Gradient ??

[Jswanson]

I currently have a fairly large (for a hobby guy) batch evaporator. When researching continuous flow types of pans I see the term Gradient . What does this refer to? Some tyPe of incline to facilitate flow??

Thanks

Joe

[tcross]

it's the darkness/thickness of the syrup/sap as it flows through a continuous flow pan. if your syrup pan has 3 sections, the first section (where sap enters) will be light, the second will be a little darker and the last (where you are drawing off) will be the darkest. basically the thinner sap is pushing the thicker sap toward the draw off so it gets thicker and thicker as you near the end/draw off!

[Big_Eddy]

See the thread titled Sweetening the Pans (http://mapletrader.com/community/showthread.php?23070-Sweetening-the-Pans-Continuous-Flow) . I took some before and after photos to show the gradient in my small evaporator.

[Urban Sugarmaker]

Here is another photo http://mapletrader.com/maplegallery/sugaring-2015/p2228-img-1647.html

[DrTimPerkins]

When researching continuous flow types of pans I see the term Gradient . What does this refer to? Some tyPe of incline to facilitate flow??

First, the gradient does NOT refer to an incline of the pans. Pans should be level all the way around to ensure that you don't have low spots that can scorch the pans.

The term gradient refers to the progressive change in density from the place where the sap enters the pan (where it is near the density of sap) to the density where the syrup exits the pan (where the syrup is thickest), the drawoff. In a continuous-flow style pan, the gradient is very pronounced and quite noticeable (the photo that Urban Sugarmaker posted is a great example). In pans with just a few dividers, the gradient might not even develop well at all.

The simplest way to think of the gradient concept is to imagine a long (100' maybe) stainless steel gutter with heat along the entire bottom surface. Sap is continuously run into one end of the gutter. As the water evaporates, the density of the solution near where the sap is running in will remain close to that of sap. However at the far end of the gutter away from the sap entry point, the syrup will get thicker and thicker. At some point you can begin to draw off the syrup at that end of the gutter, and if you're very careful, you can do this is a very small continuous stream of liquid. So you have a fair volume of sap flowing into one end, and a small volume of syrup flowing out of the other. Along the path from where the sap flows in to where the syrup runs out the solution will become progressively more dense. Thus there is a gradient in the density of the sugar solution along the pathway from sap entry to syrup exit. Now simply take the long gutter and bend it up so the sap has to go back and forth instead of a straight line and you have a maple evaporator.

[WI Sugarpop]

The term gradient refers to the progressive change in density from the place where the sap enters the pan (where it is near the density of sap) to the density where the syrup exits the pan (where the syrup is thickest), the drawoff. In a continuous-flow style pan, the gradient is very pronounced and quite noticeable (the photo that Urban Sugarmaker posted is a great example). In pans with just a few dividers, the gradient might not even develop well at all.


You would also have a temperature gradient from 212* to 219*, correct?

[DrTimPerkins]

You would also have a temperature gradient from 212* to 219*, correct?

Correct. The temperature gradient results from the density gradient.