Exam 28: Special Refrigeration Applications

The system of shipping refrigerated trucks loaded on railcars is known as "____________________ ."

Because of the large capacities of refrigeration systems installed in trucks, the trucks themselves do not need to be insulated from outside ambient temperatures.

Nitrogen changes from a liquid to a vapor at ____.

Dry ice is composed of ____.

The blast freeze method is done at very low temperatures and a high air   ____________________ .

Water-cooled condensers using sea water are usually designed and built to permit periodic cleaning by ____ .

Truck refrigeration systems are designed to have the capacity to ____ .

Seawater-cooled condensers for marine use have ____ .

When products need to be cooled during flight, ice or ____________________ is used .

A system that uses two or more refrigeration systems working at the same time and exchanging heat between them to produce ultra-low temperatures, is called a(n) ____________________ system .

Some products, such as chicken, are dip frozen in a very cold solution of brine, in the first stage of the freezing process. Why ?

At extremely low evaporator temperatures, the compression ratio for the compressor becomes too great for single-stage refrigeration .

Cold plates are usually filled with a ____.

Ammonia is extremely toxic to humans and must be used with care.  When working with ammonia systems it is often necessary for the technician to wear ____ .

The axle-driven refrigeration unit is a new system very commonly used in today's railway refrigeration .

In some applications of truck refrigeration, a liquid refrigerant is sprayed directly into the truck box to maintain low temperatures. The liquid refrigerant used is ____.

The process where a solid changes directly to a vapor without first becoming a liquid is called ____________________.

In order to keep dry ice in the solid form, the temperature of its surroundings can be ____.

Refrigeration systems that use nothing more than a thermostatically controlled solenoid valve feeding a distribution system can use ____________________ or carbon dioxide as their refrigerant.

Why is the quality of meats frozen in a home freezer inferior to that of commercially frozen meats ?