Bevel-helical gear unit B4 g details according to orderrelated documentation B4-SH27A

Flender/Flender Gear Units/Bevel-helical gear unit B4

st be heated to prevent the chilling or freezing offresh produce. Mechanically refrigerated trucks, trailers, railcars, and containers are usu-ally heated either by electric heating or by reverse-cycle running of the refrigeration unit.Once the cargo temperature is set, the built-in thermostatic controller automaticallyswitches from cooling to the heating mode whenever it is needed. However, the heating capacity of the mechanical refrigeration system operating in reverse cycle is only about third of its refrigeration capacity when set at 0 Ci na3 0 ambient temperature (Interna- tional Institute of Refrigeration, . Therefore, supplemental electric heating may berequired when transporting produce in very cold regions. When the temperature control system used in transport vehicle is ice cooling or cryogenic cooling, heating device must be incorporated in the vehicle. Heating devicescommonly used in transport vehicles are burners (with an air-to-air heat exchanger) and electric heaters. 3.3 Air Circulation Systems Air circulation plays dominant role in maintaining ideal transport temperature within transport vehicles. In fact, the refrigeration system becomes useless if cooled air is not circulated throughout the cargo. The air circulation system is used to distribute cool air around and through the cargo to absorb any heat that enters the vehicle or to absorb theheat generated by the produce. The warm air returns to the refrigeration unit, where it iscooled and cycled back around the cargo. If the air circulation system is poorly designedand the cooled air is not evenly distributed, overwarming or overcooling occurs in differentparts of the vehicle. During winter, the air circulation system is required to circulate warmair around the produce, to prevent chilling or freezing injuries. Two different types of air delivery systems are commonly used in mechanically refrigerated semitrailers, intermodal containers, and railcars: top-air and bottom-air. 3.3.1 Top-Air D