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Guided Wave Radar Level Measurement Is Best Solution	June 29, 2006
Posted by Joe Lewis at 09:17 AM \| Comments (0)

Finding the best level measurement solution for your bulk solids is not always simple and easy. There are several different technologies to consider, including smart weight & cable, guided wave radar, ultrasonic, through-air radar and laser. For the vast majority of bulk solids applications, especially for powders, the use of through-air technologies like ultrasonic, through-air radar and laser can be very problematic. That leaves the smart weight & cable devices and guided wave radar as the most viable candidates.

When you need continuous measurement updates and prefer no moving parts, guided wave radar is your best choice. Why? Because, unlike most other technologies, radar technology is practically immune to process conditions such as temperature, pressure and atmospheric composition. In addition, guided wave radar uses a continuous cable wave-guide to direct the radar pulses to the material surface. The radar energy does not disperse, unlike through-air radar and ultrasonic. This is important as only a small portion of microwaves will be reflected off the material surface. The amount and strength of reflection is based on the dielectric constant of the target material. The lower the dielectric constant, the less energy is reflected. However, because the radar pulses are guided along the wave-guide stronger reflections exist than with through-air devices. This is a major advantage of guided wave radar and is why it works!

Guided wave radar can effectively and reliably be used on challenging applications such as cement powder, flyash, slag powder and so many other bulk solid materials whether powder or granular. And guided wave radar does not require high dielectric materials to work. Guided wave radar, using TDR (time domain reflectometry) technology can measure materials with dielectrics as low as 1.4.

Need a solution? Need a reliable and high-value level measurement system? Look at today's guided wave radar units!

www.flexar.info

Joe Lewis
Monitor Technologies LLC
jlewis@monitortech.com
www.flexar.info
www.monitortech.com

Solving Shaft Leakage Problems on Top-Entry Agitators	June 28, 2006
Posted by Kay Mann at 09:34 AM

Top-entry agitator shafts on reactors, fermenters, crystallizers and similar machinery are a frequent cause of sealing problems. Picture it if you will:

Usually, the driveshaft is suspended from a coupling at the top, and ends at the bottom, inside the vessel. This lower end of the shaft is an inherent maintenance problem: if a lower bearing exists at all, it is practically inaccessible and is rarely, if ever, maintained. Lower bearing wear, or lack of a bearing at all, allows the shaft to wobble as it turns. This radial shaft misalignment causes seals at the top of the vessel to fail.

Most of these vessels have a packing gland at the top of the vessel, which also acts as a stabilizing bearing, limiting shaft runout. However, you can imagine that as the packing becomes worn and compressed, shaft runout increases, creating leak paths. This can be an environmental or safety issue when the product contains harmful vapors and these escape.

Inaccessibility of the shaft seal can only make things worse.

One processor of shampoo had a vertical shaft vacuum mixer with lip seals at the top. The seals themselves were inexpensive enough and the product was not hazardous by any means. But about every four months a seal would fail and it would take two workers two days to lift the motor and gearbox up off the shaft coupling and slip a new lip seal over the shaft, then replace the whole assembly. (n.b. These guys even had to cut a hole in the cement ceiling to allow them to lift the motor up high enough to clear the coupling!).

Another problem inherent with vertical shafts is shaft floatation. This often results from interaction between the agitator and process material, causing axial (vertical) motion of the shaft. Thermal growth and shrinkage cycles can also produce axial motion, which compromises packing and most seals.

There is hope, however. Meco has recently patented its OFS-series seal, which permits radial and axial misalignments without compromising the integrity of the seal face. (Yes, it is a single-face seal). A positive drive mechanism allows driveshafts to float axially through the seal without affecting the seal face, while maintaining spring force on the seal.

The seal's design also permits radial eccentricity, while a companion steady bushing limits angular misalignment. The OFS has proven effective in containing vacuums and a variety of gases, vapors and fumes, even at high speeds and temperatures.

Best of all, these seals are available fully-split. No more holes in the ceiling.

Photo Caption: A Meco OFS seal spinning
on a vertical agitator shaft, containing
chemical vapors.

