incubator/hatcher/brooder project

[large_ghostman]

i have posts allover the place! and i am getting lost so i am sticking all the stuff from now on to do with the incubator and hatcher in here!
ok post has been and i have
BTB08 600S 8 amp x5 triacs, these are for the heater, i went with soldering iron elements in the end because a pack of 5 was cheap and they are fairly low ohms rated at 50W 24V (i think 24V) but they have a thermistor on so for under £8 i thought i would try 3 per incubator to start with. i will get dad to drill out a cpu heat sink a bit bigger than the element then fill any small gaps with heat grease stuff for computers. fan on top and see what happens!
also got 2 MOC something or other with zero cross detect but want to save them if i can as they cost a fair bit.

 

[large_ghostman]

another reason for soldering iron elements is, they can be run from 24V straight from a soldering iron transformer, so in theory if i get a bad power out like today then because they are so small i could double the number and normally just use 1/2 then if i ever needed too i could switch in other half and run from 12V car battery. yes i could use inverter but its the whole mum thing and mains voltage blah blah blah and also at a push if my genie was near max output it also has a 12V output

 

[dr pepper]

Its not difficult to build a 12v to 24v dc to dc converter if you want battery back up.
Sounds like your idea will work.

 

[large_ghostman]

thats good news! it will run 24V AC on mains and 24V DC when the power is out and untill i can get the generator on, shame i cant build the generator bit as we have a old 2 cylinder KABOTA engine here about 13hp. that is really cheap on fuel to run. i ran the new generator today it's petrol and used 6 litres in an hour!!!!

 

[dr pepper]

Remember I said its good to know how to weld, first example.
You could bash an old car alty onto the kubota and you'd have a 12v genny.
Stick the kubota on ebay, they are valueable, I see them in canal boats from time to time, they are known for issues with the injector pump however, probably why theres a demand for second handers.

 

[large_ghostman]

i doubt dad would sell it, its been with us for as long as i cam remember! we have a kubota mini tractor with the same engine (its the tractor i drive to cut the grass) they are ace.

 

[large_ghostman]

i am going to have to go back some steps and redesign alot of this! I am now going to need a super power save mode for everything,
We had yet another power cut the other night at about 1am. luckily my mum was up but it took nearly 40 mins to get my generator hooked up and started, and the main generator was off line as it is having new bits fitted to the engine.
It wasnt too bad for the eggs although i am used to the incubators that dad builds and it came as a shock to see just how quick commercial incubators cool down!
Anyway it has me thinking, that i need to be able to have the incubators,hatchers and in some ways more importantly the brooders able to run in a power save mode and auto switch onto Battery power untill i can get the generator started, i also need a alarm that goes off when there is no power. The other reason for power save mode is capacity, the generator is only rated at 2KW and the commercial incubator runs at around 850W then you have the brooders that use 100W bulbs and so far there are 4 of these, so my idea is to go back and take another look at everything, my biggest challenge is going to be the brooder's, normally what you do is stick 150W infra red bulb over the brooder container and you get nice and toasty chicks! but because you have to be really careful with the number and types and ages of the birds in each box you can soon have alot of brooders running!
so i am now thinking along the lines of a central heat box well insulated not very big and kept a bit hotter than the brooders (say around 130f) and maybe a heat mass (not sure on that), then have square ducting (plastic square drain pipe) from the box into each brooder and have a fan behind a grid slowly pushing warm air into each box. if i use an acrylic top with a small hole in kind of like a plastic plant propagator i can regulate things like humidity a little.
I will also have a temp sensor in each, the main problem is i cant have the fan blowing too hard as they hate drafts. Also it has to be able to be run from a deep cycle battery for at least 2 hours along with everything else.
For heating i am looking at those soldering iron heating elements, i had a pack of five arrive the other day and although i havnt tried them yet i am pretty impressed. they are small and have a thermistor already inside them, each is rated 50W and 24V, they cost just over £1 each so i am thinking if i put 4 in the box and i could in theory run around 5-6 brooders on 2, so in a power cut it switches from 2 running at 24V AC to 4 running at 12VDC.
i can leave the humidity controller off for upto around 18 hours if needed in the incubator but will have to have it on in the hatcher, I am also thinking with the hatcher and incubators i am going to add more of the heater elements to each than i had originally anticipated, several reason's for this, First off when you have to do stuff inside the incubator you open the door and you get a large drop in temperature, so would be good under normal conditions to have extra heat i can switch in to bring up the temperature quicker, then i can switch to just one and maybe another one once every couple of mins just to boost the temp a little (i need to play with the heaters this weekend and get a feel for them). The hard part is i am aware you need a certain amount of watts to heat a certain mass/area, but not all watts are equal!! when dad was messing with building incubators for example, we found that 2 12V 50V halogen bulls eye bulb's didnt heat the incubator as well as a single clear glass bulb! and even better than that were the half silvered 100W spot light bulbs they got really hot!
but i am hoping that these little heaters will top them all if i mount them right .
Also i will need to look at how many fans run in power save mode but more on that next time. Also i am going to have to sync the heaters in power save so not too many are on at the same time because i want a 50% safety margin on the genie which gives me a 1KW max to run everything. I have already designed the project to use a micro for each part of the incubators and in the case of fan's they run 3 micro's, also a central 'command micro that is also a interface so i can get info in and out via rs232 when i need to, for example some settings will be in eeprom so i can update those and also get a temp log out via rs232. So i have already gone down the spi/i2c route for the micro's to talk to each other (i have a basic form of this on the bench now using spi), so i am thinking the heaters will have to fire a set number at a time and wait there turn, but retain the ability to jump the cue by a signal line if there temp is past a set level. ANYWAY more o come later when i have had a chance to rethink! but i need to move fast on this now! we had no power for 18 hours this time

