McNab Technical Papers

McNab is now in the process of putting published technical papers and posters on the website.  Please check back with this page for future updates.  The most recently published works appear at the top of the list.

Brine Turbidity Continuously Monitored In-Line

A Compton, California-based chemical manufacturer extracts chlorine from brine through the use of mercury cells. Because mercury cells are highly sensitive to particular contaminants- vanadium, for example, impinges on operations if present at concentration levels of 20 ppm or higher-the company treats and filters the brine prior to beginning the extraction process.

 Application of In-Pipe Yeast Counting Analyzer in Medium to Small Breweries

With regard to accurate pitching levels, the following requirements apply, which typically have not been met. This automatic pitching increases the performance of the brewery, simplifies the laboratory's requirements and increases the efficiency of the pitch. The new pitching system at Alaskan Brewing Company meets these requirements. Through careful design, the variability and the concentration of pitched yeast was improved by a factor of better than 10:1. This results in improved diacetyl concentration levels.

Analyses Of Yeast Data As To Its Live and Total Concentration Cell Count Using a New Optical Method Suitable for Beer Fermentation and Cropping Optimization

This poster addresses the use of an in-pipe optical analyzer system to measure total yeast count and live yeast count in brewery applications. This new data is presented showing the relationship between total cell count and live cell count in terms of cells per milliliter. The data supplied here illustrates the operation of a new fluorescence optical method.

Yeast Pitching with Relatively High Variability in Yeast Slurry Concentration

The Alaskan Brewing Company installed a new skid-mounted yeast pitching system to enhance brewery performance, simplify laboratory requirements and increase pitching efficiency.  The yeast pitching skid installation provided immediate results, improving the variability and concentration of pitched yeast by a factor of boiler than 10:1.

Correlation of Yeast Measurement between Hemocytometer, Spin-Down and Coulter Counter Laboratory Analysis with The McNab Cell Counter

This poster addresses the use of an in-line, across-the-pipe analyzer to measure yeast cell count in brewery applications. New data is presented showing the correlation between the in-line McNab Cell Counter and ASBC hemocytometer analysis. Previously presented information is provided showing the correlation between the in-line instrumentation with ASBC spin-down 0-50% and Coulter counter laboratory analysis.

Size Distribution and its Effect on Particle Measurement in the Beer Line

Particle size influences both beer D.E. filterability and subsequent shelf life. The actual concentration level of small haze particles (< 1/2 micron) is often not measured. These small particles are considered difficult to filter. In this work, particle size distribution was measured in the laboratory on a variety of sample beers. The samples were then measured using a new in-pipe dual angle particle counter. There is a greater variation in the concentration of small particles than would be expected. The data show actual examples of variation that occurs in finished product, and compares measurements from the dual angle analyzer.

Across-The-Pipe Cell Count of Yeast

This poster addresses the use of an in-line, across-the-pipe-measuring near-infrared analyzer to measure yeast cell count in brewery applications. One such application involves the monitoring of yeast pitching to ensure in-specification feed. The Model HSA allows the brewer to better control yeast dosage so as to meet specifications and improve uniformity of fermentations and filtering. It eliminates common sampling and dilution errors often found in the laboratory.

Unique Full Diameter Near-Infrared Analyzer Measuring Ethyl Alcohol in Breweries

The brewery community has an increased interest in sanitary ethyl alcohol measurement.  There has been a history of alcohol measurement using indirect density methods, off-line, or semi-on-line laboratory techniques. This new near-infrared (MR) alcohol analyzer was specifically designed as a production floor unit, eliminating complexities resulting from the earlier NIR units that were adapted from laboratory design and thinking. This reduction in complication and complexity - as well as increased stability - gives simpler, more reliable results with repeatability. It is also less susceptible to interferences.

Stack monitoring system operates under ambient temperature conditions exceeding 140� F

The smoke opacity monitoring devices employed by an electric utility to monitor the exhaust from individual oil-fired boilers would fail when ambient air temperatures approached 140�F.  McNab Model S/D Stack Opacity Monitors, which are capable of continuous operations under ambient temperature conditions of 160�F

Using combination Forward Scatter and 90� Haze Detection of filtered product as a predictor for "bits" in packaged beer

"Bit" formation can occur in beer subsequent to filtration and packaging, and this may affect the appearance of the product. It would be very desirable, at the output of the filter, to be able to immediately evaluate the batch's potential for eventual "bit" formation.  This poster presents data taken before and alter a three-month storage period at room temperature. Testing was done using simultaneous forward and 90� white-light scatter methods. A correlation was found between haze measured at 90� nephelometric scatter angle and "bit" presence three months later.  A lack of correlation between forward scatter measurement and subsequent "bit" presence was also found.

