Pressure Based Surge Device

[galleon]

With the recent discussion on surges and energies on the reeftank and their influence, I figured I'd share the principle and design of one of my favorite surge devices. The concept was originally published by engineer Kevin Carpenter, described as a "Reverse Carlson Surge Device". Not sure how many of you are familiar with the design (I haven't spoken with many familiar with it), but I figured I'd share.



Water fills the 4" pipe up to the waterline. Air is pushed (any aquarium airpump can be used) into the 4" pipe, and pushes the water out of the four inch pipe through the 4" ell, and back into the system through the bulkhead, the air pressurizes the four inch pipe as well (at this point, the 1/2" pipe manifold is filled with water and sealed). When all the air has exited the 4" pipe manifold (but not the 1/2" manifold), the pressure in the four inch pipe manifold exits, and water *explodes* back into the four inch manifold (prompting a rolling, wavelike movement of the entire aquarium water column), pushing the (now equalized) air out of the 4" manifold via the 1/2" manifold. The 4" manifold continues to fill with water until it overflows into the 1/2" manifold internal standpipe, and creates a seal. Then, the entire cycle happens again.

Pointers: Make sure the 1/2" bulkhead is very close to the waterline, as the diagram shows. The placement of the pipes as shown in the diagram is relatively crucial. Make sure the top of the internal standpipe is below the waterline in the display aquarium. Try to use an acrylic tank, less wear and torque than on a glass. The size of the airpump only changes the duration between surges, the pressure and surge, since dictated by gravity, remains the same regardless of which size airpump you use.

Re: noise; the reverse Carlson sounds close to a real breaker when it fires. A very entrancing sound...almost an inclusion factor.

Cheers,
Chris

[ 07-07-2001: Message edited by: galleon ]

[Doug1]

Interesting, I have heard of the Carlson Surge but that diagram is differnt, most of the others I remember seeing were mounted abouve the tank. The noise may be a factor in the lack of popularity tho I can see it being a great addition to in inwall setup, esp on a reefcrest scleractinian tank

[Doug1]

BTW where in the Ell do you find a 4" Ell?????????

[galleon]

Plumbing supply store. Even Home Depot might have 4" ells (slip x slip 90* elbow). Home Depot. Sheesh, one day someone will tear that place down and build a hardware store there.

The "Carlson" you refer to operates on a forward siphon forced by water entering an inverted U-tube. They are noisy, and just a pain overall (the best overhead surge device is basically a gravity toilet in a bucket (Borneman's brainchild). The Carlson design has been used for a long time on water treatment facilities to dose water with. Called "bell and siphon's". Bruce was just the first to implement the concept on coral tanks Here's a rough diagram of two ways to build one:
Here's the original article by Dr. Carlson: http://www.breeders-registry.gen.ca....sumr/surge.htm
Chris

[Alice]

I've heard that the Borneman surge device sounds basically well, like a toilet flushing but that it works well. This reverse Carlson works better and is quieter? How big is it overall? (Diagrams make my brain freeze up...I'm a hands on person, lol)

~Alice

[Doug1]

around here bulkhead fittings at a plumbing supply are non existent <IMG SRC="smilies/frown.gif" border="0">

[galleon]

Alice,
I wouldn't say this device works better, but very differently, so its difficult to compare. Instead of pushing water across the reef structure, a rapid "inhaling" of water into the device prompts a rolling, tankwide surge (you should see the gorgonians move when these things fire, very natural looking). The height depends on the height of the tank (from where you decide to put the large surge bulkead, up to the waterline). The taller the unit, the great the volume of surge (doesn't change velocity). Changing the width also increases volume, however, if you increase the size of the surge bulkhead, the inhaling motion of the surge becomes faster and stronger.

[galleon]

BTW Doug, 4" bulkheads can be had by US plastics or Aquatic Ecosystems. You can acquire their catalogs via their websites. http://www.aquaticeco.com/ http://www.usplastic.com/

[Doug1]

4" bulkhead was what I meant to say, the other stuff is available locally.
So if one had say a 180g tank would one of these devices on each end work and any thoughts as to how to alternate the sequence to get the back and forth effect?

[galleon]

Sure, these surge devices are very reliable as far as timing goes, as long as the airpump(s) is maintained and in a good state of repair. You can alternate durations on individual devices by teeing off two airpumps to the air input on the device, and timing the pumps so that they operate both at once for shorter duration between surges, or one at a time for longer duration. Basically, for two units to alternate, all you have to do is have equivalent pumps start at a different time, and add additional pumps on for shorter duration at alternating times as well. However, one unit of substantial size does accomplish both a back (water being pushed out of the unit via air pressure) and forth (water explosively reentering the unit) motion to some extent.

[galleon]

Moving up for further comment.
Chris

[Alice]

What's the minimum tank size for this design? I can't tell how big the unit is from looking at the diagram.

[galleon]

Alice, I actually built a fully operational unit for a ten gallon glass aquarium that works very well, except the unit was inside the aquarium to avoid "glass pull" and torque. So, ten gallon and up can utilize these units, but if you are using a glass tank of less than one hundred gallons, I would recommend using the unit internally, however it is not absolutely necessary. The unit in the diagram is about 16" tall.
Chris

[galleon]

Alice, Here are schematics of the two simplest ways to mount the unit internally. In your case however, mounting the units via bulkhead would be difficult. Perhaps, if you really want to use one of these units, you extend the height of the 4" pipe and mount the unit to a wall or cabinet via clamps.
.

[galleon]

Here's how to utilize the unit without drilling or bulkheads. Use circular clamps and FRP bracket mounted to a wall to hold the unit. Maybe a piece of rock underneath the 4" ell to maintain the height off the bottom.


However, in your case, if you have the height option, I would use the Borneman surge device. Or a Borneman surge device in conjunction with the reverse Carlson. The Borneman would be better at simulating tidal or major current-induced "blows", while the RCSD (reverse Carlson surge device) is a great breaker simulator. I would personally use both, especially since only one requires a water pump.

[ 07-09-2001: Message edited by: galleon ]