Siphon, Ebb and Flow

英文版, English version 

中文版, Chinese version

西班牙文版, Espanol version 

Siphon

1 A pipe or tube fashioned or deployed in an inverted U shape and filled until atmospheric pressure is sufficient to force a liquid from a reservoir in one end of the tube over a barrier higher than the reservoir and out the other end.

2兩 端的大氣壓力一樣，但管內兩端的水受重力作用而各自下墜，下墜瞬間，在圓弧頂部拉出一個真空，因真空而有壓力差，此時兩端的大氣壓 力再次從兩端將兩管的水壓回，但壓回的力量是大氣壓力減去管內的水壓(F=(Patm-PH2O)*A)，而長管內的水比短管內的水還要重，所以壓回的力 量是短管的壓力大於長管的壓力，所 以，虹吸管內的水就會不斷的由短管端流入而由長管端流出。

3如果我們用兩根連通管，所以效率會變成兩倍。

4如果用兩根連通管，但是其中一個連接抽水馬達，此時一根連通管是抽水，所以另一根把水送回，大氣壓力將兩管的水平衡，所 以，一個馬達可以有兩倍的動力，水就會不斷的循環。

問題1:請比較上連通管與下連通管的差異?

問題2:請問雙連通管時,管徑與高度差的關係?

Basic Ebb and flow operation 

1 As liquid fills the dosing tank, the level of liquid in the tank and inside the siphon bell rise at the same rate. (The siphon bell is open at the bottom). The siphon is vented to the atmosphere through the vent piping. This rising action continues until the level of the liquid reaches the open end of the outside vent pipe.

2 Once the liquid reaches the out- side vent pipe, it creates an air seal. As the level of liquid continues to rise in the tank, the liquid level in the bell continues to rise, but at a much slower rate. At the same time, the head of water in the tank exerts pressure on the air trapped in the top of the bell and the long leg of the trap. The air in the long leg of the trap is forced towards the invert of the trap.

3 As the liquid in the tank approaches the high water line, the liquid in the bell will have risen to a level just short of the top of the trap, and the air in the long leg of the trap will have descended to the invert of the trap.

4 As the liquid in the tank reaches the high water line, a volume of air is forced around the invert of the trap and out through the discharge leg of the siphon. The escaping air relieves the back pressure within the siphon and the liquid inside of the bell will rush up and fill the siphon trap thereby starting the siphon action.

5 The liquid is drawn out of the tank until the liquid in the tank reaches the bottom of the bell. Then the siphon draws air and the siphon action is stopped.

inside the siphon bell rise at the same rate. (The siphon bell is open at the bottom). The siphon is vented to the atmosphere through the vent piping. This rising action continues until the level of the liquid reaches the open end of the outside vent pipe.

Basic Bell Siphons

1.As liquid fills the dosing tank, the level of liquid in the tank and inside the siphon bell rise at the same rate. (The siphon bell is open at the bottom). The siphon is vented to the atmosphere through the vent piping. This rising action continues until the level of the liquid reaches the open end of the outside vent pipe.

2. Once the liquid rise in the tank and the inner liquid level reaches the outside vent pipe, the liquid will be overflow to the outside vent pipe.

3. As the liquid in the tank have descended to the invert of the trap, you have to evaluate the rate of fill-in and vent-out.

4. The liquid is drawn out of the tank until the liquid in the tank reaches the bottom of the bell. Then the siphon draws air and the siphon action is stopped.

Pressure type Single Automatic Siphons

1 As liquid fills the dosing tank, the level of liquid in the tank and inside the siphon bell rise at the same rate. (The siphon bell is open at the bottom). The siphon is vented to the atmosphere through the vent piping. This rising action continues until the level of the liquid reaches the open end of the outside vent pipe.

2 Once the liquid reaches the out- side vent pipe, it creates an air seal. As the level of liquid continues to rise in the tank, the liquid level in the bell continues to rise, but at a much slower rate. At the same time, the head of water in the tank exerts pressure on the air trapped in the top of the bell and the long leg of the trap. The air in the long leg of the trap is forced towards the invert of the trap.

3 As the liquid in the tank approaches the high water line, the liquid in the bell will have risen to a level just short of the top of the trap, and the air in the long leg of the trap will have descended to the invert of the trap.

4 As the liquid in the tank reaches the high water line, a volume of air is forced around the invert of the trap and out through the discharge leg of the siphon. The escaping air relieves the back pressure within the siphon and the liquid inside of the bell will rush up and fill the siphon trap thereby starting the siphon action.

