1500W Hotplate; Controller needed?
Posted: Fri Dec 24, 2010 10:40 am
I have been running a 1.2m long 1.5” column diameter reflux still based on Rad’s design with a twenty dollar Betty Crocker 1000W hotplate.
Boiling is anything but vigorous and it takes a ten to twelve quart wash almost an hour to boil with stripping runs of about 3 hours and 6 for spirit runs. Obviously with a hotplate of this power a controller isn’t necessary since I run it flat out all the time.
Hoping to shorten my times a bit I have been doing some reading on the parent site and came up with this:
“Maximum Power for a Given Column Diameter
1.00" = 800 W
1.25" = 1250 W
1.50" = 1800 W
1.75" = 2450 W
2.00" = 3200 W
2.25" = 4050 W
2.50" = 5000 W
Diameter : 1 inch is too narrow for a 1380W element, but 1.5 inch is OK with a 1800W element. Roughly, lets say to use 1.5 inch for 1000W - 1500W and 1.75 - 2 inch for 1500W - 2000W. If in doubt, go up in size by say 0.25 inch. Too narrow will lead to all manner of problems & difficult operation, but too wide will only give a minimal reduction in purity. 2" is a well used, very reliable diameter that works under...
So, in summary, to make a very cheap, short still, how about a 1500W element, with a 1.5 inch by 60-70cm column, scrubber packing, and simple external condensor (Euro style) & internal cooling coil of say 4-5 turns, directly plumbed between the two.most circumstances.”
I purchased a pretty good quality 1500W hotplate online but since it did cycle at full power dramatically cutting down on heating I bypassed the controller.
According to the parent site I should be ok with 1500W but I do have some concerns. Although my column is 1.5” the throat section is only .75” not the 1.00” recommended; I had some .75” just lying around so I took the cheaper route unfortunately.
Even if the still can take 1500W on continuously with full reflux to stabilize the column I am reading a lot in the forums about taking spirit runs nice and slow. I read that too much heat can cause the tails to be pushed into the hearts and I was wondering if anyone thinks this would be a concern?
I have read a lot of cases where people are recommending using a controller with a 1500W but these seem to be internal elements not a hotplate which I understand is about 50% less efficient so I am hoping I can get away without a controller.
I have some washes clearing so in a few days I should see if the unit can take the heat but I am curious if most feel I should have a controller anyway for slower spirit runs?
Boiling is anything but vigorous and it takes a ten to twelve quart wash almost an hour to boil with stripping runs of about 3 hours and 6 for spirit runs. Obviously with a hotplate of this power a controller isn’t necessary since I run it flat out all the time.
Hoping to shorten my times a bit I have been doing some reading on the parent site and came up with this:
“Maximum Power for a Given Column Diameter
1.00" = 800 W
1.25" = 1250 W
1.50" = 1800 W
1.75" = 2450 W
2.00" = 3200 W
2.25" = 4050 W
2.50" = 5000 W
Diameter : 1 inch is too narrow for a 1380W element, but 1.5 inch is OK with a 1800W element. Roughly, lets say to use 1.5 inch for 1000W - 1500W and 1.75 - 2 inch for 1500W - 2000W. If in doubt, go up in size by say 0.25 inch. Too narrow will lead to all manner of problems & difficult operation, but too wide will only give a minimal reduction in purity. 2" is a well used, very reliable diameter that works under...
So, in summary, to make a very cheap, short still, how about a 1500W element, with a 1.5 inch by 60-70cm column, scrubber packing, and simple external condensor (Euro style) & internal cooling coil of say 4-5 turns, directly plumbed between the two.most circumstances.”
I purchased a pretty good quality 1500W hotplate online but since it did cycle at full power dramatically cutting down on heating I bypassed the controller.
According to the parent site I should be ok with 1500W but I do have some concerns. Although my column is 1.5” the throat section is only .75” not the 1.00” recommended; I had some .75” just lying around so I took the cheaper route unfortunately.
Even if the still can take 1500W on continuously with full reflux to stabilize the column I am reading a lot in the forums about taking spirit runs nice and slow. I read that too much heat can cause the tails to be pushed into the hearts and I was wondering if anyone thinks this would be a concern?
I have read a lot of cases where people are recommending using a controller with a 1500W but these seem to be internal elements not a hotplate which I understand is about 50% less efficient so I am hoping I can get away without a controller.
I have some washes clearing so in a few days I should see if the unit can take the heat but I am curious if most feel I should have a controller anyway for slower spirit runs?