The Exhibitor (1960)

Your Stake in Water Conditiening A Comprehensive Report Concerning The Necessity of Water Conditioning B Every dollar spent on water conditioning can mean savings of many times that amount in equipment losses, operating efficiency, and customer satisfaction. That’s why every re¬ frigeration and air-conditioning contractor has a big stake in the field of water condi¬ tioning. Water is a universal solvent that will dis¬ solve hundreds of thousands of substances. When obtained from the ground, well, river or sea, it contains some 10 to 20 of these sub¬ stances in proportions large enough to in¬ fluence its character substantially. It dissolves these materials while flowing over and through the ground. Even before it comes in contact with the earth, rain water dissolves gases and picks up impurities from the air. A typical analy¬ sis of relatively pure rain water has shown 41 ppm (parts per million) of dissolved solids and 16 ppm of insoluble matter. This actually totals 12.9 pounds of solids per acre inch of rain water. Natural waters contain solids and gases in amovmts varying from relatively few parts per million to compositions exceeding that of sea water, which contains 36,000 ppm or 3.6 percent dissolved material. Dissolved material in water can be respon¬ sible for serious corrosion, eventually de¬ stroying any domestic, commercial or indus¬ trial equipment with which it comes in con¬ tact. It also can be responsible for deposit¬ ing harmful coatings in such equipment as pipe lines, condensers, boilers, and other forms of heat exchangers. All of these dissolved materials have solu¬ bility limits. At a given temperature only a certain quantity of a given substance will dissolve in water. Solubility of most substances increases with a rise in temperature, but one salt in particular — calcium carbonate — has an in¬ verse solubility relationship. It becomes less soluble as the temperature increases. This compound is the most common scale form¬ ing substance. Since water is in short supply in many areas and the cost of it is increasing, most of the larger air-conditioning or refrigeration systems are using water saving devices such as cooling towers or evaporative condensers to remove the heat from the refrigeration cycle. This is done by evaporating pure water into the air from open circulating water systems. Net result of this action is that the concentration of solids in the cir¬ culating water increases. The solubility limit of calcium carbonate may be approached. Then scale results, particularly in the heat exchanger where the water is warmed. Other substances such as calcium sulfate may pre¬ cipitate similarly. Dissolved substances such as chlorides, sul¬ fates, carbon dioxide, and oxygen are re¬ sponsible for corrosion of metal surfaces in contact with water. Both open and closed recirculating systems must be protected from excessive corrosion. Although closed recirculating heating and cooling water systems are not usually sus By Keville Development Manager^ Coil Department And SCICCHITANO Water Conditioning Service Engineer Carrier Corporation ceptible to serious scaling problems, corro¬ sion can destroy expensive piping systems. Resulting corrosion products, such as rust, can obstruct valves, strainers, gauges, and pumps. According to a United Nations report on Conservation of Materials, the total cost of corrosion in the United States in one year is computed to be $51/2 billion. One of the rea¬ sons why this figure was not many, many times higher is that an estimated $66 mil¬ lion per year (about one per cent) is spent for water conditioning. In other words, cost of corrosion prevention is only a small frac¬ tion of the loss which occiurs without proper control. In addition, losses in process efficiency decreases in equipment capacity, and result¬ ant cuts in net earnings, which occur as a result of scale deposition in water systems, run into millions of dollars annually. Methods have been developed by chemists and engineers for handling and treating water on a basis economically attractive to the water user. Water conditioning, today, is a science. Its application is technically well understood. Its use, as forcefully illus¬ trated by the figures just cited, is an eco¬ nomic necessity. HOTEL CASE HISTORY Consider the case history of one hotel own¬ er, for example. As a result of not spending a few dollars on water conditioning, he com¬ pletely lost the use of his air-conditioning system. Because of this, the hotel missed out on $30,000 worth of convention business while the equipment was being repaired. There are a number of ways in which cor¬ rosion and scale may be kept under control. The method most commonly used in refrig¬ eration and air-conditioning systems is the addition of chemicals to inhibit corrosion and scaling tendencies. For example, the use of certain polyphos¬ phates maintained in concentrations of only about three ppm will substantially increase the apparent solubility of calcium carbonate. The effect of this treatment, plus the inten¬ tional wastage or bleed-off of a small amoimt of water to control the concentration of dis¬ solved solids, will reduce the danger of scal¬ ing. Corrosion inhibitors such as chromate and nitrite salts used in concentrations between 200 and 500 ppm effectively reduce the attack on metal surfaces. Destruction of wooden cooling towers is prevented through proper pH control. BACTERIAL DEPOSITS The growth of algae and bacterial deposits, which cause unsanitary conditions and inter¬ fere with fluid flow and heat transfer, is also prevented through the proper use of chemi¬ cal additives. As previously pointed out, corrosion and scaling cause loss of capacity in refrigeration and air-conditioning systems, destruction of equipment, and lost business or reduced com¬ fort on the part of the customer. Unfortu¬ nately, many customers don’t understand this, so all such problems are likely to reflect unfavorably not only on the manufacturer of the equipment but also on the contractor who sold and installed it. Recognizing this fact, and wanting to in¬ crease customer satisfaction while reducing service costs. Carrier Corporation has for several years been conducting an intensive educational program on water conditioning. This program is headed by a specialist with training in chemical engineering as well as refrigeration. Aim of the program is to make the basic technology of water treatment understand¬ able to the man in the field, and to impress on him the fact that no “cure-all” gadget yet developed has proved to be a satisfactory substitute for a sound and scientific program of water conditioning. EXPENSES INVOLVED In many cases it is far less costly to prevent equipment corrosion by proper water con¬ ditioning than by using more corrosion-re¬ sistant (and more expensive) materials in construction of the equipment. This makes it practical for manufacturers to produce, and for contractors and engineers to apply, more economical equipment than would otherwise be possible. So the entire industry, as well as the user, stands to profit by a thorough imderstanding of the techniques involved in water conditioning and the savings that can result. Carrier’s program is a step in this direc¬ tion. It is in no way intended as a substitute for the services offered by established water conditioning companies. Advice and consulta¬ tion given is of a general nature, centering arormd the company’s own problems and relating to its own equipment. In every in¬ stance, inquirers are urged to contact a repu¬ table water conditioning firm for more spe¬ cific information. To help sales engineers, contractors, dis¬ tributors, dealers, architects, consulting en¬ gineers and equipment owners know what constitutes an adequate water conditioning program, and to assist them in evaluating any proposals made by companies specializing in this work. Carrier has published a “Speci¬ fication Guide for Water Conditioning.” Text of this guide is presented here. GENERAL CONDITIONS An adequate water conditioning program to control corrosion, scale, algae, slime, and sludge shall be provided for a period of years for open and closed water and brine systems, commencing with the start-up of the refrigeration and/or air-conditioning equipment. Recirculated water in wooden cooling towers shall be so conditioned as to prevent delignification of wood. (Continued on page 85) April 6, 1960 MOTION PICTURE EXHIBITOR-1960 THEATRE CATALOG Edition 79