1993 IIAR Technical Papers
  Vancouver, B.C.
 15th Annual Meeting

Steps for Complying with Process Safety Management (PSM) Regulations
Author:  Neil Mulvey & Peter Jordan

The words Process Safety Management, or PSM, seem to be on the lips of everyone involved with highly hazardous materials. Much of the interest has developed with the issuance of the Occupational Safety and Health Administration's (OSHA) Process Safety Management (PSM) regulations (29 CFR Part 1910.119) which became effective on May 26, 1992. These regulations are designed to protect employees from the risks associated with accidental releases of highly hazardous chemicals. Besides wondering how the PSM movement developed momentum, many of those individuals responsible for their company's compliance with industry guidelines and state and federal regulations are struggling with questions like, "What are we required to do?", "What is our current status?", and "What should we do first?" In response to these questions, this paper outlines the background and history behind the Process Safety Management regulations, describes the requirements from the regulations, and presents a list of steps to follow in order to comply with the regulations.
Administration of an Ammonia Industrial Emergency Response Team
Author: Patrick Harmon

OSHA is the ultimate inspector for the training, certification and administration portions of the HAZWOPER regulation and any other safety program. Unless OSHA is on-site during an incident or simulation, they have nothing to evaluate except your written program documents related to your Emergency Response Team. A significant number of OSHA citations are given to companies that have had no catastrophic worker injury, and no history of injury. Many OSHA citations are for paperwork violations. The administrative side of safety programs is usually not well documented. You may know what you have done, but OSHA can only review your documentation. This presentation will outline what OSHA may look for in an inspection, and how you can document what you do so OSHA will understand it.
Article 80 of the Uniform Fire Code: Compliance Case Study for Ammonia Refrigeration Systems
Author: Ellis Norton

IIAR and other refrigeration industry groups are working with ICBO and IFCI to remove ammonia refrigeration systems from Article 80. This will not happen immediately, however, and in the meantime we must comply. The methods presented in this discussion are designed to meet the requirements in Article 80 with a minimum impact on refrigeration system safety operation and cost.
International Codes and Standards of Industrial Refrigeration Valves
Author: Fred Herl

This paper describes the development of international codes and standards for industrial refrigeration valves. In particular, German, European and international documents that cover valves used for refrigerating systems are reviewed. The origins of German standards (DIN) and accident prevention regulations for refrigeration plants, in particular refrigeration valves, are described. The German pressure vessel regulations which apply to refrigeration plants, including pressure vessels, pipework and valves, are also discussed. A new European Community (EC) Pressurized Apparatus Guideline for refrigeration plants will be established. The Guideline will be supplemented by European standards for refrigeration plants (EN 378). A draft standard for refrigerating system valves, based on the German valve standard (DIN 3158), is being developed and should be available in June/July 1993. The requirements of the draft valve standard are described in this paper. When the final standard is published, a comparison should be made with U.S. standards.
Refrigerants after CFC’s - What are the Choices?
Author: Kenneth E. Hickman

Alternative refrigerants are being developed and tested as successors to the CFC's and R-22. Some of the alternative refrigerants can be used in existing systems with proper changeout procedures and modifications. Other alternatives are best used in new systems only. A few of the new refrigerants are flammable, leading the industry to conduct a fresh examination of applications where they may be used safely. A number of the new refrigerants are "zeotropes" - mixtures with constituents that boil and condense over a range of temperatures, calling for thought about new heat exchanger designs. Some of the mixtures contain flammable components, but the proportions are adjusted with other nonflammable components so that the mixture remains nonflammable under expected operating and storage conditions. This paper presents an update on the near-term and "next generation" refrigerants under test to succeed R-12, R-502, and R-22. The present state of knowledge about these refrigerants is explained. A major program to evaluate these refrigerants, being conducted under the auspices of ARI, is described. System design modifications needed to employ these refrigerants, some of the performance changes to be expected, and implications for system servicing are described.
Lubricants for Use with Highly Fluorinated Refrigerants
Author: Glenn D. Short and Thomas E. Rajewski

