H4-VV-25-D ings Highly flexible couplings are wellsuited for Helical gear reducer H4

Flender/Flender Gear Units/Helical gear reducer H4

geration, . Perishable foods may be carried in insulated porthole containers or in mechanically refrigerated containers. clip-on refrigeration unit is attached to the insulated porthole containers during transportation on land, during waiting periods on the loading or un- loading docks, and on board when stacked on the deck. However, porthole containers aregenerally carried below deck, where they are connected, via their portholes, to the shipsrefrigeration system. Refrigerated air is then circulated, via the bottom porthole, throughthe container and returned to the ships refrigeration system via the top porthole. In oneof the most common arrangements of porthole containers they are stacked and connected to vertical duct equipped with fan and an air cooler capable of cooling the entire stack. The stack must be composed of produce with the same temperature requirementand compatible odor and respiration (International Institute of Refrigeration, . Theair coolers are generally fed by multitemperature brine system. Mechanically refrigerated containers are usually equipped with recessed refrigera- tion unit. The unit composes the front of the container to permit on-deck stowage compati- ble with dry cargo containers. Many of the refrigeration units operate with diesel engine during highway or rail travel and then are plugged on shipboard to operate with an electricmotor (Ryall and Lipton, . Mechanically refrigerated containers are generally carriedon deck to ensure that there is sufcient air to remove the heat rejected by the refrigerationunits condenser. Some recently built ships also provide space below the deck for mechani-cally refrigerated containers. These ships have additional air renewal below deck to take away the heat of the condensers (International Institute of Refrigeration, . Mechani- cally refrigerated containers should preferably be carried on the center part of the deck,which is the part that is least sensitive to vertical acceleration (Int