Document ZBBz9E4RLV58g8G76VK6D9z8V

1044 CHAPTER 41 1957 Guide cordingly, it is necessary the designers of electric heating installations obtain specific information from the local electric utility company on both existing and anticipated future conditions at the location, before specifying the capacity and voltage for equipment, wiring and. controls. BIBLIOGRAPHY Electric House Heating--Load Characteristics and Economics, by W. F. Friend (Proceedings of Midwest Power Conference, April 1951). Electric House Heating, by E. E. Parks (Electrical Engineering, August 195!). Electric House Heating, issued by Rural Electrification Administration (REA Bulletin 142-1, November 1952). -Complete Electric House Heating, by F. A. Compton (Edison Electric Institute Bulletin, May 1950). Experience with Electric Space Heating, by R. H. Giedd (AIEE Conference Paper, January 1953). House Heating Experience, by C. E. Simpson (Electrical World, October 9, 1948). Heating by Electricity in Tennessee Valley Area, by B. H. Martin and T.' W. Newberry (Heating and Ventilating, May 1948). - Longview House Heating Data, by H. G. Kelsey (Electrical West, September 1945). Electric Storage Heating Serves New Oregon School, by W. Bruce Morrison, (Healing, Piping and Air . Conditioning, June 1949). Electric Space Heating and Resulting System Load Factors, by T. H. Allen and C. D. Anderson, Jr. (AIEE Conference Paper, January 1953.) Electric House Heating Load Characteristics, by R. E. Sinclair (Electrical West, September 1950). House Heating Load Characteristics as They Affect Wiring Costs, by J. B. Cochran (Electrical World, April 12, 1947). Heat Factor Formula to Calculate Electric House Heating, by H. C. Bender (Electrical World, May 12, 1945). Modulating and Load-Limiting Controls for Electric House Heating, by W. F. Friend (Proceedings of American Power Conference, March 1953, also Heating and Ventilating August 1953, p. 82).. Progress Report on the Heat Pump, by W. F. Friend (Refrigerating Engineering, January 1951). Methods Developed for Built-In Radiant Heat (Electrical West, December 1948). Performance of Electrical System of Panel Heating with Four Stages of Insulation, by R. J. Lorenzi and J. F. Schreiber (Heating, Piping and Air Conditioning, January 1949). Radiant Heating by Electricity, by L. N. Roberson (Heating and Ventilating, September 1940, p. 89). Low-Voltage High-Current Radiant Heat, by R. S. Tice (Electrical West, December 1947). Applications of Radiant Energy (Lighting Handbook, Illuminating Engineering Society, 1952, Section 18). Radiant Glass Heating Panels (Technical News Bulletin, National Bureau of Standards, May 1953). Radiant Glass Heating Panels by P. R. Achenbach (Heating and Ventilating, January 1953, p. 83). American Standard--Household Automatic Electric Storage-Type Water Heaters, ASA C72.1-1949 (Na tional Electrical Manufacturers Association Publication No. WHl-1949). Federal Specification for Domestic Electric Storage Water Heaters, W-H-196, amended May 1949. Application of Electric Water Heaters to Domestic Service, by C. G. Hillier (Heating, Piping and Air Conditioning, November 1946). Industrial Electric Resistance Heating, by Lee P. Hynes (American Institute of Electrical Engineers, Paper Nol 48-247). Induction and Dielectric Heating, by Kennard Pinder '(Electrical Engineering, February 1947). EEI-NEMA Preferred Voltage Ratings for A-C Systems and Equipment (Edison Electric Institute Publica tion No. R-6, May 1949, also National Electrical Manufacturers Association Publication No. 11, May 1949). Standard Handbook for Electrical Engineers (McGraw-Hill Book Co., 1952). CHAPTER 42 CORROSION AND WATER-FORMED. DEPOSITS, CAUSES AND PREVENTION Definitions, Classification and Characteristics of Water, Causes and Prevention of Scales and Sludges, Causes and Prevention of Slimes, Underwater Corrosion, Atmospheric Corrosion, Buried Pipe Lines, Handling Water Treating Chemicals, Legal Regulations THE puipose of this chapter is to discuss some of the common prob lems arising from corrosion of heating and air conditioning equip ment and to suggest methods of preventing or reducing corrosion. DEFINITIONS Common terms used in the field of water treatment and corrosion are defined as follows: Alkalinity, The sum of the carbonate, bicarbonate and hydrate ions in water. Other ions such as phosphate or silicate may also partially contribute to alkalinity. Ordinarily the difference between the total hardness of a water and the alkalinity gives the amount of permanent or non-carbonate hardness present. Anode. A positive electrode toward which negatively charged non-metallic ions migrate and at which.reduction occurs in an electrolytic cell. In corrosion processes, the anode is usually the electrode having the greater tendency to go into solution. Biological Deposits. Biological deposits1 are water-formed deposits of biological organisms or the products of their life processes. Biological deposits may be mi croscopic in nature, such as slimes, or macroscopic, such as barnacles or mussels, bhmes are usually composed of deposits of a gelatinous or filamentous nature. Cathode. A negative electrode toward which positively charged metallic ions migrate and at which reduction, occurs in the electrolytic cell. In corrosion proc esses, the cathode is usually the electrode tending to resist corrosion. Corrosion. Corrosion* is destruction of a metal by chemical or electrochemical reaction with its environment. In the corrosion process, the reaction products formed may be soluble or insoluble in the contacting environment. Insoluble cor rosion products may deposit at or near the attacked area, or be carried along and deposited at a considerable distance therefrom. Corrosivity. Corrosivity* is the capacity of an environment to bring, about de struction of a metal by the process of corrosion. Corrosivity is a property of the environment, but it has no significance until the metal in question is specified. Electrolyte. A solution through which an electric current flows. . G&lvanic Corrosion. Corrosion generally resulting from the contact of two dis similar metals in an electrolyte. It is characterized by an electron flow from the metal of higher potential (anode), to the metal of the lower potential (cathode), re sulting in corrosion of the anodic metal. Galvanic cell corrosion may also result from 'ue contact of two similar metals in an electrolyte of non-uniform concentration, h ^iar(^ne3s- The sum of the calcium and magnesium contents in water. It is this "fcrdness that causes the water to resist the formation of soap lather. Temporary of carbonate hardness is that portion of the total hardness which can combine with tne carbonate or bicarbonate ions. The balance of the hardness, principally that 1045