The heater is a kind of used shell- and-tube heat exchanger which consists of head cover, Shell, nest of tubes and accessories.

本加热器是常用的管壳式换热设备，由端盖、壳体、管组和附件组成。

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Suffolk Wildlife Trust helped erect nest tubes and later found dormice in three of them, with a further six containing nests.

BBC: Dormouse in hand

To fill them, spring-loaded rods push high-volume drugs like ibuprofen from their tubes into a small nylon nest moving along the conveyor belt at the bottom of the machine.

FORBES: Drug Lord