Category: Cleaning & Maintenance

Articles about removing pesticide residue and disposing of rinsate from horizontal boom sprayers

Continuous Rinsing
We’ve recently been talking about how to save time while cleaning a sprayer. Although it’s very important to be thorough while cleaning, and to take the necessary time to do the job properly, there is always an opportunity to fine tune and spend less time. This is especially true when diluting the tank remainder down and pushing clean water to the booms. A method promoted in Europe, and coming to us via Joachim Herfort of Agrotop, is called “Continuous Rinsing”.
Continuous Rinsing requires a dedicated pump that delivers the clean water (which may contain a cleaning adjuvant) to the tank via wash-down nozzles. It works like this:
1. The operator, having carefully measured the pesticide mixture, has only a small remainder in the tank when spraying is complete.
2. This remainder is sprayed out in the field, either on a set-aside area, or over the already sprayed field at a reduced rate, product permitting (the operator would pay attention to crop tolerance and carryover issues)
3. As soon as the tank is empty, indicated by the boom spray pressure dropping, the operator switches on the clean water pump which delivers the clean water via the wash-down nozzles.
4. Soon, the main product pump starts delivering the wash-down liquid to the boom and the return lines.
5. Because the clean water pump will deliver less than the boom flow, the cleaning mixture is delivered somewhat intermittently. We are told that this helps with the cleaning action of the lines. Be cautious that the main pump does not run dry long enough to damage its seals.
6. Once the clean water tank is empty, the pressure drops again for the final time and the tank rinsate is now very dilute.
7. Testing in Europe has shown that the whole process takes only about half as long as batch mode. One key time-saving feature is that the sprayer never has to stop, and the operator never dismounts. These data also show that a significantly lower water volume is required to achieve a greater dilution of the remainder than a batch mode would have achieved.
8. For example, the European tests (we believe these were done by the Landwirtschaftskammer of Nordrhein-Westfalen, a German regional government) used a single rinse of 80 L, as well as four batch rinses of 20 L each. As expected, the four-batch process was superior to the single rinse, but took a lot of time. They then tested a continuous rinse with 40 L. The continuous rinse resulted in greater dilution than the 4 x 20 L rinse, in less time. In this case, the quality went up, and the time went down.
Our challenge in North America is to roughly match the clean water pump, wash-down nozzles, and main sprayer pump capacities so the system works. Our larger sprayers easily deliver 30 gpm, and some adjustments may be necessary.
Dilution of the tank remainder is only one aspect of sprayer cleaning. The other aspect, decontamination of surfaces and components, is also important and the process depends on the active ingredients and formulations in the tank.
An animation developed in Germany and shared via Agrotop is available here.
Note that Agrotop has suggested components to convert a sprayer to a continuous rinse system here.
March 22, 2016
Lessons Learned from the Top 5 Field Sprayer Articles of 2015
When Jason and I launched the Sprayers101 website in June, I wasn’t sure what to expect. Seven short months and 150 posts later, we’re stoked to have had such a great response. About 70,000 page views. 17,000 users. Of the over 100 countries that have visited, Canada, the US, Russia, Australia, and the UK are the top 5. Jason provided some great background to the venture in his recap of the top horticulture posts. I owe him a debt of gratitude for leading this effort.
It was a pleasant surprise that a very specific subject matter such as agricultural spraying could generate this level of response. Without a single mention of the Kardashians!
Here are the top five posts on field spraying for 2015:
1. Agrifac Condor: A Wake-up Call for North American Sprayer Manufacturers? 3078 views. Prior to writing this article, I’d been watching this relatively new (to me) Dutch company for about one year. I noticed that they thought big, and featured technologies that had benefits for applicators, like air-assist or twin-fluid nozzles, wide booms, and clever plumbing. On seeing the sprayer first-hand at Canada’s Outdoor Farm Show in Woodstock, I knew it was just what the industry needed. A wake up call.
2. Exploding Sprayer Myths Episode IV: Speed Spraying. 2211 views. What is life without a bit of fun? Writing and filming these episodes had us in stitches. With generous support of Shaun Haney and the gang at RealAgriculture.com, we’re producing these in our spare time and with gifted resources. A big thanks to Bern Tobin for being the videographer, director, and rough cut editor, and Jason Stroeve for the final editing, special effects, voice-overs and all those other things that go into it. We hope to do more of these, resources permitting.
1. A New Way to Purchase Sprayers . 1058 views. A friend recently reminded me that I used to urge producers to spend more money on sprayers. Well, the industry responded by making sprayers more expensive (you’re welcome), without actually improving our control over deposition uniformity, coverage, or drift. So yes, people are spending more, but not the way I intended. In the meantime, the innovations that matter, those on the spray boom – width, aerodynamics, recirculation, better sectional controls, droplet size and rate management – are still considered special options that are probably too expensive. We’re still looking for the right balance here.
