Hot food Case for Meals-on wheels
Hot food Case for Meals-on wheels
(OP)
I am designing a hot box for delivering meals-on-wheels.
I have built an insulated case of stainless steel, that will hold the required number of meals. The prototype is using refrigeration heater cable, on 240v/195W which produces enough heat to keep the case at 70 deg. c. .
My problem is that I need to run this with a small 6v rechargable battery. I can get a 6v battery with 18ah, but I need to find some low resistance cable that will do the job and run on the 6v battery. I may be able to go to a 12 v battery but this increases the size of battery and weight. I need to keep the battery size and weight low.
I have built an insulated case of stainless steel, that will hold the required number of meals. The prototype is using refrigeration heater cable, on 240v/195W which produces enough heat to keep the case at 70 deg. c. .
My problem is that I need to run this with a small 6v rechargable battery. I can get a 6v battery with 18ah, but I need to find some low resistance cable that will do the job and run on the 6v battery. I may be able to go to a 12 v battery but this increases the size of battery and weight. I need to keep the battery size and weight low.





RE: Hot food Case for Meals-on wheels
it for 1/2 hour.
Why not use butane or the cooling system of the car ?
<nbucska@pcperipherals.com>
RE: Hot food Case for Meals-on wheels
RE: Hot food Case for Meals-on wheels
Would'n butane be simpler ?
<nbucska@pcperipherals.com>
RE: Hot food Case for Meals-on wheels
How about using nichrome wire as a heating element and just finding the right length based on wire size and such. I'm planning on using some myself on drains and covers for fish transport tanks to keep them thawed out in the winter.
RE: Hot food Case for Meals-on wheels
1. Take some time to make the best possible insulation. A little effort here will be well rewarded by reduction in heating energy requirement.
2. Consider adding thermal capacity to the inner box (possibly use bricks like in night storage heaters). Then use your present element to pre-heat the box. During delivery runs a thermostatically controlled small wattage element run directly from the car battery will suffice.
RE: Hot food Case for Meals-on wheels
Where can I get nichrome wire and how does it work?
From Davido.
RE: Hot food Case for Meals-on wheels
Nichrome wire is a commonly used resistive heater wire. It acts as a resistor and gives off heat. It is available in many sizes and any length you want. You choose the sizes based upon your available voltage and current and your application. One place you can get it is...
http://www.morelectric.com/nichrome.htm
Cost is about a $1 a foot and I'm sure they will help you choose a size if you can't figure it out from the chart they have.
RE: Hot food Case for Meals-on wheels