Category Archives for Refrigeration

Large Releases of Ammonia

There are-few situations where discharges of ammonia are planned. An exception might be where a plant is being decommissioned or reduced in size. Even when ammonia must be removed from a section of the plant being repaired or retrofitted, every … Continue reading

18. June 2018 by Jim
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Discharge of Ammonia – Flaring

The third method of disposing of ammonia discharges is by flaring or burning the ammonia. This method is particularly applicable when the release to be treated will be located at an identifiable point, such as the discharge vent of a … Continue reading

18. June 2018 by Jim
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Discharge of Ammonia – Absorption in Water

Another concept for handling discharges of ammonia from a refrigeration system is to absorb the ammonia in water. ANSI/ASHRAE Standard 15–94has traditionally listed the discharge of ammonia into a tank of water as an option. The recommended proportions of water … Continue reading

18. June 2018 by Jim
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Discharge of Ammonia – Directly to Atmosphere

In the routine operation of the plant there should be no discharge to atmosphere. In well-maintained plants, it is not possible for a visitor to detect from the smell that ammonia is the refrigerant. Slight smells of ammonia sometimes occur … Continue reading

18. June 2018 by Jim
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Ammonia Sensors and Leak Detection

Both for reasons of safety and to prevent interruption of refrigeration service, it is important to sense leaks of refrigerant. Since halocarbons are odorless, sensors are important in installations using such refrigerants to ensure that a leakage of a major … Continue reading

18. June 2018 by Jim
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Fire Protection in Refrigerated Warehouse

Fires in refrigerated structures are rare, but they do occur and can be costly. The major loss associated with a fire may be the product, whose value may be 5 to 10 times that of the building. It may at … Continue reading

18. June 2018 by Jim
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Relief Devices

Questions that arise and decisions that must be made with respect to relief devices include the following: Where must a relief device be installed? Which of the several available devices should be chosen? How many should be installed at a … Continue reading

18. June 2018 by Jim
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Additional recommendations for safe piping practices.

Several technical specifications13 that result in safer ammonia piping are the following: • Use A106B or A53B pipe for low-temperature service. Some engineers also specify seamless pipe for liquid and hot-gas lines. • Use 3000 lb socket weld fitting (A-181) … Continue reading

13. June 2018 by Jim
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Valves in an Oil Drain Line

Accidents sometimes occur when draining oil in an ammonia system. What can happen is that the operator cracks the shutoff valve, shown in Fig. 13.6, but nothing happens because the oil is cold and stiff. The operator then slowly continues … Continue reading

13. June 2018 by Jim
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Liquid Hammer

Another critical time when there is danger of liquid hammer is upon termination of defrost. Near the end of the hot-gas defrost the pressure in the coil builds up to that of the pressure-regulating valve relieving the refrigerant condensate. If … Continue reading

13. June 2018 by Jim
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