Once your fry battery’s installed, you probably don’t give it much thought, so long as your units deliver the fried goods when you need them without too many hiccups, breakdowns or filtration issues.
But back at the factory where your fryers were made, there’s a lot of attention focused on equipment these. Perhaps more attention than ever, and with good reason. While fryers of the past were busy not being the stars of the kitchen, they were also busy sucking up energy like crazy.
That’s slowly changed. Until The NAFEM Show in 2005, the most exciting development in gas frying had been the qualification of several models under the Energy Star program. Since that show, though, a half-dozen new units have come out that offer you greater efficiency than ever before. And now manufacturers are reaching even further to develop new products, for two key reasons: energy and oil.
A Look Back
For a long time fryers were simply a commodity. Every so often a manufacturer would introduce some new technology—remember the first tube-type fryers?—and leap ahead until others copied it. It wasn’t until PG&E’s Food Service Technology Center in San Ramon, Calif., developed an ASTM test method for fryers that manufacturers really had a way to differentiate their performance. Even then, not many took advantage of the testing until the Environmental Protection Agency set Energy Star criteria for fryers in August 2003.
Fast forward to 2006, a year when operators and manufacturers alike were demanding energy efficiency like never before, and the <I>trans<I> in trans fat became anathema to legislators. Both energy costs and oil issues have sent equipment engineers back to drawing boards to tweak existing technologies and ramp up new ideas in the quest for a better fryer. Several new models are on the market now, and the next 12 to 18 months promise more.
Manufacturers are taking several approaches to the issues you face. One reason, of course, is that frying isn’t as simple as dropping food in a vat of hot oil. Type of fryer, type of oil, volume, the food you’re cooking, how frequently you filter and change your oil, cooking temperatures and procedures all have an effect on the energy efficiency and productivity of your fryers.
A fryer obviously uses oil as the cooking medium instead of steam, water, air or infrared radiation, and food products absorb some oil during the cooking process. The faster food cooks, the less oil it will absorb. And the cleaner the oil is, the longer it will last and the less likely food will absorb an off taste or odor. That means you want a fryer to stay at as constant a temperature as possible.
The more efficient the fryer, in other words, the faster product will cook, the less oil will be lost to the food, and the cleaner the oil is likely to remain between filtering cycles.
In general, manufacturers are zeroing in on one or a combination of these three areas to improve fryer performance: energy efficiency, oil consumption and equipment controls. R&D is making a contribution to each.
Burn, Baby, Burn
To drive efficiency, equipment engineers have focused largely on burners, heat exchangers, pot design and, to a lesser degree, insulation.
Some time ago, engineers came up with a couple of advances in burner technology. One was the infrared burner, which transfers heat to the pot through ceramic, and now metal, plates that radiate heat more evenly than an open flame. The shift for some manufacturers resulted in perhaps a 5% gain in efficiency.
Another advance was the so-called “turbo” or fan-assisted burners that pre-mix air and gas before forcing them into the burner. The air-gas mixture burns more efficiently, and in addition to the heat transfer from the burner, the superheated air is circulated through the combustion chamber before exiting up the flue.
Frymaster, for example, has done ongoing tweaking of this technology to attain ever higher efficiency gains. The H55 open-pot fryer the company introduced in late 2005 offers a 55% efficiency rate, according to FSTC test data.
Aga’s Infinity fryers also use this type of fan-assisted burner technology. In addition to the burners and heat exchanger under the flat-bottom pot, the fryer is designed with a flue wrapped around the sides of the pot, which transfers even more of the heat into the oil. Infinity’s fryer operates at about 57% efficiency, says the FSTC.
Meanwhile, Pitco Frialator is eking out efficiency gains from an “old-fashioned” atmospheric burner. The advantage, the company says, is fewer moving parts (no blower) and a simpler, more reliable system. There are several keys to the 55% efficiency rating on the company’s Solstice Supreme Series. First, the burners are baffled and closely coupled to the heat exchanger to let in lots of pre-heated primary air but restrict secondary air. The unit, in fact, has a draft protection device that shuts the fryer down if the sensor detects an imbalance in makeup air under the hood, for example.
The fryer’s “matchless” ignition uses an electronic spark to light a pilot when the unit is first turned on, so no further spark is needed to fire the burners when the fryer’s heating or recovering. And finally, the burners clean themselves. With the push of a button at the start of the day, a valve releases gas across the mesh surface of the burner instead of through the Venturi valve and fires it, burning off any debris or carbon buildup from the previous day.
Future efficiency gains may come from an existing technology that until recently was considered too expensive. Pulse combustion burners, developed and patented by the Gas Research Institute (now the Gas Technology Institute), burn gas in spurts instead of a continuous flow, as the name suggests. With gas prices rising, advances could bring the cost of pulse combustion burners down to the point of offering attractive energy savings.
Heat Transfer Improves
Another area where manufacturers have made efficiency strides is in transferring heat from the burners to the pot and into the oil. In many cases, ceramic heat exchangers, which are costly and fragile, have given way to metal mesh exchangers. Not only do these do as good a job or better of transferring heat, the new high-temperature metal alloys are extending the life and reliability of the exchangers and the fryers themselves.
Alto-Shaam, for example, says the design of the rectangular, baffled heat exchanger in its new ASF-75G fryer is one of the reasons the unit blew the doors off the previous efficiency champ in ASTM testing. The Alto-Shaam unit is 71%, according to the folks at the FSTC, compared to the previous record holder’s 64%.
The key, of course, lies in increasing the surface area of the heat exchanger. Alto-Shaam says the design of its exchanger nearly doubles the surface area compared to older designs. In addition, the company designed nipples into the bottom of the fry pot, again to increase the amount of metal transferring heat into the oil.
