Vortex Breaker design 1

[skyporker]

Why do some liquid vortex breakers have caps on top of the usual cross type design? what is the advantage?

thanks for any help

 

[prex]

As a vortex is vertical gaseous vena that extends from the outlet to the surface of the liquid, the plate will stop it from forming. prex

http://www.xcalcs.com

Online tools for structural design

 

[skyporker]

But wont the crossed plates on top of the outlet pipe do that? why add the cap? does it make much difference if the cap is there or not?

 

[prex]

Yes, it makes a difference, as the vortex may pass through one quarter of the outlet hole: it will possibly be smaller, but still existing. prex

http://www.xcalcs.com

Online tools for structural design

 

[skyporker]

makes sense. thanks.

do you know of any available literature which details the pros & cons of different designs of vortex breakers? or of any research available?

 

[BRT549]

I think you are seeing a combination of two different vortex breaker designs.

The first is a crossed plate inserted into the throat of the outlet pipe in a tank; the length of which is roughly 1.5 times the diameter. This works best if the outlet pipe is on the side of a tank. A design guide is "ANSI/HI 1.1-1.5-1994 Centrifugal pumps for Nomenclature, definitions, applications and Operation." No design dimensions are given, pointing out the "seat-of-the-pants" origin of this device.

Alternative:
If the outlet from a tank is on the bottom, a baffle plate can be placed over the mouth of the pipe. The rough dimensions are as follows: The outlet pipe diameter is "d" (known), the baffle plate diameter is "4d", and it is placed a distance "d/2" from the outlet pipe. Installing the baffle plate above the pipe opening will simulate a larger intake area, thereby reducing the vortex and air entrainment.

The crossed plate will work okay for a bottom-mounted outlet pipe too. A crossed plate with a cap sounds like a home-brewed solution to vortex breaking.