Monday, April 30, 2012

Rememberence of Things Past: Fluidyne Instrumentation, Urethane Foam, Artificial Kidneys and Flowmeters

imageI started Fluidyne Instrumentation from my Oakland, California apartment in 1970, after selling my first company, Polytron Corporation to Olin Corporation (previously Olin Mathieson Chemical Corp.). Olin was best known for its Winchester rifles and ammunition but had ventured (mis-adventured as it turned out) into the chemical business. By 1970, Polytron was the largest manufacturer in the US of rigid polyurethane foam (R-PUF) components, trademarked Polycel and Autofroth, with chemical plants in Richmond, California and Brookpark, Ohio. Rigid [poly]urethane foam is commonly used to insulate refrigerators and freezers; refrigerated warehouses, trucks and rail cars; raise sunken ships; and manufacture surfboards by foam-in-place techniques. Polytron also manufactured (in Richmond) machines to mix and dispense R-PUF for insulation and marine salvage.

Below is an early Fluidyne foam dispensing machine with a reciprocating mixing head for filling 4-foot by 8-foot insulated building panels for refrigerated warehouses:

A 3,450-rpm motor drove the pin-type mixer in this close-up of the foam mixing head for the dispensing machine pictured above:

Fluidyne had its offices for several years in the second and third floors of this architecturally significant “flatiron” style building at 17th St. and San Pablo Ave, Oakland, 94612.

Image courtesy of Catherine Haley

Urethane Foam for Surfboards and Salvaging Ships

My No More U.S. Custom Surfboards? Squidoo Lens describes a major event in the foam surfboard industry and a brief description of the use of urethane foam to raise the Navy’s U.S.S. Frank Knox:

Salvaging a Beached Destroyer with Polyurethane Foam
A bit off the foam-surfboard topic but an interesting foam-related story

In the early 1960s, Polytron developed and patented a method for raising sunken ships with urethane foam, which led us into some interesting projects for the U.S. Navy. Our largest project in 1965 was refloating the U.S.S. Frank Knox (DDR-742), which had run hard aground (at 16 knots) on Pratas Reef in the South China Sea.

The official U.S. Navy story and a brief third-party account of the salvage effort make interesting reading. Unfortunately, the Time and Newsweek articles about the grounding aren't available on the Web.

As mentioned in the official account, use of explosives to free the vessel resulted in blowing much of the foam back out of its hull. Thus, Polytron made multiple air/sea shipments of more than 100,000 pounds of foam components for the project. The Navy's final challenge was chopping and scraping the foam out of the vessel at Subic Bay prior to a trip to Yokosuka Japan for remaining repairs.

Subsequently, William E. Lowery, a former Polytron vice-president, and I started a company called Polycel One, which manufactured a single-component semi-rigid urethane foam sealant of the same name delivered from an aerosol can. This clip from the October 1980 issue of Popular Science magazine shows Polycel One in action:


We sold Polycel One to W. R. Grace and Co. in 1979.

Fluidyne Analytical Instruments for Polyurethane Foam

Fluidyne’s initial product line consisted of instruments to measure the reactivity of urethane components by determining the foam’s rate-of-rise after mixing the components together,  machines for accurately dispensing very small amounts of urethane foam and elastomers (rubber), trademarked Microshot, and ultimately positive-displacement fluid flowmeters, automotive fuel economy measurement systems, and computer-based data acquisition and control systems. Max Machinery Co., Lafayette and later Healdsburg, California, owned by John K. Max (deceased), manufactured the instruments, dispensing machines, and flowmeters for Fluidyne.

The Journal of Cellular Plastics published my “Instrumental Analysis of the Performance Characteristics of Rigid Urethane Foaming Systems” article in its May, 1969 issue (subscription to SAGE periodicals required). 

L. H. Hanusa and R. N. Hunt’s The Microcomputer in the Laboratory: Data Acquisition and Calculation of Foam Reactivity Profiles published in the Journal of Cellular Plastics, Volume 18 (2), January 1982. From the introduction:

Foam reactivities are determined in a variety of ways. The most prevalent characterization is visual observation and the determination of discrete values. For example, with lab or machine free rise samples, values such as initiation, gellation or string point, tack, and rise time are generally determined with just a stick and a stopwatch. In 1964, ASTM issued a Standard Method (D2237) for determining the “Rate of Rise Properties of Urethane Foam Systems.” The method describes a “continuous” measurement of the volume expansion of Urethane foam systems as a function of time. A comprehensive paper by Roger Jennings (ref. 1) described both method and equipment for the “instrumental determination of various characteristics of rigid urethane foaming systems.”

