Z-Trim™, a specialty food ingredient from FiberGel Technologies, Inc of Mundelein, IL, has found a ready market among the diet-conscious. This corn bran-derived, self-emulsifying gel is a palate-pleasing, calorie-free fat substitute.
Dr. Triveni P. Shukla, vice president of technology development at FiberGel, developed the processes that made Z-Trim commercially viable. Corn bran, the skin of the corn kernel, is the raw material.
"We take the good dietary fiber in the corn bran and make it very white," explains Dr. Shukla. "Then, through our exclusive process, we render that bran into a material that becomes a gel when you drop it into water. It actually can be used in place of gelatin. People who cannot eat nonkosher gelatin can eat our gel. This gel mimics the behavior of fat in almost any high fat food other than fried foods."
Efficient Steam Production
FiberGel''s two production lines include equipment such as a centrifuge, drum dryer, milling, sifting, bagging, and sealing machines. The product is sold in several forms, but initially, the plant produces Z-Trim as either a wet gel or dry powder. The processes use 50,000 gal of water per day. More than half of the water is raised to a temperature of 185º or 190º F. Once the gel has been created, some of it is dried to make the Z-Trim powder. The rest of the water is used in this process of creating the powder.
FiberGel Technologies installed two Miura LX (Low NOx) 100 BHP Boilers.
"We chose Miura Boilers . . . because they are very efficient," Dr. Shukla recalls. "You can click the button and the boiler gets to 135 psi in no more than 6 minutes. This was unheard of in the many processing operations I''ve been called upon to advise. The boilers are very compact. I''m looking at the boiler room and it is not more than 25 x 14 ft. I have two boilers and all the other accessories in there -- a compressor, the two boilers, and a water tank. Using old style boilers would take the entire basement.
"Generally, as a rule of thumb, when I look at the two boilers, one is for heating the water close to the boiling point -- which takes 100 hp. The other Miura boiler goes for the drying of the gel, because we also make dried product. You need roughly 1.2 lb of steam to pull a pound of water from the gel. So one boiler is dedicated to hot processing and the other is dedicated to the drying process of the drum dryers."
If you compare the available radiant surface area of one 100 BHP firetube boiler versus one 100 BHP Miura, the firetube has about three times the surface area. This area will radiate a constant amount of heat whether the boiler runs at 100% or at 10% of capacity. The lower the use of its capacity, the higher the ratio of radiation loss to usable steam production.
Additional energy savings result from the Miuras'' fast startup capability. Most boilers are turned down, but not off, when steam demand drops. Miuras can be switched on and off like light bulbs. They go from a cold start to steam in five minutes. And, of course, less energy is required on restart because there is much less water to heat, thanks to Miura''s floating headers. These headers allow the water tubes to be short and straight so the whole boiler can be very small, taking up 33% less floor space.
The "low water content" water tubes'' surface serration optimizes heat transfer. This design is a major contributing factor to their 85% fuel-to-steam efficiencies. Fuel savings average 10-40%.
The fuel-to-steam boiler efficiency of Miura boilers remains consistently high (85%+) at all steam loads from 35-100%. Standard firetube boilers only operate at their peak efficiency (±80%) when they are operating at 100% steam load. Since steam load is constantly fluctuating, Miura''s consistent efficiency provides consistent energy savings.
Online Data
"The efficiency of the boilers is clearly why we selected the Miuras -- in terms of space for installation and in terms of converting water into steam. We are using less cubic feet of gas to produce a pound of steam at 125 psi. Its third value is that is a very automated boiler," Dr. Shukla says, describing an unusual technology unique to Miura boilers. "They sold us, along with the boilers, a computer program that I can feed to my master system and I can almost watch the efficiency of the boiler. You can see what it is doing and it records the boiler''s activity over time. Since the second shift -- the night shift -- has no attendant, I use this history to instruct the day shift operators. I can show them that at such and such time, so many hours into production there was less steam and why. They will know, then, how to manage the process in accordance with how many pounds of steam are available and at what psi."
The system that FiberGel bought, the Miura Boiler Monitor (MBM), was designed to enable customers to do their own basic troubleshooting. A cable is hard-wired in a daisy chain, going from boiler to boiler. The computer that formats and displays the boiler data can be up to 3,000 ft from the boilers. Thirty-one days of boiler operating data can be viewed on the computer screen.
To ensure immediate comprehension of the boiler data it presents, MBM uses an intuitive organizational approach. Since an operator always wants a reminder of what a boiler''s settings are, the settings are grouped on one screen, along with the Miura phone number, in case the operator has a question. Another screen displays, in diagram form, the real-time current boiler status (valves on or off, temperatures, psi, and conductivity).
Alarms, Cautions, and Combustion
Once the current situation has been checked, the operator can monitor three aspects of boiler feedback -- Alarms, Cautions, and Combustion. He or she can look through historical data to see if there are any indications of a development that needs attention. The Alarms, Cautions, and Combustion histories are on separate screens: Alarms totals include various flame, water level, power, temperature, and pressure alarm totals; Cautions totals include times reminded about filters, blowdowns, softeners, batteries, sensors, etc; Combustion history records the time period''s cycles, low and high firing, blowdowns, blower and pump cycles.
A scrolling screen shows the various signal, pressure, temperature, conductivity, and SCF monitors and is listed, day-by-day, for the prior 31 days. And finally, a monthly report screen provides a recap of the month with comparative data from the prior month.