Agitation System Maintenance
Last month's newsletter described the mechanical agitation system we use on many of our SDI sprayers. Depending on the sprayer configuration, we also use venturi jet agitation for mixing.
Venturi Jet Agitation System  |
Venturi Jet agitation operates off of the bypass system of the pump. The picture above shows a six jet system that we use in many of our golf course sprayers. One of the venturi's (black piece) has been removed to show its design and its internal ceramic orifice (white piece).
The orifice accelerates the liquid through the venturi causing the liquid in the tank to be pulled in the side of the venturi and exit out the end. All this movement creates turbulence in the tank to keep your spray materials in suspension.
Maintenance of the venturi jet system requires monitoring the fluid flow in the tank. If the flow is reduced or doesn't seem to mix as well as it used to, you should first check for debris trapped in the venturi system.
As mentioned above, in some of our systems we use a ceramic orifice in the venturi to accelerate the mixing and direct it to different points in the tank. The orifices are an important part of the mixing system and they should be part of your agitation inspection procedure. Other factors that can impact your jet agitation system are; reduced pump performance from wear, debris on your strainer basket or trash in the spray tank. Any of these items can add to the problem of inadequate mixing. |
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Greetings!
Welcome to the July issue of the SDI Email Newsletter. If you have topics or ideas you would like to see integrated into future newsletters please email me at sam@sprayingdevices.com with your suggestions. |
Computerized Spray Controls
Another type of control is based on spray flow instead of pressure. These are called computerized controls. What is unique about computerized controls is that, onceSDI MicroTrak All Function Control
 | properly set, the spray rate automatically adjusts based on the ground speed of your sprayer. As you speed up or slow down, the flow automatically adjusts to maintain the predetermined rate. This is an advantage when spraying acreage that is hilly or restricted areas that require the operator to slow down to maintain precise control. For someone comfortable with pressure based controls, sometimes the switch to flow based controls can be confusing due to the lack of a pressure gauge.
We are pleased to have worked with MicroTrak to develop the MT3403 All
Function Control shown in the picture above. In addition to utilizing a
GPS speed sensor, the SDI All Function side car integrates switches for
functions that previously required their own individual switch boxes.
This eliminates the cluttered look you get when using other computerized
systems.
Included on the side car are switches for the foam
marking system and the electric boom wing lift actuators. This greatly
reduces the clutter for the operator and places all the major control
functions at their fingertips.
The most important component of computerized control systems is the speed sensor. If your speed isn't accurate, everything else will also be out of whack. There are several different types of speed sensors currently used and include wheel sensors and radar. The wheel sensors utilize magnets attached to the wheel and a sensor mounted in close proximity to the wheel. The sensor reads how fast the wheel is turning by picking up the pulses as the magnets move by.
The radar sensor is typically mounted on the side of the spray vehicle pointed at the ground parallel to the path traveled. It reads grass differently than asphalt so it is important to do the setup on the surface you intend to travel over.
The latest type of speed sensor is the GPS sensor. This type of sensor utilizes the system of Global Positioning Satellites that are in geosynchronous orbit in space. The sensor receives data from several Astro 5 GPS Antenna | satellites and computes its position and speed. This system was built by the military and was opened to civilian use in the 1980's. There is no charge to use the satellites. The Astro 5 antenna supplied with the SDI MicroTrak system, gives the system rapid feedback by computing the ground speed 5 times every second . Slightly smaller than a hockey puck, these antennas are very competitively priced to wheel sensor systems and much easier to install and maintain.
The MicroTrak system has been successfully used by applicators for many years. It is easy to program initially and even easier to reprogram with new rates than other systems. If you have a question about the SDI MicroTrak system, give us a call, we'll be glad to help with your GPS or computerized control system questions.
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Tank Maintenance
Last months article on tank construction generated a response from a loyal SDI user in the midwest wanting to know how to restore his tanks to a showroom fresh finish.
 If your SDI tank has lost its luster from exposure to the elements, you can get it looking like new again by buffing
out the fiberglass. There are several types of polishing compounds available commercially. Generally these are graded by color, with white the least abrasive and pink the next step up.
We suggest you start out using the least abrasive compound (white) and move up to pink if the finish requires something more agressive. If you use an electric buffer be sure to keep it moving across the surface of the tank as you work to prevent a "burn" from occurring to the finish. Thanks to Mark Utendorf from Emerald Lawn Care in Illinois for that suggestion!
Also, whether your sprayer is brand new or you've just buffed out an older model, put a coat of wax on your tank and it will make clean up easier and help keep your sprayer looking new.
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That's it for the latest edition of the SDI Email Newsletter. Keep sending in your comments and ideas!
Thanks!
Sam Bennet
Spraying Devices Inc.
800-564-7548
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