A few years ago, on a cold December evening, a massive, vintage steam train rolled into my hometown as part of an American history tour. Steam trains have become so rare that I imagine seeing this locomotive was a once in a lifetime opportunity for Jim and me…
There is not a sugar maker alive who wouldn’t pause to marvel at the amount of steam that can be generated by these trains. And that awe-inspiring heat/steam generates enough energy to power the 200+ ton train up to 126 miles per hour. Unbelievable.
Similar to a steam train, your evaporator’s firebox generates a great deal of power as well! In this article, we’ll discuss four ways you can harness the firebox’s heat to increase efficiency and maximize resources.
1: Capture Heat to Preheat Raw Sap
The most common way maple producers reuse their evaporator’s heat is via a sap preheater. As its name suggests, a preheater warms your raw sap so that it is closer to boiling temperature when it enters your evaporator pan. Hot sap allows you to sustain a healthy boil. In contrast, cold sap will hinder a boil. Tests completed with a Smoky Lake Preheater have shown an increase in the gallons evaporated per hour by up to 15%. That means you could be saving 9 minutes out of every hour, as well as saving that same ratio in fuel.
TIP: When choosing a preheater, the best designs will prevent condensation from dripping back into your evaporator pan. At the same time, hot steam should be able to travel through/around the drip tray and come in contact with the heating tubes. (See the photo example below of a Smoky Lake Preheater with Drip Tray)
2: Capture Heat to Filter Syrup and Prepare for Bottling
After you draw syrup off the evaporator, you will need the syrup to stay hot for filtering and bottling. This is the perfect job for a Water-Jacketed Draw-Off Tank. This tank uses hot water from your hood drain to heat its outer “jacket”. In doing so, the syrup inside the tank is kept at a hot, even temperature until you are ready to either bottle it or put it through a filter press. The beauty of this method is that it employs a FREE resource that would otherwise be sent down the drain. No need for electricity or gas. We are simply converting a byproduct (condensed water) into a heating agent. Another bonus is that the water-jacket ensures that there are no hot spots within the holding tank. Hot spots would promote sugar sand and are common when a pan of syrup is in direct contact with a burner/flame.
3: Capture Heat for Cleaning
Just like the last example, this idea utilizes the condensed steam coming from your hood drain. This concept takes our initial Water Jacketed Draw-Off Tank design one step further by adding a wash basin. Now you can access the hot water that would otherwise be sealed inside of the jacket so you can use it for cleaning your instruments. All the condensation draining into the Water Jacketed Draw-Off Tank is clean, hot, circulating water. It is constantly being renewed as fresh water from the hoods enters the jacket and pre-existing water is pushed out via the overflow drain. Super convenient! Especially if your sugar house does not have plumbing.
4. Capture Heat to Increase Vacuum in Your Steam Hoods
Last year, Smoky Lake introduced the Concentric Exhaust System. The “concentric” portion of this system is configured so that the smoke exhaust pipe travels up through the center of the steam pipe, resulting in both pipes exiting through just one roof penetration. Among the many benefits of this system is the fact that the central hot smoke exhaust pipe boosts the draw within your evaporator’s steam hoods, improving steam evacuation. Now large evaporators which used to require more than one steam pipe can often get away with just one. Another benefit of the Concentric Exhaust System is that since there is only one roof penetration, there is decreased potential for snow jams and roof leaks.
The Possibilities Do Not End There…
There are so many ways to harness the power of heat. We have only scratched the surface. I am itching to share Smoky Lake’s current development projects, but I’ve been sworn to secrecy until next Fall. I will be sure to tell you all about it when the time comes!
How are you utilizing the heat from your evaporator? Do you have ideas for reusing your existing resources and maximizing their potential? We would love to hear from you.
Please send feedback to:
Angela K M Schumacher, firstname.lastname@example.org, or join the conversation in the comments below!