Idea Curing Box

[AmaxB]

Hi guys took LeverHeads advice and read up on this a bit. Below is a sketch design for curing chamber (box) not sure of heat source yet but am sure I will use a Pid control. Note the TCs one is for Pid control the other two are to monitor temps only, can use cheap multi meters for them. One side of the box will come off completely to allow for easy access. Am considering a water tray would love to get any input you guys might have. More than 1 brain is a good thing.......
Should add damper on one end (heat) is air in the one on other end is air out.
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[leverhead]

Yup, you've got the idea of it. For 200 plants, 3 leaf prime, about 18 square feet of hanging area (Two layers of leaf 3' X 3'). Sheet metal or flue pipe for holding heater elements and moving the air outside the box. If you don't have too many leaks in the system (you will need vents that you can control), you won't need a source of moisture until the cure is done, to bring leaves back to order. You will need to measure Relative Humidity during the cure, either a wet bulb thermometer or a humidity sensor.

 

[AmaxB]

Damn Leverhead you got the numbers down... I'll use what you just fed to me as a base for dimensions. I have a cheap pid for temp (temp control only no ramp or stepping) and I got a box put away with ceramic heat emitters in it that range from 350 watts to 650 watts. Might use 2 350 watt emitters but these are 240V so I'll think about them a bit would like to use em cause I have no other use for them.
Thinking about something like this for humidity http://www.ebay.com/itm/Digital-EGG-incubator-THERMOMETER-Hygrometer-Remote-/270728590583

 

[leverhead]

Damn Leverhead you got the numbers down...

I've done it before, the numbers are still subject to tweaking. Think hard about a ramp function! The days will come when you wished you had. Heaters don't care about a lower voltage, if you run them at half the voltage, figure for half the watts. Multiple elements with switches will give you some flexibility, just keep your connections sealable.

 

[Knucklehead]

Damn Leverhead you got the numbers down... I'll use what you just fed to me as a base for dimensions. I have a cheap pid for temp (temp control only no ramp or stepping) and I got a box put away with ceramic heat emitters in it that range from 350 watts to 650 watts. Might use 2 350 watt emitters but these are 240V so I'll think about them a bit would like to use em cause I have no other use for them.
Thinking about something like this for humidity http://www.ebay.com/itm/Digital-EGG-incubator-THERMOMETER-Hygrometer-Remote-/270728590583

Will the 240V emitters be more energy efficient?

 

[AmaxB]

Don't know if they would or not. I do like the thought of the ceramic though because they are thick bout 3/4 of an inch and it takes a few minutes for them to cool would mean less on off cycles. Start up it takes them about 4 minutes to reach temp on a 220V line so I guess it would be 8 minutes or so on a 110V line. Leverhead you R right bot the voltage and watts had not considered that. I don't want to buy any more than I have too and have to Pids on hand the one for temp on off is cheap was like 30 bucks but no other control ( is not in use). The other is a Eurotherm it has a ton of control it's a programmable Pid so if I wanted as an example I could set a ramp at 1C for a period of 30 hours giving a 30C climb at the end of the ramp. The thing will accept up to 5 ramps up or down in a given recipe (profile) and will store 4 profiles. This thing was not cheap bout 500 bucks but did come with free software so above manual programming it can be linked to PC and operated remotely. The PC software has got graph views live and saved nice to see history. I don't use the oven it controls now to much so I guess I'll take the good advice on ramp and use it for my box.

 

[AmaxB]

My idea is becoming a plan - wall construction - heat type and mounting - cure chamber size I think it will weigh maybe 45 pounds see pic below
any ideas to help this along?
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[johnlee1933]

Increasing the thickness of the foam board to say 2" will save you energy dollars down the line. I looks like you are making a substantial tool. Why short yourself at the outset? -·-

 

[leverhead]

I take it from the box size, you're planing on racking one layer of leaves. It's kind of short for the depth either way. Is the top going to come off, or are you going to reach in from the side to place the leaves? You'll want to be able to hang them pretty evenly, open or areas that are too tight aren't a good thing. Having the emitters in with the leaf sounds kind of dangerous! If you loose air flow late in the cure, when the leaves are pretty dry and it gets too hot in a spot that the thermostat can't "see", you could burn up your leaf or more. I'm not a big fan of fiberglass, getting rid of the smell inside the cure chamber might take quite a while. I would think Aluminum flashing, done well, might be cheaper and better.

