1997 IIAR Technical Papers
  New Orleans, LA
 19th Annual Meeting

Gentlemen, Start Your Engines
Author: David Boldrick

This paper examines the opportunities to use engine drives and gas fired prime movers for refrigeration compressors in ammonia refrigeration. This subject is certainly not a new topic, but it is worth reexamining in light of current gas and electric costs. In addition, “off-the-shelf’ equipment fitted with engines is now available as a standard catalog item.
Material Selection Criterion for Ammonia Refrigeration Equipment Operating at Temperatures Below -20°F
Author: Dr. Zahid Ayub

One of the important aspects of industrial refrigeration, and in particular ammonia refrigeration, is that the majority of the equipment is designed for installation in cold warehouses, meat packing plants, creameries and other food related facilities. The basic nature of these applications calls for low temperature, requiring that systems must often operate at temperatures below -20°F. Since most of the equipment for industrial refrigeration is fabricated with low carbon steel, this requirement can create unnecessary headaches for contractors and end users who are not familiar with the metallurgy of materials and the governing codes and standards. They generally follow what the specifications call for in a job, without challenging the validity of the specifications. It is possible that the person or company behind the specifications does not understand the complexities of relevant codes, but rather is following the previous trend. The previous trend could be obsolete since ASME codes are dynamic, meaning they constantly change as new knowledge is gained with time. This short informative paper will try to address some important issues related to the subject and try to clarify ambiguities regarding low temperature material selection governed by the ASME codes.
The Development of Lubricants for Ammonia Refrigeration Systems
Author:  Jill Oberle & Tom Rajewski

The demand for ammonia refrigeration systems to operate over wide temperature ranges has lead to the development of new, synthetic lubricants for ammonia applications. This paper discusses the development and application of synthetic and semi-synthetic hydrocarbon fluids, as well as ammonia soluble lubricants. The potential benefits and advantages over conventional mineral oils are described.
Preparing the PSM and the RMP for the 2002 Winter Olympics Bobsled/Luge Track
Author: Dr. Ronald Block, Dr. Paul Lessard, and Roy Iverson

It is estimated that up to 12,000 spectators will be observing the bobsled run, while another 20,000 spectators will be on hand to observe the ski jumping during the Games. At the base of Bear Hollow is a small town with a population of several hundred. A Process Safety Management Plan (PSM) had to be prepared prior to the facility becoming operational. Because of concerns of a potential ammonia release, a Risk Management Plan (RMP) was also prepared to predict the possible impact of ammonia on the spectators and the town populace should a release occur.
Improving Effect of Atmospheric Stability Class on Hazard Zone Predictions for an Ammonia Release
Author: Dr. John Woodward

The experimental database supporting heavy gas modeling is quite sparse, because of the expense of full-scale field tests. In particular, the number of experiments conducted at F stability has been woefully inadequate. This is mainly because such tests must be conducted at night or in the early morning under low wind speed conditions. The percentage of time a region experiences F stability ranges typically from 3% to as much as 60% at a pump station on the Alaska pipeline. Fortunately, a large body of experimental data on heavy cloud dispersion has recently been released by the German government in which atmospheric stability is addressed, for the first time, in a reasonably substantial manner. We discuss these findings here, along with a discussion of model improvements generated therefrom and compare our model with two others used to generate the EPA tabulated predictions.
Emergency Planning Issues Relating to Ammonia
Author: Dr. Robert Michaels

Risk assessment accuracy for emergency planning can be improved by separating risk assessment from risk management, and by avoiding redundant application of safety and uncertainty factors to data which has already been downwardly adjusted, given the possibly greater sensitivity of humans. In regulatory review for industrial emergency planning, a chosen level of health protection can still be maintained, with significant economic benefits to host communities and corporate employers, by improving risk assessment accuracy. Ammonia toxicity benchmarks derived from the investigation described in this paper are summarized.
A Certified Industrial Hygienist Looks at Personal Protective Equipment for Emergency Response to Ammonia
Author: Dr. Robert Miksch

This paper considers choice of personal protective equipment (PPE) for emergency response to ammonia releases at private facilities by employees. It is assumed that the employees are acting in an extraordinary capacity, outside of their normal range of duties. This paper presents the view that PPE must be carefully selected with due consideration given to several issues: (1) whether the tactical objectives are offensive or defensive; (2) whether the objectives are realistic considering the capabilities and training levels of responders wearing PPE; (3) whether the PPE will protect against all of the potential hazards posed by the tactical objective; and (4) whether the hazards inherent in the PPE itself are minimized.
Incorporating Semi-Welded Plate Heat Exchangers into Secondary Cooling Systems to Address Plant Safety and Efficiency Issues
Author: Keith Gifford and Ralph Tator

As part of its PSM Safety Review Program, the Campbell Soup Company implemented a project in August 1995 to review the existing ammonia refrigeration system at its Fayetteville, Arkansas facility. The primary objective of the project was to identify components and/or areas of the refrigeration system that could be improved for safety and maintenance reasons. However, as with any engineering project, cost implications and system efficiencies could not be ignored and likewise were factored into the decision making process. In the pages following, we will provide a case history of the Fayetteville facility’s PSM project, including an overview of the plant, an understanding of the plant’s operation, potential safety related areas identified in the PSM, available options (including pros and cons), the decisions which were made, and the reasons why. 
Use of Pulse Width Modulated Valves in Industrial Refrigeration
Author: Lars Mou Jessen