5 The liquid is drawn out of the tank until the liquid in the tank reaches the bottom of the bell. Then the siphon draws air and the siphon action is stopped.

水會一直流出，直到水位低到讓潮汐開關吸入空氣。然後，潮汐開關回歸起始位置。

3A

Operation of Dual Alternating Automatic Siphons

1 Two siphons are set in a single tank at the same elevation. Both traps are primed with water (figure 3a).

3B

2 As the tank fills, the siphons are sealed and the air in the long leg of each trap descends towards the invert of its trap (figure 3b; please see the 'Operation of Single Automatic Siphons'). The air displaces nearly half of the water in the trap.

3C

3 If the siphons were set perfectly, they would both go into operation at the same time. Slight variations, however, are inevitable, and will bring one siphon into operation before the other (figure 3c).

4 The first siphon to operate will empty the tank and shut off with its trap fully primed with liquid. The siphon that did not operate will have lost nearly half of the liquid in it's trap as described in stage 2. Since it did not operate, its liquid was not replaced (figure 3d). The extra air in this siphon will cause it to go into operation next, resulting in alternating operation.

3D

4A

None Drilled Siphon Operation

1. A reef-ready, or drilled tank, is of little value to those that already have a tank up and running and don't want to break it down to have it drilled. It is for this situation that hang-on overflows were invented. They hang on the back of the aquarium and extend over into the aquarium. Hang-on overflows (see figure A) are less reliable and generally can handle less water flow than a "drilled" overflow. This is because overflows must fight against gravity and flow the water "over" the top of the tank rather than through a hole in the tank. Hang-on overflows use a technique called "siphoning" to move the water up and over the edge of the tank and down into the sump. As long as the siphon is maintained, there is no problem, but if the siphon is broken for any reason, then water will cease to flow into the sump and the display tank will continue to fill up until either the sump is drained or water flows over the top of the display tank. (see figure 4B)

4B

2. If the siphon tube fills with air, then the siphon will break, preventing any water from draining from the tank. The water level in the tank will overflow until the sump runs out of water, resulting in a flood.

After exiting the overflow, water flows through the standpipe and down the drain line into the sump. From there, the return pump (named such because it "returns" the water to the tank) pushes the water back up into the display tank. This raises the water level in the display tank, which in turn causes water to spill over the top of the overflow, and starting the whole cycle over again.(see figure 4C)

3. There are very few reasons why a sump is not the best choice. One potential downside to a sump is increased noise. It can sometimes be a challenge to eliminate the noise of water cascading into a sump. In most cases the sound can be easily reduced to inaudible or nearly inaudible levels, but getting to that point can sometimes require a good deal of effort. Reducing the noises associated with sumps is a topic that will be covered in Part II. Another reason to avoid installing a sump is lack of space.

5A

Floating Trash Can with Siphon Operation



5B

1. Cause there are some floating trash within the tank, it pollutes the water. We modify the siphon tube to a raft tank named STOPPER. (see figure 5A)

2. When the raft is at the low position, fill the tank till the raft tank reach the high position.  Power on the pump, while it is OPEN status. (see figure 5B) So water fill the tank. When raft reach the high position, it is CLOSE status. (see figure 5C) So the Floating Trash will overflows into the raft tank till it reach the low position.



5C

3. However, the floating trash will still stay within the raft tank, cause the siphon will overflow from the bottom inlet. (see figure 5D) Then it fills again.



5D

Adjustable of External Loop

1 As liquid fills the dosing tank, the level of liquid in the tank and inside the siphon bell rise at the same rate. (The siphon bell is open at the bottom). The siphon is vented to the atmosphere through the vent piping. This rising action continues until the level of the liquid reaches the open end of the outside vent pipe.

2 Once the liquid reaches the out- side vent pipe, it creates an air seal. As the level of liquid continues to rise in the tank, the liquid level in the bell continues to rise, but at a much slower rate. At the same time, the head of water in the tank exerts pressure on the air trapped in the top of the bell and the long leg of the trap. The air in the long leg of the trap is forced towards the invert of the trap.

3 As the liquid in the tank approaches the high water line, the liquid in the bell will have risen to a level just short of the top of the trap, and the air in the long leg of the trap will have descended to the invert of the trap.

4 As the liquid in the tank reaches the high water line, a volume of air is forced around the invert of the trap and out through the discharge leg of the siphon. The escaping air relieves the back pressure within the siphon and the liquid inside of the bell will rush up and fill the siphon trap thereby starting the siphon action.

5 The liquid is drawn out of the tank until the liquid in the tank reaches the bottom of the bell. Then the siphon draws air and the siphon action is stopped.