1. No Flashback ? How is that possible ?
Yes, Safeflame unit will not get flashback from their flame and
torch. It is not magic. Safeflame was the result of an EU funded
project to research for a "safer flame" without using compressed
gas bottles, chemicals and/or alcohols.
Traditionally all flames from Propane, Acetylene, Natural Gas, HHO
fuel gases are "pre-mix" flames ie the Fuel gas is mixed with
oxygen before it reaches the torch tip for combustion. These flames
are very prone to "Lightback" or "Flashback". Too much gas, the
flame will try to lift off, too little gas the flame will try to
travel in the opposite direction into the torch.
Flashback can and will occur because it is a "pre-mix" gas system.
Hence for those applications there is a requirement to install
flashback arrestors (Fba) in the gas hoses / torches for safety
reasons.
These Fba's have to be certified for the appropriate fuel gases.
There will be Fba for propane, acetylene, hydrogen etc. We are not
aware of any Fba's that are certified for HHO fuel gas over 0.5 bar
that is available in the market and therefore care should be taken
to ensure that the correct certified Fba's are used by whatever
system that you choose to use.
Some of those HHO suppliers are claiming that they use Fba's that
are tested to safety standards, in particular ISO 5175 and EN730.
However these standards specifically excludes Oxy-Hydrogen systems
or HHO. That is a blatant mis-representation of facts. The
responsibilty for the use of those machines to make sure they are
safe and "fit for purpose" lies with you. So care should be taken
in choosing your "Gas from water system".
Stoichiometric HHO gas mixture is the worst mixture for flashback
to occur. For a lot of HHO systems in the market today, they use a
few Flashback arrestors in series to try to overcome this problem.
For Safeflame unit with the specially designed "post-mix" torch
(i.e the gases are only mixed at the tip of the torch), Fba is not
necessary and flashback is not possible. Why ? Because the fuel
gas, hydrogen is only mixed with oxygen at the tip of the torch
nozzle and on the outside. When there is too little gas or too
large a torch nozzle tip, the flame will try to travel back to the
inside of the torch. It will not produce a flashback because when
the flame tries to go back into the hydrogen gas line which has
100% pure hydrogen, it won't combust. If the flame tries to go back
into the 100% pure oxygen gas line, it will be the same because
oxygen on it's own won't combust. Hence Flashback is not possible.
Another side benefit of the "post-mix" torch is that the torch
nozzle is very tolerant and frequent change of nozzle tip to match
the flame size is not necessary. Of course if the post-mix gas is
too much it will eventually lift off but usually at reasonably high
gas output. Hydrogen is a very diffusable gas and so is the perfect
gas for post-mix flame.
2. Is the Safeflame unit suitable for 110V power supply ?
Yes, all Safeflame units can work with 110V / 240V. For the single
phase 110V version units, they are made to order and therefore when
ordering, please indicate that it is the 110V version that you
require. The 110V / 240V Safeflame units are available from 1LPM
right up to 15 LPM. For units up to 5 LPM, the normal 240V 13A plug
is sufficient.
For units over 6-15 LPM we need to have the single phase "Blue
plug" power supply. Units over 15 LPM are 3 phase machines and will
require the "Red plug"
3. Why do you quote your Safeflame unit output in LPM whereas most
other HHO systems quote in LPH ?
Safeflame unit produces separate streams of Hydrogen and Oxygen
gases by electrolysis from PEM Electrolysers. When we quote our
machine output, let's say 4 LPM (litres per minute), it is
indicating that it will output 4 LPM of hydrogen gas and 2 LPM of
Oxygen gas as water is made up of H2O ie 2 parts Hydrogen and 1
part Oxygen. The total combined gas output is actually 6 LPM. Most
HHO systems which usually quote in LPH (litres per hour) of
combined gases (because the gases produced are already mixed HHO
and so they cannot quote separate gas output) making the gas output
figures look a bit bigger and appear more impressive.
In order to make a true comparison between a Safeflame unit (LPM of
Hydrogen gas only) with a HHO unit (LPH of combined H2 and O2
gases), one has to work out the Safeflame "equivalent" gas output.
In the above example for a same size machine, the HHO system will
quote their machine output as 360 LPH (4+2=6LPMx60mins=360). In
addition most HHO systems don't recommend their users to use their
machine at full capacity.
In fact in some cases. they are recommended to use them at no more
than 50% capacity !!!. So make sure you make the correct comparison
before making your decision.
4. Can Safeflame unit work above ground level ?
Safeflame unit produces separate streams of Hydrogen and Oxygen
gases by electrolysis from PEM Electrolysers. Hydrogen being
lighter than air can rise easily up the gas hose. Similarly oxygen
gas travels up the gas hose from the electrolyser. There is hardly
any registable pressure increase for up to 5m vertically. In
addition, for the Safeflame unit there is a facility near the torch
end for the remote "On/Off" and "boost button". Visit the "Gallery"
tab on this website to see the test done on using the Safeflame
unit 5m above the Safeflame unit.
