Patent Application
20200187434
The present invention relates to the field of irrigation systems designed to conserve water, such as low volume drip irrigation emitters, bubblers, micro bubblers and any other watering type emitter whose output is limited in volume and is concentrated in a small circumference around itself. It details a design and method of manufacture for a device that will attach under a drip emitter or drip bubbler and that uses the gravity flow of the water leaving the emitter to slowly dissolve and release chemicals within the water soluble device underneath it during the irrigation cycle. More specific, the present invention relates to a method and system for attaching a fertilizing device to a standard drip irrigation emitter providing a low cost, replaceable, and controllable fertilizer delivery each time the emitter releases water in the watering cycle of the drip irrigation system. In another embodiment of this design, the present invention relates to a method and system for attaching a fertilizing device underneath a standard bubbler irrigation device or underneath any number of micro bubblers and micro sprinkler devices, which in the same manner provide fertilizer each time the emitting device releases water in the watering cycle of the drip irrigation system. The primary anticipated use of the irrigation releasing device will be in the delivery of fertilizing nutrients. However other practical applications include delivery of plant insecticides to deter those insects most likely to feed on the plant and delivery of plant herbicides that will counter grass or weeds growing around the plant. In practice a grower may use all three devices simultaneously as they can all release their chemical additives when exposed to irrigation flow at the emitter or bubbler without interfering with each other in a stacked array. The present invention details a device that attaches to a irrigation system emitter pipe or drip tube and a method of manufacture that will allow it to provide any number of chemicals combinations in a water soluble medium for slow release dissolution by water emitted during normal irrigation cycles. For simplicity sake, the following descriptions of prior art will focus on the device used as a fertilizing medium.
Fertilizer delivery systems are generally found within two categories, waterborne systems or dry application systems. Waterborne systems are used to feed water based fertilizers in-line to an existing irrigation system. They must be plumbed into the irrigation system and remain a permanent part of the system, and must be maintained as a function of the watering rate. Waterborne systems offer the advantages of instant and concentrated fertilizing, but are expensive and difficult to use in a manner that allows for gradual, long term continuous feeding within the irrigation system. Water fertilizing systems have holding tanks of premixed fertilizer which can only be so large, so they use concentrated amounts that are dispersed fully within one or more watering cycles. They must be re-filled for the next fertilizing cycle, usually within days or weeks. Complex timing controls are needed on the injecting fertilizing unit to time the controlled release of fertilizers, further adding to the cost and complexity of the system. Therefore, most water borne fertilizer distribution is a very expensive and complicated process and is used mainly on large sprinkler type applications such as parks and golf courses or in large commercial nursery environments.
Dry application fertilizing systems are used outside the water delivery system. Most of them contain chemicals pellets that are coated with a resin designed to break down when exposed to the micro bacteria in soil. They are designed to slowly release their nutrients over time but must be physically spread over the surface of the desired fertilized area such as around a plant or landscape surface and must be buried beneath the soil and wetted during the watering process to achieve a nutrient release. This small pellets are often spread by a seed spreader machine that rotates the fertilizing pellets in a drum while throwing them out in a circular pattern so that it can be easily applied to a large area by walking in circles around the area to be fertilized. This is commonly done on home lawns and small area landscaping. Larger, farm type systems use automated machinery that dispense the fertilizing pellets directly into the soil as the equipment turns the soil in the field or plants the seeds during initial stages of the planting cycle.
