantime, three boom retrofit kits and one sectional conversion kit have become available.
The first was developed by Arag Australia, and is available there via Nozzles Online, and in Canada through Nozzle Ninja. Designed for John Deere R-Series and Case Patriot sprayers, the kit uses the existing line that feeds liquid to the outermost section and simply extend that line to the end where it enters the boom via two installed elbows. The liquid returns to the centre via the installed boom sections which are connected together by removing the boom end cap (or “aspirator” for John Deere) and replacing the gap with a section of hose. Back at the centre rack, the liquid from both booms meet in the middle. At this point, a three-way valve gives the choice to return the spray to the tank, or to receive pressure from the pump. There is also a manual valve that allows the return to be dumped for safe disposal.
The system does not tie into the sprayer’s electronics. instead, it adds a switch in the cab that the operator uses to switch from spray mode to recirculation mode. The switch is not activated at the end of each swath, but instead to prime or flush the boom.
Raven offers a recirculation kit for 3000, 4000, and 5000 series Case Patriot sprayers with Aim Command HD and an ISOBUS terminal. The approach is slightly different, as they retain the pressure feed through individual sections but also tie the sections together so the spray is returned to the tank. By including a shutoff valve between each section, the system retains the option to use conventional sectional control for high flow situations, or to isolate a section should a leak occur. The system can be configured and controlled from the sprayer monitor, either a Viper 4+, CR7, or CR12.
On March 2, 2021, John Deere announced a 2022 factory option called Pressure Recirculation and Product Reclaim. The system keeps several existing sections and adds two steel lines the flull length of each boom wing. One is for supply, the other return. As these lines approach a section, the supply is fed to one end of the section and the return is connected to the other end. On a 120′ boom, there are five recirculating sections, two on each wing and the centre.
This approach adds one more line than the other designs, and this line will hold materials that ultimately need to be cleaned, flushed, and possibly dumped or sprayed out for cleanout. A possible reason for the extra line is the ability to deliver 220 gpm to the boom, an advertised feature of John Deere high flow booms that may come in handy for topdressing liquid fertilizer. These levels of volume are not needed for pesticides.
This Wisconsin company has developed an innovative product that converts any existing plumbed section that contains boom ends into a recirculating section. It does this by incorporating a boom recirculation valve” (it calls it “Merlin IC System”) into the original section feed line. Boom end caps are removed and replaced with sweeps and hoses that return flow to these boom valves. The flow from the boom ends is incorporated back into the sectional feed thanks to a venturi design in the recirculation valve.
Advantages of this design include simplicity. No moving parts are required, the valve simply recirculates the flow from the boom ends automatically whenever that section operates. Existing sectional control, whether it’s by plumbed section or individual nozzle bodies, is unaffected. Flushing the boom with water is done with normal spraying. It takes some extra time to incorporate and dilute the contents of the boom end return lines but results in a clean boom and no section end residue. We’ve seen the results of testing and agree that it works.
This product does not allow boom priming without spraying. However, a key advantage is that it can be used with direct injection since no product is returned to the tank. Latitude Ag says it will provide the necessary flow sensor and software to make this possible.
Read more about the Merlin IC System here.
Precision Planting ReClaim
ReClaim is capable of operating on a sprayer with or without individual nozzle shutoff. For conventional nozzle bodies containing the original spring-loaded diaphragm check valves, the concept is to drop the liquid pressure below the cracking point of the check valves so flow continues through the sections and back to the tank without engaging the nozzles.
Recirculation fittings are added to the end of each boom section. These feed into 3/4″ lines are installed on section ends, which in turn feed increasing diameter collector lines that eventually return all flow to the tank. Flow reaches the sections as before. When recirculation is turned on, flow exits the boom section through the new fittings and returns through 3/4″ lines to the centre of each section, where it enters 1” lines that take the flow to the center of each boom wing. There the flow in the 1” lines is combined moves to the center of the sprayer on 1.5” lines where it meets the flow from the other wing. From there, the flow returns to the tank through an electronic ball valve and 2” line. This system ensures no back-pressure and balanced flow from each section.
For some sprayer rate control systems such as John Deere, the pump won’t operate below about 20 psi despite operator settings. This means the priming or flushing procedure would trigger nozzles to spray if the bodies were fitted with spring-loaded diaphragm check valves. A pressure reduction kit (a second restrictor valve) is required to reduce the pressure sufficiently for ReClaim to work in these instances. More here.
ReClaim operates independently of any electronic control systems, relying on a toggle switch to initiate recirculation. When flow back to the tank is detected, a light indicates that recirculation is working, and the operator waits approximately 60 sections for a 120’ boom to circulate all volume back to the tank. Download the operator’s guide, here.
This system requires a lot of additional lines. A 120’ boom would require 120’ of additional 1” line and 60’ of 1.5” line. The manufacturer states that ReClaim adds about 14 gallons of volume that would need to be displaced back to the tank, adding to the standing volume. This volume can be circulated using solution from the main solution tank, or displaced back to the tank using flow from an existing clean water tank, or displaced using compressed air via an optional pneumatic port. It is not clear how spray mix in the ReClaim system can be removed from lines without returning it to the tank and draining it from there. Users should consider the additional surface area and volume that will have to be addressed during cleanout.
Do It Yourself
If none of the available options work for your sprayer, consider building your own system. Sprayer plumbing parts are available from the major manufacturers Banjo, Hypro, TeeJet, and Wilger. Wilger, in particular, has developed a nice suite of parts well suited to recirculating booms, including flanged sweeps and thin gauge steel booms, punched for nozzle bodies or unpunched to move product. See their support for DIY projects on this dedicated page: Wilger Retrofit.
All these recirculation options improve the status quo of plumbed boom sections with boom ends. They should be considered essential equipment on sprayers.