1987 Technical Papers
San Diego, CA
9th Annual Meeting

No Such Thing as Safe Enough 
Author: John M. Jacus

It is hoped that this presentation will not be seen as merely puffery, over our success, as it were, in one Workmen's Compensation ammonia accident case. For when all accounts are made there are no winners in accident cases. No matter who pays, nor how much, all must suffer through the dance which we call litigation. And all lose. Even the attorneys, winners and losers alike, if they've done their work well, leave a pound of their own flesh on the trail of legal justice for their clients. The paper hopes to motivate you to a course of action.
Author: Weston G. Strauch

How does Superheat affect compressor discharge temperature? There are many ways Superheat operates within the refrigeration and air conditioning system. Today we are going to see how it affects the operation of the compressor and how the Superheat varies with different refrigerants and operating conditions.
A. Strong Look at Control Valves
Author: Arthur P. Strong

The term "control valve" includes a host of types, variations, combinations and sizes used for many different purposes and applications. However, this talk will deal only with Solenoid Valves and Pressure Regulators. While the variations are many and sometimes complicated, the basics are few and simple. So, in the midst of our world of solid state controls, microprocessors, and black boxes with digital readouts, I promise to abide by the often forgotten and frequently overlooked "KISS" Principle; that is, "Keep It Simple Stupid". Personally, I find it a lot easier that way.
Ammonia for Air-Conditioning 
Author: Ronald P. Vallort, John Sanchez and William V. Richards

In today's market, you would not expect to find industrial quality ammonia refrigeration installed for air conditioning in a new, three story, suburban office building. This report describes a 200 HP ice storage and water chilling system in an 85,000 square foot building. An analysis of alternative compressors and refrigerants for static ice builders is included. Operating experience with the computer control system is described. Satisfactory experience in two seasons suggests there may be many opportunities to apply industrial cooling systems for commercial buildings.
IIAR Minimum Safety Criteria for a Safe Ammonia Refrigeration System
Author:  Joseph A. Smith

The objective of this publication is to set forth minimum safety criteria in which a qualified person may determine that a new or existing ammonia refrigeration system is a safe operating refrigeration facility.
A Fire Chief's Perspective of Ammonia
Author: Gary W. Smith

In order to properly address the fire departments' emergency concerns existent in industrial refrigeration we must consider the concept of "perspective". The attitudes, viewpoints, training, and experiences of members of a fire department are different than industrial refrigeration employees. In fact, the emergency response concerns of a fire department sometimes run counter to the profit motive of industry. The best emergency response answers include a joint concern for human and product safety. The goal of our current efforts is to narrow the gap between the fire service and refrigeration industry by joint training and proper prevention and preplanning.
Small Screw Compressors: Bringing Big Advantages to Small Sizes 
Author: Joseph W. Pillis

Twin helical rotary screw compressors have been well accepted in the ammonia refrigeration industry and today account for a high percentage of the compression equipment in use in the 200 to 3000 CFM range. However; the application of screws below the 200 CFH level has been much more limited, due primarily to relatively poor efficiency and prohibitive price, compared to reciprocating compressors in this smaller size range. Through the incorporation of relatively new technology, small screws have been designed and brought to market, having efficiency and price competitive with existing reciprocating compressors, while stlll having the advantages that have made screw compressors so popular in the larger size. One approach to the design of a compressor specifically suited for ammonia refrigeration is presented. 
Qualified Ammonia Refrigeration Operating Engineer vs. Unqualified Operator
Author: Robert L. Norcross

To prepare a trainee to be a "Qualified Operator" you must have some tools to work with. 1.) You need standards and safety practices which are provided to the industry through IIAR, RETA, ASHRAE, ASME, and RSES. 2.) You need educational material which is available in the Industry through IIAR, RETA, RSES, and Public Education and Refrigeration Text Books. 3.) Goals for the Trainee: 1. Job Description 2. Certification or License 4.) Record Keeping through: 1. Log Books 2. Preventive Maintenance Records 3. Daily Log Sheets 4. Computer Printers 5.) Safety: Emergency Evacuation Procedures, Respirator Training, Color codes, labeling pipes, and Direction of Flow arrows, Relief Valve Replacement Procedures. Examples of some of these tools are presented in this paper.
Dry Operation of Evaporative Condensers 
Author: Steven M. Benz

