Savage Electric Truckmounts

[Duane Oxley]

"...it doesn't "fire" anymore than anything else when set properly..."


Not true, actually... Let's take a #6 jet or equivalent one for example...

Set a LG at 200 degrees (which you can't technically do, since there's no actual calibrated temperature gaga...) and a boiler at 200 and wait a minute. The LG fires immediately for a minute or so, then turns off.

As soon as you turn the system on and pull the wand trigger, it fires again and continues to do so as long as the wand is keyed... because it can't ever catch up... It can't deliver 200 degrees at 1.5 GPM. (It's rated at 90 degrees rise over the incoming temperature at 1.5 GPM. So, at 65 degrees input, you get a whopping 170 or so... ATM... at the heater)

Do the same with a boiler. Turn it on and set the temp to 200 and wait as long as you want. Nothing happens, because there is no flow and it's flow- fired...

As soon as you turn the system on and pull the wand trigger, it fires and, if you keep the trigger keyed, it stops firing in less than a minute... Then, it cycles on and off every15 seconds or so... because it has more heat than a Little Giant #3... or a Little Giant #4, for that matter... (A 220,000 BTU boiler has 40,000 BTU's more than a LG 4 and 100,000 BTU's more than a LG #3. At 1.5 GPM, it gives, when set up properly, about 170 degrees rise over the incoming temperature.)

So, it fires less, because:

a.) It doesn't fire until it's called via flow to do.

and

b.) It has more than enough BTU's available, so it cycles on and off as it reaches the set point.

On a boiler, the thermostat is a "High limit switch"... turning the heater "OFF" when the set point is reached.

On a Little Giant, the thermostat is a "low limit switch"... turning the heater "ON", when the set point is NOT reached...

A Little Giant depends upon temperature drop, in order to fire, in other words. And, since it can't keep up, it falls below the set point routinely... and fires more as a result...

If you define, "set properly" as "being set within it's limited temperature range", then you may say that it fires less... but all things considered, a boiler will still come up to whatever the set point is within the LG's range, quicker than the LG will... So even in terms of pre- heat burn time, it burns less total time...

 

[hogjowl]

Doowayne ... you'd be much less boring if you had less time to post.

Know what I mean ...?

 

[floorguy]

hummm should i then take out the little "cap" from the burner then???

so that it "flows" a little better when fired???

Mind you i have one of them nasty flow fired monsters

 

[Bill Soukoreff]

Duane and Greenie, great posts.

Bob's heater is rated at 2 gpm. I don't know anyone who has have ever turned it up past 240, because they don't need to. Few people have haver cleaned at a CONSTANT 240 at the truck.

Duane, is there a sweet spot for these 200,000 BTU boilers (gas consumption versus heat output)?

 

[Bob Savage]

WIlliam,

The "secret" to our flow fired heater is our afterburner circuitry.

This circuitry allows the heater to continue firing, because even when you stop keying the wand, the burner continues to burn for a set number of seconds, to only be over-ridden by the high limit thermostat and where you set the dial.

IOW, I can set the temp dial to 200º on our TM's, and get a constant 235º at the machine on the Murphy temperature gauge while cleaning.

That way our heater is actually heating the water when the flow has stopped, so it doesn't cycle on and off as much as other flow fired boilers do when keying your cleaning tool.

That also explains why Greg Loe was using less propane with his SAVAGE heater as compared to the Little Giant 3HT.

Our heater is quite HOT and very efficient, and is now also available in a kerosene burner version.

 

[Bill Soukoreff]

Took you long enough to get on here Bob!

My earlier post may not have been clear. Because Bob's (and it sounds like Duane's heaters) can put out constant 240 with high flow, most people I have talked to do not ever need to turn it up more than that. Most people with other types of heat have never experienced what a flow of constant 240 is like. The Everest I worked with would get to 230-235 at the truck eventually but only for brief moments, it would spike up and down dramatically. The average temperature would be much lower.

I believe what Bob says about his after burner circuity. The guy I bought mine from runs a multi-truck operation and swears that it the most efficient heater he has ever used, period. I have never used a LG so I will not be able to make comparisons in the future, but let's face it, there is no free heat. At least with the savage heater, you can dial it lower if want to save some pennies on heat or depending on the job.

Thanks Bob and Duane for all the engineering you have done in designing your systems and passing on what you have learned.

 

[Duane Oxley]

Hi, William...

I was out of town all day, so just now got back to see the responses here...

No, I've never really done a study for a specific sweet spot / balance, in terms of heat vs. consumption. "My thing" has always been to generate more heat than needed, so that there is heat in reserve to call on when and if needed.

Also, with a reserve, as the system ages and loses efficiency, it's all but unnoticed, because it can still deliver as much as, if not more than, is needed for tough jobs.

I have a system in my shop right now, that I built in 1997. It's one of the first "Hammers" I ever built. In testing it, even now (granted, with some cleaning of the heater's core and jets), it delivers 230 at the wand, at my standard of 600 PSI through a #6 jet equivalent (2 @ 11003)... with the wand held open... not cycled in order to allow the heater to "pulse" and generate heat when not called on to do so. (I see that as the only "real" test. Cycling the wand ON / OFF, is o.k., but inconsistent, in terms of two people doing it identically.)

In 2000, I demoed a system I built at an open house "mini fest" here in Atlanta, in which everyone... including all competitors... were invited. Vortex and Shawn York was the only one that accepted the invitation, and there were about 50 people there in total, I guess (Bob Savage was one, and there were several from the ICS board..).

That system, the "SplitSteam", delivered 265 degrees at the wand, at 600 PSI, through a Prochem wand that had 4 jets each 1.5's, for a total of 6, if I recall correctly.

... but it did it with two wands running simultaneously... held open... and we shut it off before it stopped climbing in temperature.

I don't build systems that are allowed to do that now. I limit them to 300 at the machine, which means that they don't get over 270 ATW, and typically max out a bit less than that.

I'd be willing to bet that that system burns a little bit more than a Little Giant 3, or 4, since it's 350,000 BTU's...

 

[floorguy]

I guess heating to the dials temp is ok...

I was just going to point out with my flow fired one, that once it gets hot...(and I do mean hot) that when I am done and shutting things down, turning off the burners and allowing cooler water to go through...That at the very first when i put in that open ended line, there is a 10 sec purge of steam...From letting it sit pressurized that 1 or 2 minutes I am making my way back out to the truck...So i wouldnt want it to continue to burn any longer...

Also on one test I did just after i bought it, we hooked it straight to a city line...oodles of "flow" and decent pressure...It was right after spring thaw, so the water was 40ish if i remember right...ran it full tits and it hit around 200...that was just flow through test...

when hooked to the machine,(at that time my engine exchanger worked) we set it up on 100' of 1/4" hose, and ran it through a #12 (4 11003s) took it a while because I want to see if the "high limit" switch kicked in and where...

they told me 250...it tapped out at 240 at the wand...

So if their number is right then I lost only 10 degrees in 100' of 1/4" hose..

and by the way, it was hissing and popping like nuts...

So while you could go higher then 240...all it is, is vapor..no liquid to flush with..

now unless someone can show the altitude #s and pressure #s that are different between sea level and 4700 feet...I hold steady that anything higher then 240 ATW is crap...

 

[Duane Oxley]

Yes, I agree on that one.

There is a point where magic starts to happen... 220 ATW and continues... to about 240...

Past that, and the "magic" doesn't noticeably increase... and, as has been said, it can actually decrease, when you have only vapor leaving the wand.

I posted to this effect on ICS in 2000 or 2001, if I remember correctly...

 

[Willy P]

I remember that post Wasn't it 250 at 600psi?