FIELD OF INVENTION:

The invention relates to scaling machines of fishes.

PRIOR ART:

The WO 91112725 Shows A process and apparatus for descaling and skinning tuna fish and the like wherein the fish is at least partially cooked and then cooled to a backbone temperature of about 70 to 100 of. The fish is placed on a conveyor (c) and passed through horizontally (24, 26) and vertically (22) disposed brushes. Jets of water are sprayed on the fish at the point of contact of the fish and the brushes to thereby wash away the scales and skin as removed by the brushes.

The WO 95/18536 According to the invention the descaling operation is performed by means of high velocity water jets. Incidentally, the means for performing the descaling can be made to perform additional ancillary cleaning steps as will become clear from the following detailed description.

The US 7,273,630 B2 shows A composition and process for improving the quality of raw food product such as seafood, meat and fowl including a treatment of a bath, rinse, ice blend, steam or spray for preparing the raw food product, such as fresh fish, meat or poultry or produce. Before the treatment is used, the raw product is cleaned in a conventional manner. The treatment composition is intended to clean, deodorize, and disinfect the raw food product. The present invention removes slime and odor from fresh fish in preparation for cooking, and further, disinfects the fish and other food product to be cooked in the event that hannful bacteria or other microbes reside on the raw fish, such as harmful microorganisms which may be a residue of polluted water from which the fish was taken, or may have originated from filthy food preparation facilities

OBJECT OF INVENTION:
Processing and value addition of fish is an important commercial activity and involve many steps which are labour intensive and time consuming. Any type of value addition of fish in the form of value added products viz., fillets, steaks, gutted fish require pre-processing operations such as washing, sorting, evisceration, descaling etc. prior to processing. These operations are labour intensive and time consuming and in many cases affect the product quality, if not carried out within a specific time under chilled conditions.

Mechanization in the fish processing sector is the need of the hour and many machines are being used in the commercial fish processing operations. The meat bone separator, fish gutting machine, filleting machine are to name a few successful ones. Significant inputs of labour and time are required for descaling the fish, which is an important step in the pre-processing operations. The descaling machine designed and developed is suitable for commercial operations for medium and small sized fishes viz., sardines, breams, sciaenids, tilapia and carps.

Shortage of skilled manpower is a major problem faced by the fish processing industry. Development of a fish descaling machine is a step to reduce the drudgery of manual descaling of small sized fishes. Mechanization of descaling activity can significantly reduce the handling time thereby shortening the pre-processing period. This in turn reduces the overhead costs and also enhances the quality of the final product.

The descaling machine is based on a new design equipped with a perforated rotating drum and an induction motor of variable frequency drive. The process time and speed of the drum are standardized for each category and size group of the fish.

DESCRIPTION OF THE INVENTION:
The descaling machine can remove scales from small and medium sized fishes and proven effective for sardines, breams, sciaenids, tilapia and carps. The machine essentially consist of a rotatable drum of SS 304 make attached to a 1.5 HP induction motor and equipped with Variable Frequency Drive (VFD). Water inlet and outlet provisions are provided to supply water during the operation and also to clean the drum after each operation.

The drum has a capacity to load 10 kg fish. The time of operation and rpm of the drum has to be standardized for each species under different size categories for the efficient removal of scales. The rpm of the drum can be adjusted at minimum of 2 rotations to a maximum of 80 rotations per minute. Trials conducted have shown that 98% of the scales can be removed using descaling machine. For sardine, the descaling process requires 5 minutes at 20 rpm, for rohu it is 10 minutes at 30 rpm and for tilapia it is 8 minutes at 25 rpm. This is a batch process and the material can be loaded and unloaded easily and only one person is required to operate the machine.

The de-scaling machine developed can remove scales from almost all types / sizes / species of fishes ranges from Sardine, Tilapia to Rohu. The machine is made of SS 304. It contains a 1.5 HP induction motor and a Variable Frequency Drive (VFD) to vary the speed of the drum depending on the variety of the fish loaded. The drum is made of perforated SS 304 sheet fitted in a strong SS Frame. Water inlet facility is provided over the drum for easy removal of the scales and to provide more contact surface for removal of scales. The water outlet is provided to remove scales and water from the machine.

The operation of the machine can be extended for removal of scales from all types of marine as well as fresh water fishes. This is achieved due to the incorporation of the Variable Frequency Drive (VFD). VFD convert single phase 230V, 50 Hz AC to 230V DC and again converted to 440V AC with variable frequency using PWM and IGBT technology. This technology provides variable frequency without compromising the torque. The RPM of the drum can be varied from 2-80 rotations per minutes. A time lag is introduced between the variable frequency drive and the rotation of the drum for the safety of the VFD.

The 7 performance of the equipment for different species of fish depends mainly on the rpm of
the drum.

An rpm recorder is also attached to the De-scaling machine to get the read out of the rpm of the drum.

The sensing part consists of a magnetic sensor attached to the motor. The signals received from this sensor is conditioned and processed to get a standard voltage output in the range 0-5V. Necessary calibration is incorporated to display the data in a digital panel meter. Display in the LCD panel meter directly gives the rpm of the drum. An LED indication is also given to sense the drum rotation. Speed control of the drum, START and STOP switches are also fitted in this meter.

DRAWINGS:

Fig. 1 Descaling machine as per invention. Fig. 2 Left side view of Descaling machine Fig. 3 Right side view of Descaling machine Fig. 4 Elevation view of Descaling machine

Attempt has been made to describe the invention to the best knowledge of the inventors and examples, illustrations have been provided for sake of understanding and not for limiting the invention. All variations and modifications that will be known to the skilled person shall be within the scope of the invention.

WE CLAIM:

1. An apparatus comprising for descaling fishes comprising of:

a. a perforated drum for loading the said fishes, and

b. an induction motor with variable frequency drive operably associated with the said drum characterized in the rotational speed of drum is directly on the basis of speed of the rotating induction motor but with a time lag.