In fact, articles continue to be published describing either simplified or specialized techniques for studying the expansion polymerization of urethane-like foam systems. The equipment described by R. Jennings was produced by “Fluidyne Instrumentation.” In fact, many “Fluidynes” can be found throughout the Industry. Some have been modified either for special applications or to improve the operation of the equipment. In our own labs, we have such modified “Fluidyne Equipment” along with equipment developed by Bayer AG (ref.2).

The equipment was extensively used for quality control of our products. Despite this, it was often bypassed in our development efforts because of time constraints. The problem was the laborious and time consuming steps required to obtain data from the charts and carry out subsequent calculations. To overcome these problems, we decided to interface a Radio Shack TRS-80 microcomputer with the Fluidyne equipment. The conversions greatly increased the usefulness and facilitated the operation of this equipment. Rapid changes in integrated microcircuitry provide alternatives to traditional analog circuits. Selected applications are described. …

This paper was originally presented at the [Society of the Plastics Industry] (SPI) Polyurethane Division 26th Annual Technical Conference, November 1-4, 1981, Fairmont Hotel, San Francisco, CA.

Urethane Elastomer Processing Equipment for Artificial Kidneys and Skateboard Wheels

Over the years, Fluidyne urethane dispensing equipment became the world standard for manufacturing hollow-fiber kidney hemodialysis cartridges. The cartridges consist of a plastic cylinder containing thousands of strands of hollow synthetic fibers anchored at both ends by cast-in-place urethane elastomer dispensed from a Fluidyne machine. The machines injected liquid urethane components into cartridges spinning in a centrifuge; spinning kept the urethane at the ends of the cylinder. After curing, a microtome sliced the relatively soft ends to enable blood to flow through the fibers, as shown in the diagram below (courtesy of Wikipedia):


Another major market for urethane elastomer processing equipment was the production of skateboard and rollerblade wheels.

Positive Displacement Flowmeters for Measuring Fuel Economy

Fluidyne became well known for its positive displacement (piston) low-flow meters, which the world’s major automobile manufacturers and their suppliers used for measuring vehicular fuel consumption. Here’s the first Fluidyne Model 214 Positive-Displacement Flowmeter manufactured for me by Max Machinery:

This view shows the same flowmeter (before black anodizing) with Fluidyne’s first analog flow rate transmitter, which consisted of a small d-c generator magnetically coupled to the Brooks piston flowmeter mechanism sandwiched between two machined flanges:

Caterpillar Tractor Co. used Fluidyne 214 flowmeters with the 5P2150 fuel flow meter, which Fluidyne manufactured for the firm under contract.

One of the few references to Fluidyne piston flowmeters on the Internet today is in United States Patent 4192185, Flowmeter for Liquids, published on 3/11/1980:

Mention should be made of the fact that a flowmeter for liquids is known (see "Precision Automotive Fuel Economy Testing System" published by Fluidyne Instrumentation, O[a]kland, California), in which four measuring cylinders are provided. The pistons within these cylinders are connected via piston rods to a common crank shaft and a single counting element is provided to count the piston strokes of the measuring piston. This flowmeter is, naturally, extremely expensive and difficult to fabricate and, because of the more complex mechanism, may not be as reliable in practice as a system using free-floating measuring pistons.

Fluidyne piston flowmeters weren’t extremely expensive; they cost less than competing methods for measuring low flow rates, such as fluid wheatstone bridges, which were then used for automotive fuel flow measurement.

image Fluidyne Helix flowmeters gained widespread use for measuring larger flows of more viscous liquids, such as bunker fuels for cargo and passenger vessels and diesel fuel for large generators. At the right is a copy of an advertisement for Helix flowmeters from the November 1977 issue of Chemical & Engineering News magazine.

imageMax Machinery, Inc. (@MaxFlowMeters) continued to manufacture piston, gear and helical flowmeters after protracted litigation with Fluidyne in the Northern District of California federal court over the rights to product designs, registered trademarks and copyrights. The litigation ultimately concluded in Fludyne’s favor with a 7-figure settlement from Max Machinery.

