Technology transfer

A plant for separation of frozen fish blocks into detached trunks

Fig. 1. Schematic view of a pilot plant for separation of frozen fish blocks into detached trunks

1 – tank,  2 – water level control unit,  3 – wire-belt conveyor,  4 – spark discharge,  5 – detached fish and ice debris,  6 – electrode holders connected to earth and provided with shockwave deflectors,  7 – temperature-activated water drainage control device

Operation principle

Operation principle of the plant (Fig. 1) is based on the electrohydraulic shock phenomenon. A frozen fish block (Fig. 2) immersed in water undergoes disintegration by shockwaves launched from strong underwater electric discharges. Blocks of frozen fish chute from feeding conveyor onto wire-belt tank conveyor immersed in water, where they further turn into separate trunks due to serials of hydraulic impacts. Low-sized tank sidewalls retain fish, but byproducts like ice debris and froth are readily disposed with water overflowing through special tank openings. Consecutive electric blasts agitate water close to trunks thus providing intensive heat exchange and preventing their icing.

Innovative value of solution

The process and device are covered by Russian patent RU2495578.

Capabilities and competitive strengths

  • By contrast with the existing processes based on thawing or mechanical crushing techniques, electrohydraulic technology provides virtually instantaneous fish blocks separation (the process lasts seconds including time for recharging capacitors)
  • Virtually no damage of fish
  • About tenfold decrease of fish losses. Such organoleptic parameters of the final product as appearance, color, odor and fish texture can be enhanced compared to results of traditional defrosting processes
  • Only one person is required to attend to the plant
  • Estimated productivity – up to 120 blocks per hour
  • Total energy consumption will not exceed about 3.5 kWh/t


  • Develop an industrial-scale plant on the base of existing prototype
  • Acquire EU and Russian certificates
  • Market the plant
  • Start sales                                                                                                                            Fig. 2. Conventional frozen fish block