I have seen photos of foam troughs, designed to keep foam from entering the drypipe. If such a device is in place would it have the same effect on an engine that is prone to priming. It seems that priming is a local, close to the drypipe, occurance. if a foam trough were in place then I would think that it would be harder for the boiler to pime.

I always thought they would be better put just in front of the photo line.....to prevent washouts.

I've seen them shown in the Cyclopedias, have no personal experience with them being a narrow gage and shortline guy.

dave

Frisco was big on using what they called a "Gunderson Device". It was suppposed to collapse the foam allegedly. My literature is all packed away, but I'm sure someone here can expound on it.

Oh! I thought you were referring to the box lunch line on a fantrip!

:-)

Could we get back to Bobk original question? I have heard of these devices but never been around them. It would be nice to learn about them.

Robby Peartree

A number of railroads used a device called the "Signal Foam Meter" manufactured by the Electro Chemical Engineering Corporation (subsidiary of Dearborn Chemical Company). The Foam Meter used 2 electrodes mounted in the boiler to automatically open a blow off valve. The diagram I have also mentions a "NOX Foam Discharger".

They also devised a "Foam Collapsing System", that I am less familiar with.

I've tried conducting some research into the Signal Foam Meter, but its been difficult as most of the (CNR) engines equipped with this device are located out west. I was able to get some photos of the equipment on CNR 5093 on display at Casino Regina (Saskatchewan). However the pictures raise more questions then answers. For example, the system is supposed to have 2 electrodes, however on this engine I can only see 1. Plus the cab is in rough shape so its hard to really identify much of anything. Here are my photos of CNR 5093:

http://www.trainweb.org/j.dimech/6167/sfm.html

You can also look up the patent online:
http://patft.uspto.gov/netahtml/PTO/srchnum.htm
Search Patent #1911756

And wouldn't you know: the name on the patent is GUNDERSON!

I have also included 3 PDF's of scans of an advertisement from the 1938 (I think) Loco Cyc.

So, review all this material and pick it apart. I'm curious to hear what everyone makes of these devices. The engines I'm associated with use the Nalco Continuous Blowdown, so I really haven't had a chance to develop a thorough understanding of the Foam Meter or the Trough System.

US Patent Number US1911756[url]books.google.com/patents/US1911756.pdf[/url]

It is not a foam separator, but a detector, which triggers an alarm, operation of an anti-foam solution pump, or both.

Similar devices are currently available " off the shelf " with the advantage of adjustable sensitivity and modern electronics.

Many already know this, many do not, some believe, some don't want to know;
In this era of modern technology, it is an easy thing to have a continuous digital readout or a hand held Conductivity / Total Dissolved Solids meter. This can be for either automatic or manual control of a surface blowdown to prevent TDS from getting out of control and causing foaming.

Take your pick of water treatment technologies and products. We don't have to act like it is 1890 or even 1940. It is not necessary to be " behind the times and Behind the 8 Ball ", when the rest of the steam power world is using it and getting great results.
Prevention is 100 times better than trying to deal with a problem that is already out of control.

The foam trough, and I have only seen drawings and photos is a pan that is under the drypipe above the tube bundle and goes back far enough that it is also under the drypipe opening to the throttle. I do not know the dimensions however I am guessing 36' x 60" with verticle sides. It is a pan. if the engine foams then the foam is held away from the throttle drypipe opening so that you do not get the foam into the units and then cylinders. I believe that examples of this may be in some of the locomotive cyclopedias. I can not remember if the foam meter probes were associated with this system.

Bob, there is a brief mention of such a trough, and a depiction of it in the second PDF I posted.