Non-chemical insect elimination
April 01, 1998
by Teresa Acklin
Centrifugal force is alternative to methyl bromide and other chemicals.
By George Sackett
The impending removal from the market of methyl bromide and other environmentally questionable pesticides has led many mill operators to seek alternatives for insect elimination. The technology of centrifugal force has been used in some mills for as many as 50 years, and continuing improvements in the technology and machine design have made this option more economical than ever for mills of all sizes.
The first of these machines, commonly referred to as “entoleters” from the name of the company that manufactures them, was the Infestation Destroyer (E.I.D.). It was introduced to the milling industry for the elimination of insect infestation in flour mills back in the early 1940s.
Its effectiveness was established officially shortly thereafter by the U.S. Department of Agriculture after exhaustive testing at Kansas State University, Manhattan, Kansas, U.S. In following years, thousands of E.I.D. installations all over the world have confirmed that the unit provides 100% effective kill.
The U.S.D.A. states in its Circular 720: “A device using centrifugal force has been perfected for the destruction of insect life in milled cereal products such as flour. Flour spouted to the machine is hurled by centrifugal force between two flat steel discs or plates that revolve on a central shaft at sufficient speeds to impact the flour. Small, round, hardened-steel posts are closely spaced between the two discs. The impact of the flour against the revolving discs and posts, and against the housing of the machine, is so great that all insect stages, including the egg that may be in the flour, are killed. The treated flour is carried off through an outlet spout or dropped directly into a bin.”
Units today range in capacity from 0.5 tonnes to 115 tonnes. They may be used separately or in conjunction with reels or sifters.
The past 50 years have seen great changes in the milling industry to keep pace with an increasing world population. There is no question that the milling industry has become more automated with a greater concentration on efficiency.
This fact has prompted the development of a whole new generation of Infestation Destroyers. The new design encompasses all of the positive performance characteristics of the original design, but is sized to fit the needs of the modern milling industry. The highly refined processing elements of the original configuration have been fully retained to insure continued performance and to allow the use of available “on hand” components.
“Blow through” or pressure operation capability is standard on all units. Running flour through an Infestation Destroyer when unloading into a silo and again when loading out is an economical and safe method of ensuring sanitary flour.
A natural progression in this technology was to clean whole grain using centrifugal force and aspiration, and the Scourer-Aspirator (E.S.A.®) is standard equipment today in flour mills around the world. The E.S.A.'s centrifugal impact action effectively cleans dry and tempered wheat and other grains. Grain is hurled against impact pins, dislodging hulls, grease, dirt, rodent hair, wheat beards and beeswing as well as destroying internal and external insect life.
The impact action of the unit can be closely controlled for either deeply infested grain or grain that is relatively clean. The result is minimum grain breakage and minimum fragment count. After impact, grain is thoroughly scoured in a swirling action against the conical inner surface of the scourer casing and discharged into the aspirator section.
Grain is dispersed against the housing in a very thin film. Uniform air velocity throughout the aspirator separates the debris with maximum efficiency and carries it to the dust collector. In many cases, the cleaning produced by this equipment improves the yield and lowers the ash.
The proven capabilities of centrifugal force make it a safe, economical and effective option for mills of all sizes.
George Sackett, a sales engineer with Entoleter, Inc., has been involved with the milling industry for 20 years, working to improve sanitation.