How to turn plastic waste into diesel fuel cheaply

[Excalibur]

At least 2 hours

[Col]

Sight Glass / Discs

Hi everyone
I bought some borosilicate sight discs (111mm diameter x 15mm thick) and sandwiched them between standard 3" flanges using NAF (non-asbestos fibre) gaskets. Carefully torqued it up and thought it was job done. The next day one of the discs shattered. I replaced it, this time not as tight. I left the project for a couple of months and came back to it yesterday. Left it in the sun for a couple of days and the other sight disc shattered. Lucky I bought 4 sight discs!
There is not much compression or give in a NAF gasket. I suppose I had the bolts done so tight it was just below the shattering point of the glass, then on a hot day the sun heated up the flanges and the extra expansion added too much pressure on the glass.
Excalibur - what has been your experience with the O-rings in your sight glass set up? Which material worked best - Silicon, Viton or Nitrile? How thick are the O-rings?
Does anyone else have experience or thoughts on this?
Much appreciated.
Col

[Excalibur]

Could it be the glass is not borosilicate but toughened or tempered glass? Has the glass crumbled into small granular chunks? Tempered glass is specifically made to break in the manner it does for safety reasons. Hence the name "safety glass".
Both silicon and viton seals have worked though I haven't measured the temperature they're subjected to. Probably 150°C at the most, only a guess though. They're 3.5mm thick

[sunilkm153]

Hi everyone
I bought some borosilicate sight discs (111mm diameter x 15mm thick) and sandwiched them between standard 3" flanges using NAF (non-asbestos fibre) gaskets. Carefully torqued it up and thought it was job done. The next day one of the discs shattered. I replaced it, this time not as tight. I left the project for a couple of months and came back to it yesterday. Left it in the sun for a couple of days and the other sight disc shattered. Lucky I bought 4 sight discs!
There is not much compression or give in a NAF gasket. I suppose I had the bolts done so tight it was just below the shattering point of the glass, then on a hot day the sun heated up the flanges and the extra expansion added too much pressure on the glass.
Excalibur - what has been your experience with the O-rings in your sight glass set up? Which material worked best - Silicon, Viton or Nitrile? How thick are the O-rings?
Does anyone else have experience or thoughts on this?
Much appreciated.
Col

borosilicate never shatter in sunlight Excalibur sighted right that it simply may be toughened glass regarding seals Compressed Asbestos Fiber (CAF) Jointing Sheets are best where temperature is less then 200 - 250 degrees . BE CAUTIOUS IF IT IS NOT BOROSILICATE YOU MAY BE AT RISK

[Col]

Sight Glass / Discs

Thanks guys
Spoke with the manufacturer of the sight discs. He insists the discs are made of Schott Borofloat 33 which he says is a German product within the Borosilicate family. He says the English call it Pyrex. There are a number of names for it but it is definitely borosilicate. He was very surprised they were breaking, suggested a couple of things to look at such as flatness/smoothness of flanges, method of tightening, machine a step into flanges for placement of discs, agreed the O-rings would be a good and more acceptable method than the low-compression NAF gaskets.
Here are a couple of photos.
I'll go get a step and O-ring groove machined into the flanges and see how I go after that.
Col

[Excalibur]

The way it's broken suggests it's not toughened glass.

For Viton or silicone rubber o-rings I suggest a crush of the rubber to about 70% of the original thickness, so if a seal was 3.5mm, crush to say 2.5mm. I have o-rings on both sides of the glass. One chipped once because the steel housing came into contact with glass edge. As an afterthought I fit a rubber band around the glass perimeter to isolate it from direct steel contact on the periphery. I made it from old motorcycle inner tube though it needs replacing once in a while.
Later I thought the ideal seal would be a "right angle corner section" so it fits on the face and the rim perimeter of the glass at the same time.

Those are serious bolts! How about a spring under each nut so the rubber seal squish can only be as tight as the spring tension. The fact is we're not running our machines at any real pressure to speak of.

[rozier56]

Hi Excalibur, When you start up your system, whilst climbing to your required temp i.e 330*c in your reflux, you must produce some water and paraffin products. What are you doing with this and how do you discharge them?
Also notice your temp probe for the retort is placed on the retort top!
Is this a long probe that measure the liquid phase? Other wise it must be similar to the reflux temps!