5. For Oxy-propane / Oxy-Acetylene, the hottest part of the flame
is at the tip of the inner cone, where's the hottest point of the
flame for Safeflame?
Traditional Oxy-propane / Oxy-Acetylene, the hottest part of the
flame is at the tip of the inner cone. Safeflame produces a pure
hydrogen flame and it is soft and hot (~2700C). Due to the high
diffusivity of hydrogen (which comes out of the torch in the centre
), it is mixed with oxygen outside the torch and so it does not
have an inner cone. The temperature of the flame is evenly
distributed and about 2700C. Hence it is much easier for brazing
pipes.
6. How does the cost of owning and running Safeflame compared to
Gas bottles and Oxy-Acetylene gas / torch?
The Safeflame units are a bit more expensive to start off with.
Once the unit is purchased, the on-going costs are de-ionised
/distilled water and occasional water filter and Silica Drying
pellets to replace. The capital cost of the Safeflame unit can be
depreciated over the lifetime of the unit, typically 10 years or
more.
For Oxy-Acetylene system, one has to pay rental on the Oxygen and
Hydrogen gases. Then there is the cost of the Oxygen and Acetylene
gas itself. In addition in-direct costs like running out of gases
and spending time getting replacement gas bottles, transport costs
etc. If a brazing piece using Oxy-Acetylene is damaged because of
the high flame intensity, time taken to remove and re-do takes time
etc.
Over a 5 year period, comparison of Safeflame v Oxy-Acetylene gas
system, that come out to be more or less the same (this will depend
on the amount of brazing done for a particular business). However,
what is the price of Safety and of your life ?
7. Can a big output Safeflame unit be used with multi-drop off
points for many torch terminals ?
Unlike many HHO flame from water system which pipes combustible
gases (Hydrogen and Oxygen) for example around the factory,
Safeflame do not approve of it. In addition there are strict
guidelines in piping combustible gas mixtures which needs to be
complied with. In addition if there is a problem with the unit
supplying the combustible gases to the various terminals, the whole
work application area will have to stop. Safeflame advocates the
use of multiple smaller Safeflame units to be more efficient and
safer.
8. Can Safeflame system be used to braze Aluminium or Aluminium to
other metals like copper ?
Safeflame is ideal for brazing Aluminium to Aluminium due to the
softer Hydrogen Flame. It is particularly great for brazing
Aluminium to copper or other metal. It is much more difficult with
Oxy-acetylene and one has to be very skilled to do that. One can
also braze Aluminium with Oxy-propane but that involves compressed
gas bottles.
9. Can Safeflame system be used for cutting metal ?
Safeflame unit can be used for cutting metal only in conjunction
with compressed oxygen which does the actual cutting but that
defeats the Safeflame object of "not using compressed gas bottles".
Safeflame is mainly used for brazing and flame polishing
applications. The hydrogen flame is softer and wraps round the pipe
for easier brazing compared to other forms of brazing fuel gases
and it is much safer.
In addition, the brazing process is being "de-skilled" due to the
ease of use of the Hydrogen flame from the Safeflame unit. The
temperature of Hydrogen flame is around 2700C compared to
Oxy-acetylene of 3300C.
Existing HHO systems in the market today which are also a form of
"Flame from water" uses a "booster" by bubbling the HHO gas mixture
through an alcohol like MEK to give the flame a bit of colour.
However, the resulting flame is no longer a pure Hydrogen flame,
instead it is a hydrocarbon flame with lower temperature and not so
kind to the environment.
10. Can Safeflame units be joined together safely to produce higher
Hydrogen and oxygen outputs system ?
Safeflame has been designed to be able to couple together to
produce higher Hydrogen and Oxygen outputs. In most applications, a
smaller Hydrogen output unit will cope with about 80-90% of their
normal day to day requirements. However occasionally higher
Hydrogen output may be required and the coupling up of units comes
in very handy.
For example, if an organisation has 2 units of Safeflame with
standard output of 4.5LPM each which can be boosted to 6.5LPM.
Joining the 2 units together gaseously with non return valves on
each unit gas pipes it will be able to produce a standard output of
8LPM and when boosted, it will produce 13LPM. That output will be
able to braze pipe sizes up to 1 5/8". There is a video in the
Gallery Section demonstrating this facility.
11. Can the Safeflame unit produce a less than stoichiometric
mixture of Hydrogen and Oxygen flame ?
All Safeflame units have the facility to dump some of the Oxygen
produced from the process of electrolysis of water. Therefore it
can produce a less than stoichiometric gas flame.
This may be particularly useful for certain application where less
oxidation is required. A good example will be the brazing of silver
or glass beads that uses some silver compound.
Safeflame can reduce the oxidation of the silver and can prevent
the finished piece from turning black due to formation of silver
oxid