johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most. n.b. There is a list of my first 800 posts in my post of 17 June 2021, titled "800 Posts"

Tag: Gas burner

March 27, 2019

More Gas Burner Experimenting

First I tried the Sievert 2943.  I tried different gas settings, and different positions of the burner in the fire box.  I quickly discovered that an opening had to be present next to the supporting flange.  Despite that, steam was produced in 10 minutes, and 20psi was achieved in 15 minutes.  My aim is to obtain 40psi, and maintain 40psi during engine operation.

Unfortunately this burner does not work if there is any significant back pressure in the system.  Stuart has advised me to try the Sievert 2954 which he says will cope better with back pressure.  The Sievert 2954 has a similar appearance to the 2943, so I have not photographed it.

I have borrowed a Sievert 2954, but it needs some setting up, so I thought that meanwhile I would try a burner style which had been mentioned earlier.  It is a tube with multiple transverse slots.  Despite being constructed rather roughly and quickly, it produced a good hot flame.  Perhaps a bit small, but promising.

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If the next Sievert is not satisfactory I will come back to this style, and experiment with different slot numbers and sizes.

If you are becoming a bit bored with all of these gas burner experiments, I understand.  When the burner is finally sorted I will be delighted and relieved.

I have machined some wood to be used for lagging.  It is West Australian Jarrah.  A dark coloured wood which is often used for exterior flooring.  I will apply it to the boiler soon.

 

6 Comments
March 26, 2019

Experiment Failure

Sometimes information derived from a failed experiment is just as useful as a successful experiment.  Several readers predicted that burning coal would not not work in my dredger engine boiler, but I had to be convinced.

So, I removed the gas burner.

I have 3 types of coal.  One is Welsh steaming coal in 25-30mm lumps.  It has an attractive shiny appearance.  The other is coal lumps which were picked up next to a local railway line and are probably from Newcastle NSW.  I also have some brown coal, but it is in the form of briquettes, and I did not attempt to use them.

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Welsh steaming coal top, railway line droppings bottom.  All too big. 

Both black coal types were too big for the ~60x40mm diameter firebox in the dredger engine.  How to make them smaller?

Smash them up with a hammer and pass them through a sieve?  That would leave a lot of unusable tiny fragments as well as bigger bits.  And be very messy.  And require making a sieve.   If my experiment was successful that is what I would do in future.  Did not happen.

Meanwhile, I tried a hammer with a splitter edge.  The Welsh coal had definite layers, and split fairly predictably, with not too much dust or tiny fragments.   The Australian coal crumbled unpredictably into many fragments with a much lower usability fraction.

I started the fire with newspaper, then pine and hardwood kindling.  I should have paid more attention to the wood sizing, because it was problematic getting the wood alight.  Also, I had not set up a blower for the chimney.  I was relying on a really long chimney extension to provide enough draught.

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Chimney extension.  worked well.  Now what is that black circular patch on the ceiling?

Got the fire going with the assistance of a gas torch.  When the fire got going the draught seemed adequate.

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The wood fire at its best

Tried to add coal lumps, but they would not fit the firebox while the wood lengths were in place.  Firebox is just too small.  So I persisted with wood.  Soaked some in mineral turps.

I was not impressed with the appearance of the fire, but surprisingly, eventually, steam was produced, but never enough pressure to run the engine.  And the fire did require constant attention.  The front of the boiler was quite dirty after all of this.  I am glad that I have not yet painted it.

I will give the wood + coal fire another attempt, but size the pieces better (smaller).  The Sievert type burner is looking more likely.

Later in the day…..

…after a further discussion with Stuart I have decided to try the Sievert burner.   Made some steel rings which are a press fit on the burner, and an easy sliding fit inside the firebox.

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This is the new burner inside the firebox.  Not exactly @Trevithick, but I bet that he would have used it if it had been an option.

I still need to make a fitting to hook up a valve and the propane hose.  And try it out maybe tomorrow.  Another experiment.  I hope to not see flames shooting out of the chimney.

 

 

6 Comments
March 23, 2019

A Coal Grate. And Monster Emperors of Rome.

Firstly, the book review.  It is short, because I did not enjoy it.  Not that it is badly written, or poorly researched.  But it is really shocking.

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EMPERORS OF ROME.  THE MONSTERS.  by PAUL CHRYSTAL

From Tiberius to Theodora.  AD 145-548

This book is one of the series published by Pen & Sword on the architects of terror. Other volumes include Al-Qaeda, The Armenian Genocide, Bloody Mary, Einsatzgruppen, to give you an idea of the scope of the series.

Now that I have finished with the book, I am examining my own motives in choosing it.  I have read many books about ancient Rome, and find the era fascinating; the personalities, the reasons for the rise and fall of the empire, why the military was so spectacularly successful etc etc.

But to be truthful, I did not actually finish the book.  I had a similar reaction when I read about the Nazis and the concentration camps.  Just too horrible to contemplate.  And I closed it after reading about half.  And will not reopen it.