In recent years, electronic controllers have been introduced to the industrial refrigeration market. As a result, new control devices have been developed such as the pulse width modulated valve. The pulse width modulated valve is a digital alternative to analog types of modulated valves, like motorized and temperature actuated valves. This paper discusses the basic principle of pulse width modulation and presents two applications where pulse width modulated valves have been used. The first application involves the control of liquid level in a pump recirculation accumulator where a capacitance rod is used as a liquid level measuring device. The signal from the capacitance rod is processed in an electronic controller that continually signals a pulse width modulated injection valve. The second application involves the automatic control of refrigerant injection into an air unit on a liquid overfeed pump recirculation system. A heated temperature sensor on the air cooler, an air temperature sensor and a pressure transmitter are used as inputs to a newly developed electronic controller. The controller continually manages the modulation of the pulse width modulated valve that injects refrigerant into the air unit. This controller is an alternative to fixed injection, which is traditionally used on such applications.
Safety Aspects and Installation Experiences with Packaged Ammonia Water Chillers in Public Buildings
Author: John Ritmann and Bent Wiencke

The number of installations with ammonia (R717) chiller units for industrial and A/C applications is growing rapidly in Europe. This is primarily because of the accelerating phaseout of HCFC and HFC refrigerants, and the rising prices of these refrigerants. This naturally impels decision-makers, who are responsible for the purchase of refrigeration equipment, to consider long-term solutions such as natural refrigerants. Of the natural refrigerants, ammonia is unquestionably the most suitable and widely applied refrigerant for chiller units because of its high thermodynamic efficiency. In the following discussion, comparisons between R717, HCFC and HFC refrigerants used in indirect systems will be made in regards to environment, operation and economy.
Organization and Execution of a Mock Ammonia Spill Response
Author: Charles Kulp

This presentation shares a Rosenberger cooperative experience with the local fire and HAZMAT response teams that is part of the process of developing the ammonia emergency response aspect of a PSM program. It is hoped that other industry members will be encouraged to connect with the many resource people available in their efforts to develop safety programs that improve the emergency preparedness in their places of business. An ammonia emergency response plan can benefit from the cooperative expertise of both company engineering people and local emergency responders. Responders are trained to deal with many hazardous materials in emergency settings and the plant engineering people are trained to understand and manage the operational controls of the refrigeration system. By bringing the two together, a response plan can be specific for the plant, and serious losses resulting from an emergency situation can hopefully be greatly reduced.
District Energy Center Employs Trigeneration and Ammonia Refrigeration for Economical and Efficient Energy Production
Author: Mark Strutz

The District Energy Center at McCormick Place is the state-of-the-art in district energy. By utilizing an ammonia based refrigeration system, Trigen-Peoples was able to maximize operating efficiency and minimize costs. By combining proven ammonia refrigeration with patented Trigeneration technology, Trigen-Peoples is able to maintain its competitive advantage as Chicago’s lowest cost producer of district heating and cooling.
Ammonia - The Ultimate Refrigerant for Cooling Hot Mines
Author: Anton Meyer and Dr. J. (Olla) Van Der Walt

This paper addresses the history of cooling mines and, in particular, the role of ammonia, including its thermophysical properties. In addition, the paper reviews the needs of the mining industry and the equipment used in modern mine cooling plants. The potential for using ammonia in deep underground cooling plants is also reviewed.
Back to the Future - With Ammonia
Author: Ted Martin

This paper examines the results of applying up-to-date ammonia refrigeration technology to a frozen vegetable processing plant dating to the 1960’s. The project was initiated in order to meet increasing production demands, while at the same time seeking methods of reducing the net energy cost per pound of product. Funding of the project was through energy consumption savings, a contribution by the local electrical utility, and reduced operating costs. The technologies implemented include natural gas driven screw compressors with steam generators, plate and frame water cooled condensers, a microprocessor control system and segregation of the loads into multiple temperature levels. A technical discussion of individual components, their effect on savings and plant operation, and a review of results to date are included.
Conversion from R22/R502 to R717: Practical Experiences from Four Industrial Plants
Author: Myles Forbes and Stefan Jensen

The practical experiences associated with the conversion of four industrial refrigeration systems from R22 to R717 (ammonia) refrigerant are described in this presentation. The refrigeration plants all service commercial cold storage facilities and the conversions took place from 1991 to 1995. In all cases, the refrigerant changeover coincided with a conversion from single stage to dual stage compression. In two of four cases, the refrigerant feed was liquid recirculation both before and after the change; in two cases the feed was altered from direct expansion to liquid recirculation as part of the change. All facilities included chilled and frozen storage; two of four plants incorporated blast freezers. Three facilities were extended as part of the refrigerant change, one was not. In three cases, the refrigerant change (R22) had to be completed within a 48 hour period in order to avoid product spoilage. It is concluded that, although complete R22 removal prior to charging R717 is desirable to minimize chemical residue in the system, this is almost impossible within a 48 hour period. The practical consequences of less than adequate R22 removal are described and comments are made in relation to the effects of the conversion on compressor wear, gaskets and seals. Guidelines are provided for planning of similar conversions and safety issues are discussed. Energy savings of 5% to 17% directly attributable to the refrigerant change are recorded for one plant.