| 摘要 |
A food freezing tunnel has an inner trough member 42 and a roof member 40. In order to gain access to the interior of the tunnel, for example for purposes of cleaning the tunnel, the inner trough member 42 is able to be raised and lowered. The tunnel has a spray header l6 for liquid nitrogen and fans 24 for circulating resulting cold nitrogen vapour. The tunnel has an inner trough member 70 spaced from the outer trough member 42. The inner trough member 70 has a floor 7l extending underneath the upper run 66 of a conveyor passing through the tunnel and has sides 72 which prevent direct impingement of liquid nitrogen onto the outer trough member 42 and which co-operate with the roof member 40 to inhibit the passage of cold gas from within the trough member 70 over the sides 72. |