1. Sprayer Tank Cleanout. 968 views. Cleaning a sprayer remains one of the top concerns of an applicator, actually the whole industry, and we’ve written about it several times. But it wasn’t until we had a guest contributor, Katelyn Duncan, offer her views that we had any real success. Katelyn is a Regina area farmer with her own blog and an interest in machinery. She approached the issue from a practitioner’s perspective and this really resonated and generated a lot of discussion.
1. Calculators and Tables. While no single table or calculator broke into our top 5, collectively they did and this is worth mentioning. Much of spraying is mathematical, from rate calculations, to calibrations and nozzle size selection, travel speed ranges and so forth. Despite living in an age of connectivity and touch screens, a laminated table in the sprayer cab is often worth its weight in gold.
So what are the lessons?
For one, we showed that a dedicated website for just one aspect of a farming operation seems to be in demand. That should encourage those specializing in seeding or harvesting techniques, commodities, fertility. Where are those sites?
People seem to want alternative, independent views, sometimes voiced as controversial opinions. Much of our media is controlled by corporate interests with soft-sell implications. Yes, it’s interesting and valuable information. But a reality check, whether it comes from an independent researcher or a new entry from the corporate world, is still needed.
Alternative formats for information are important. Not everyone learns by reading articles or deciphering charts. By offering a bit of entertainment, we can reach new clients or demographics that we’d otherwise leave behind. Plus, for Jason and I, the opportunity to be creative is probably the single most important thing about Sprayers101 that keeps us going.
Lastly, we are so pleased to have guest contributors on our site. Anyone can contribute – just drop us a note. I think it’s important to hear different viewpoints, and learn from each other. That’s one of the great things about agriculture – the willingness to share information. Any applicators out there who want to describe an aspect of their operation, from innovations in how they fill faster, to their experience with boom lights or cameras, to their thoughts on boom height controllers or PWM, we’d love to hear from you.
Thanks everyone for supporting Sprayers101.com!
January 10, 2016
Agrifac Condor: A Wake-up Call For North American Sprayer Manufacturers?
Agrifac Condor Endurance (Source: Agrifac)
I like good ideas. And at Canada’s Outdoor Farm Show in Woodstock this fall, I saw a sprayer that puts a lot of them in one place. I’m talking about the Agrifac Condor Endurance. I’ve seen European sprayers before, even operated a few. And although they are all well-engineered machines, the Netherlands-based Condor might be the first one to gain traction in North America. Why this one? Let me explain.

Size: If you thought European machines are too small for North American conditions, this one breaks the mold. Sporting an 8000 L (2100 US gal) tank, track widths up to 4.6 m (15 ft), a 320 hp Tier 4 engine, and booms up to 55 m (180 ft) wide, it’s a monster. The smaller Condor offers tank sizes of 1050 or 1300 US gal and is a smaller machine overall.
The tank sump design ensures minimal remainders.
Tank and Pump: The large tank has a molded funnel sump that feeds directly into the pump. Net result is a design that empties the tank completely, leaving a tiny remainder amount, less than 2 gallons according to Rob Blijdorp, with Agrifac North America. Because most of us clean tank remainders by diluting them with clean water, this small remainder needs less water to dilute residues to safe levels, saving time when switching products. The machine is equipped with a Hypro centrifugal pump as standard equipment in North America. A diaphragm pump is optional. This pump type is unusual for North America, but it is self-priming, can run dry, and can produce very high pressures.
Wide booms with recirculating plumbing boost productivity and minimize waste (Source: Agrifac)
Boom: The boom widths available on the Condor are astounding, and there’s no easier place to use them than the North American Great Plains. Wider booms are one of the most effective efficiency boosts in spraying, and allow slower travel speeds while creating fewer tracks. The Condor boom has a recirculating design with a pressure feed from both ends, eliminating boom ends and increasing cleanout speed. Since it uses the boom as part of its circulation system, the boom primes at filling so the new product is at the nozzles right away. Sectional control is flexible, with nozzle-by-nozzle control available.
Four wheel steer on a walking beam chassis
Chassis: The frame and suspension system looks like a walking-beam setup, and is claimed to give a smoother ride with less transfer of bumps to the boom. The system has four-wheel steer capability for less tracking in turns, and a tight turning radius. The weight of the smaller Condor machine equipped with a 120’ boom is 24,500 lbs, the Condor Endurance with the same boom is 31,000 lbs.
The HighTechAirPlus atomizer is a twin fluid design that uses air to control flow and atomization.
Nozzles: I saved the best for last. Since 1989 (yes, I remember the year!), I’ve been a fan of “twin fluid” nozzles, but have not seen them take hold anywhere. The HighTechAirPlus nozzles are Agrifac’s version. Here’s how they work: Liquid is delivered to the nozzle in the usual way, by pressure. But air is also delivered, created by a dedicated air pump that has modest volume and pressure requirements. Both air and liquid make their way through the same nozzle (a deflector style, similar to the TeeJet FloodJet).