Nature tells us that the wet bulb temperature is always lower than the dry bulb temperature unless 100% relative humidity conditions (rain) are present. Therefore, evaporative condensers offer the lowest possible design condensing temperatures because they cool according to the wet bulb temperature in one efficient heat transfer step. Design wet bulb temperatures are typically 15 to 25 degrees lower than design dry bulb temperatures. The lower condensing temperatures afforded by evaporative condensers result in energy savings of 20% to 40%, smaller and less costly compressors, lower discharge temperatures and less compressor maintenance. Air-cooled condensers offer relatively few advantages. They are competitive on a first cost basis only up to about 10 or 20 tons. In general, they cost more to install and operate. Energy costs are much higher and maintenance costs are higher due to higher discharge temperatures. But, some users may prefer to operate air-cooled condensers because they have concerns regarding water availability, water costs, water quality, water treatment, visible plume formation or sub-freezing operation. So, the only possible advantages are related to water or lack of water. However, evaporative condensers can be designed to operate both wet and dry, thus providing the economies associated with evaporative heat transfer for design days, but also eliminating concerns regarding evaporative cooling equipment at off-peak conditions.
Large Capacity Heat Pump Using Vacuum Ice Production as Heat Source
Author: Knud Andersen and Flemming V. Boldvig

The paper describes a pilot plant comprising the newly invented Vacuum Ice Maker utilized as an industrial Heat Pump with cold water as a heat source, in a Danish Central Heating System. The technical principle is described, and the economical benefits are calculated. It is concluded that the invention is well suited as large industrial heat pump under extreme ambient conditions, and economically attractive under the conditions existing in Denmark.
The Effects of Contaminants on Compressor Oil in Ammonia Systems 
Author: James F. Landry

The purpose of the lubricating oil in an ammonia refrigeration system is to lubricate the compressor. Many consider the lubricating oil the lifeblood of the compressor. If this lifeblood becomes contaminated, the whole refrigeration system is in jeopardy. Contaminants of the oil can cause many varied effects which are the subject of this paper. This paper's objectives are: 1. To present the common ammonia compressor oil contaminants and their common sources. 2. To explain what harm these contaminants can cause to the refrigeration system. 3. To point out other important consequences of contaminants. 4. To explain the importance of used oil analysis. 5. To show how to make the system more resistant to contaminants, and how to reduce them.
Heat Recovery Technology: Old and New 
Author: Vernon C. Alexander, P.E.

Today only the foolhardy or uninformed would risk using ''old" type heat exchangers where potable water service is involved. However, where the heat is to be transferred to air or to a liquid in a closed recirculating system the "old" heat exchangers can still be used. It should be recognized that they are not leakproof and that reservoirs or expansion tanks should be regularly checked for the presence of ammonia fumes. The present day double wall vented heat exchanger though similar in function differs greatly in design and appearance.
Safety Responsibilities: The Manufacturer, The Contractor, and the End User 
Author: LeRoy Molsbee

The objective of this presentation is to set forth a challenge that will assist all concerned to provide improvement in operations with the net effect being safety. Fifty plant engineers were surveyed and asked the following questions: (1) What would help in assisting to make your operation safer? (2) Where do you turn for answers regarding the safe operation of equipment? The answers received fit into eight major categories as outlined below.
Interfacing Computer Control with the Refrigeration System
Author: Wilbert Stoecker, Derek Lunn, Dr. John Hench, David G. Frackelton, and Jacob P. Persem

At the outset we should admit what we are trying to accomplish by this presentation. We are trying to promote the application of computer control systems for industrial refrigeration systems. The principal application of computer control so far has been for compressor packages, and there are reasons for progress in that application. The installation can be done in a factory rather than a field environment, and the compressor manufacturer knows the characteristics of the compressor and can build on the experience of past installations. The target for computer control that we are trying to push in the next hour is of the refrigeration system that could include the overall control of the compressors, but also regulating valves, coils and their defrost, pumps, and all other parts of the systems that otherwise would be under manual regulation. The panel members making the presentations today represent considerable experience in successful application of computer control. Both system designers and end users are represented. Derek Lunn will present the overview of how to decide what can and should be monitored and controlled, John Hench will bring the information from the system to the computer in his discussion of sensors and transducers, Dave Frackelton covers the path in the other direction from the computer to the devices being controlled, and Jake Persem concentrates on communicating between computers such as between a central computer and sattelite controllers.