We met up at Solid State Depot around 1PM and started drawing up some plans for a setup to test different sprayers with the 1/2 horsepower 1″ water pump. Pretty quickly, we realized that we needed bins, more pipe and fittings, and a ball valve to make it all work. So, we went on a run to McGuckins to pick up supplies.
Liz, Willy and I worked on cutting, priming and gluing the PVC. We drilled and tapped 3 holes into a length of 1/2″ PVC for the sprayers, and put a pressure gauge at the end of the length to get a reading on psi.
The glue set while Dan and I cruised over to Bococo. The guys there were kind enough to hook us up with 2 IDE hard drives to get some new workstations up and running at our space.
When we returned, I filled up the reservoir and turned on the pump. Nothing happened. Well, the pump was running but no water was flowing. It turns out you have to get water into the system first, at least with the approx. 1′ rise we had in our intake line. Filled the pipe with some water by hand, then turned it on and it started flowing nicely.
Before the test we had no idea how much psi we’d be able to achieve with the pump. To operate misting nozzles you need 40-80 psi. When the system started up, the regulator valve was fully open, so the sprayer line was receiving hardly any pressure. At about halfway closed, the 1″ regulator valve raised the pressure in the spray line to about 25 psi which was enough to get the sprinkler-type spray nozzles working pretty well. Turning the regulator valve to ~80% closed sent the pressure up to 65 psi and the misting nozzles started producing a fine mist.
The brass nozzle creates the finest mist with the lowest flow rate. The white plastic nozzle creates a mist that’s slightly less fine, and it looks like more water flows out.
We wrapped the spray line with a section of 4″ sewer pipe to simulate the tube-within-a-tube setup for an aeroponics rig. In this video you can see the brass mister in the foreground, a sprinkler in the middle that is off (serving as a plug), and the other mister at the far end. The black thing at the near end of the sprayer line is the pressure gauge.
You can see how the mist from the far misting nozzle is bouncing off the tube and creating a nice chaotic blizzard of fine particles. This is good because it means the roots should get fairly even coverage as the mist blows around the interior of the pipe.
Thanks to Henry for bringing the waterproof video camera.