| ≥1 piece |
Freezing of standard blocks takes place in horizontal plate freezers.
The plate freezers are generally for manual loading and unloading. However, freezers for automatic operation are available, too.
The freezing plant must have ample capacity to operate at an evaporating temperature of -38?/SPAN>C to -40?/SPAN>C to ensure a surface temperature of the freezing plates of app. -34?/SPAN>C.
The effective freezing time of freezing fish blocks to a core temperature of app. -18?/SPAN>C will typically be 105 to 120 minutes, provided the freezing plates are free from ice and the bottom plates of the frames are smooth so that good contact is obtained.
The handling time for unloading and loading of a plate freezer depends on the size of the plate freezer, the number of frames in the freezer, availability of a full number of packed frames for a freezer and the quickness of the handling. Generally, the handling time can be estimated to 15 - 25 minutes.
The effective freezing time plus the handling time gives the duration of each freezing cycle. Based on the above operational periods, 9.5- 11.5 freezing cycles per 23 hours can be obtained. 1 hour per day is allowed for cleaning and defrosting of the plate freezer.