This invention relates to apparatus for eviscerating scallops after they have been shucked.
After scallops have been harvested they have to be shucked (removed from their shells) and then eviscerated, which involves separating the membrane, entrails and roe (if any) from the adductor muscle which is the meat portion most often consumed by humans. Various arrangements have been devised for shucking and/or eviscerating scallops but the present invention is concerned with the evisceration operation. The scallops to be eviscerated can be shucked by known arrangements or by hand although it is preferred that they not be subjected to heat treatment which could cause partial cooking and accelerated bacteria growth which may reduce shelf life and product appeal. An apparatus for shucking scallops is disclosed in U.S. Pat. No. 4,361,933 of William K. Rodman, issued Dec. 7, 1982. Rodman uses high volume, low pressure, water jets to strip frill and internals from the meat. However, meat damage (splitting and erosion) occurs at pressure and flow levels which could cause 80-90% entrail removal, whereas a jet adjustment which does no damage removes no frills and organs. Such damage is commercially unacceptable.
Another apparatus for processing scallops is disclosed in U.S. Pat. No. 3,562,855 of Elmer Dryden Willis, issued Feb. 16, 1971. That apparatus, which uses a thermal and/or chemical bath for shell removal, eviscerates the scallops by passing them over an inclined bed of pinch rolls in a direction perpendicular to the roller axes. The counter rotating roller pairs oscillate, clockwise, and then counterclockwise, thereby stepping the product down the incline. The rolls are covered with a rubberized abrasive grit tape. Water sprays are used to regulate the residence time of the scallops on the bed of rollers and to clean the rollers. In practice, many of the scallops have to be recycled through the eviscerator. This is due to gaps between roller centers due to fixed bearing design and abrasive wear as well as clogging of the "grit" by thin membrane waste. An eviscerator of the type shown in this patent may have quite a large number of rolls, e.g. 80, requiring numerous sprockets, a complex chain drive and several horsepower to drive. The oscillator drive is also fairly complicated and costly. The overall device is quite large in size e.g. 42".times.96" in comparison to its capacity and effectiveness.
Franken B. V. in Holland makes a roller bed mussel debysser which is also capable of eviscerating scallops although sometimes the liver and the roe sac do not pull through. Also, thin tough membranes from the scallops wrap around the rolls, reducing their roughness or "bite" which greatly reduces their eviscerating ability. This device is essentially identical in use and construction to the Willis device except that it uses continuous roll rotation without oscillation.