Plantoil/diesel conversion basics
Sign up Latest Topics Chat
 
 
 


Reply
  Author   Comment  
jermedic

Registered:
Posts: 8
Reply with quote  #1 
I unfortunately do not have access to a garage and I did not want to run fifty feet of hose from my basement to my vehicle, therefore I decided to station my pre-filter and dewatering unit with thermostat outdoors.

Does anyone else have an outdoors setup? Any tips for keeping rain out of my filter socks? Right now I am using a large trash bag to cover all of the holes in the top of my drum; it is suspended by my pump and filler neck. I have the advantage that the drum is plastic and is raised toward the center, so water at the edges just drains out little drain holes on the side of the drum.

Any advice for how to insulate my 110v ac thermostat (with live wires) from rain? It is mounted on the outside of the drum (it is the two wire variety).

Last question...any idea how to "snug" a threaded fitting that seem less than a millimeter too large?  My hand pump came with a bung fitting that must be within a millimeter of a 2 inch fitting, and it occludes the bung hole but does not seem to want to "dig in" securely to the threads in the bung. I have the same issue with my 2 inch PVC fitting on the other bung for my water heater  
JohnO

Registered:
Posts: 16
Reply with quote  #2 
Some of my setup is outdoors, some is (now) inside the woodshed. I've long-used a square of plywood as a weather cover for the barrels and suchlike outside. I've also wrapped the barrels in reflectex insullation to help stabilize temperatures. A 110 volt band drum heater works quite well to keep things liquid, but generates a lot of thermal currents that will prevent settling.

I've also tried building an insulated box around the settling drum, with a thermostatically controlled heater inside. It still didn't provide reliable settling, and I eventually concluded that my oil was "difficult" and resorted to other, more aggressive methods for dewatering.

I think the theory of a well insulated box to stabilize temperature for settling is sound, but in practice it's not simple. One thing lacking from my attempt was thermal mass. Here's my recommendation:
The box should have thick insulation (2 inch styrofoam, minimum), and be tightly sealed. The barrel should be closely surrounded by mass, such as bricks stacked in close contact with the drum. The insulation is outside of the thermal mass of bricks. The heater, in theory, should NOT be in direct contact with the drum, but rather should heat the thermal mass. If it's in direct contact with the drum, it will generate currents in the oil when it's ON. The thermostat needs a narrow dead band. A PID controller is ideal, but there are some home heating thermostats that are equally precise.

This arrangement closely duplicates the environment inside a home - stable temperature with very little variation.

If your primary goal is to filter and only get out the worst part of the water, then the extreme insulation and added thermal mass aren't necessary.

__________________
JohnO
jermedic

Registered:
Posts: 8
Reply with quote  #3 
JohnO, I appreciate your reply, it seems that you've had a lot of hands-on experience with outdoor applications. I suppose that I should have been more specific with my use of insulation - I intended to ask how I could achieve >electrical< insulation at the point of my thermostat which is mounted on the exterior of the plastic drum, which is outside and exposed to the elements, so as not to cause an electrocution risk.  Basically what I am worried about is precipitation causing an electrical hazard if it is to come into contact with the thermostat terminals.

Any advice for the pipes that are not very snug in the bungs?

I am giving serious consideration to buying a shed.
JohnO

Registered:
Posts: 16
Reply with quote  #4 
Sorry to hear about the poor fit of the pump fitting in the bungs. My limited experience with plastic barrels has been better than yours, unles your problem is the pump. Cheap Chinese pumps frequently have very poor pipe threads, in general. Can you somehow substitute a proper-fitting pipe fitting for the one that doesnt' fit?

Regarding a weather cover for an electrical thermostat with exposed connections - frankly it sounds dangerous in several ways unless the barrel is enclosed somehow. I can imagine a small plastic electrical box fastened to the side of the plastic barrel to provide a weather cover for the thermostat, but the image it brings to mind makes me ask "why"? What sort of heater are you using on a plastic drum that uses a non-weather proof thermostat? I'd like to understand it better, first.

For indoor use I've potted exposed contacts with insulating sealant (urethane or silicon). That prevents accidental contact with live electrical contacts, but doesn't weather-proof the hot water thermostat. For weatherproof thermostats I use emersion probes - the industrial kind that has a long skinny copper tube with a bulb on the end. The bulb is inside the tank, the long skinny copper tubing runs over the top edge of the tank to the thermstat unit, and the thermostat unit either controls a relay in an electrical box, or directly controls the heater without any exposed electrical connections. In that case, the thermstat is only protected from direct weather exposure, not necessarily sealed inside an enclosure.

cheers,
JohnO

__________________
JohnO
Previous Topic | Next Topic
Print
Reply

Quick Navigation:


Create your own forum with Website Toolbox!

This forum is brought to you by A proud sponsor of Invest in the future.