CURTIS/AGRI-LINE ASC Rotary Atomizers

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Effective June 2001, Curtis Dyna-Fog, Ltd. acquired the ASC Rotary Atomizer line originally developed by Mr. Cal Butler and produced by the Agri-Line Company in Bend, Oregon USA. Mr. Butler was one of the early pioneers of crop dusting in the United States. He spent over 40 years using rotary atomizers and throughout this time period learned the deficiencies of the various designs. Shortly after retirement he began to apply what he had learned and began working on a design of his own. His efforts eventually led to the development of the ASC Rotary Atomizer. Today, the ASC Atomizer is recognized as the leader in aerial spraying and has been in use worldwide for over 20 years. Mr. Butler passed away on July 14, 2004 in his hometown of Bend, Oregon. His contributions to the field of agricultural aviation and fire fighting are far to numerous to mention, but his ASC Rotary atomizer continues to gain popularity and serves as a testimonial to his dedication to the industry. I was fortunate to get to know Cal Butler and and share some of his insight in this industry. He was a great man with many accomplishments in life. Seeing the production of the ASC Atomizers continue was very important to him and he was proud to see his product live on. A Biography of his life is currently being written by his daughter and should be published within the coming years. -Dennis A. Roudebush

A Brief History of Rotary Atomizer Development for Aerial Spraying
By Cal Butler

The rotary atomizer has been around for many years in one form or another. The original ICD brush was a unit using a wire brush as a droplet distributor. A 4-blade fan mounted on an aluminum rod that spanned the chord of the airfoil propelled it. It was clumsy, had a tremendous air drag, and was very expensive for its day. The ICD and the early British units produced droplets of a fairly uniform size and in turn were a boon to the grower of fruit trees as well as deep crops such as pole beans, hops, and other hard to penetrate crops. In some areas such as the Salinas Valley in the early spray years, an operator with no such method of application found it extremely difficult to find work. Early rotary atomizers were large and cumbersome with excessive amounts of gyroscopic action. The nozzles required heavy, strong and well-engineered mountings. They were popular with growers, but not with pilots, owners and maintenance people. They did an excellent job of distribution and micron control, but were difficult to mount, maintain and slowed the aircraft, allowing less acres per hour than the normal boom equipped aircraft. The largest drawbacks to both the ICD and older rotary atomizers were the difficulty of installation and the loss of performance of the aircraft. These drawbacks were often offset by the superior quality of workmanship. However, during this time period competition was high and profit rather than quality often became the controlling factor. The controlling factor for the applicator should be the acceptance of the droplet distribution by the actual grower and owner of the crop in question.

During the 1950's the USDA got into the act with a "mini-spin" nozzle. It worked fairly well for low and ultra-low volume applications but maintenance problems soon made the nozzle obsolete. In the early 80's electric powered units emerged to apply Malathion and reduce paint spotting on automobiles with their smaller 25 micron droplets. Even with these atomizer developments there was still a need for a reliable, cost effective wind driven atomizer (for both Low and Hi volume applications).

In the late 1980's the Advanced Spectrum Controller (ASC) was developed to fulfill this need and to cover an application not being addressed. It was designed to operate at airspeeds in excess of 200 miles per hour while continuing to excel in the low speed area. The ASC-A10 has been tested at flight speeds from 45 - 210 miles per hour as desired and needed by both twin engine and 4 engine aircraft that can be used successfully on large scale Forest Service projects at great savings to the government over current practices. In addition, "ASC" has a higher potential gallonage available for uses in tree fruit areas and all high foliage crops.

Coverage and droplet distribution has always proven to be superior with rotary atomizers. Cotton fields are regularly defoliated with one application of normal volume spray from a rotary atomizer. This would have required as many as three applications using standard boom nozzles and high flow rates. Generally speaking, because of the superior ability to keep most droplets of near equal size, eliminating the large gobs and the excess of mini droplets, the majority of the droplet spectrum will average near one another. This spectrum control factor allows better coverage and superior control of most pest problems. We like to believe this control factor is near or exceeds 20% over normal hydraulic spray nozzles. In a more understandable manner, a 10 gpa application with hydraulic nozzles can be accomplished in a superior manner with an 8 gpa application using the rotary atomizers.

To date, the ASC has been used in several different parts of the world for a variety of applications including: forestry spraying, spraying densely planted row crops such as orchards, pole beans, hops, celery, potatoes, tomatoes, alfalfa, mint, bananas, olives, palms, cocoa and citrus. Applications include but are not limited to applying herbicides, pesticides and fungicides.

Technical Specifications:

Options VO-7 Variable Output Restrictor valve easily adjusts to one of (6) flow settings or shut-off position. High Volume Shut-off Valve for high flow rate applications. Multiple boom mounting configurations available (type and size to be specified when ordering).

• ASC-A10 Atomizers are available in kits of 1-2-4-6-8-9-10-12 & 15
• ASC-A10H Atomizers are available in kits of 1-2-4-6 & 8