Emulsion is a “fine dispersion of minute droplets of one liquid in another in which it is not soluble or miscible.” So what does that mean in plain English?
Grease globules, which normally float on top of water rather than mixing with it, mingle with the water molecules throughout the liquid. For that to happen, FOG globules have to go through either physical emulsion or chemical emulsion.
Physical emulsion is what happens when you shake a bottle of Italian dressing. The oil is blended with the water and vinegar and other ingredients. But, once the shaking is over, the oil soon separates out from the water, vinegar and spices.
Chemical emulsion is what happens when oil is mixed with water or other liquids through a chemical process. It is, in other words, what happens when you put Dawn (or other detergents) into a sink with greasy or oily water.
So why do we care? Physical emulsion is quickly reversed. Wastewater may have emulsified FOG in it as it leaves a sink and drains into a grease interceptor, if it has just been physically emulsified, that process will soon reverse. In grease interceptors that means the grease particles will float upward and the water will sink downward. That’s how hydromechanical grease interceptors work.
While the type of detergent and the water temperature varies depending on the kind of dishwasher used, soapy water is inevitably going to contain emulsified grease.But chemical emulsion doesn’t reverse as quickly, if at all. And chemical emulsion happens in most commercial kitchens. Dishwashers — whether machines or a kitchen worker standing over the sink — need detergent to clean dishes. (None of us want restaurant dishes that were washed without soap.)
REDUCING EMULSION LOSSES
First, any pots, pans, racks or dishes being washed should be wiped before they’re put into a sink or dishwasher. The wiped off food particles and grease is simply disposed of in a trash can, and as a result there’s less grease that can be emulsified, and less grease that gets into the wastewater system. Wiping dishes before washing them is a commercial kitchen best practice.
But even with well wiped dishes, some grease will still be emulsified by detergents. Although you can’t easily prevent this emulsified grease from escaping into the sewer system, you can reduce the amount of additional emulsification that could happen inside your grease interceptor because detergents are passing through there.
Here’s where grease interceptor design makes a big difference. When soapy water enters a grease trap, detergents in the water can eat away at the floating mat of grease at the top of the interceptor. Grease that was previously trapped emulsifies and flows into the sewer system.
Well-engineered grease interceptors, such as Thermaco’s Trapzillaline, are designed to minimize the effect of this secondary emulsion. First, Trapzilla interceptors have horizontal baffles reduce the amount of soapy water that flows up (instead of falling down) when it enters the trap through the inlet pipe.
In addition, the compact footprint of the Trapzilla means there’s far less surface area on the underside of the floating “grease mat” that’s exposed to water. That reduces the amount of grease that could be emulsified inside the interceptor when soapy water is added.
Q: Why is venting a grease trap so important? A: Water isn’t the only thing flowing into your grease trap. Air gets in, too. As water levels rise inside your grease trap, this air compresses. This isn’t just any air, either. It’s some of the funkiest air you’ll ever smell. Without proper grease trap venting, it will affect you in one of two ways:
Written by Andrew Crook published in FFR For many years I have had issues with the drains at my shop, not regularly, but every so often there will be a blockage. My shop is on a parade of shops which are mostly occupied by food premises. In the past, previous owners of some of the takeaways have been caught pouring used cooking oil down the drain so when we have had a blockage, I always put it down to the other operators as the drains run my way. With the Government’s Environment Bill currently ‘ping ponging’ between the House of Lords and the Commons, and Cop26 taking place as I write this, it’s a good time to explore this issue.
It's Monday and it feels this could be the best week ever. Well-rested from the weekend, time off all the work issues as well as a much-needed break and quality time. Thriving from Monday energy, to-do list are crossed of at super sonic speeds, coffee a pleasure not a necessity and tasks are getting done quicker than expected. Would it not be nice to carry this momentum through the week?