Turbidimeter system reduces fuel and water costs, eliminates need for pollution control capital equipment

To comply with clean-water regulations, a wood products company needed to reduce or eliminate the condensate contained in its discharged effluent streams. A McNab turbidity monitoring system was installed to monitor the condensate for impurities before returning it to the boilers.

pH sensor life extended from 3 days to 75 days in fluoride mixture

McNab Model AP-IH pH analyzer extends sensor life in caustic fluoride mixture from 3 days to 75 days with antimony probe.

Payout Economics on Process Stream Analyzers

The installation of process instrumentation can result in lower product cost, improved product specification and/or compliance with governmental regulations.  Economic evaluation of the cost of instrumentation as compared to savings in any of these areas may be made to justify each installation.

Turbidity monitoring system helps reduce settleable solids to less than 40 ppm

A Model HSA turbidity monitoring system, to monitor settleable solids content, was installed on each clarifier at a dairy company to allow them perform automatic desludging.

Turbidity monitoring system aids in the removal of solids as small as 0.5 microns

A steel company installed an automatic diatomite filtration system to remove solids from its liquid waste. To monitor the effectiveness of the filtration process, the company installed a McNab Model HSB turbidity monitoring system in the line immediately after the diatomite filter.

Turbidimeter system prevents shutdowns

Model AP-VIE Indicator/Controller used for maintaining proper concentration levels as a sulfur dioxide plant through an in-pipe effluent stream to provide continuous real-time turbidity measurement.

Brewery uses turbidimeter to constantly monitor beer clarity

McNab turbidimeter (turbidity monitoring system) was installed at a brewery to control beer haze and continuously monitor clarity.

Continuous effluent analysis replaces batch testing

McNab Model HSA color monitoring system was installed in the effluent stream from ion exchange columns, shutting down the process when corrective actions are necessary, and provides a record to prove regulatory compliance.

Monitor provides early warning of tainted liquid

A McNab Model HSA turbidity monitoring system was installed at a pigment manufacturer�s plant to monitor waste water and reduce water pollution.

Turbidimeter system controls ash waste

A McNab Model AP-VIE turbidity monitoring system was installed at a pigment manufacturer�s plant to monitor waste water and reduce water pollution.

The Effect of Measurement Angle and Particle Size on Scattered Light in the Beer Line

Beer appearance is important to brewers because it reflects product quality, and is the single characteristic most apparent to the buyer at the time of purchase. The light transmission and scattering characteristics of beer are used to determine beer haze and, therefore, appearance.  The "shadow box" laboratory instrument is used in most breweries for visual estimates of clarity in the glass. The large volumes of beer now processed demand continuous measurement, and scattered-light hazemeters are currently used in major breweries, installed in the beer pipe after the kieselguhr filter.

Turbidity using New Dual-Angle Light Scattering Instrumentation

There is a recent interest in multiple angle simultaneous in-pipe turbidity measurement. This is in addition to the 90� ASBC/ EBC or forward scatter measurements now made.  This paper presents actual simultaneous measurements by a single instrument showing the various sensitivities of the two angles to yeast, diatomaceous earth, and protein size particles. The paper includes a description of the apparatus, experimental method and laboratory technique with photographs.

Turbidity monitoring system continuously checks filter performance in fruit juice production

A producer of fruit juices required a filter- and product quality- monitor to continuously check the performance of its filtering of orange and grape juices. A McNab Model HSB turbidity monitoring system was installed to monitor the juice as it passed through the process line immediately after the filter.

Handbook - Optical Measurement of In-Process Fluids

In 1974, the National Oceanic and Atmospheric Administration recommended, after due deliberation, to call turbidity a "non-technical appearance descriptor." While turbidity certainly has become a common description, relied on in industries, it still is accurately defined as an "appearance descriptor."  What this means is that turbidity is a human phenomenon. It is the "reduction" of transparency due to the effect of particles. Clarity or clearness is the lack of turbidity. Turbidity is, only in part, the effect of suspended particles on light passing through a liquid.

For hard copies of these papers, please contact McNab.