Dry fertilizing applicators suffer the physical problems of positioning the pellets or powder widely and evenly around the target plants, while avoiding the effects of wind, rain, and runoff and of physical displacement from workers, animals or machinery to stay in the target area and deliver its nutrients. They must also be buried enough to be in contact with the soil and have access to a water source that will cover them fully and dissolve them at a slow, steady rate so they can be absorbed into the soil and used by a plant over consistent, long periods of time. Most of the dry fertilizers are used with sprinkler type irrigation systems over large areas where high pressure and a high volumes of water are needed to dissolve the fertilizing material. Typical pellet type fertilizers can last from three to four months depending on the watering cycles they receive. Over time and exposure to water and air they lose some of their fertilizing potency, especially if they are unable to dry out between watering cycles. Over wetting of the pellet type fertilizer causes it to dissolve and be applied too rapidly to the soil causing irregular and short term nutrient delivery. This is another problem in many dry fertilizer irrigation delivery systems, one that need to be watched carefully. One can sometimes see burn marks on lawns when the fertilizing pellets (or powders) are absorbed too rapidly over a short time. None of the dry fertilizing systems now in use were designed for low volume, water efficient drip irrigation systems which typically require liquid fertilizing systems if they fertilized at all. Liquid fertilizing systems present a particular problem to drip irrigation systems because the dissolved solids of the fertilizers tend to clog the emitter ports. A typical drip emitter is designed with millimeter tolerances to limit flow from high pressure sources and should not be subjected to any liquids having chemicals. Even normal tap water having high mineral (hard water) content tends to clog emitters making their replacement more regular and adding expense to the irrigation maintenance program.
Accordingly, there exists a need to provide a fertilizing distribution system which is simple to use and is effective with low volume drip type emitter irrigation systems and other low volume or medium volume emitters such as bubblers and micro bubblers. This system should spread the fertilizing medium evenly and gradually in a targeted area over long periods of time, in-line with the water delivery source but not inside it. The system should be easily installed and replaced, be of low cost, and be able to be designed to match the specific fertilizing needs (or other needs) of a given plant or landscape by simply varying the formula contained within it.
In the research for wet fertilizer applicators, Schmidt, U.S. Pat. No. 5,252,302 introduces and liquid fertilizer apparatus that employs an internal cavity that receives a porous bag member having fertilizer contained therein and attaching to a water supply source such as a hose bib. This invention does not lend itself to modern irrigation systems much less a drip or bubbler irrigation system it shows no delivery system for the pouch to the desired planted areas and because of the chemicals it releases, if connected to a drip irrigation system will clog the emitters down line of the input pouch. The present invention provides a means for a molded device to attach to each individual emitter and whose chemical content can be varied for each individual plant as opposed to a one position (at water input) fertilizing system that also requires maintenance in the refill the porous container. Strong, U.S. Pat. No. 5,005,601 discloses a waterborne delivery system employing one air tank and one tank of fertilizing solution to be injected into an irrigation system. Irrigation water is allowed to fill the air tank where the remaining compressed air is allowed to pass through the top of the fertilizing container forcing the fertilizing solution from the bottom of the container into the irrigation system. Davis, U.S. Pat. No. 6,173,732 discloses a system whereby liquid fertilizer is mixed with irrigation water in a mixing chamber attached to the valve of an existing sprinkler system. Adler, U.S. Pat. No. 4,859,157 discloses a device that injects liquid fertilizer into an irrigation pipeline by means of an axial turbine impeller. Similarly, Johnson, U.S. Pat. No. 6,997,350 relates a system for adding liquid fertilizer into a sprinkler system by means of a mechanical injector comprising a paddle wheel within the water line. Astle, U.S. Pat. No. 5,383,601 describes a liquid fertilizer for a drip irrigation system wherein a reservoir holding the liquid fertilizer is held and controlled by means of inlet and outlet valves.
Other liquid fertilizing applicator systems include Terrell, U.S. Pat. No. 4,768,712, Agius, U.S. Pat. No. 4,456,176 Roberts, U.S. Pat. No. 7,093,606, Jester U.S. Pat. No. 5,836,518 and Francis, U.S. Pat. No. 6,267,303. Each of these systems relies on liquid fertilizers that are in some way injected into an irrigation supply line. Water based injector type fertilizer systems are most effectively used with higher volume irrigation systems like sprinklers where large areas of plants or landscape are watered and fertilized at one time. These systems are not suited well to low volume, high efficiency systems like drip irrigation because they tend to clog the drip elements and are not effectively absorbed into the soil in small areas due to the concentration of fertilizer content.