Paul Chrystal is a well-respected author who has written many books about ancient Rome. He states an aim to use primary sources, and to balance the horror with the mitigating aspects of the monsters. The book is 127 pages long, and it covers 10 emperors, so there is not a lot of space to give a balanced view. Mostly, despite its aims, the book is about rape, murder, treachery, nasty and insane men and women with absolute power doing whatever they felt like doing.

And to be realistic, even the “good” emperors started wars, executed rivals, instigated massacres and mass maimings.  That was the way things happened in ancient Rome. And twentieth century Germany, China, Cambodia etc etc.

So, if you enjoy seemingly endless descriptions of sadistic torture, rape and mass murders, with many illustrations, this book might be for you.

Not for this this reviewer though.

John V.

Now, back to getting enough heat into the 1:8 Trevithick Dredger Engine.

I have made a grate to place into the firebox, and which will replace the gas burner, which has proved to be inadequate, despite many, many experiments with improving it.  So here is the grate.

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Putting a rather unpleasant book to good use.

The holes in the grate are tapered, with the smallest part of the holes uppermost.  The fold at the back is to prevent coal being pushed off.  The taper is to prevent clogging the holes with clinker, and possibly to improve the velocity of air flow through the fire.

And how did I drill so many small holes so neatly?

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CNC of course.  Took about 45 minutes.

But after that I had a conversation with Stuart Tankard.  He reckons that I will do no better with coal than I have with propane to date.   Hmmm.   Might give it a go anyway.

Stuart’s suggestion is to try one of these….

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It is 50mm diameter, has a large jet (0.81mm diameter) and has a fearsome flame.  Looks more like a silver soldering torch.  If I use it I might get a flame coming out of the chimney.  Hope that it does not melt the silver solder.

 

 

3 Comments
March 4, 2019

Trevithick Dredger Engine. Almost There.

Firstly some pictures.

 

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So, I have reassembled the engine and the burner and the base.

Did you notice the base?

No?   Excellent.  That is the idea.  A nondescript matt black base which is barely noticed.

Yes?  OK,  well it must be OK.

Then a trial of the burner inside the firebox, using the changes which have evolved over the past few days.

During the video I am constantly changing the propane flow, and there is a clear “sweet spot” point where it looks really good, and feels very hot.  I have not yet tried to steam with it.

4 Comments
February 26, 2019

Trevithick Engine. Tweaking the gas burner. Winning?

Looking at yesterday’s photo, the yellow flame indicates inadequate air for the amount of gas going in.  The air holes at the gas jet level were already at maximum size, so I drilled some holes in the burner base itself.

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Yesterday’s photo.  Feeble flame.  Not enough air.   So I drilled holes in the burner end, next to the gas inlet.  (thanks for the suggestion Huib!).  Unfortunately, the improvement was minimal.  And gas flames shot out backwards towards the operator and gas jet.  A bit disconcerting.  And, I wondered, could the ceramic burner itself be restricting the flow?

So the next step was to remove the ceramic burner, and make changes to the spreader tube beneath.

The ceramic burner broke in pieces during the removal.  Possibly still useable.

But I thought, maybe I will see what the flame is like without the ceramic burner altogether.

And this is what the flame looked like…

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Now, that is more like it!  (you can see the holes which I drilled in the end of the burner to increase air intake)

Admittedly, the flame will change when the burner is back inside the boiler, but this is the most encouraging flame yet.  Minimal yellow.  The gas flow will need to be reduced.

Next session, I intend to experiment with the hole sizes and number and angles.  I do not expect to be using the ceramic insert in the final version.

2 Comments
February 8, 2019

Trevithick Dredger Engine Burner

Reader Huib suggested that I would need to modify the gas burner for my model steam engine even before I had tried it.

He was absolutely correct.  The burner was difficult to light and keep going, unless I blocked off at least half of it. (see previous post).

So, today, I modified the burner along the lines suggested by Huib.

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I added this stainless steel tube with drilled holes to the bottom of the burner, underneath the fire clay burner.  It is wedged into position.

And this was the result.  The burner li up easily when gas was admitted.

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From above you can see that the fireclay burner is red hot over most of its surface.  And hottest at the end which is deep inside the boiler.

I measured the temperature of the burner, and it was 790ºc.  I think that it will do nicely. After that, I sealed the fire clay burner into the brass container with a high temperature boiler sealant.

Yesterday I received in the mail a tiny pressure gauge.  3/4″ diameter, 0-80psi.  from EJ Winter, Sydney.  Order was placed Wed, arrived Thurs.  Great service.  Thanks Ben deGabriel.

Trevithick would not have had a pressure gauge in 1803, but modern boiler regs insist on one, so I have bowed to the inevitable, and will install this gauge on top of the boiler.  Photos to follow.   I expect to be running the engine on steam next time I am in the workshop.   WooHoo!   Not tomorrow though.  Baby sitting.

 

2 Comments