July 2001 [updated March 2003]
By Brian Ward, with reporting by Robin Ashton and Allison Clark
SPECIAL REPORT: Filing The Flight-Type Plan
If youre looking into the semi-custom world of flight-type warewashers, youll have plenty of spec choices to sort through. Check out five major makers here, and how to plot your course.
Call em the aircraft carriers of the dishroom. The big uns. Flight-type warewashers, also known as rackless conveyors, are the highest-output workhorses in the scullery, inhaling water and utilities and exhaling humidity. Mostly youll find them in universities, prisons, schools, hospitals, cafeterias, hotels and so on. If youre shopping for one, even one of the more moderate ones, its because youre moving a heck of a lot of ware.
Just how much is a lot? These rackless machines start at about 8,000 pieces per hour, with several in the 15,000 to 20,000 pieces per hour range. Optioned-up big-belters can go way beyond that. Just ask the flight-kitchen folks.
Converting pieces to meals, figure peak periods of 600 to 700 meals per hour as the transition point. Thats where you shift from a big rack machine to a flight-type washer. Your mileage may vary, of course, depending on your average pieces per meal. But if you figure 10 to 14 pieces of flat-, glass- and dinnerware for an evening setting, youre around 6,000 to 8,000 pieces per hour. And, well, there you are.
If you need that kind of capacity, you can benefit from other flight-type advantages well. First is the rackor lack of one. Racks have their own advantages for specific kinds of ware, but the racks themselves limit capacity. For flexibility and the ability to take in all kinds of odd-shaped ware, including all but the deepest trays, flight-types are the choice. Another plus: In most all situations, flight-types show a clear advantage in water consumption per piece.
As youll see in the information box at the end of the story, eight manufacturers currently battle for your attention in the flight-type category, and theyll soon be joined by a ninth. And soon Market Forge will have a unit of its own. The MF200+T.S. will come in at just about 80, a compact model offering a blower dryer as standard equipment.
Any Way You Want Em
At the moment, however, five makers have the highest profile, some with single models and some with multiple units. Alphabetically, Champion Industries, Hobart Corp., Insinger Machine Co., Jackson/Enodis and Stero Co. are the leading players.
Purely for sampling purposes, our spec boxes focus on single models from each of the five makers. Each is a three-tank model (one tank per prewash, wash and power rinse section), and each has a conveyor width as close as we could get to 30. We picked them that way because its a very popular configuration, and in most cases theyre the makers biggest sellers in the segment. All run 2-hp or 3-hp prewash pumps, and 3-hp units in the wash and rinse tanks, with 1&Mac218;2-hp motors propelling the conveyor. Ordinarily this is where wed lay out a few paragraphs about how the competing models differentiate themselves. But in this case, its not that simple. Youve got water flowing, soap dispensing, spray arms all over the place, plus multiple tanks, heaters and pumps and so on. And did we mention belt variety? If we tackled all the details here, the topic would take the entire issueand youd wander off into traffic, dazed and mumbling to yourself.
The main thing to remember: You can get just about anything you can dream up. The models described in the spec boxes here are just starting points. Every model can be customized beyond recognition, from electrical connections to additional tanks to load and unload section options, to choice of tank heat and boosters and beyond. You want to double the wash-rinse sections? Okay. You want a different belt composition? Some or all the manufacturers can change all those things and more. Which is why specifying a flight-type is much like filing a flight planWhere do you want to go, and how do you want to get there?
First things first. Every manufacturer we grilled said you have to confirm your available space. Typically, a basic flight-type with just a wash and rinse section will take an absolute minimum of about 8 without any load/unload space. Will you be scrapping in-line, or separately? Youll probably want at least 8 of unload-side, and 3 minimum on the load side. By the time you add on the features youll likely want with such volumes, figure a more realistic length of 18 to 25 or more.
Then consider flow into and out of the dishroom. As one maker put it, If the machine can process 15,000 pieces per hour, but you can only move 3,000 through the room, you only get 3,000.
Where will soiled ware collect prior to loading? Carts? Tables? What about clean ware? Some of this sounds obvious, and it is if youve been working with warewashers anyway. But obvious things have a way of slipping by in distraction-laden, cell-phone-riddled work environments.
Another point to consider in room layout is labor. Dont forget that these are rackless units. The ware lies directly on the belt, without racks, and youll have a person stationed at the unload. Also decide whether you want the ware flowing left to right, or vice versa.
Next up: ventilation. Youve got a lot of hot water turning to heat and humidity here. If youre upgrading from a big rack conveyor, your ventilations probably already in the ballpark. But think about it. One manufacturer estimates youll need to turn the kitchen air at least six times an hour for the warewasher alone, maybe more, apart from the other kitchen needs.
Utilities will be an issue, too. Many of you larger operators will have steam systems available on site, and most of you will take that option for tank heat. But all the makers offer you electric options, too. Insinger adds a gas option as well, and Stero adds an infrared gas choice.
If youre already set up for a warewasher, upgrading or modifying connections probably wont be prohibitive. Youll have tons of wiring options. If at all possible, make provisions for separate circuits for each tank section. Some models offer that on the warewasher side, allowing a single facility connection. But others will need the wiring done on the house side. Think about your water lines.
