Author Topic: A filtering method is developing (Read 16695 times)

Julian · « **Reply #15 on:** November 26, 2015, 08:47:00 PM »

Quote from: alexanderfoti on November 26, 2015, 06:05:02 PM

Yes indeed. It's touching the bottom (via a big rubber buffer). My thermometer still shows 11 degrees. My calculations show 2 hours max to heat that amount to 40 degrees. Hmm not sure what's happening there.

Hmm, silly question in retrospect, sorry!

Heat losses in current temperatures must be massive.

alexanderfoti · « **Reply #16 on:** November 26, 2015, 08:50:37 PM »

It's okay

I thought so as well, I have also insulated the barrel, doesn't seem to make much difference.

Julian · « **Reply #17 on:** November 26, 2015, 08:52:48 PM »

You're going to have to move it inside!

alexanderfoti · « **Reply #18 on:** November 26, 2015, 09:01:46 PM »

No chance. Petrol dewatering it is!

dgs · « **Reply #19 on:** November 26, 2015, 11:22:05 PM »

Heating around 200litres of oil with the M67 (approx 10 KW's ) to over 50 degs takes roughly twice as long in winter than in summer.

knighty · « **Reply #20 on:** November 26, 2015, 11:57:22 PM »

very very rough numbers, it takes 1.2 watt hours to heat 1 litre of water 1'C

so you have 200 litres, that means you need 240 watt hours per 1'C rise in temp

your heater is 300 watts not 240, so with no losses, heating 200 litres, it should heat it by 1.25'C per hour

ok.. that's no heat loss and heating water, but you get the idea, it'll take a long time to warm up, and cost about 4p/hour to run :-)

EDIT: someone check these numbers for me? they look right, but feel wrong

alexanderfoti · « **Reply #21 on:** November 29, 2015, 01:13:15 PM »

1st issue with the numbers, it has 80liters of WVO in it, rather than 200

I calculated a while back, to reach 40 degress, with an ambient temperature of 10 degrees, should take a little over 3 hours with a 300 watt heater. Apparently not....

Julian · « **Reply #22 on:** November 29, 2015, 03:03:07 PM »

Alex, just a thought ... if it's an aquarium heater, does it have an in built thermostat? Fish wouldn't be too happy swimming around in 45°C water!

Have a look at KHs "Tosser tube" ... http://www.biopowered.co.uk/wiki/Melting_stick ... it uses a grown-up version of the heater used in most 3D pronters!

I have one here if you want to borrow it (cant remember the wattage, but it's not massive). There's no thermostat on it, it's just a heater, so will want watching.

Let me know.

Glycer-rides · « **Reply #23 on:** November 29, 2015, 07:23:31 PM »

The specific heat capacity of water is roughly double that of oil, meaning oil heats in half the time as water, heat losses disregarded.

alexanderfoti · « **Reply #24 on:** December 02, 2015, 09:03:17 AM »

Quote from: Julian on November 29, 2015, 03:03:07 PM

Alex, just a thought ... if it's an aquarium heater, does it have an in built thermostat? Fish wouldn't be too happy swimming around in 45°C water!

Have a look at KHs "Tosser tube" ... http://www.biopowered.co.uk/wiki/Melting_stick ... it uses a grown-up version of the heater used in most 3D pronters!

I have one here if you want to borrow it (cant remember the wattage, but it's not massive). There's no thermostat on it, it's just a heater, so will want watching.

Let me know.

I have modified the stat so that it operates at a higher temperature, but I think whats happening is that the oil is heating locally around the element and then switching off. If there was a pump to circulate the oil it would probably work a tad better,

I may borrow it, the only issue is that container is not the thickest plastic, so not hugely happy heating the oil up to high temperatures.

Julian · « **Reply #25 on:** December 02, 2015, 11:32:34 AM »

A pump might help, but I'd have thought thermal convection should come into play even with a low powered heater.

Try the tosser tube. I should be in tomorrow afternoon (give me a ring on the home phone to check before you leave). It'll be a higher wattage, but thermal convection is quite evident when you use it ... bubbles and steam rise to the surface! I can also show you the effect of a 3KW immersion heater on wet oil.

alexanderfoti · « **Reply #26 on:** December 02, 2015, 11:43:34 AM »

I thought so as well, there is a warm layer of oil at the top when using the aquarium heater, but the rest is very cold.

Excellent, I will do, I Should be about.

alexanderfoti · « **Reply #27 on:** December 04, 2015, 11:48:49 AM »

Have added 5L of petrol (approx 5%).

I'm finding that the petrol is staying on the top end of the barrel.

I have taken to draining 15 liters, and putting back through the top to attempt to get them to mix. Will let it sit for 24 hours and see what I get on the bottom.

Going forward, I think I will mix the petrol in the cubies before adding it to the barrel.

greasemonkey · « **Reply #28 on:** December 04, 2015, 01:08:18 PM »

It doesn't make an awful lot of difference if you mix the petrol in, or just tip it on top. You'll pretty much have the same effect after 48 hours.

Take two samples in a jam jar, mix one, and tip the other on top. You'll see what I mean.

It's worth doing this anyway, it's quite fascinating, and gives a good insight into how it works.

I mix 10% petrol, myself.

alexanderfoti · « **Reply #29 on:** December 04, 2015, 01:09:42 PM »

I thought so, but I definitely have a thinner oil at the top than at the bottom, I have also not had any water come out of my wvo, which I was surprised at.

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A filtering method is developing