Cambio el LFOM y el CDC a la una sistema quadratico.

[eak24]

Debemos calcular la valor de Kminor y Kmajor y despues diseñar una vertedera para eso profil. Hay una pagina sobre vertederas aqui. La idea es eliminar la necessidad de la guitarra para la plantitas.

[eak24]

@monroews I'm thinking of building a prototype of this doser. Any thoughts would be much appreciated!

The new idea is to use an integrated CHT that takes the CHT, slider on the dosing arm, and major headloss device, and to put it all into one dosing device. We need to reduce the ways operators can modify the system. The linear major headloss manifold has always been a source of confusion. A minor headloss, quadratic dosing system is far easier to understand intuitively. Here is a draft of such a design that uses 3" PVC pipe for the CHT housing, and a sliding 3/4" pipe over a 1/2" pipe with an oring to form the seal between the two. In the 1/2" pipe would be drilled very small holes. By exposing more of the holes by sliding the 3/4" pipe up, you can increase the dosing rate. By modifying the hole size, you could have a logarithmically increasing dose rate to handle extreme events. Other pros of this design are (over the current design):

• Easy to clean the dosing tube with a screw-on, screw-off access
• Compact design that takes up a fraction of the space.
• Completely independent dosing+cht systems that can be turned on and off independently
• Balance is far simpler without a slider
• No need for the major headloss system

[eak24]

To build a prototype of this from the states, I'm purchasing:

• micro drills
• rotary tool
• oRing for the outside of a 1/2" pipe

[monroews]

Comments on this design.

• The hole diameter will be significantly smaller than the dosing tube diameter and thus there might be more problems with clogging
• The LFOM would be replaced with a simple single row of orifices at 20 cm of depth or perhaps a single horizontal orifice.
• This might be most appropriate for high flow plants where the chemical flow rate is higher and thus larger diameter holes can be used.

[eak24]

@monroews I just purchased 0.1-1mm drills from amazon for 4$. Let's see what happens! I'm unclear as to when clogging would be an issue as well... I imagine by rapidly moving the sliding pipe up and down, you may be able to unclog the orifices (to be tested.) Right, no more LFOM!

[eak24]

In order to be able to plunge and clean out the holes with high pressure, I suggest making the plunger slide that adjusts how many holes are exposed to be within the pipe with holes. One could clean the holes by closing the outlet valve, and rapidly lifting and dropping the center plunger to push the fluid through the holes at high velocities, clearing any obstruction. One challenge is fabricating the oring slot all around the inner plunger. You would grab the 1/2" nominal pipe with a drill chuck and use the drill as a lathe to get a concentric slot. Alternatively, with a bit narrow enough, you could use a rabetting bit on a router. You might even use a saw blade. On the other hand, maybe you could keep the design as is, seal the handle, and force chemical with the same up and down action. Perhaps the ease of fabrication with the other method is enough of a benefit to use that instead.

[eak24]

@monroews Here's a video of the initial test. This is without PACl, but shows steady flow regulation with one 0.4 mm hole. Something to note is that EPDM orings are NOT compatible with chlorine. We would need to get some teflon orings, which seem to have better sliding ability as well. This one I found is rated as "very hard" but has a durometer rating of 55, so it's not as hard as some of the EPDM seals... I think this may warrant a Cornell fabrication team! A big question is selecting the ideal Oring material. From what I've found on Grainger and online, there are hundreds of different materials - and they are all quite cheap ($15/25). If this worked well, we could easily send out 50 with each new plant and it would still be substantially less expensive than our current system. There's also the option of making this same design in the square method.