How many plants or leaves are you looking to do?

Steve

 

[DrBob]

Will the 240V emitters be more energy efficient?

120 volts or 240 volts makes no difference. it is the watts you pay for. volts x amps = watts

 

[AmaxB]

These are all good points you guys are making....the fiberglass resin smell after 100% cure would not be a problem couple heat cycles would fix that. With the Tc for temp control placed top or bottom center risk of fire would be low or maybe at heat source would be better. The emitters would not kick on unless temp fell below lower set point and will shut off at upper set point with or with out fan I have a few pieces of equipment that use this type of control and is pretty safe. The emitters them selves would be the worry All I am showing in the pics are just ideas nothing concrete. But the emitters ya they have to be a minimum 2- 3 inches from any surface that could burn even with low temp of 200F max. I am thinking of a double wall sheet metal in this area allowing air flow between the walls. Keeping them in the box will keep it more efficient.
Been thinking about air flow soft easy flow is better than strong or am I wrong?
Box size been thinking about it too.

 

[AmaxB]

Am thinking 5 feet w x 5 feet h x 3 feet deep for size now.
Yes leverhead it will be front load

 

[Aaron]

120 volts or 240 volts makes no difference. it is the watts you pay for. volts x amps = watts

I admit I had to think on this a bit. If I'm following.. You mean that if it's a 1000w device it doesn't matter if its at 120v or 240v supply because the wattage is still the same? Say if it were something that could be operated at 120v or 240v then the wattage would be higher with 240v than the 120v. I guess it depends on how I look at it, but I tend to over think things sometimes.

 

[DrBob]

I admit I had to think on this a bit. If I'm following.. You mean that if it's a 1000w device it doesn't matter if its at 120v or 240v supply because the wattage is still the same? Say if it were something that could be operated at 120v or 240v then the wattage would be higher with 240v than the 120v. I guess it depends on how I look at it, but I tend to over think things sometimes.

you pay the electric company for the watts you use. In resistance heating devices if you have a 240 volt 1000 watt heating element and fed it 120 volts it would give 500 watts of heat. The amps stay constant. If you took a 1000 watt 120 volt element and gave it 240 volts the output would be 2000 watts of heat. But not for long, the element would probably burn out.
I hope this helps explain things a little better.

 

[leverhead]

Been thinking about air flow soft easy flow is better than strong or am I wrong?
Box size been thinking about it too. Am thinking 5 feet w x 5 feet h x 3 feet deep for size now

With that size of box and for a number, 100 Lbs of green leaf. To get 1/2 cubic foot of air per minute per Lb of leaf, the air would be moving 3 1/2 feet per minute.

 

[johnlee1933]

With that size of box and for a number, 100 Lbs of green leaf. To get 1/2 cubic foot of air per minute per Lb of leaf, the air would be moving 3 1/2 feet per minute.

Just being picky -- Doesn't ½ cu.ft/lb.min. X 100 lb = 50 cu.ft/min? or have I missed something? -·-

 

[Chicken]

i dont have the proper math education to follow any of this,???????

i believe in keeping it simple but effeciant,

wouldnt it be better to just run a radiator type heater, with a on/off thermostat,

and a crock pot for humidity,

thats what my system is based on, and my chamber works perfect.

 

[leverhead]

Just being picky -- Doesn't ½ cu.ft/lb.min. X 100 lb = 50 cu.ft/min? or have I missed something? -·-

It was kind of early for me, the box is 75 cubic feet. The box is 5 foot high, the air needs to move through every minute and a half. 5'/1.5 min = 3.33 Feet per minute. I bumped it up because the leaf has volume that would be subtracted from the box volume.

...Unless I've missed something

 

[Knucklehead]

i dont have the proper math education to follow any of this,???????

i believe in keeping it simple but effeciant,

wouldnt it be better to just run a radiator type heater, with a on/off thermostat,

and a crock pot for humidity,

thats what my system is based on, and my chamber works perfect.

They're working on a flue cure system for home use instead of a kiln.

 

[AmaxB]

Thanks guys for the ideas and pointers...
I think this will work for heat source and build to move air. With the heat shaft surrounded by a heat exchange chamber it should be much safer in ref to fire (thanks leverhead for making me think more about it). Added fans to give more control over air flow and volume, each fan will have it's own on /off plus speed control. Still thinking about wall build material and size but am going to ad more foam (thicker) board.
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