1998 IIAR Technical Papers
   Colorado Springs, CO 
  20th Annual Meeting

Steps to Implement the US EPA's Risk Management Program Requirements
Author: Peter Jordan &  Ed Freedman

The Clean Air Act (CAA), as amended in 1990, requires the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA) to address concerns that chemical accidents could pose a risk to employees, the public, and the environment. The objective of these regulations is to prevent accidental chemical releases and minimize their impact. OSHA published its Process Safety Management (PSM) standard (29 CFR 1910.119) on February 24, 1992 (1). The focus of the PSM standard is protection of employees and on-site contractors. EPA published the "List Rule" (40 CFR Part 68) on January 31, 1994 and Risk Management Program (RM Program) regulations (40 CFR Part 68) on June 20, 1996 (2). The focus  of the RM Program regulations is protection of the public and the environment. 
Since 1994 we have advised companies to concentrate on the OSHA PSM standard since there was time (approximately 3 years) to comply with the EPA's regulations and the regulations were likely to undergo revisions. The time has now come to implement the RM Program regulations and contains step-by-step procedures for complying with the regulations. It is meant to complement the PSM and RMP Guide prepared for the IIAR. You should be able to gain an understanding of the regulations and be able to work toward compliance at your facility. 
Scenario-Based Emergency Planning for Ammonia Releases 
Author: David Moore, Larry Aleksandrich, & Chris Youngerman

The recently-enacted EPA Risk Management Program (RMP) regulations (40 CFR Part  68) require over 66,000 facilities nationwide to establish a Risk Management Program, including an Emergency Response Program. Most facilities ion the ammonia refrigeration industry have simple emergency plans to address onsite releases, but not necessarily plans to address the off-site consequences of an ammonia release. Though releases are rare, one that affects the public requires careful emergency planning and procedures to adequately manage. As such, it is prudent to take a second look at the current emergency plans for regulated facilities and to upgrade the emergency plans in light of the requirements of the RMP regulations.
This paper will present an outline of the Emergency planning and response requirements EPA has imposed on regulated facilities. Practical guidelines for preparing emergency plans based on hazard scenarios identified in the process Hazard Analyses (PHA) and for conducting drills necessary to satisfy the RMP requirements are presented. An outline of a complete emergency response plan is included.
Practical Use of Hazard Assessment Data
Author: Neil Mulvey

Section 111(r0 Accidental Release Prevention Regulations of the Clean air Act Amendments of 1990 (CAAA 19900 require EPA to promulgate regulations and develop guidance to prevent, detect and respond to accidental releases to the air, and mitigate the consequences of such releases by focusing prevention measures for toxic and flammable substances. As a result, EPA finalized its accidental release prevention requirements for all facilities covered by these regulations on June 20 1996. Stationary sources that have processes covered by these regulations are required to develop and implement a Risk Management Program.
How Piping Affects Safety Relief Valve Performance
Author: William V. Richard 

This paper the reduction in capacity of safety relief valves due to pressure drop developed by flow in the inlet and outlet piping. Flaws in the present code formula for allowable lengths of relief valve discharge piping are discussed. The new method being adopted is the ASHRAE-15 Standard for sizing relief valve discharge piping are detailed. Methods of estimating the effect of the three-way valve and inlet piing on the capacity of dual relief valves from six manufactures. The effect of using oversized three way valves is shown. A difference between the set pressure and the re-seating pressure) provides the designer with assurance that the operation of the relief valve will be stable. The need for more information on the individual characteristics of safety relief valves is discussed.
Effects of Water Contamination in Ammonia
Author: Per Skaebeack Nielsen

Water contamination is often an underestimated problem in industrial ammonia refrigeration systems. The aim of this paper is to point out which problems, often seen in industrial ammonia refrigeration systems, can be related to water contamination. Often these water contamination related problems are the reason for a severe increase in service, maintenance and running costs without the cause of the problems being realized and cured.
Design Considerations of Evaporative Condensers for Severe Seismic Zone and Wind Load Applications
Author: Jeffery W. Nank & Bob Shriver

