Fluid sprinkling – spraying – and diffusing – With mobile tank-type supply means – Spray boom or bar type distributor
Reexamination Certificate
2000-12-11
2003-08-19
Evans, Robin O. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
With mobile tank-type supply means
Spray boom or bar type distributor
C239S166000, C239S167000, C239S169000, C239S175000, C239S176000
Reexamination Certificate
active
06607146
ABSTRACT:
FIELD OF TECHNOLOGY
The present invention relates to an apparatus designed to be mounted on an agricultural sprayer with the purpose of decreasing the drift and improving the deposition, penetration and uniformity of distribution when applying liquids such as pesticides and liquid plant nutrients used in agriculture, horticulture and forestry.
BACKGROUND OF THE INVENTION
Application and handling of pesticides is a delicate task which may cause substantial costs, both economical and environmental. Consequently, it is of outermost importance for a long-term efficient and persistent production, e.g. food supply, that the distribution of pesticides is executed in an efficient and safe way. For the application method to meet these needs it is required to:
Reduce environmental impact: Decreasing the environmental pressure exerted by the chemicals requires reduced doses and decreased drift and leach. To make it possible to reduce the doses without forgoing the final result an efficient application method is required which ensures optimal chemical deposition onto the spray target.
Reduce costs: The modern application method required for better utilization of the chemicals must also be as cheap as possible for the decreased usage to result in reduced overall costs. This is a prerequisite of the method to result in common use.
Application of pesticides may be executed with a real spraying with agricultural sprayer, band spraying or contact application. A real spraying implies that the whole field is prepared/sprayed while band spraying means that only one band including the planting row or the space between the planting rows is sprayed. Contact application means that the pesticide is transferred by direct contact. This type of control occurs only to a limited extent and only in specific control situations. Conventional methods for a real spraying comprise agricultural sprayers equipped with hydraulic sprayers uniformly spaced at a distance of 50 cm along the boom. When spraying, only a fraction of the sprayed liquid reaches the noxious object. Portions of the spray liquid will drift with the wind or evaporate, and some portions will land on the ground or on parts of the plants where the liquid has no effect. Different estimations of the fraction of the sprayed liquid which actually has effect, i.e. reaches the spray target, varies between 0,1 to 30%.
The most important element in reducing the dose, and decreasing the environmental impact, is to achieve good deposition onto the spray target. This is difficult to accomplish with conventional methods because of the following reasons:
High boom level: High boom level, 50 cm above the ground, is required to achieve a uniform liquid distribution. This increases the risk for drift. A cause of increased drift is, among other things, that the droplets are exposed to the wind during a long time period on their way from the nozzle to the spray target. This, in combination with the fact that the wind velocity increases exponentially with increasing distance from ground, makes the boom level an important contributor to the drift.
Boom movements: Boom movements is one of the most important causes for a non-uniform liquid distribution. Both horisontal and vertical boom movements may cause substantial dose variations over the field. The non-uniform liquid distribution results in poor treatment effect, which must be compensated by an increased dose. In addition, there is a risk of damage on the crop in places which receive the highest doses. The vertical boom movements involve also often damage on the nozzles when these are forced into contact with the ground and crop.
Drift: The drift is a problem of great concern which is affected by weather conditions, spray quality and exposure of the droplets to weather influence. At given weather conditions, the only possible measure to reduce the drift with conventional methods is to choose a coarser spray quality. Conventional methods normally use medium or coarse spray quality (big droplets). Coarser spray quality involves lower degree of coverage and therefore lower pesticide control effect which must be compensated with higher dose.
Penetration: With conventional application methods the droplets have low velocity when they reach the stand, which impair the penetration into stands with high density. The droplets also fall vertically which gives poor deposition under leaves and onto vertical surfaces. The penetration is of special importance for instance in control of Phytophthora infestans on potato. Phytophthora infestans on potato causes great losses and the fungus is often hiding in high density stands.
In application with conventional methods, liquid quantities in the order of 200 l/ha (litres per hectare) is often recommended in application onto low crop stands and 300-400 l/ha onto high density and high crop stands. These relatively large liquid quantities decrease the efficiency of control because of the increased number of refillments required, which increases the costs and decreases the spray time. It is not rare that refillments, including transports, occupy one third of the total treatment time. The weather is a very limiting factor for chemical control and the number of opportunities to spray are few. Consequently, it is of great importance that the spray opportunities are efficiently utilized. The possibility to conduct control at optimal time also maximizes the biological effect and facilitates dose reduction.
PRIOR ART
Traditional spray methods have been used since the beginning of chemical control by the end of the 19th century, and it is the purpose of the present invention to solve the accompanying problems. Below, band spraying, contact application and the conventional methods of areal spraying with agricultural sprayer will be described. Regarding areal spraying also more modern methods, intended to solve the problems of conventional areal spraying methods though with unsatisfactory solutions, will be described.
Conventional methods imply that the nozzle
ozzles is/are positioned and mounted on the boom with downwardly directed spray direction.
Band spraying means that a band, including the planting row or the space between planting rows, is sprayed. The method is used for row growing crops such as sugar-beets, strawberrys and outdoor cultivated vegetables. Band spraying may be performed with a modified agricultural sprayer or a separate suitably equipped machine. In order to keep the distance between the ground and the nozzles, one or more, at a constant level, the nozzles are often mounted on runners, such as described in U.S. Pat. No. 2,580,145 and German patent no 1482350. In some cases also tunnels are used to protect both the spray shower from external influence and the portions of the ground/crop not to be sprayed.
In case of contact application, pesticides are transferred to the target by direct contact using ropes, sheets or rolls. Contact application is used, for instance, to control late high-growing weeds in different crops, weeds in watercourses and during control in connection with harvesting with combine. The precondition of using this method, and accomplishing the selective weed control, is that the control object has a deviating, higher height than the surrounding. This makes this method only applicable in very specific control situations.
Irregularities in the liquid distribution when using conventional methods are to a great extent due to boom movements, both horisontal and vertical, while running. These movements depend on the dynamical characteristics of the boom and the sprayer and may to some extent, particularly in the vertical direction, be damped by the use of suspension attachments, as described in German patent no. 2359400.
New application methods used today are often based on some sort of air assistance. Air assistance may be classifed according to two principles, internal or external air assistance.
Internal air assistance means that air is added (by means of a compressor or a fan) inside the nozzle so that the air, together with the liquid, contributes to the
Alness Kenneth
Andersson Sven
Bengtsson Per
Bergman Sven
Enfalt Patrik
Acanova AB
Bacon & Thomas
Evans Robin O.
LandOfFree
Apparatus for application of liquid used in agriculture,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for application of liquid used in agriculture,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for application of liquid used in agriculture,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3102407