This paper provides an update on lubricants for use with HFC refrigerants and HFC refrigerant blends. The omission of other refrigerants, such as ammonia or hydrocarbons, does not mean that they should not be considered for an application. In fact, the authors believe that the use of ammonia as an alternative refrigerant to CFCs provides many performance advantages. The International Institute of Ammonia Refrigeration (IIAR) is investigating the opportunities for ammonia both for retail refrigeration and chiller applications. Also, while the author’s company supplied some of the lubricants, this paper is intended to be a general survey of current practices.
Ultraviolet Leak Detection as a Tool for Reducing Ammonia Emissions
Author: John T. Duerr

Leak detection of ammonia systems has been regarded as a "last ditch" effort. The attitude of ''we don't need any sort of leak detection system, we can smell the leaks!" was, and still is prevalent. When it was necessary, searching for leaks consisted of a time consuming, monotonous, inch by inch search over every potential leak site with an ultrasonic leak detector, a smoldering sulfur stick, or ammonia test paper. Even if this uncomfortable and burdensome job was undertaken, leaks were not consistently found and potential leak sites which were in unexpected areas, such as in straight tubing lines, were not even checked. Labor costs were prohibitive when they were compared to the minimal costs incurred if the system was simply "topped off". Leak detection of a system was far from being a prime concern. Now, however, legislation and the need to minimize negative public reaction to the expanded usage of ammonia as a refrigerant may force the ammonia refrigeration industry to search for a new and more efficient method of finding leaks.
A Device for the Efficient Storage and Recycling of Ammonia During Pump-Out and Emergency Situations
Author: Uwe Rockenfeller, Ph. D., Paul Sarkisian and Lance Kirol, P.E.

Ammoniated complex compounds are viable media for use in a pump-out product. Their large refrigerant holding capacity, which is significantly greater than competing media, allow their use in a practical device. A pump-out product utilizing complex compounds is now available for use in ammonia plants. Field experience has shown the product to be capable of reducing system maintenance downtime dramatically.
The Control of Moisture in Food Plants
Author: D. B. Devendorf

To meet the technology required for food plants in the 1990s, one must control what phase moisture appears in the plant. If moisture appears as a solid (ice), the plant owner will experience lost production and the inability to freeze a continuous, high quality product. If moisture appears in a liquid form (water) in a food plant, problems with quality control, poor shelf life, and governmental inspections are sure to follow. If moisture appears in a vapor form, the plant will invariably produce a high quality product with resultant high profitability. For the purpose of this presentation, we shall consider the three most common areas in food processing plants: Freezers, Coolers, Processing and Production Areas and Special Material Holding Coolers.
Plate Heat Exchangers in Refrigeration
Author: Paul C. Cogan

Plate heat exchangers offer a number of advantages for refrigeration applications: Heat transfer coefficients are much higher for plate heat exchangers for both evaporating and condensing duties. This results in smaller heat exchange surfaces in comparison with the equivalent shell and tube exchangers. Fouling rates are five (5) to ten (10) times lower because of the artificially induced turbulence in plate heat exchanger channels. Plate heat exchangers can be rearranged for a new duty without much down-time. The gasketed and welded pair plate heat exchangers are resistant to freeze-up and flow induced vibrations. Because of the high heat transfer coefficients and the narrow gaps between the plates, plate heat exchangers are very compact, requiring a quarter to half of the floor space needed for a horizontal shell and tube heat exchanger. The refrigerant charge is much smaller for plate heat exchangers than for the equivalent shell and tube. For example: the ammonia charge of a 300 T.R. shell and tube flooded chiller is approximately 500 lbs., while the equivalent plate chiller has a charge of less than half of this. Plate heat exchangers are made of stainless steel, titanium or other corrosion resistant metals. When built from the same material, capital costs are always lower for plate heat exchangers in comparison with the equivalent shell and tube design. However, prices can vary when compared with a carbon steel shell and tube heat exchanger depending, on the application and the size of the unit. The low temperature limit for conventional plate heat exchangers is -30°F; the maximum design pressure is 435 psig.
Development of Enhanced Surface Aluminum Tubes for Ammonia Flooded Chillers
Author: James C. Pyper and Resul Danis