Your goal, as indicated earlier, is to match peak demand, not average demand. Many of you try an average figure and cross your fingers, usually with bad results.
What youre washing will make a difference, too. If its just plateware, flatware and glass, you can go with close peg spacing on the conveyor, usually around 21&Mac218;2. But if youll be handling serving bowls or other deeper items, you might need to spec wider peg spacing, 3 or more.
And a side note: Several of the factory engineers cant figure out why a lot of you run separate tray washers when you 0dont need to. Once more: Other than the deepest compartmentalized trays, most flight-types will take trays quite handily.
Dressing Up The Beast
Once youve got that under control, move onto the rest of the machine. All these makers start you with a basic wash/rinse module, and build out from there. Champions UC-CW8-3T, for example, starts you with a 8 center section thats half wash and half rinse, or an 6 version thats also half and half. The core building blocks for Hobart, Insinger and Stero are eight footers, while Jackson comes in at a 4.3 wash and power rinse section with a 3 prewash section. (Note smaller flight-types can scale back to a center section of close to 4.)
From there on out, its mix and match. Youll probably want a load section, which will run 3 to 8 or so, depending on which model youre looking at. If you want a prewash (scrapper/soil removal) section, thatll be worth about 3 of that load-section length. The unload end will run about 5 to 10 or longer, if youre needing extra length. In between, you have the option of doubling the wash or rinse sections, as well.
In most cases, these components will come in standard sections, which you can spec in multiples as needed. Any section with a water tank (prewash, wash and power rinse) will be standard lengths. But some manufacturers will custom-cut the other sections for special circumstances, and Stero in fact positions itself for such special requirements.
After youve sorted out the basic size and shape of things, move to more details. As mentioned earlier in the discussion of utility connections, youll get your choice of tank heat, whether its steam injection, steam coils, electric heaters, gas or infrared gas. Booster heaters are on the menu, too. Champion offers a built-in one; others offer add-on units on their options lists, or else you can go out and get your own.
Which brings us to myriad utility angles. These are high-production machines, pure and simple. The nature of flight-type operations necessitates high-temp washing, and sanitizing is high-temp as well. No chemical-sanitizing versions are offered in this league.
So youll be using some energy. Typically youll have three pumps that output up to 3 hp, which equals roughly 2.2kW each. Input will be different, but guesstimate 2.2kW per. Add a bit for the conveyor motor. If youre running electric tank heat, figure roughly 25kW per tank. While the units runningwhich wont be constantyoull have various thermostats and other switches kicking on and off a lot of energy.
To Blow Dry, Add Tanks Or What?
And thats before you add in some optional goodies. Another item to work out is drying. Will your particular ware, under your conditions, dry sufficiently in a basic system? If not, you might look into adding a blower dryer. If so, will it become part of your unloading length or add to it?
Also consider that a blower, while it definitely does its job, adds another big item to your utility load.
One manufacturer suggests that, depending on your particulars, an alternative to the blower might be to add a fourth tank to the washer. Not that it would get your electricity backin his companys case an electric tank heater would take 5kW more than the blower-dryerbut you could avenge the extra electricity by saving huge amounts of water as well as getting your ware dry.
His point is that the extra heat from the extra tank raises dish temperature enough to aid drying, and the water from the extra tank gets recirculated, as opposed to a fresh uncirculated rinse, reducing water consumption. And less water means less to heat.
As for water consumption: All these washers are more efficient than their earlier counterparts. The models described in the spec boxes use 324 to 426 gallons per hour with rated production from 8,500 to 19,000 pieces per hour, ranging from pretty good water efficiency to excellent.
Champion, Hobart and Stero all offer variants that greatly improve on their basic three-tank water usage. Champion and Hobart add rinse sections that recycle water, while Stero adds a tank and recirculates. All three produce the same or greater pieces per hour, while cutting water usage by a third or more. Nothing in life is free, and tradeoffs in these cases are in length and/or energy. But depending on your local specifics, your utility issues and cleaning needs, the trade can be well worth it.
Final Notes On Performance
Judging productivity and utility consumption can be tricky. How do you know what your model will really do?
Fortunately, NSF Intl. has been testing warewashers for years, looking into cleaning, sanitizing, productivity and water consumption. Its Web site, www.nsf.org, lists the results. The non-technical test description is this: NSF first tests for cleaning effectiveness with a precise procedure we wont describe, other than to say it involves a glass and buttermilk residue dried to a paint-like coating. Assuming the washer passes that part of the regimen, NSF then tests for sanitizing, which involves getting the dish surface temperature up to 160&Mac251;F at the exit.
The conveyor speed that gives the dish time to rise to that temp becomes the prescribed speed. That speed then gets plugged into a formula for computing productivity in pieces per hour. The point is that the productivity figure is all contingent on the conditions that produced the required sanitizing temp. The only factors missing in the equation are the labor delays at the load/unload stations. So reduce the listed number by a little bit, and you should be close to real numbers.