Kay Mann
Meco Seals

Solving Downstream Pressure Problems with LIW Feeders
Posted by Delmar Schmidt at 12:26 AM \| Comments (0)

We all know that gravimetric feeders cannot weigh accurately when feeding into even a slight downstream pressure. However many applications, especially the polyolefin resin producers, will have the feeders feed directly into a purged blending screw, or even worse a poorly vented rotary airlock. Everyone complains “but it’s only 1 inch of water purge, so why is the scale weight always erratic?” And no, our PLC-based retrofit control system will not fix a pressure problem.

The Cause

The classic feeder discharge method is a vertical elbow welded solidly to the feed tube. A flexible connector is then clamped to the bottom of the stub and the downstream inlet. Let’s do the calculations on a theoretical feeding application:

You have a LIW feeder running at 60 lbs/hour. The downstream flexible connector is 6” diameter. Looking at the 28 square inch cross-sectional area of a connector exposed to the 1” purge, there will be a resultant lifting force of one approximately one pound (yes I picked easy measurements for my example). Whenever the purge is rapidly applied or removed from the process, like when the operator opens an inspection hatch, you just negated a full minutes’ worth of material loss from the scale. Double the purge pressure, or cut the feed rate in half, and the problem gets twice as bad.

Exaggerating the pressure problem are two unexpected forces:

1. The flex connector will balloon under pressure, increasing the cross-sectional area exposed to the purge with a corresponding increase in the resultant lifting force.

2. When you add an extended helix and nozzle to the feeder, the lever arm is increased with a corresponding increase in the resultant lifting force.

The “Melfi Elbow” Solution

The obvious solution would be to put the flex connector in its side. Most good scales will have horizontal flexures or linkages to minimize effect of side loading. While a horizontal flex connector will not negate all the effects of downstream pressure, it will greatly improve the weighing accuracy when the feeder is exposed to unpredictable changes in the pressure level.

The horizontal design will require a slightly custom flex connector design, but most suppliers should be able to supply a reducing sleeve. Email me for the name of a local connector company we use. Alternately you could weld on a tube blank with a matching OD of the elbow stub and use a straight connector.

Regards, Delmar Schmidt

Melfi Technologies Houston

dschmidt@melfitechnologies.com

K-Tron International Again Named to FSB 100 List of America's Fastest-Growing Small Public Companies	June 27, 2006
Posted by Don Dunnington at 05:28 PM \| Comments (0)

For the second year running, K-Tron has been listed among America's fastest-growing small public companies by Fortune Small Business (FSB) Magazine.

This is the sixth annual ranking of the nation's top 100 small public companies as measured by earnings per share growth, revenue growth and total return to investors. The companies are screened by Zacks, a financial research firm, and the list includes companies with annual revenue of less than $200 million and a stock price of more than $1.00. They are ranked based on the past three years' earnings per share growth, revenue growth and stock performance. The FSB 100 excludes banks and real estate firms.

K-Tron was ranked No. 77 on the 2006 list and No. 69 on the 2005 list. In a related article, "Growth guru," K-Tron CEO Ed Cloues was featured for his role in guiding K-Tron and two other companies into the FSB 100 ranks. Fortune cites Ed’s “gift for acquisitions” as one of the factors that makes his “the name that shareholders love to see.”

To my mind, there are two characteristics--patience and humility--that distinguish Ed’s leadership style, that make him the miracle worker of Fortune’s article. He is very patient. He is willing to wait for the right opportunity, and he’s willing to walk away when things don’t work out as expected. And he’s a genuine guy, humble in a way that allows him to see the hidden value, in people and companies.

Finding our value, I think, is the secret to real growth. It’s true for people as well as for our companies: when we focus on growing our value, all the other good things follow.

Don Dunnington

Chicago Powder and Bulk Solids Show is great for Emerging Companies
Posted by Delmar Schmidt at 09:20 AM \| Comments (0)

We have all heard the comments about the PBS Show….too expensive…smaller attendance…can market on the internet instead…the Chicago traffic…Yada Yada Yada.

