1986 Technical Papers
 Tarpon Springs, FL
8th Annual Meeting

Water Dilution Ammonia Tanks
Author: Henry A. Saye, P.E.

The purpose of this presentation is to bring to the attention of the membership the code requirements for handeling ammonia discharge, using water tanks. What are water dump tanks? They are tanks of water, for use, if necessary, to relieve pressure or remove the liquid charge from a central ammonia system. The water dump would normally be used during an emergency condition. The emergency condition that first comes to mind would be a fire, although there could be others. The system may be manually activated, or automatically activated by the system relief valves.
An Update on the Design of Ammonia Rotary Vane Compressors
Author: Jeffery A. Leonard

The key to the prolific success of the rotary vane compressor is its utter simplicity. The rotary sliding vane design has fewer moving parts than reciprocating and screw compressors. There are no valves, pushrods, crankshafts or timing gears to inspect or replace. What the vane compressor does have are vanes, bearings and mechanical seals and all of these are readily accessible and easy to replace. Major components including the cylinder, rotor, and cylinder heads will last well over twenty years when maintained properly. When a major overhaul is required, the vanes, bearings and seals can typically be replaced in one day so downtime is minimal. The rotary sliding vane compressor is the only design available which automatically compensates for wear over time. Other types of compressors lose efficiency as parts wear resulting in greater than normal clearances. Since centrifugal force holds the sliding vanes tightly against the cylinder wall, the rotary compressor does not lose efficiency due to routine vane wear. Because of its single rotor design, the sliding vane compressor operates without vibration, greatly simplifying installation requirements. These features combine to make the rotary sliding vane compressor as viable today as it was forty years ago. The inherent simplicity, reliability, ease of maintenance and low first cost have resulted in thousands of successful ammonia refrigeration installations.
An Update on the Design of Ammonia Rotary Vane Compressors
Author: William Maxey

With the advent of the screw compressor during the last 15 years, the rotary has been overlooked in many compressor applications. However, the compressor is still used quite extensively and presents a good solution to many refrigeration application requirements. I would like to provide you with a comparison of performance and cost of the redesigned rotary vane compressor with reciprocating and screw compressors for booster compressor applications in ammonia refrigeration systems.
A New Concept in Small Screw Compressors for Refrigeration
Author: David H. Johnson and Peter A. O'Neill

In this paper, we show that as a result of fundamental research into rotor profiles and a totally new look at small screw compressors and their systems we have been able to produce a "New Concept in Small Screw Compressors". These are highly efficient at both full and part load and very compact while still maintaining the simplicity and high reliability of larger sizes and retaining the many technical developments built in the larger units.
How Codes and Regulations Affect the Design of Your Plant
Author: William V. Richards

This discussion traces how the record of ammonia accidents involving piping influences the writing of standards. Comparisons are made of ammonia diffusion, called for in fire codes, government regulations and ANSI standards. New ventilation requirements for machinery rooms proposed in ANSI and ISO standards are shown. The author concludes that new initiatives by IIAR are needed to implement safety in ammonia piping and diffusion methods.
Pressure Loss in Cone Stop Valves: Economic and Technical Consequences
Author: Knud Andersen and Flemming V. Boldvig

The present paper concerns the selection of cone stop valves for ammonia refrigeration pipe lines, with the objective of presenting some guidelines which an investor should take into consideration before selecting valves for a particular plant. The paper deals with two separate and independent issues, i.e. - Cone stop valves for suction and discharge gas lines, and - Cone stop valves for liquid lines. Furthermore some aspects of importance for the final decision are discussed, and some thoughts about future developments are offered. The primary reason for an investor to consider selection of optimum cone stop valves, along with all other plant components, is of course that the economic life of investment goods, a.o. ammonia refrigeration plants, can be expected to become ever shorter. It is therefore important that these installations should give the best possible return on investment.
Programmable Controller vs. Computer in the Controlling and Monitoring of a Refrigeration System
Author: David A. Murphy

