Displacement Lubricators Question

[HughT]

I came across this lubricator on plans for a marine engine. I wonder if someone could clarify how it is supposed to work? My understanding of displacement lubricators usually has the steam inlet pipe connected at the top, relying on small amounts of steam condensate to lift the level of the oil.
This one has the steam pipe at the bottom and I don't quite understand why then the central oil pipe is so high when there is no obvious means of condensing.

 

[agr]

Hugh,

As I understand it, this design works exactly as you describe, except that the steam enters from the bottom and travels up the centre tube. It then condenses, sinking to the bottom of the oil, thereby "displacing" the oil level up, forcing it to travel down into the steam line.

Hope this provides some insight.

Tony.

 

[HughT]

Hi Tony,

Thank you very much. before I posted I had read a paper written by a prominent engineer from the 'Society of Engineers' published in 1870 in which he discussed the various types of 'steam lubricators'. In this document is specific mention of marine engines that states "For such purposes it is necessary to lead the steam to the lubricator (seen at Fig. 2), through at long pipe in the engine room, that pipe then supplying the necessary condensing surface".

So there I was working till 6am researching all this stuff and naturally assumed the long pipe in this example served the same purpose, but as you quite rightly pointed out, the steam would travel along this pipe and condensate within the chamber and not in the pipe. It is really quite obvious and maybe I should have got some sleep before posting - I just had a notion of the steam condensing in the pipe after reading that paper!