[wheels]

Thanks guys
Spoke with the manufacturer of the sight discs. He insists the discs are made of Schott Borofloat 33 which he says is a German product within the Borosilicate family. He says the English call it Pyrex. There are a number of names for it but it is definitely borosilicate. He was very surprised they were breaking, suggested a couple of things to look at such as flatness/smoothness of flanges, method of tightening, machine a step into flanges for placement of discs, agreed the O-rings would be a good and more acceptable method than the low-compression NAF gaskets.
Here are a couple of photos.
I'll go get a step and O-ring groove machined into the flanges and see how I go after that.
Col

The breakage has been caused by stress due to the plates being too tight and the seals having not enough thickness to allow for the movement. Fibre seals like you are using are not right for this situation.
Excalibur has good advice re springs on the bolts and the use of an O-ring as the seal.

[Beyond Biodiesel]

Yes, I agree, the bolts and flanges are massive compared to the brittleness of Pyrex. The suggestion of an o-ring on both sides of the glass is good, verses a thin fiber seal.

You would want to have about .5cm of thickness of the seal on both sides to afford some flexibility.

Also, you will not need more than a slight compression of the o-ring. The problem was most probably differential thermal expansion in the sun. So, a thick seal will allow some flexibility in the seal if it is not fully compressed.

[Col]

machined flanges for sight discs

Yes, the bolts are overkill, but that is what suits the flanges available off the shelf at the fittings store. I know we're not expecting any pressure in our systems but so much talk earlier of retort flanges not sealing led me to think better over kill than under done.
I've attached a picture of the flanges now machined to have a step to retain the sight glass and a recess to locate the O-ring. All four flanges have been machined so there is an O-ring on each face of the glass.
Planning on pressure testing the system this week.
For low pressure relief I have a bath plug sitting in a hole in the final bubbler lid. For high pressure relief I intend to use a boiler relief valve at the retort. But I expect if I wind it back off it won't seal very well. Will see.
Regards
Col

[Excalibur]

Yep. Good work.

Because the glass needs to be removed from time to time for cleaning, one other thing I did was to fit short lengths of hose over the bolt shanks adjacent to the glass. This helped centralize the window and made nipping the bolts up easier. Just a thought that might help..

Recently I fitted a LED light to outside of one sight glass. The effect was great, especially after dark. I'm a great believer in observing the quality and quantity of the condensate stream as a live indicator of plant health.

[Col]

Ammonia in fuel

Yep, will light it up (heavily diffused if I remember correctly).
I have a lead on some oil I can get (will find out more info tomorrow). It has ammonia in it. Sometimes enough to hit you in the face when you take the lid off, sometimes not so strong. Are there any issues with ammonia in fuel? Any issues with ammonia at high temperatures in a retort? Maybe I should just blend it?
Col

[Excalibur]

Sounds like refrigerant waste oil. I've had ammonia in oils in the past. I'd try venting it off before doing anything else. It has a boiling point of -33.34 °C so should lift off at ambient temperature.
Another thought is I've had situations where the same oil was holding water in suspension. I thought the oil may be engineered with water absorbing additive. Not sure. If it's the case it wouldn't suitable for constant feeding a retort until the water was removed.

[wheels]

Yep, will light it up (heavily diffused if I remember correctly).
I have a lead on some oil I can get (will find out more info tomorrow). It has ammonia in it. Sometimes enough to hit you in the face when you take the lid off, sometimes not so strong. Are there any issues with ammonia in fuel? Any issues with ammonia at high temperatures in a retort? Maybe I should just blend it?
Col

BE CAREFUL!!!!
Ammonia is an interesting compound. The number of other Chemicals it will react with is vast. Because Waste Oils can contain all sorts of things, you never really no what possible reactions and by products could be produced. Leaving aside the fact that Ammonia itself is deadly, many of the resulting Chemicals that can be created can range from Nitric Acid through to many other toxic gasses.
Interestingly Ammonia is used in the Oil refining industry. But that doesn't make it useful for us as it is used in a very specific and controlled way that we can not duplicate.
It's toxicity to us is interesting. Our body actually produces ammonia, so it is not specifically poisonous to us. However, it is still highly Toxic to us. It quickly accumulates in our Blood and only a very very tiny amount can cause us to lose consciousness, enter into a Comma and even death.

[kedigen]

hi everyone

with the chemical mixture, is there a formula similar to diesel fuel?