Patent Application
20220341062
This disclosure relates to preparation of coir, more particularly to methods and apparatus for reducing the electrical conductivity of coir.
As used here, the term cocopeat, coir, coco, and coir pith all refer to loose coconut husk material, which may be shredded and mixed with inner husk pith materials. Some may be familiar with the material available as bricks of compressed material. Soaking it and separating it allows it to be used in one of many applications. Gardening environments have several applications that may use coir, such as moisture retention, soil amendments, etc.
However, an issue that can arise with the natural state of coir lies in its native electrical conductivity. The measure of electrical conductivity (EC) captures the level of total dissolved salts in the media. Each type of plants has different needs, but in general most grow media should have an EC of less than 1.0 mS/cm with test method EC1:1.5. This method measures 1 part coco to 1.5 parts distilled water. After agitating the coco, the mix settles and an EC meter measures the EC. However, hydroponics applications may use media with EC as low as 0.30 mS/cm. All measures of EC used in this discussion are by the EC1:1.5 method.
Previous approaches of adapting coir typically involve washing to obtain an EC of 1 or 1.6. Currently, only higher quality and higher priced coco products undergo washing multiple times and have an EC or 0.7 or lower. Multiple washing and rinsing processes both slow down the production and raise the cost. Current processes soak coir in large concrete pools, tubs or treatment bays by fully submerging or sprinkling the coir for long periods of time. Further, it is difficult to regulate the exposure of the coir to treatment agents in these large containers. Also, testing remains inconsistent because the large containers make it difficult to uniformly spread the treatment agents into the coir.
The embodiments here provide a precise method of controlling the rinsing process and/or the buffering process for coir material. Some embodiments use screw conveyors to gradually and constantly move the material in a defined channel and at a controlled rate. The apparatus also provides for consistent application of the liquid, whether water or buffered treatment solution. By separating the coir material through the screw conveyors and then drying it on further conveyors, the testing can have much higher consistency. In addition, the apparatus allows for uniform dispersion of any treatment agents used and monitoring of both the electrical conductivity of the coir and the balance of the treatment agents. Even further, the conveyors provides a more consistent way to sterilize the coir using low and high pressure steam.
In
Each conveyor system such as 20 has a material inlet such as 12, a conveyor bed having first end and a second end opposite the first end. The material inlet 12 resides at the first end, and a material outlet such as 14 resides at the second end. The conveyor system has a waste discharge outlet 16. While
The system may include one or more aging hoppers, such as that shown as 25, between the second and third conveyors of the particular embodiment, but may be included anywhere in the system as needed. The hopper allows the material to “age” after application of one or more agents to the material. This allows the material combined with the treatment to reach a consistent level of treatment agents throughout the material. The hopper may take material from a conveyor in the system that applied a treatment solution. The size of the hopper, as well as any conveyance mechanism included inside, can regulate the amount of time available to age the material. Larger hoppers will pass the material through more slowly, as they can hold more material, allowing for longer aging. As will discussed in more detail further, the speed of the conveyors may also be controlled to allow the material to age. The amount of time needed to age the material depends upon the concentration of the treatment agent in the applied solution, the speed of the conveyors that may provide some level of aging, and the density of the material, among other factors, so the exact time of aging is left to the system designer. Aging may occur for a period of time in the range of 2 to 24 hours.
The embodiment of
As will be discussed in more detail later, the conveyor beds may comprise an open bed, meaning that the top of the beds are open to the atmosphere. In other embodiments, the conveyor beds may be closed, meaning that the tops of the bed are covered. In a system with open beds, the liquid dispensing system 18 may comprise sprinklers or other types of liquid dispensers that can apply the liquid to the coir. With closed beds, the liquid dispensing system may comprise similar dispensers but inserted into openings on the closed bed. The systems may use other types of liquid dispensing depending upon the configuration and the particular components used, discussed later.
In the system of
In
The embodiment of
As in the vertical embodiment, the material outlet 54 of one conveyor bed may connect to the material inlet of another bed as shown, until it reaches the final material output 56. This may repeat for as many conveyors as desired. In the horizontal configuration, each succeeding conveyor bed is arranged horizontally from the previous conveyor bed. As in the previous embodiment, the conveyor beds have an angle relative to flat horizontal. Also as in the previous embodiment, the conveyor beds may have an angle in the other direction or may be flat. The choice of configuration lies with the designer and may be based on the nature of the material source, the liquids being used, the space available, etc.
As discussed above, the apparatus may include sensors or probes to monitor the composition of the coir, the waste water, or both. This process could also be done manually by testing the composition to ensure the proper balance of the buffering treatment, monitoring the process at 66. The operation of the apparatus can then be adjusted at 68 as needed. This may include increasing the amount of the liquid, the pressure of the steam, the balance of the elements in the buffering solution, the speed of the conveyors, the rate of dispensing of the coir, among other.
The process of moving, rinsing, monitoring adjusting may repeat as necessary to achieve the desired balance of treatments in the coir material. In addition, if desired, the adjustment may include adding or adjusting the time used to age the material between rinsing and/or application of treatment or buffering agents and the testing part of monitoring to allow the material. This may allow the agents to develop further or finish reactions to achieve a final level for that cycle. The aging may also be included after the monitoring if the monitoring results indicate that the treatment agents have not fully reacted yet. One should note that while the process of
A key aspect of this process and system lies in the ability to spread out the coir and move it at controlled rates. Screw conveyors provide a conveyance mechanism that meets these requirements. The screw conveyor 70 may have shafts such as 72 and the threads or flights such as 74, such as those shown in
In general, the screw conveyors have high contact with the coir and should be made of materials that do not chemically interact with the coir and assist with maintaining the balance. Stainless steel works well for this. In addition, the bed could have a lining. As shown in
In the manner, coir can undergo rinsing, sterilization, and buffering treatments in a controlled fashion with monitoring. This allows for monitoring and adjustment of the process as needed.
All features disclosed in the specification, including the claims, abstract, and drawings, and all the steps in any method or process disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in the specification, including the claims, abstract, and drawings, can be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise.
It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the embodiments.
