Pulse Jet Type Combustion System

[enb54]

Hello Folks, my Canadian (Alberta) professional registration/certification apparently does not qualify me to post on the "official certified" forum, so here's the question...

I am wondering if anyone in Europe is using or playing with the system used in the "Lennox Pulse G21 (or similar)" installed mainly here in Canada/USA. Just curious, and wondering. Am researching and experimenting with various heat exchangers and came across some very interesting stats on this particular machine, unfortunately a bit too advanced for its' time (IMO)...

Your comments are expected and welcome, thanks in advance...

 

[dcawkwell]

The brief bit I read about on the internet is it is using pulse width modulation on the gas valve to control gas usage.

This is old and boilers have moved on here in the UK using fan speed to
control the gas and boiler. Also condensing recovery units in the flue system.

Like most of the heating stuff your side of the atlantic lagging behind
current technology.

 

[simond]

The lennox g24 mce sold in the uk until 2004 pulsed the gas train, if I remember correctly.

Current Johnson & Starley warm air heaters (furnaces in Canadian parlance) also pulse gas valves, I think they did this to lower stresses on the heat exchanger, according to one of their HQ people a few years ago.

Current Lennox units use two stage burners and they achieve an industry leading efficiency of 94.5%.

I think it unlikely that pulsed burners offer much advantage, they seem to have been and gone, anecdotally.

 

[Boilerman2]

Only ever worked on Two on an MOD site on colhester Garrison
haven't seen one since (that was 15 years ago!)

 

[enb54]

Hello folks...

I was referring to the combustion (gas/air) system, similar to what was used in the old German V1 "Doodlebug" cruise missile of WWII, and it is apparently pretty obvious that you don't have any (or hardly any) of those types of boilers/furnaces/heaters over there.

Thanks for your responses, will keep researching...

Edited on April 26/2012...

Additional information... www.auer-gianola.fr apparently describes one maker in Europe, and the Lennox Pulse G14 and G21 are the common (obsolete) residential models here, commercial would be like the Fulton PHW-2000 or the Hydrotherm "Hydro Pulse" . These devices were/are approximately 95% energy efficient, and have no moving parts except for the gas/air intake flapper disk valves (self sustaining combustion after initial ignition), but are very loud and require mufflers on the intake and exhaust because they operate at between 50 and 90 Hz (rate of combustion detonations). I am surprised that no one has heard of them in UK, they are quite common in industrial settings as driers...

They apparently went obsolete in residential because of very poor installation and maintenance, the industry generally does not like devices that last too long with only basic maintenance...

April 30 additional information...

The auer-gianola link above goes nowhere, but http://www.eberspacher.com/products/ do manufacture pulse combustion heaters, apparently used for vehicle preheating in very cold climates. The primary use for pulse combustion technology appears to be for high efficiency boilers and driers in industrial settings, I suppose even with mufflers they are somewhat noisy for residential...