Operating, Calibrating, and Maintaining Spraying Systems Lesson 5

Next Generation Science / Common Core Science Standards Addressed 4 CCSS.ELA Literacy. RST.9 ‐ 10.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text. 4 CCSS.ELA Literacy. RST.11 ‐ 12.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explain HSSIC. 4 HSSIC.B.6 Evaluate reports based on data. (HS ‐ LS2 ‐ 6)

Bell Work / Objectives 4 Identify the types of sprayers. 4 Describe the selection of sprayers and their components. 4 Explain the operation of a sprayer. 4 Describe the calibration of sprayers. 4 Identify how sprayers are maintained.

Terms 4 air sparging 4 atomization 4 control valves 4 nozzles 4 pressure gauge 4 pump 4 relief valve 4 screens 4 strainers

Interest Approach 4 Have a student come to class wearing personal protective equipment and carrying a hand sprayer. Lead a discussion concerning pesticides, their application and safety associated with them.

Types of sprayers 4 Knapsack or back-pack sprayers 4 Hand operated sprayers –operate in 5 to 40 psi range –commonly used by home gardeners –1 to 5 gallon in size and simple in design –pressure provided by hand operated air pump –air is compressed in tank forces liquid out –small piston or diaphragm pump that is powered by hand or small gasoline engine

Types of Sprayers 4 Low-pressure sprayers –most widely used type of field applicators –operated in 20 to 50 psi range –applies 5 to 60 gallons per acre –relatively inexpensive 4 Controlled droplet applicators –apply low volumes of pesticide mixtures –1 to 3 gallons of spray mix per acre

Types of sprayers 4 High pressure sprayers –similar to low pressure except capable of working with pressures of up to 1000 psi –force spray through dense foliage or tops of trees –single nozzle on a hand gun to large units with multiple nozzles 4 Air carrier –high speed air stream carries pesticide to the surface being treated –capacities range 5,000 to 60,000 cubic feet per minute

Types of sprayers 4 Air-boom sprayers –uses a blower to carry small spray droplets into the target –lowers volume of carrier used to better coverage and reduce drift 4 foggers –apply pesticides in very fine droplets –commonly used in confined spaces for insecticides

Types of Sprayers 4 Rope wick applicators –apply liquid herbicides by wiping it onto the weeds –pesticide is in a pipe and a rope acts as the wick bringing out chemical to plant 4 Direct injection systems –holds undiluted pesticide and carrier in separate tanks –undiluted pesticide is metered into nozzle line by pumps for blending with carrier –eliminates need to mix chemical in spray tank

Direct injection system!

Objective #2 How are sprayers selected and what are their components?

3 basic functions of sprayers 4 Storage of chemicals prior to application in the field. 4 Meter the quantity of material being applied. 4 Distribution of material into desired pattern.

Sprayer selection factors 4 chemical being applied 4 application rate 4 crop being treated 4 required accuracy

Sprayer components 4 Sprayer tanks –sufficient capacity –easy to fill and clean –be corrosive resistant –shape suitable for mounting and agitation 4 agitator –maintain a uniform mixture

Agitation systems 4 Mechanical –propellers mounted on a shaft near bottom of tank 4 hydraulic –returns a portion of the pump output to tank 4 air sparging –agitation by bubbling air through the liquid

Sprayer components 4 Pump –moves liquid from the tank to the nozzles and creates pressure to produce droplets

Types of pumps 4 Diaphragm pump –flexible diaphragm that produces the pumping action 4 Centrifugal pump –creates a high speed impeller that forces liquid out of pump –not self priming

Types of pumps 4 Piston pump –self-priming –pistons travel inside cylinders and force liquid through one way valves 4 Metering pump –driven by ground wheel –ground speed changes so does the pumping rate proportionately

Types of Pumps 4 roller pump –cylindrical rollers that move in and out of slots in a spinning rotor –as rotor spins creates space for liquid during half its rotation –liquid is discharged from pumping chamber during remainder rotation –self-priming –easy to repair –operate efficiently on PTOs

