Adding new ports to my reactor whilst its down - how many and where?

[julianf]

Im going to move my reactor soonish, and convert it to being heated by a water coil.

Its one of those 400ltr why-waste units, with a large port at the bottom of the cone.

So far, all ive gotten arround to doing is making up a plate for the port, with 2off 1" and 1off 3/4" ports.  The two 1" will go to two 110lpm pumps, and the 3/4 is the lowest point, for draining off the dregs.

Three 10mm coils will run through these (i might not on the 3/4 as it may be too tight - might have to heat it some other way).

But anyway -

My units thermocouple is currently on the pipework (as the heater is inline) but, with the water heating, i wont have the pump running, so im going to drill some holes in the side of the reactor, to weld in, either sockets, or barrel nipples, to put in a thermocouple.


Im going to use 1" fittings, and then adapt for a standard pocket, but, whilst im at it...


What else should i weld in, do you reckon?  And is there really much point in having another thermocouple in the head space?

[julianf]

...and

Would you weld on barrel nipples (so a male thread sticking out of the reactor) or sockets?

Im thinking that nipples leave me less danger of thread damage when welding, but the female thread on sockets seem more convenient.

[greasemonkey]

I don't know so much about the ports, but my reactor (now in bits for moving) is heated by a radiator. I found that the oil heated much, much quicker with the oil circulating, than it did without.
The head space gets really hot. It was like the oil dropping through the hot air picked up the heat much quicker than it did when it was stagnant. Something you may want to consider.

[julianf]

What im trying to achieve is a unit where i can load it, and let it sit (hot).

The massive disadvantage of inline heaters is that you have to have the pump running.  If youve got one of those batches that wants desperately to go solid before the glycerol has a chance to fall out, the inline heaters a horrible.

What i actually plan on doing is having the 1" pipes from the bottom of the reactor running as such -


base of reactor
1" pipe
1" cross (in, out, 10mm coil in, valve to drain)
valve
1" cross (in, out, sight tube, valve to drain)
pump


So, in that, a small part of the pumped system will have a 10mm pipe inside of a 1" section.    I want to be able to drain the pump pipework as best as i can, and keep all of the system hot (that has fluid in it) without any movement.


At present, i have a 22mm stub at the base of the reactor to drain the glycerol from.  Even in this, the glycerol sets, and i end up having to 'rod' it with a bit of hosepipe.  Im sick of all those inconveniences!


As the third port on the base plate is only 3/4" i dont think this is really large enough to run a coil through, so i will probaly just adapt to 22mm, and then think as to if 28mm will be large enough to make a small water jacket around it.

My reactor is in an unheated, draughty building, which is probably part of the issue.

[greasemonkey]

Hmmm, I can see where your coming from. You've got me thinking now. Being as I'm on a big rebuild, I ought to be considering the same thing.

[julesandtash]

Now I wonder where you got the idea of a hot water heated coil in the reactor from 

Mine gets to 80C if I leave it for a couple of days even with no circulation. I suspect the convection currents move it arounda  fair bit. Like you are planning, the bottom of the coil enters inside the 1" pipework, somewhat like internal trace heating.
I pump in the water hot at the bottom and it comes out cooler at the top.

I use female sockets on everything i build rather than nipples. I presume you are going to use stainess ones and TIG them into the stainless processor.
When I did mine, I didn't have access to a TIG welder so use stainless wire and pure Argon in my MIG. That seemed to work ok.

A thermocouple pocket is only needed in the headspace if you plan to recover methanol. Otherwise I wouldn't bother. I just have one about 4" above where the domed bottom joins the vertical sides. That is about the 100litre mark. It seems to give a representative reading from there.

[julianf]

Yep, ill TIG weld them in.

I was going to use one of those long thermocouples that you put me on to, but ive got a few standard 1/2" pockets arround, that i must have taken off scrap copper cylinders, so i think i will just use some of the 'free with PID units' thermocouples, and stick them down the tubes.

Its not as if i need rapid response, so im sure that will do, more or less.

For the sake of a few fittings, and a bit of time, im tempted just to put in two or three, in case there's anything i think of in the future.  More points to leak from, but i never have much of an issue with threaded fittings leaking.