This Venturi nozzle is designed to efficiently aerate water without the need for an expensive air pump and air stones. Some sample applications are hydroponic deep water culture beds, large fish aquariums, or ornamental ponds.
A Little History
Venturi tubes have been around for ages, but folks don't really use them in their systems for one simple reason - they aren't efficient to run - until now!
If you're a hydroponics grower, you know how important it is to keep a high dissolved oxygen value in your deep water culture beds in order to maintain healthy roots in your plants! Plus the aquaculture growers need to maintain healthy oxygen levels in their fish tanks!
The traditional method is to use an air pump, weighted air tubes, and air stones. There are countless problems with air stones needing to be cleaned, air lines getting tangled, stones popping off the tubes, or even worse, water siphoning back into the air pump during a power failure. On larger systems, the regenerative blowers are expensive and loud! Along with the many mechanical problems are the costs to purchase a large air pump and good quality stones.
The majority of off-the-shelf Venturi nozzles are not designed for injecting air into the water stream. Typically they are used to add liquid compounds like fertilizer or soap.
This Venturi nozzle is designed for one specific task: To efficiently add air into the water. Instead of a single point of air entry into the water stream, this new design offers multiple entry points, allowing the nozzle to maximize the Bernoulli principle to inject air into the water stream.
Although the concept of the Venturi tube is fairly simple, calculating the perfect size to maximize the water-to-air efficiency can be frustratingly complex! According to our tests, this nozzle injects twice as much air into the water with the same amount of energy!
Standard Design vs New Design
The design possibilities are endless! A single nozzle could be connected to a small pump in an aquarium system, or dozens of nozzles could connect into a manifold for a a small pond or hydroponic system.
Standard Design vs New Design
Why Is It Better?
- They don't clog...well, almost don't clog: The largest particle that can pass through the nozzle can't exceed 7mm (a little over 1/4 inch). As long as you have a standard screen over the water pump's intake, these should be maintenance free!
- Less expensive: A properly diffusing air stone can cost well over $15 each and usually cost more for larger ones. The air pumps can become very expensive for larger systems whereas a water pump for an equivalent area can be cheaper and consume less power. This aeration system can be constructed with these Venturi nozzles, an inexpensive water pump, and standard plumbing fittings!
- Better circulation: Not only do the nozzles help to add air into the water, they also jettison water which circulates water several feet away. This helps to maintain better circulation of air and nutrients through the system, plus can reduce the amount of suspended solids settling out of the water.
To test the effectiveness of the nozzles, an array of nozzles were installed on a manifold and added to our 8' wide deep water culture bed. At various distances from the nozzles, we measured the percentage of oxygen in the water. Even at a substantial distance from the nozzle, it is evident that oxygen remains in the water and the currents help to keep the water mixed well.
This chart demonstrates the normal oxygen levels in the DWC bed. At a set time, the Venturi circulation pump is turned on resulting in oxygen being added to the water. Three hours later, the pump is turned off.
Oxygen levels at 0, 3, 7, and 11 feet away (0, 0.9, 2.1, and 3.4 meters)
Some water pressure is needed to force water through the nozzle. It's recommended have at least 150 mbar (2.2 psi) of pressure for the nozzle to be effective. This will equate to about 2.3 lpm (140.3 cu in/min) of air being injected into the water. It is possible to operate a system under higher pressure which will produce more air, but it will take more power to run the pump.
Nozzle Flow Rates
(Note: The wattage per nozzle was high due to this particular testing fixture. While running a 20 nozzle setup, the wattage per nozzle is less than 7 watts!)
This design utility can aid with calculating the number of nozzles you can use and the size of pump to insure proper operation. It primary function is to design for hydroponic deep water culture beds. Click
to use the design tool.
A bit more technical, this calculator can be used for systems that utilize more plumbing parts, such as installing Infusinators into an aquculture system. Click
for the calculator.
We're offering a few add-in items so you don't have to go searching for the specialty parts! You can choose from extra nozzles, clear tubing, tees, and elbow fittings. Also available are 1/4" and 1/2" NPT taps so you can make your own air and water manifolds! Please visit the Designer Tool
for a list of needed components.