Device Evaluated
"Linear Kinetic Cell"
manufactured by Enertec, Inc., P.O. Box 85, Union City, Michigan, 49094, phone:
517.741.5015

System Data
A Water Dynamics, Inc. "Model CTTS 30SF"system, based on the above non-chemical device (NCD), was installed on a 500 ton cooling tower system used for chiller cooling at Sky Harbor Airport, Phoenix, AZ. The system included the NCD, a copper metal ion generator, a pumped bypass sand filter, and a conductivity based blowdown controller. The cooling towers were older, galvanized steel construction crossflow units.

Claims Made
Sales literature on the NCD claimed that it "is an effective, proven means of scale control for all types of commercial and industrial applications". It was stated that treatment of water with the NCD "results(ing) in a neutral condition in which the solids remain in suspension and will not form scale buildup; decreases the surface tension of the water, facilitating the removal of existing scale deposits over a period of time."

History
The above NCD system was installed in March 1994, on an existing cooling tower system. Makeup was untreated City of Phoenix city water with the system operated between 10 and 18 cycles. Chiller approach temperatures have been reported to be between 3 and 4 F with no scale problems reported. PCT personnel visited the site in November 1995, and obtained water samples. During the visit, chiller approach temperatures were again reported to be in the 3 to 4 F range and system operation was considered to be acceptable. Our examination of the rather poor condition cooling tower showed some very hard scale present in wetted fill areas, but no major scale problems.

Update, 1998, the entire cooling tower system and NCD have been replaced by a new cooling tower system which is operated with a "standard" chemical product based water management program. Operators report that the decision was made to return to a chemical program based on the large amount of "sludge" that formed in the cooling tower basins with use of the NCD based water treatment program.

Removal of the sludge was deemed to present a substantial cost and potential trouble spot as to deposition and under deposit corrosion.

Analytical Data
The following data was obtained from the water samples.

Parameter	Makeup	Cooling Tower	Expected
pH su	7.55	8.67	9.43
total alkalinity mg/l	156	512	2824
conductivity mmhos	719	13030
calcium mg/l	51.0	260	923
magnesium mg/l	26.2	495	474
silicon mg/l	5.0	46.8	90.5
chloride mg/l	72	2700	1303
dissolved solids mg/l	390	6840
suspended solids mg/l		47
total hardness mg/l	235	2687	4254

Discussion
Literature supplied on the NCD, bulletins dated 1982, 1993, and 1994 examined, notes that it controls scale by aligning and "polarizing" molecules within the water stream passing through the unit via a DC powered electromagnetic field. This magnetically induced alignment then allows molecular chains to form, which persist in the liquid, as it flows through the cooling system. This explanation, that passing a water stream through a DC powered electromagnetic field can have any effect on downstream water properties; much less prevent scale formation, reduce water surface tension, or remove existing scale; contradicts the laws of physics and chemistry. Simple Brownian random motion due to the temperature and non&-linear flow of the water would quickly disrupt any such alignment, or molecular chains, produced in water by an electromagnetic field the moment the water passed out of the field.

The analytical data clearly shows a major loss of scale forming constituents from the cycled cooling water. Our computer simulation cycling of the makeup water also confirms that the cycled water is extremely scaling and should have deposited scale in large amounts. This information, combined with the report of no scale problems in the chillers and our finding no major scale deposition in the cooling tower fill, presents a problem stated simply as "where is the scale".

The manufacturer of the NCD, naturally enough, claims that the NCD is responsible and its ability to control scale has thus been proven.

The literature shows an apparent similar control of scale by ozonation with the actual mechanism for control of scale being precipitation of the scale forming minerals in the bulk water due to the high pH and alkalinity values of the cycled cooling waters.

On consideration of the water chemistry in the cycled cooling tower, it is apparent that the actual mechanism preventing massive scale formation in the cooling tower and chillers is precipitation of calcium carbonate and magnesium silicate in the bulk water due to the high pH and alkalinities obtained by cycling. The precipitate is then filtered from the recirculating water by the bypass filter (provided as part of the NCD device package) and disposed of with the backwash.

We would point out that this particular chemistry has been used in chemical treatment of boilers for almost 100 years and is described in the literature as "carbonate cycle" treatment. This chemistry, commonly called soda&-lime softening, is also used to soften water; the water pH is increased by addition of lime and/or soda ash to precipitate the hardness in the bulk water as a settlable floc. 

Conclusion
While on initial examination it appears that the NCD was actually controlling scale formation in a highly cycled cooling tower, it is apparent on critical review that this is not the case. The actual mechanism preventing scaling of the cooling towers and chillers is precipitation of the scale forming minerals in the bulk water brought about by the high pH and alkalinity conditions created by high cycles operation. Precipitated material is then removed from the system by filtration and disposed of in the filter backwash.

An experiment to confirm this method for control of scale was carried out by our firm in 1994 and 1995. The experiment consisted of eliminating the blowdown from a cooling tower used in HVAC service at Eriez Magnetics, Erie, PA, and carefully monitoring it and the solids removed by the bypass filter. With no NCD present, the system was operated for two years with no scaling of either the chiller or cooling tower. The scale minerals were accounted for in the solids removed by the bypass filter.

A valid question is why this method has not been put into use by the mainstream water treatment companies. The answer is complex and involves the following factors at a minimum:

• A general lack of bypass filtration on cooling towers (if the precipitated material is not removed a deposition problem can quickly result)
• Reduction in use and sales of scale control chemicals by the companies involved
• The high cycles needed to attain the required pH and alkalinity values
• The corrosion control problem presented by "white rust"
• Inability of the chemistry to control scale in high heat flux industrial applications
• The need to control the program in the precipitation range at all times.

Of these problems, the control problem is deemed most critical, as severe scaling will take place quickly during any period when cycles drop, reducing the pH and alkalinity to values insufficient to cause bulk precipitation. "White rust" corrosion control is also a major problem where galvanized steel components are used in the cooling system. This problem has only been addressed by Fremont Industries and ProChemTech, which are the only two firms in the water management industry that have developed specific white rust inhibitors.