Originally posted by wheels
View Post
Announcement
Collapse
No announcement yet.
How to turn plastic waste into diesel fuel cheaply
Collapse
X
-
-
Originally posted by torak View Post
Leave a comment:
-
Control
I see no one has commented on Sunilkm describing PID control as two state, ie on-off control (see post 3780) This would only happen with a PID controller if the proportional band was very small (gain very high) effectively causing the controller output to go fully on or fully off. Three term control would give a closer control of the measured variable than on-off control, but the heat rate would need to be capable of being controlled.
PID 101 PID stands for Proportional, Integral and Derivative action which are distinct actions depending on the size and polarity of the Deviation (Error) the difference between the Desired Value (Set Point) and the Measured Variable (Process Variable) of the parameter being controlled. There must be a Deviation (Error) before any action can be taken by the controller.
Proportional Action (Gain) changes the output in proportion to the Deviation (Error). If used on its own it will always have a Deviation (Error), which may not matter in some cases if small enough. Integral action is usually added to overcome this.
Integral Action (Reset) continually tries to remove the offset by ramping the controller output up or down until the Deviation (Error) is zero. Ie MV=DV (PV=SP), the integral output will then be zero with the output constant.
Derivative Action (Rate) changes the output depending on the rate of change of the Measured Value. If the MV changes quickly, the output will change by a large amount. Derivative is normally used (with P and I) for temperature control.
The three effects are combined to give PID control and the effect of the P, I and D actions must be set (tuned) to suit the process.
I hope Im not teaching how to suck eggs.
btw Ive never seen any discussion on how closely the Reactor or Reflux temperatures need to be controlled or what the maximum rate of initial temperature increase should be. Any ideas?
Leave a comment:
-
My first try had to stop half way through because of leakage.
this is 100%pp strange why its yellow?
isnt pp black?
Leave a comment:
-
Originally posted by VAST View PostDerek`s problem is that he installed a new diesel burner, now it performs too well compared to the lpg gas burner and his measurements is all out of sync, so the reflux need to be adjusted if he cannot adjust the diesel burner in the correct way.
Waxing was described in detail, why it occurs and what to do to fix it.
I speculate that Dereks' burner is supplying heat well in excess of the requirements of the retort. Without thermocouples monitoring these critical parts we are in the dark. During a recent run, I discovered that to simmer the contents of my retort at 400C, I only required a flame front temperature of 425C. In an ideal situation we would match exactly the flame temp to retort requirement but on at least some of those diesel burners, there is not the adjustability. It occurred to me that apart from fitting a smaller spray nozzle, moving the burner further away from the retort would achieve a similar result. Then I thought, why not have a burner that is moveable while in operation!
I liken the heating of a retort to that of heating a pot of liquid-food on a stovetop. During initial heat up, you could use a high setting, but once the contents begins to boil, a low setting is selected. A retort is no different, only we cannot see into it. Therefore we need to be well informed as to the exact conditions with regard to temperature, level, applied heat, etc, etc.
HTH
Leave a comment:
-
I was caught up for awhile in a new relationship, but now I can focus my attention here again.
My prototype is almost finished, I must just do the insulation, connect my exhaust heat with my reflux chamber and with my first condenser and connect all the pid controllers and the temp probes, then I can start the system for the first time and test. Before I start my first run I will put it under a pressure test to see if the system is leak proof.
I`m going to get all the welding done by professionals as my welding will not be up to standard. Once this is done I will post some pics.
As I go I take pictures to record my progress and for the satisfaction it gives just to see what you accomplish.
The system will deliver between 80 and 86 liters per run, this one will be a batch system.
Leave a comment:
-
Derek`s problem is that he installed a new diesel burner, now it performs too well compared to the lpg gas burner and his measurements is all out of sync, so the reflux need to be adjusted if he cannot adjust the diesel burner in the correct way.
Waxing was described in detail, why it occurs and what to do to fix it.
Leave a comment:
-
Originally posted by rozier56 View PostThe female bottom flange is cut 20mm deep with a 10mm round groove machined through center.
so your rope goes circles allot of times all the way to the center for a tight fit?
Or just 1 circle and compress?
also how do you compress a female 10mm groove with a 10mm protrude male with the 10mm graphite gasket?
What I understood:
Example
I have a 4 inch outer diameter ring flange male female.
female 20mm deep 10mm milled at 3inch going to 1inch then hole.
male on the 3rd inch i protrude 10mm and 2.5inch to 1inch I fill with a graphite rope 10mm (square) until I reach my desired hole of 1inch?
Leave a comment:
-
Originally posted by rozier56 View Posti have a system that seems to produce a lot of wax right up to reflux temp of 330*c.Has anybody else had this happen when using plastic raws?What temp does this wax start at and do i need to run at higher temp?
The very fact that wax is appearing in the condenser/s demonstrates the fact that the reflux isn't working as intended. Raising the reflux C will not help. I suggest to make the retort and reflux vessels more separate. In addition, dedicated thermocouples for the retort and flame temperature seem prudent. Where the flame temperature is applying too much brute force, this could easily upset the balance essential to distilling fuel from a boiling liquid.
HTH
Leave a comment:
-
Originally posted by rozier56 View Postmy answer for the retort opening gasket is to make a male and female steel ring flange.The female bottom flange is cut 20mm deep with a 10mm round groove machined through center.The male top flange is also 20mm thick with a 10mm vertical groove protruding.All grooves are square.There are 8 threaded bolt holders spread around the plates.The female groove is then filled with graphite 10mm rope for machine gaskets available from Bearing Man.The lid is bolted together and never failed.Cost of the system approx 150 dollars.Built four units like this and no failure when constant opening and closing.
Leave a comment:
-
Originally posted by MangiPNG View PostMy problem with the setup you describe is, most of the materials are very difficult to source locally and going to a machinist cost an arm an a leg here. Plus I am trying to build everything from scraps with minimum cost, except for the precision instruments like for controlling temp and pressure etc.. But always keeping the safety aspect 100% in mind.
go through this album, hopefully it will helpLast edited by torak; 10-13-2014, 09:49 AM.
Leave a comment:
-
Originally posted by MangiPNG View PostI think I will get an air compressor as you say. What type of pressure pressure is needed? I don't want to end up sucking all the WMO out of the retort. The main products I am after is Diesel.
One wee tip, reduce the oil level in the compressor pump a little. Not essential, but when you use it as a vacuum pump, it can pick up some of that oil and blow it out the outlet. It shouldn't do any damage, just annoying.
Leave a comment:
-
Originally posted by rozier56 View Postmy answer for the retort opening gasket is to make a male and female steel ring flange.The female bottom flange is cut 20mm deep with a 10mm round groove machined through center.The male top flange is also 20mm thick with a 10mm vertical groove protruding.All grooves are square.There are 8 threaded bolt holders spread around the plates.The female groove is then filled with graphite 10mm rope for machine gaskets available from Bearing Man.The lid is bolted together and never failed.Cost of the system approx 150 dollars.Built four units like this and no failure when constant opening and closing.
Leave a comment:
-
Originally posted by wheels View PostWMO is not quite so much of an issue re having to vacuum out the Air. But if you want to be sure, then a cheap air compressor works the best. Just connect the suck side instead of the pressure side. A Vacuum cleaner would not suck hard enough. I am not sure what part you mean re the Air Conditioner. But the Refrigeration pump can be used, although it would be slow. Once again, you need to connect the suction side. Leave a little oil in it, but not too much or it will blow the oil out everywhere.
Leave a comment:
Leave a comment: