waste oil pre heater thoughts

[unabomber]

I would like to use a copper pre heater block instead of aluminum, it transfers heat almost twice as good. wont cost a million and is still easy to work with as far as machining goes.
 I also would like to use a small heating element say 200 watts 120 v with a thermal couple and temp controller. the oil would flow in a u shape around the element twice through the block and then off to the thermal couple and out the siphon nozzle. I believe it would be efficient in heating the oil but am not sure about the wattage rating being enough.
 I intend to flow about 1.5 gal an hour possibly more depending on heating demands.
 Another thought run a tube through the fire box with the by pass oil from the pump to help with pre heating, located in such a way that it wont over heat the oil.
Any help would be great thanks in advance

[Russ]

I would recommend a 500w heater.  A friend recently burnt his 500w out and replaced it with a 300w and he is going to remove it and put a 500w back in.  He said it takes a really long time to heat up the block if the garage is cold.  Is there a reason you want to go that small? 

[unabomber]

Less cost for electric provded it does not run all the time. and smaller overall size.  in theory it would need less to heat because copper conducts heat almost 2x better. how is his heater/ bloc set up ? is it made of aluminum ?
 once up and warm i would not shut it off unless necessany.... Thanx

[Dead Eye]

 I would stay with 500w . Yes copper conducts better but you still need a bit more power considering the high fire rate.
 The air will remove lots of heat as well as the oil getting preheated. You want to get 1.5 gpm fire rate so will you be using a metering pump or a constant level device above centerline (pressure over siphon).

[unabomber]

500 watts it is then, I will build the block and report my findings. Thank you

[Dead Eye]

Consider this whan designing the block. Air and oil need to be preheated, then after the burn is done the oil needs to drain back from the nozzle or else it will polymerize from the heat inside the nozzle/block.

  In the typical siphon setup the oil is drawn up(a few inches) from the constant level device by the air exiting the nozzle (venturi effect) . When the air is stopped this same few inches pulls the oil from the nozzle as the feed line drains back into the C/L devece.

  Most well tuned setups keep a slight tilt downhill from nozzle to the C/L to assist in this drainage or the nozzle will require more frequent cleaning of the carmelized/polymerized/baked oil.

 If you plan to overfeed the nozzle (anything over 1gpm) this can still be done by using a 3 way solenoid valve and a catch can for the drain back.

Just a few thoughts

D.E.