 

[dr pepper]

A larger fan run slower can move as much or more air than a small fan whizzing round, so you might get the flow you need without too much of a draft.
If you put a switch on the door of the incubator if thats practical you could program the controller to boost the heater power for a while to make up for the lost temp.
Heat mass is a good idea, how about a house brick or breeze block, there'd be enough energy stored to keep the little blighters warm for a while without anything electrical which could and does go wrong.

 

[large_ghostman]

THIS IS JASON GM11
I am posting with LG next to me, for reason's i wont go into for now he has to tell me what he want's to put and how he wants it!
Heat mass is sort of not needed, 400+ eggs act like a good heat mass (actually only partially correct GM). The incubator is a old under counter fridge, so it has a switch for the door i can use, great idea!
I am stuck with fan size but that's ok, small pc fans running with variable duty cycle, regulated by temperature, gives me very fine control of temperature in different parts. What i wanted to do was add servo's to the array's as well, but the need to watch power has caned this. At times i wont have many Watts to play with, trying to get the heating elements working but things don't add up . The packet say's 24V 50W
but in the instructions, it mentions the resistance being 16-17 Ohms. I worked that out to 36W not 50W.
HMMmmm unless, the 50W is measured at temperature? so the element starts at 17 Ohms 36W, and as it heats the resistance drops enough to give 50W?
anyway time up got to go back to it

 

[KeepItSimpleStupid]

With many heaters, the cold and hot resistances can really vary by temperature/ Take an incandescent light bulb. The Resistance is about 10-15x lower that the hot resistance when cold.

 

[ghostman11]

So that would explain the discrepancy with Wattage then, at least they have a thermistor (i presume it is) attached, so temp can be monitored on the element (roughly). And not my project, not my problem
And to think, in the beginning all i got was... Dad it isnt rocket science! It's dead easy, I don't see why you make it look so hard
Time is running out LG you need it up and running by the end of next week, or automatic disqualification! BTW take a look at mine, running sweetly away in the outside workshop , Oh and only around 220W all in

 

[Pommie]

I think you (LG) may be worrying too much about heat loss by air escaping. To raise the temperature of 1m³ of air by 1ºC requires about 1250 Joules. So a box 1m*1m*1m is a pretty big volume but will only take 1250/200 = 6 seconds to warm 1 degree, for 20ºC rise it will take 1 minute. Note, this is for dry air and it'll take longer for relatively moist air (about twice as long for 50% RH).

As for a thermal mass, eggs are pretty good as they are mainly water which requires 4J/g to heat/cool or 4,000,000 Joules per m³. A very good heat backup would be a well insulated water container that you keep at the right temperature with pipes running through it to send warm air though the chambers. If the air is simply circulated through the water and brooders then it should be pretty efficient.

It sounds like you're having lots of fun and learning as well and that's what is the most important thing.

Mike.

 

[large_ghostman]

Hi, no it isn't the temperature thing as such, although because the hatcher for example can run up to 85% RH (egg dependent), I have to offset low ambient temperature as well (will be in outside building down to 0C at night, lower in a month or so), but main concern is that I now have to count each and every Watt i use! Wouldn't be so bad if i was building just a box to hatch eggs, but i am trying to beat the master's fertile hatch rate!
So all the nifty idea's i had, too super dooper the contraption, are having to be rethought. One thing i do need, is the ability to switch to limited power, sometimes lasting 12+ hour's.
My real problem was, a night time outage, but i have sorted that i hope. Now it's a case of balancing function against limited power, during our VERY frequent power cut's!

 

[dr pepper]

Makes sense about the heat mass, using a fridge is a good idea they are well insulated.
The problem is storage, you need to store warmth either directly or in the form of power, either requires something large and heavy.

 

[large_ghostman]

i will get pics later! i have cut a hole in the front door, and installed a old double glazed panel in it so you can see everything going on inside the incubator but hardly any heats loss because it is double glazed! i found a old window in the recycle center (dump), so we used the panel out of that

 

[dr pepper]

They say you can loose up to 50% of the heat in a domestic oven if you open the door for a few seconds so that is a good idea.
Also heat rises, afridge normally is cold and if anything you want heat to escape, if you want to look at improving the insulation on said fridge then the top would be a good place to add some insulation.

 

[alec_t]

~3 inch thick expanded polystyrene slabs (from builders merchants) are good for making/lining thermally-insulated boxes.

 

[dr pepper]

If your on a farm eggtrays also work.