HighTechAirPlus installed. Note the air supply and the air-activated shutoff for individual nozzle sectional control.
The advantage? Liquid flow and droplet size can be adjusted independently, with air and liquid pressure. More air results in lower liquid flow. It also reduces droplet size. More liquid pressure increases flow, and also reduces droplet size. Clever combinations of both can keep droplet size fairly constant over a wide flow rate range. Alternatively, the nozzles can change droplet size while keeping the same flow rate, depending on the drift or coverage needs at the time. The travel speed range achievable is similar to that with PWM.
Verdict. The jury’s out. As a newcomer to North America, the Agrifac faces a few challenges. Many say it needs a dealer network, inventory and parts. It needs to prove its reliability. It needs to be able to service its machines, especially if parts are non-standard. It needs field cred out here.
But I’m a bit tired of our North American sprayers adding horsepower, speed, and weight to their sprayers each year, and little else. They leave applicators to struggle alone with equally important productivity factors such as quick and thorough cleanout, drift management, nozzle selection and others.
The things that strike me with this new sprayer are Agrifac’s innovative design, and its emphasis on issues that matter to applicators: productivity and excellent control over application rate and droplet size. The company has the right priorities in my books.
November 6, 2015
Hydraulic Fittings: A Galling Metallurgical State of Affairs
So it’s been a long spraying season and as you perform your annual maintenance you grudgingly admit that the hoses have given their all. Before you run out to get more of the same, give some thought to the hydraulic fittings (i.e. hose adaptors and couplers). Many feel that stainless steel (SS) is the best choice for hydraulic fittings: It must be, because it’s certainly the shiniest and most expensive choice! But before you opt for stainless, here are a few things you should know.
SS requires surface oxidization to resist corrosion. Oxidation forms a protective barrier called a “passivation layer”, but it’s susceptible to mechanical damage. It can be penetrated as abrasive powders flow past. The layer will reform when it dries, only to be sanded off again during the next spray. The wear is on-going. If the newly-exposed SS remains submerged in a liquid, the passivation layer will not reform. Without it, SS surfaces corrode at a high rate, and in extreme cases SS will even corrode inside of itself and become a hollow shell.
When two pieces of stainless steel are forced together, the passivation layer gets scraped off, allowing parts to gall (or ‘weld’). In fact, any similar metals in physical contact will naturally gall to each other, but stainless steel is especially susceptible. When disassembled, the ‘welded’ material must be torn apart. This destructive galling can be reduced with lubrication during assembly and avoided altogether by mating dissimilar materials (e.g. bronze and stainless steel). Technically, mating different types of stainless steels (e.g. martensitic against austenitic) could work, but it is possible that two different alloys electrically connected in a humid environment may act as a voltaic pile and corrode even faster. This is probably a moot point because many do not have access to different SS alloys when choosing fittings.
Sometimes we see black or galvanized pipe fittings on sprayers, but I don’t recommend either. Galvanizing is only slightly better than black pipe and since the threads are cut after being galvanized the threads are essentially black pipe, anyway.
So what about plated steel fittings? They’re available with swivels and can seal on faces and seats (rather than on the thread – which is much easier to assemble and disassemble). They can be crimped onto the hoses, eliminating the need for hose clamps that fail or snag and cut the operator. (As a related aside, hydraulic hose is not really compatible with most spray products – the steel wire inside the rubber begins to corrode and unexpected failure is common. Even when spraying above 200 psi there are better high pressure-rated choices than hydraulic hose.) Mechanically, these fittings are a great option, but unfortunately the plating is designed for oil, not pesticide. Within a year they rust internally and seize up. To add insult to injury, the flaking rust is notorious for plugging nozzles.
A better choice is brass (or even bronze) fittings (e.g. pipe, SAE 45° and hose barb). Just like the crimped plated steel fittings, brass SAE 45° fittings can swivel and seal on seats and they are easily assembled and disassembled over many seasons. Brass fittings are more costly than black or galvanized pipe but cost less than hydraulic or SS fittings. Conveniently, they’re available at most hardware stores.
While brass may be the best metal material for the sprayer fittings, I feel that plastic is the most economical and in many applications is superior to metal. But, that’s a topic for a follow-up article. So, before you spring for SS hydraulic fittings, consider cheaper and more effective alternatives like brass or plastic. And, if only for the sake of your mechanic, please don’t over tighten fittings. It is unnecessary and causes endless damage and frustration.
October 28, 2015
Exploding Sprayer Myths (ep.3): Nozzle Pressure
Here’s the third in our series of short, educational and irreverent videos made with Real Agriculture.
We wanted to explain where pressure readings are taken on a sprayer and why it’s so important to know what pressure your nozzle is experiencing, rather than what the screens in your cab are telling you. Not only does pressure affect your application rate, but it affects your spray quality, which can be critical if your rate controller allows the pressure to drop below 30 psi.
IT’S MY TURN TO DRIVE!
October 23, 2015