Fluidyne Data Acquisition Systems Using Electronic Calculators and Computers

Fluidyne manufactured electronic data acquisition systems for its flowmeters in a plant in Santa Rosa, California. Wang Laboratories announced the Wang 700 programmable calculator and priced it at US$4,900 in 1969. I purchased one in 1970 to perform gas flow calculations for an apple vacuum-drying plant in Sebastopol, California I was designing at the time for Vacu-Dry Company. (At that time, running Fluidyne wasn’t a full-time job.) As a side note, Vacu-Dry and Polytron shared the same patent and trademark attorney firm, Eckhoff, Hoppe, Slick, Mitchell & Anderson of San Francisco, California. Ernest Anderson’s advice regarding protection of Fluidyne trademarks and copyrights was critical to Fluidyne’s success with its litigation with Max Machinery.

The Wang 700 calculator I received had a connector marked I/O on the back. I was interested in using the Wang 700 to make real-time urethane foam rise-rate and pressure calculations from Fluidyne foam instruments, as well as liquid flow measurement calculations by connecting it to one or more flowmeters. I called Wang labs and talked to Dr. An Wang about the connector’s purpose, but it turned out that it wasn’t wired. (Dr. Wang often answered phone after working hours in those days.) He sent a tech to the shop to wire the connector, and I designed an interface with wire-wrapped DEC DTL (digital-transistor logic) boards to handle the BCD (binary-coded decimal) output of the flowmeter electronics.

One of the most interesting applications for data acquisition systems with Wang calculators was an automated system for screening carriers of Tay-Sachs disease with an Abbott Laboratories ABA-100 Bichromatic Analyzer developed by physicians from Toronto’s Hospital for Sick Children. Fluidyne manufactured the electronic interface between the ABA-100 and the Wang Calculator under contract to Abbott Laboratories, Inc. and assisted in programming the automated screening tests. The FDA required Fluidyne to conform to its Good Manufacturing Processes (GMPs) for medical devices, which included NASA-grade component soldering. The Fluidyne Interface was instrumental in later screening procedures for Sickle Cell Anemia carriers.

Fluidyne continued producing interfaces for Wang computers, including the 2200 series (which had a BASIC interpreter in ROM), the Commodore CBM (a commercial version of the Commodore PET), DEC PDP-11s, and (ultimately) IBM-compatible PCs.

Programming Intel Personal Computers with Microsoft Windows and Writing Books, Articles and Blogs

image After the litigation with Max Machinery concluded, I decided to write computer software. I wrote a program to manage the business of American Leak Detection franchisees in dBASE III+ Developer Edition (compiled with Clipper), a few other dBASE front ends, and then a WordPerfect macro to Microsoft WordBasic converter for my wife, Alexandra. I became acquainted with Ron Person, who wrote Special Edition Using Microsoft Word and Special Edition Using Microsoft Excel for QUE Books, at the Bay Area Microsoft Word Users Group and became technical editor for his then-current Word title. He was too busy to write Special Edition Using Microsoft Access and recommended me as the author to QUE. The rest is history, including 12 more editions of Special Edition Using Microsoft Access, the latest edition of which was renamed to Microsoft Access 2010 In Depth.

My Amazon Author Page lists the 30+ books I’ve written about Microsoft operating systems and related software.

For decade-old details of my proclivity for BASIC programming, see my An (Almost) Lifetime of BASIC post of 4/25/2006, which contains the archive of my entry in Apress's 2001 VB @ 10 Years Project as previously cached by However, since about mid-2010, I’ve adopted .NET’s C# as my programming language of choice. I became a contributing editor for Fawcette Technical Publication’s Visual Basic Programmers Journal (VBPJ) and wrote many cover articles for it and its successor, Visual Studio Magazine.

Subsequent Events

I currently curate the OakLeaf Systems and Android MiniPCs and TVBoxes blogs and write articles for TechTarget’s site and other cloud computing Web sites.

Most of Fluidyne’s registered trademarks for the products described above have expired because of disuse.

My apologies to Marcel Proust for using the earlier English translation of his À la recherche du temps perdu classic.