Sprayer components 4 Relief valve –safety device that releases liquid when pressure exceeds a safe level 4 pressure gauge –used to measure the pressure in the system and valuable diagnosing tool 4 strainers and screens –used to remove particles from the system

Screen & strainer locations 4 Tank screens –removes foreign materials when filling tank 4 line strainers –removes foreign materials from reaching the pump 4 nozzle strainers –removes foreign material from clogging nozzles

Sprayer components 4 Pipes and hoses –convey the liquid through the sprayer system 4 sprayer frames –must be strong and durable –be able to attach the nozzles 4 control valves –used to start and stop the flow of liquid to the nozzle

Sprayer components 4 Nozzles –meter the liquid, atomize the liquid stream into droplets, and disperse the droplets in a specified pattern 4 atomization –liquid breakup caused by the tearing action of the air

Sprayer nozzle patterns!

Selection of nozzle type and size 4 Nozzle determines –amount of spray applied to the area –uniformity of the application –the coverage of the sprayed surface –amount of drift 4 flow rate depends on the effective size of the orifice and pressure 4 described according to the shape of the application pattern

Nozzle types 4 Extended range flat fan –frequently used for soil and foliar applications when better coverage is required 4 even flat-fan –apply uniform coverage across the entire width of the spray pattern –only used for banding pesticides over the row 4 flooding flat-fan –wide angle, flat fan pattern and are used for applying herbicides and liquid fertilizers

Nozzle types 4 Turbo flood –combine the precision and uniformity of extended range flat spray tips with the clog resistance and wide angle pattern of flooding nozzles 4 turbo flat-fan –improved pattern uniformity and reduction of drift 4 raindrop –recommended when spray drift is a major concern

Nozzle types 4 Wide-angle full cone –produces large droplets over a wide range of pressures 4 drift reduction pre- orifice –reduce the development of drift-able fines in the spray pattern

Objective #3 How are sprayers operated?

Guidelines to use when spraying 4 Decide is appropriate for use. 4 Adjust and set sprayer based on label info. 4 Calibrate sprayer 4 Load the sprayer –quantity of pesticide & procedure to follow while mixing pesticide 4 Transport loaded sprayers as little as possible 4 Maintain constant ground speed & pressure 4 Monitor for plugged nozzles and leaks

Calibrating a sprayer 4 Proper calibration helps insure area being sprayed receives right amount of chemical 4 Variables 4 nozzle flow rate 4 ground speed 4 width sprayed/nozzle

Calibrating a sprayer 4 Gallons of spray / acre (GPA) = 4 GPM X 5940 / MPH X W 4 GPM = gallons per minute 4 MPH = speed in miles per hour 4 W = effective width sprayed per nozzle = constant to convert GPM, MPH, and inches to GPA

Selecting correct nozzle tip 4 Select spray application rate in GPA. 4 Select proper ground speed. 4 Determine effective width sprayed per nozzle. 4 Determine flow rate in GPM. 4 GPM = GPA X MPH X W / Select nozzle that will give flow rate needed with the recommended pressure range.

Calibrating a Sprayer 4 Calculate ounces per minute (OPM) 4 to convert GPM to OPM 4 GPM X 128 (1 gallon = 128 fluid ounces) 4 Collect output from a nozzle in a container marked in ounces

Calibrating a sprayer 4 Determine amount of pesticide/herbicide, add the pesticide to partially filled tank of carrier, then add the carrier to desired level with continuous agitation. 4 Operate the sprayer at proper ground speed and pressure in tank. 4 Check nozzle flow rate frequently.

Objective #5 How are sprayers maintained?

Maintaining a sprayer 4 Preventative maintenance will reduce chances of breakage, repair bills, & loss of time. 4 Adequate and timely adjustment, repair, lubrication, and protection from weather adds life to the sprayer. 4 Clean thoroughly inside and outside after each use and always wear protective clothing when cleaning.

Review 4 What are the types of sprayers? 4 How are sprayers selected and what are their components? 4 How are sprayers operated? 4 What are the procedures to follow when calibrating sprayers? 4 How are sprayers maintained?

The End!