How about the show location? O’Hare airport is the hub of the world so flights are reasonable. You can take a quick & free shuttle from O’Hare across the highway to the Rosemont. What traffic? There are plenty of hotels within walking distance to the show, you can’t get much more convenient. Yes the hotels may be a bit expensive, but try going downtown in any major city for that price. When you subtract the cost of a taxi, or rental car with daily parking, it’s really not all that bad.

I think the PBS is a great avenue for smaller companies looking to make the jump into the big leagues. Chicago is a conveniently located up in a heavy manufacturing sector with good enough attendance from end users. These users want to learn something, anything, when they attend the show. They want to find that perfect widget that can make their job easier. The best way to learn is to touch and feel and play with all equipment in the various booths.

If you have an emerging product to bring to the market, conventional print and online media will have a difficult time connecting the benefits of your product to that process engineer with the problematic application. We have our PLC control systems featured in many of the leading industry publications. Both full-page and multiple-page spreads. And the response had been totally underwhelming. Have you seen our articles? I rest my case. But have the exact same PLC control system powered up in the booth, connected to an operating LIW feeder continuously metering powder, and the attraction is irresistible. Even people who do not know what a gravimetric feeder is will stop and check out what we are doing.

Maybe the big players in our industry have already reached market saturation. These guys already spend millions of dollars a year on back-cover magazine advertising and awesome websites, you would have to be from another planet to not know what Flexicon or K-Tron has for equipment to offer. There may not be many surprises in the booth, but it’s always great to have the chance to touch and play with the equipment. Anyway I have no reason to have them scan my card and mail me yet more advertising material. I am not going to show up on their lead count. I know where to find them. I know their local rep.

See you at PBS 2008.

Regards, Delmar Schmidt
Melfi Technologies Houston
dschmidt@melfitechnologies.com

Answer this question: would civilization have survived if ancient Egyptians had known about mass flow?	June 24, 2006
Posted by Joe Marinelli at 08:44 AM \| Comments (0)

In good times when there was plenty of grain, the ancient Egyptians stored their grain harvest in huge flat bottomed bins. As they drew the grain out, most of it would remain in the bottom of the bins (a typical funnel flow pattern developed whereby some material moved while the rest remained stationary). Essentially, the first material that entered the bin was the last to exit.

In times of plenty, as grain was used it was replaced with fresh grain while the older grain remained stagnant. However, during times of famine, the Egyptians would draw the grain out completely, thereby using the grain that had remained stagnant in the bottom of the bins. Unbeknownst to them, as grain remains stagnant, it produces tetracycline, which as we now know is a powerful antibiotic.

Had the Egyptians known about mass flow (first-in-first-out), the grain would not have remained stagnant long enough to produce antibiotic. Egypt's civilization, and those that followed, might have perished if the Egyptians had discovered how to insure a more efficient flow pattern from their bins.

Today, if you need tetracycline to fight an infection, you go to the doctor. And if you have flow issues where your product isn't moving reliably from your bins and feeders, you might want to consult a modern day flow doctor. In most cases, you'll find that the funnel flow pattern that serendipitously benefited the ancient Egyptians is a serious detriment in today's storage applications. Funnel flow leads to ratholing, flooding, segregation and many other flow issues. Mass flow is typically required to overcome these flow issues.

Joseph Marinelli
Solids Handling Technologies, Inc.
1631 Caille Ct.
Fort Mill, SC 29708
Ph: 803 802 5527
Email: info@solidshandlingtech.com
Website: www.solidshandlingtech.com

Guided Wave Radar Level Measurement Is Best Solution

June 29, 2006

Solving Shaft Leakage Problems on Top-Entry Agitators

June 28, 2006

Solving Downstream Pressure Problems with LIW Feeders

K-Tron International Again Named to FSB 100 List of America's Fastest-Growing Small Public Companies

June 27, 2006

Chicago Powder and Bulk Solids Show is great for Emerging Companies

Answer this question: would civilization have survived if ancient Egyptians had known about mass flow?

June 24, 2006