The International Conference of Building Officials developed the Uniform Building Code to provide structural engineering design guidelines in an effort to protect human life. Portions of this code apply to all building structures and mechanical equipment, such as evaporative condensers, in earthquake and hurricane prone regions. While there are numerous local and regional codes that also apply, most of these are quite similar to the UBC. The Uniform Building Code is undoubtedly the most universal and widely accepted. Therefore, a proper understanding of this code as it relates to seismic and wind load is essential.
Water Dump Tanks: Fact or Fiction?
Author: Henry B. Bonar II 

I am going to let you be the judge and jury: let me give you the evidence and then you decide between fact and fiction. The evidence and facts I have to give you are divided into three categories: 1. History of the Water Dump Tank 2. Chemistry of the Tank 3. Mechanics and Mechanical Safety of the Dump Tank
Designing Air Coolers for Direct Expansion with Ammonia
Author: Bruce Nelson 

Designers and operators of ammonia refrigeration systems with direct expansion air coolers must have a basic understanding of the unique characteristics and limitations of ammonia in order to successfully operate such systems. This paper will deal with the special design considerations required for ammonia air coolers using direct expansion.
Screw Compressor Basics
Author: Joseph Pillis  

Rotary screw compressors are widely used today in industrial refrigeration for compression of ammonia and other refrigerating gases. Simple in concept, the screw geometry is sufficiently difficult to visualize that many people using screws today have only a vague idea how they actually work. An understanding of the basics of their operation will help in applying them correctly, avoiding nuisance problems in operation, and achieving the best overall system designs.
Ammonia Piping Design
Author: Vernon Alexander, P.E.  

The piping which interconnects the many equipment components is a very important element in a refrigeration system. Its design can have a substantial effect upon the performance and energy efficiency of the system. This paper deals with the sizing and layout of the various lines through which the ammonia flows. No attempt is made to become involved in the fundamentals related to any particular type of fluid flow which may occur nor any unusual instances. Rather, in keeping with the theme of this meeting, we start with a review of several basic principles related to flow in pipes.
Ammonia Versus Refrigerant 22
Author: Walter Gameiro  

It is difficult to establish rigid laws of design for industrial refrigeration, however, one can outline a few trends of this industry. When designing a new system, a designer should check out the following basic details: 1. Verify which system has the smallest capital cost and the smallest running costs. 2. Consider carefully before designing systems requiring refrigerant replacement within a few years. 3. In small systems, it is normally cheaper to design HFC or HCFCs, especially on medium or high temperatures if one can use direct expansion. In medium-sized systems, sometimes it is still cheaper to use HFCs because the efficiency difference of ammonia will not always amortize the investment in short enough time. In large systems, flooded or recirculated Industrial Refrigeration. 4. Always design with ammonia. (Cheaper investment. Cheaper to run. No oil management nightmares.)
Internally Enhanced Carbon Steel Tubes for Ammonia Chillers
Author: T.J. Rabas 

Heat transfer and pressure-drop data were obtained with two different tube geometries in the turbulent, transition, and laminar flow regimes. The experiment with one tube was conducted at Rensselaer Polytechnic Institute (RPI) and with the other at Ohio State University (OSU). Above Re = 10,000, the enhancement levels are essentially constant at 2.5 and 3.0 and are a function mainly of the tube geometry. The friction-factor increase is about the same as the thermal enhancement level for both tubes for Re < 10,000 but it continues to increase with increasing Re. For Re < 10,000, the enhancement levels increase even further, reaching a value of 5.9 at Re = 2,000 for the tube tested at RPI. The reason for this significant enhancement in the Re range of 2,000 to 5,000 is the earlier transition to turbulent flow with enhanced tubes. For Re values in the 2,000 to 7,000 range, the friction-factor is significantly less than the heat transfer enhancement.
Applications for Factory-Packaged Chillers
Author: Bo Frejd

In today’s market, there is a clear trend towards using indirect systems based on compact factory packaged chillers. In many ways, these chillers are now playing a vital role in refrigeration technology irrespective, for the most part, of the refrigerant being used. Indirect systems are found in more diverse and more extensive applications than ever before. As a result of new technologies that are reducing the refrigerant charge needed in systems, refrigerants such as ammonia are finding wider usage beyond industrial cooling and freezing plants - their traditional field of application. Ammonia liquid chiller units have become an attractive and competitive alternative, and their use now extends into lower capacity ranges than previously.
6000 TR Ammonia Water Chilling System
Author: George C. Briley, P.E. 

