bell siphons


Friends who are new to fish and vegetables are often particularly interested in siphons, but are often discouraged from doing so. Sometimes it's hard to start, sometimes it can't cut off the flow. One day it feels fine, but tomorrow it doesn't work. Even if it works, noise becomes a problem again. . . So is there a siphon that can guarantee smooth start-up and flow interruption? Is there a siphon that is low-noise and does not affect rest at night?

There is nothing new in the world. When you want to break your head, it is better to search. In 99.99% of cases, the problem will be solved.


About 10 years ago, another open source sharing blogger on YouTube shared this kind of siphon. This idiot has been open source for more than ten years and still has not been able to expand the scale. But he is better than a big fool like me. At least his Open source projects are all crowdfunded by netizens without spending their own money. Different from ordinary siphons, its water outlet is equipped with a water trap, which ensures that there is a water seal at all times, so the siphon can definitely be started. Of course, you can also place the water outlet below the lowest water level of the return pool, or place a water trap at the water outlet. Small containers that store water can play the same role. This is what some friends call a water-sealed siphon. In addition, a small water cup is installed at the mouth of the destruction pipe. When the water level is lower than the mouth of the cup, the destruction pipe will suck up the water in the cup. The cup is lifted up under the action of buoyancy. There is only air in the cup and no water. Therefore, The destroyed tube can only suck in air, ensuring that it can destroy the siphon and cut off the flow in an instant. This design is foolproof when starting up, and shutting down is clean and refreshing. The only problem is that there is a moving part, and if debris gets inside, it can easily get stuck and cause problems.


Let's take a look at the siphon that has been used in sewage treatment for half a century. This industrial product is extremely reliable and practical, without any moving parts. It also ensures that the siphon will start inevitably under the action of the water trap, and can be damaged under the action of the damaged pipe. Guaranteed to cut off the flow. It is used for super-large flow drainage in sewage treatment. The diameter of the siphon pipe can be as high as hundreds of mm. Compared with it, the siphon flow rate of the aquaponics system is basically smaller. Different from the common sabotage tubes in fish dishes, this sabotage tube goes deep into the siphon. Due to the effect of pressure, only when the water level is lower than the external air inlet of the sabotage tube for a certain distance, the inside of the sabotage tube will enter the air under the action of negative pressure. , at this time, the destruction tube is suspended and can only suck air but not water, which can ensure the interruption of siphon flow. In addition, a pressure relief port is installed at the water outlet pipe to help discharge high-pressure air and reduce noise during startup.

For some reason, I haven't seen anyone share these reliable designs that have been used for many years. I have never paid attention to siphon before. I started to pay attention to it in the past month when I was working on a small system at home. Now I would like to share these designs with you.

The first type of siphon is very stable and reliable, but due to the fast air intake speed, there will be momentary noise when the flow is cut off. The second type of siphon has no moving parts and is more reliable, but it does not pay too much attention to the issue of silence. To be even more silent, combining both designs, I made this silent siphon with no moving parts.


Experimental Silent Siphon

To facilitate installation, an inverted U-shaped siphon is used. The actual situation is not limited to the form of the siphon, and any siphon can be transformed in this way. The water outlet uses the same concept as the two siphons above, that is, use a trap or place the water outlet below the water surface to ensure that the siphon will start. The lower the depth into the water, the better. It is best to use a water container so that the outlet just touches the water. If you go directly into the tank, place the outlet at the lowest tidal level of the tank.

The breaker tube must be installed higher than the siphon pipe to ensure that no water will be absorbed into the breaker tube when the siphon is started. The air inlet of the destruction tube should be lower than the siphon water inlet. The specific height difference varies according to the flow rate. You can adjust it yourself. The instantaneous flow rate when the siphon is started cannot be too high, otherwise the instantaneous negative pressure will cause the damaged pipe to absorb water, causing flow interruption and noise problems. When the water level is a certain distance below the destruction tube, the negative pressure will suck up the remaining water in the tube. At this time, the destruction tube is completely suspended and there is no water around it. When the air is inhaled, water will not be sucked in at the same time and cause noise. Of course there will still be a little bit of noise, but it won't affect your night's rest at all.


The golden bell-type silent siphon modified after the successful experiment, the water in the damaged tube is being sucked up.