In reviewing the prior art of dry fertilizer applicators used with drip irrigation systems, only one specific reference was found of devices to be used with drip irrigation emitters. Greubel, U.S. Pat. No. 5,769,318, discloses a plastic housing encompassing a drip emitter and a chamber where a chemical fertilizer tablet, surrounded by a plastic jacket with holes is positioned downstream of the emitter. When water flows from the emitter within the housing, it flows through holes within the jacket and through the tablet, absorbing fertilizing chemicals and flowing outward through holes in the end of the housing. This system is ineffective in use because using a tablet in this manner will impede the natural flow of the drip emitter until it is somewhat dissolved, as the tablet itself contains no holes, only the surrounding jacket. Unless the tablet is very porous in nature water will not easily flow through it until it has dissolved to some degree and it would seem to present a problem as it softened and clogged the housing. The tablet inside such a housing would not receive enough air between watering to allow the fertilizing chemicals to dry out and therefore the tablet would become soft and disperse fertilizer too rapidly if soft or not rapid enough (or at all) if clogged within the enclosure. In addition, having the fertilizing tablet before the emitter and in the same hosing as the emitter would allow for backflow of chemicals into the emitter clogging the delicate and microscopic emitter plunger with dissolved solids and keeping it either permanently closed shut or wide open, as does even high PH (hard or calcified) supply water over time. It would also seem to be complex to manufacture and difficult to keep dirt and foreign materials from entering the drain holes, another potential source of water stoppage. Finally, it is difficult to use in the field since there is no way to tell when the tablet has dissolved and the device needs to be replaced. The present invention described below overcomes these design flaws and delivers a device that works independent of and with any external drip emitter as well as with other low volume emitters like bubblers and variable flow emitters now common to the irrigation industry. It creates no chemical backflow that can cause emitter damage while fully draining after each watering for long chemical life and low waste. In addition, its fertilizing source can be visually checked for content during maintenance and easily changed when needed. In the research of current patents there is none that provide the clear advantages and usefulness of the present invention.
The present invention provides a low cost and effective means to introduce fertilizers and other chemicals into a drip irrigation system by simply placing a water soluble molded device underneath the drip emitter or bubbler where it stays and place and slowly dissolves with each watering cycle with water for optimum penetration into the plant's root system and surrounding soil. The invention involves three distinct embodiments. In the preferred embodiment (
The present invention thus provides a very cost effective way for growers and landscapers to fertilize with very low associated maintenance. It allows for easy installation, easy status checking and easy replacement and can be made to any chemical specification desired by the grower. For example, the grower may specify a certain fertilizing formula during early plant growth and be able to vary that formula by replacing the device as the plant matures or as it blossoms and needs others nutrients. Or the grower may add another device that releases a herbicide during the season when insects are most active protecting the plant in place without need for further spraying or control. The devices are cost effective, easily to install and change and do not degrade over time.
There are several ways to manufacture the present invention. One method involves mixing the desired medium with a type of chemical starch and adding water. The mixture is then poured into a mold heated and dried. Other products can be added to the mixture for color, stability, flexibility and to slow or accelerate the dissolution rate of the product. The resulting product is flexible, water soluble and can be formed into the various shapes and sizes indicated by the drawings. Another method involves using micro-wax additives that are water insoluble and when heated will attach to the desired medium and stay attached, protecting it from water and allowing for a slow dissolution of the medium. The micro-waxes are thoroughly mixed with the medium and other products are added for color, flexibility, stability and dissolution rate control. The mixture is then poured into molds and heated. The resulting product is again flexible, water semi-soluble and can be formed into the various shapes and sizes indicated by the drawings. Yet another method of manufacture involves using water soluble polymers that are mixed with other additives for color, flexibility, stability and dissolution rate control and are heated together at various temperatures until liquid and then extruded or injected molded into various shapes suitable for same use. The resulting product is again flexible, water semi-soluble and can be formed into the various shapes and sizes indicated by the drawings.
Although the present invention has been described in its preferred forms with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only. Numerous changes in the details of the compositions and ingredients therein as well as the methods of manufacture and design will be apparent to those skilled in the art without departing from the spirit and scope of the invention.
Each of the three preferred embodiments of the drip irrigation fertilizing system are shown in
1. Insertion hole for Release Device fitting Water Supply Pipe or Drip Line Riser Tube
2. Release Device as a molded ring (Embodiment 1)