The Louisiana State Capitol building was air-conditioned in the middle 1930’s, employing 100% outside air, and the air distribution system has remained the same over all these years due to space limitations. There is no room for a return air system. There were over 20 water chilling systems in other office buildings which have been built since the 1930’s in a campus-like setting on the banks of the Mississippi River. All of the systems employ CFC and HCFC refrigerants. Each independent system employed centrifugal or screw and/or reciprocating compressors purchased from various manufacturers. Maintenance had become costly and rental equipment had to be employed from time to time due to equipment breakdown. Some years prior to this project being funded, a detailed study of the air conditioning load for each building was completed. This study, along with some planned expansions, was used in the analysis required to establish the size of the central water chilling system. The final design was based on six 1200 TR systems with one chiller being a standby. Since the planned projects were some years away, only five 1200 TR systems were installed.
What Can We Learn From the Shreveport Ammonia Fire?
Author: Andres Lindborg 

The March 1985 Fire Journal contained an article about the Dixie Cold Storage fire in Shreveport, LA. The article, written within a half year after the accident, provides unclear theories about the cause of the fire from a fire expert’s point of view, and little was learned from the incident. At the time of the article, legal proceedings were underway and all involved preferred not to distribute their experience. Some years later, I (by chance) met the refrigeration expert who was called to the site on the second day for investigation. He indicated that one stop valve was wrongly installed, with the stem downward. We can learn more from this accident! This paper is not intended to identify scapegoats, although there may have been several. People have suffered, tears have dried and much water has passed under the bridge since 1984. But we want to learn what happened in Shreveport and prevent these things from happening again. All of the material in this paper is secondary information collected from a distance over the years, which means that some items are speculative on the part of the author or are hearsay. However, speculative inferences are good enough to learn from if they can be related to similar situations. I will not get into discussions that blame or free other parties/persons.
External Surface Corrosion of Carbon Steel in Use on Ammonia Refrigeration Systems 
Author: Gregory S. Bergtold 

One of the less understood problems of carbon steel in refrigeration systems reliability is corrosion. The threat of corrosion is a major concern to everyone in the industry as one wants to protect refrigeration systems and operators from the  consequences of any failure. Secondary to the safety of workers is the economic impact losses resulting from sudden failure of piping systems, tanks and n=metal components of machinery. I order to evaluate the economic losses resulting from corrosion failure, two types of losses must be considered, the direct cost of replacing the failed equipment and the indirect cost which is more difficult to determine... It is the intent of this paper to help the reader understand how corrosion of carbon steel takes place in order to better predict where potential problems may surface in a refrigeration system.
Case Study of Hydraulic Shock Events in an Ammonia Refrigerating System
Author: Christy Glennon  

Occurrences of “hydraulic shock” events in ammonia refrigerating systems have been widely reported, particularly as they have been associated with hot gas defrosting of low temperature systems. In most of the reported cases the “shock” or “hammer,” as it is often referred to, was of sufficient magnitude to be destructive; that is, some component of the system failed to the extent of fracture resulting in a release of ammonia. Many aspects of those hammer events that are associated with hot gas defrost are understood to some degree and there are published guidelines to help designers and operators avoid their occurrence [IIAR (1992)]. There are, however, numerous other hammer events that regularly occur in ammonia refrigerating systems. Some of these other hammer events are less well understood and not widely reported. But, it is important that the design and operating issues that affect the potential for the occurrence of all types of hydraulic shock events be understood. In this way the likelihood of their occurrence can be reduced by “designing out” possible contributing factors. This paper deals with hydraulic shock events that occurred during commissioning of a major addition to the refrigerating system in a large food processing plant. Two separate recurring hydraulic shock events in different parts of the piping system are reviewed. It is intended that this discussion will add to the body of knowledge about these kinds of events and the contributing factors so that they can be eliminated from future projects.