Am trying to figure out what sort of size hx I will need for herms system. Ie what length of what diameter copper tube? Ideally want it small enough to fit in a domestic kitchen kettle, save building another vessel, but not sure if its possible.
What size / length of tube are people using??
My Mash tun is a 40 litre Eski, looking to yield 25 to 30 liters wort including sparge water.
Think my basic maths has got me partly there?
max power into the hot water bath / kitchen kettle is 2kW
I want to be able to raise the temperature of the fluid flowing inside the pipe by a maximum of 1C per minute, up to 70 Deg C.
I 'think' it takes 4200 Joules to heat 1litre of water by 1deg C. Am i right? Is this the same from 20 to 21 as 60 to 61Degrees? Is it roughly the same if its wort, SG=1050? Assuming it is, think that means 70W will heat litre 1 degree in 1 minute, which seems pretty impressive for a light bulb? Anyway, if it does that means 2 kW 'should' heat a flow of 29litres by 1degree over 1 minute?? Max published flow rate of march 809c is 15litres per min, but realistically 10, and can throttle down to 5 or less if i need to. So I have more heat than I need if element goes full bore, which is good, as the PID will flick the element on and off, and i can have a constant flow rate.
My copper tube is 14.73mm OD, wall thickness 1.02mm.
Assuming the water bath is near boiling, say 95C, so at worst case temp difference is 25 Deg C, is there a formula that tells me the surface area / length of copper tube i need for 5l/min, 10 l/min and 15l/min flow rates to give 1Deg C per minute rate of temperature change??
Plenty of questions!
What size / length of tube are people using??
My Mash tun is a 40 litre Eski, looking to yield 25 to 30 liters wort including sparge water.
Think my basic maths has got me partly there?
max power into the hot water bath / kitchen kettle is 2kW
I want to be able to raise the temperature of the fluid flowing inside the pipe by a maximum of 1C per minute, up to 70 Deg C.
I 'think' it takes 4200 Joules to heat 1litre of water by 1deg C. Am i right? Is this the same from 20 to 21 as 60 to 61Degrees? Is it roughly the same if its wort, SG=1050? Assuming it is, think that means 70W will heat litre 1 degree in 1 minute, which seems pretty impressive for a light bulb? Anyway, if it does that means 2 kW 'should' heat a flow of 29litres by 1degree over 1 minute?? Max published flow rate of march 809c is 15litres per min, but realistically 10, and can throttle down to 5 or less if i need to. So I have more heat than I need if element goes full bore, which is good, as the PID will flick the element on and off, and i can have a constant flow rate.
My copper tube is 14.73mm OD, wall thickness 1.02mm.
Assuming the water bath is near boiling, say 95C, so at worst case temp difference is 25 Deg C, is there a formula that tells me the surface area / length of copper tube i need for 5l/min, 10 l/min and 15l/min flow rates to give 1Deg C per minute rate of temperature change??
Plenty of questions!