The question, Should I use a programmable controller or a computer to control my refrigeration plant? is often asked. While the question is somewhat subjective and dependant upon individual circumstances and preferences, it is possible, knowing the relative merits of the two control methods, to make an objective judgement. Many factors enter into this decision process. Some of the factors are technical in nature, others relate strictly to people. The people issues, sometimes referred to as "the man-machine interface", are at least as important, if not more important, than the technical issues. The following is a list of questions that should be asked when deciding which type of control system to select: 1) How complex is the control task? 2) Will the system be expanded in the future? 3) What type of reporting/documentation is required? 4) Who will be designing/programming the system? 5 ) Who will be operating the system? 6) Who will be maintaining the system? This paper will attempt to provide guidance in the answering of the above questions.
Food Plant Process Air Conditioning
Author: Bruce A. Paulson

Process air conditioning is again just what it says, the conditioning of air to satisfy the requirements of a process. Process air conditioning could be for a specific machine, area, or space, not necessarily just for the comfort of the personnel. The total area of process air conditioning is very large and would be impossible to discuss in a short time here today. Most of the IIAR members are involved with the food industry. Therefore, I will confine my process air conditioning discussion to this industry.
Lubricating Oils for Refrigeration Systems
Author: Michael J . Zion, P.E.

I discuss here today some of the basics of refrigeration oils and their proper application. There exist other factors which may affect the actual selection of the best oil for a particular use. There is also continuing development of refrigeration oils which may affect this process. It behoves all of us to keep abreast of the changes occurring in this important area so that we can do our jobs of furnishing and maintaining efficient, cost effective and productive refrigeration systems.
Litigation in the Refrigeration Industry (In Two Parts)
Author: Vernon C. Alexander, P.E. and Ronald W. Sondee

The findings which will be presented today are those obtained as a result of our personal involvement in the litigation process -- Mr. Sondee, as attorney in many product liability cases, including three trials involving ammonia refrigeration, and your speaker as an expert witness in 16 lawsuits. Sixteen actions do not appear to be a very large number, yet from my experience a trend seems to be developing. Unfortunately it seems to be worsening rather than improving.
Evaporative Condensers: The Good, The Bad and The Ugly
Author: Richard P. Merrill

The evaporative condenser is often the most neglected and abused component of the refrigeration system. And that’s where the title comes in. Over the years we’ve seen plenty of GOOD evaporative condenser installations. We’ve also seen some BAD installations and some UGLY ones too. The problem is that the good ones are easily forgotten while the BAD units have reputations that seem to last forever. It’s my hope that by sharing some our experiences with you that we will have mostly GOOD ones to remember.
Design and Application of Semi-Hermetic Refrigerant Pumps
Author: Charles C. Hansen III 

Usage of hermetic refrigerant pumps is more widespread as they are more understood and better protected. Although some positive displacement pumps are still being used, especially in smaller sizes, they have fallen out of favor due to wear of close fitting parts as the result of abrasive particles or cavitation. Especially as systems have become larger, the trend has been toward centrifugal pumps using double mechanical seals or having hermetic motors. Perhaps the most important element of successful pump operation after achieving adequate suction head is the correct routing and sizing of suction piping to avoid bubble buildup or vapor vortexing into the pump.
Application of Integral Two-Stage (Compound) Reciprocating Compressors in Industrial Refrigeration
Author: Eugene A. Cosijn

It can be said that two-stage compression should be considered when one or all of the following conditions apply: The allowable maximum discharge temperature is exceeded in single-stage; The swept volume of the two stages together is less than the swept volume of a single stage, for a given refrigerating capacity; The C.O.P. is higher, or the specific power consumption is lower for two stage operation.
High Tech Ice-Making
Author: David C. Frackelton

The expressions "HIGH TECH" and "STATE OF THE ART" are bandied about frequently. How are we trying to use these expressions? Generally, we imply that we are doing things with more foresight, are using new products giving the user more control, we are lowering maintenance and increasing reliability, or just providing the user higher quality in his end product. In the ice machine business there are different "STATES OF THE ART", some of which have not changed in 20 years. I would like to relate some of the changes that have been brought to bear in the tube-ice machine business in the last few years. Some of these changes are not industry-wide among tube-ice manufacturers. The first items are examples of using existing technology in a new application.