Pot design is another way engineers are squeezing out more efficiency. The three primary types of pots—open, tube-type and flat bottom—all have advantages, depending on your application. Open-pot fryer design has been tweaked more than the others as engineers play with the depth of the cold zone where sediment can settle. If the cold zone allows oil to cool too much as it circulates in the pot, the unit takes longer to recover. Too warm, and sediment will carbonize.
Now, when you consider flat-bottom fryers, you should remember that this design offers no cold zone, and thus nowhere for debris to settle except on the hot bottom of the pot, where it can carbonize, or on the food being cooked. This makes flat-bottom units less advantageous for foods with a lot of breading.
But the big advantage of this type of design is that it uses far less oil to cook the same volume of food. Sometimes called “low-volume oil” or LOV fryers, flat-bottom units like the Anetsberger FB and the Infinity can use about a third less oil in the pot. And makers say they’re easier to clean than open-pot or tube-type fryers.
Taking A Look At Oil
Many of you know that oil costs, already a concern for anyone who does a lot of frying, may go up 20% or more in the next year. The trans fat issue, bubbling at the edges of consumer and legislator consciousness for more than a decade, has finally come to a head with the New York City ban. A lot of you saw it coming and have been experimenting with alternatives for years.
Unfortunately, the new trans-fat-free oils are more expensive and in short supply. Plus, one of the reasons edible oils were hydrogenated in the first place was to extend their shelf life. Hydrogenation makes oil less susceptible to heat degradation and oxidation, oil’s two biggest enemies. And for this reason, you’re likely to see more suppliers introduce more low-consumption LOV machines in the future.
Extending oil life is another area of focus for many fryer makers. Filtration is where most of the technological changes have taken place. Today you can find numerous fryer models that include built-in filtration systems. In some cases it’s as easy as opening a drain cock and pushing a button.
Gone, too, in many cases, are the old paper filters and/or powder once required to filter oil. Today’s systems use metal mesh filters, usually in two stages, to screen out debris and crumbs. Filter pumps and seals have been improved, too. Some systems can filter a fryer’s oil in less than three minutes.
Vulcan-Hart in particular will bring an upgraded filtration system to market this year. The company’s Kleen Screen Plus has been redesigned to allow you to filter via mesh screen or a non-paper fabric envelope. Vulcan says the envelope is FDA approved and tear proof, meaning it can withstand most scraping implements without being damaged. The company also reports that envelope testing by the University of Georgia showed no microbiological growth with continued use of up to three weeks.
Continuous filtration systems, first developed in the 1980s but abandoned due to pump and seal issues, now are getting a second look. Improved technology could make cost-effective systems available within the next few years. The advantage, in addition to keeping oil clean and free of debris that can carbonize and degrade it, may be another small bump in efficiency.
You’re In Control
The third approach manufacturers are taking to fryer improvements is in the controls themselves. Fry station management is critical to maintaining oil life and getting the most productivity out of your fryer. Training employees on the right procedures—proper breading, loading, skimming, cleaning, and filtering—is just one step.
While you still have to make sure employees don’t make mistakes like shaking salt on food over a fryer, manufacturers are finding ways to take as many decisions out of the hands of employees as possible.
Electronic controls have helped make fryers more efficient by automating cook times and tightening temperature ranges in which they operate. Programmable features let you predetermine cooking temperature, cook time, hold time and basket lifts, eliminating guesswork and improving consistency.
Solid-state thermostats can help you adjust cook times based on both initial product temperature and efficiency of the fryer itself. In many cases, they’re also more sensitive, enabling fryers to recover faster and maintain temperature more easily. Smaller fluctuations in temperature also mean greater efficiency, higher productivity and more savings in energy and oil.
In addition to pre-heat and melt cycles, many models now have an automatic energy saving mode that puts the fryer into idle after a certain period of inactivity. This lowers the fryer temperature to around 250º F instead of 350º to 400º F, saving energy and extending oil life.
The latest advance in controls is making them compliant with the NAFEM Data Protocol. Anetsberger, for example, was the first fryer maker to complete the NDP certification process. More than half a dozen of the company’s fryer models now have NDP data connections, which allow them to communicate with a PC. This means you can program fryers from a centrally located computer to adjust for new menu items in your stores. You also can monitor the performance of all your fryers, including data such as Btu usage, temperature and cook cycles, so you can make adjustments to get greater efficiency or simply single out underperforming fryers for maintenance or service calls.
A Hot Future
Energy Star’s commercial fryer criteria caused a lot of the recent development in the fryer market. And now that a number of fryer makers have tweaked their equipment to qualify for the Energy Star label, count on another flurry of development as manufacturers try to leapfrog the pack and differentiate themselves even further.
Activity we know of right now includes Anetsberger launching a second generation of its NDP-enabled fryers in December, units with new features like a shortening lock-out that shuts off the fryer if the oil needs filtering. The new fryers also are RoHS compliant for use in the European Union, and soon in Japan and China, when their regs take effect.
Building on the high-efficiency Solstice Supreme platform, Pitco says it will have yet another new fryer improvement at the National Restaurant Association Show this May.
And Frymaster says before the year’s out it will be known for new filtration improvements.
If the past year is any indication, you’ll continue to see exciting innovations in gas fryers in the near future. But if you’re in the market now, you don’t have to wait around. Today’s high-efficiency gas fryers are better than anything you’ve seen yet. Turn to the next page for a run-down on recently introduced high-production and high-efficiency models.
And if you’re looking for a comprehensive list of all makers of gas frying equipment, visit the Buyers Guide at our Web site, www.fermag.com.