The manufacturers of shell-and-tube chillers and condensers for the commercial segment of the industry led the way into applications of enhanced, or microfin, surfaces and showed that the increased efficiency in heat transfer caused a considerable reduction in unit size. Further developments made it possible to provide the same savings for industrial low temperature applications, but only for halocarbon refrigerants. As a supplier to both the halocarbon and ammonia markets, our company has applied the same research to ammonia. The principal obstacle was the traditional use of carbon steel tubes which were difficult to machine to the fine grooves required to duplicate the surfaces available with copper tubes. The result was the development of aluminum enhanced surface tubes. Aluminum is one of the common heat transfer surfaces available, having excellent thermal conductivity. The well known heat transfer rates of aluminum had to be applied to the new surfaces initially on a theoretical basis, then verified by laboratory testing and field tested on units which could be measured against identical applications where carbon steel tubes had been used. This paper presents the results of this work, and the advantage it gives to the ammonia industry in meeting its goals of reducing the size of ammonia flooded chillers, with subsequent savings not only in space and shipping weights, but also in substantially reduced ammonia charge in the system which is one of the projects on IIAR’s research priority list.
Aluminum and Galvanized Steel Evaporators: Effects of the Operating Environment
Author: Mark C. Stencel

The refrigeration of food products and processes involves their exposure to a refrigerated airstream. The refrigeration of this airstream is provided (in our industry) by its flow across an air-to-ammonia heat exchanger, the evaporator. By sharing a common airstream with food products, evaporators are exposed to a wide range of environmental conditions related to sanitation, humidity, desired product temperature and airborne product particulate. Additionally, the necessity for and methodology of coil defrost introduces another environmental variable for consideration. It is imperative that sound design methods be used to ensure evaporator material compatibility with the environment, for reasons of safety, performance and food product integrity. Existing methods for evaporator material selection are subject to bias and the limitations of personal experience. It is believed that our industry could be served by a comprehensive engineering-oriented approach to defining evaporator material/operating environment compatibility. Therefore, a study was commissioned with a major university to develop such a methodology.
Current Uses and Future Possibilities for Ammonia in Refrigeration and Air Conditioning
Author: John R. Mott

Ammonia is presently used in a wide variety of industrial refrigeration applications. Programs for phasing out many of the popular CFC refrigerants are well established, causing a serious review of the available alternatives, including ammonia. There is no doubt that ammonia can be used in many areas where CFC’s have dominated, provided proper precautions are taken. A well designed ammonia refrigeration or air conditioning system combines excellent efficiency and reliability, while minimizing negative environmental impacts. This paper examines ways in which ammonia systems can be applied in areas formerly dominated by other refrigerants, while taking account of safety issues and statutory requirements. Also included is an analysis of an indirect ammonia system which is efficiently air conditioning a building in New South Wales, and has provided reliable service for 40 years.
New Approaches to Ammonia System Designs
Author: Vito Lampugnano and Nick Kawamura

To minimize the effects of possible accidents from ammonia leakage the following should be considered: Minimize the charge of ammonia in the system, Use dry expansion system with oil that is soluble with ammonia, Optimum design for smaller piping, Minimize ammonia gas leakage, Use factory pre-assembled package, Use totally enclosed compressor with canned motor, Utilize automatic operation,  Use leak detector, Totally automatic operation with computer controlled system, Check-up system for preliminary maintenance, More efficient system and equipment design, High efficiency evaporators for dry expansion ammonia, High efficiency heat exchanger tubes. Two new systems have been designed to test the above concepts. The novel approach taken has utilized new concepts for the design and operation of systems using ammonia refrigerant.
CO2 Subcooled Refrigeration System
Author: Walter Broderdorf and David Giza

From this work, it was found that a more immediate need for using carbon dioxide for refrigeration purposes is its use as a low-side refrigerant in an ammonia or fluorocarbon/carbon dioxide cascade system. This technology has been installed in our own carbon dioxide production plants to improve the purity of carbon dioxide by removing impurities at lower temperatures than can be easily and efficiently obtained with either ammonia or fluorocarbon refrigerants. This technology is further being applied to food processing, food storage and other process chemical applications.