Auger Type Ice-Making Apparatus

The present invention relates to an auger type ice-making machine and more particularly to an improvement in such an apparatus for effectively flushing the inside of the water supply pipe and the freezing cylinder during ice making to thereby remove the condensed water and precipitates from inside of the water supply pipe and the cylinder.

In the conventional apparatus, it has been the practice to discharge all of the ice-making water when a level of ice storage is detected or when the ice making operation is halted temporarily in order to clean the inside of the water supply pipe and the freezing cylinder. However, in the former case, that is, when the cleaning operation is performed upon detection of a level of ice storage, it may not always be possible to assure a daily cleaning operation as this depends on the size of the ice reservoir or the amount of the ice used. Thus, it is not always possible to remove the rapidly increasing amount of condensed water or precipitates.

In the latter case, that is, when the cleaning operation is performed after the operation of the ice-making portion is halted temporarily, the ice-making efficiency is lowered with increased energy loss.

It is an object of the present invention to provide a means whereby the aforementioned deficiencies may be removed effectively. Thus, the present invention provides an arrangement according to which the cleaning of the inside of the water supply pipe and the freezing cylinder may be effected without obstructing the ice making operation and with an amount of ice-making water within the operating range of a water level switch within the ice-making water tank when the cleaning timer and the water level switch are operative to open said water discharge valve during the time that the water supply valve is closed in the ice making operation. Above all, it provides an auger-type ice-making machine wherein the cleaning timer and the water level switch are operative to open said water discharge valve during the time that the water supply valve is closed in such a manner that the insides of said water supply pipe and the freezing cylinder are cleaned with an amount of ice-making water within the operating range of the water level switch in the ice-making water tank.

In the drawings which illustrate an auger type ice-making apparatus according to the present invention:

FIG. 1 is a diagrammatic view of the auger type ice-making apparatus provided with a water-cooled condenser according to the present invention;

FIG. 2 is a circuit diagram showing a control circuit construction;

FIG. 3 is a timing chart diagram in connection with several operating elements; and

FIG. 4 is a diagrammatic view of the auger type ice-making apparatus provided with an air-cooled condenser according to the present invention.

Reference is made to an auger type ice making machine according to suitable embodiments of the present invention along with the drawings.

Referring to FIG. 1 illustrating a first embodiment of the invention, the numeral 1 denotes a substantially cylindrical freezing cylinder. An auger shaft 3 having a screw edge 2 is mounted for rotation within the cylinder 1, and a compressing head 4 is mounted to the upper end of the screw shaft 3. An ice discharge duct 5 is attached to the upper end of the freezing cylinder 1. An ice reservoir 6 provided with an ice storage detecting switch 6a is annexed to the ice discharge duct 5.

A freezing pipe 7 connected to a compressor CM of the freezing unit and adapted for guiding the refrigerant is coiled around the periphery of the freezing cylinder 1. The refrigerant supplied from the compressor CM is supplied through a route indicated by the arrows by way of a pressure regulator 8a and a water-cooled condenser 8. The lower end portion of the freezing cylinder 1 is provided with a water inlet section 11 connected to a water inlet pipe 10 for transporting ice-making water contained in an ice-making water tank 9 and also is provided with a water discharge section 13 having a water discharge pipe 12 including a water discharge valve WV1. The auger shaft 3 is rotatably driven by a geared motor 15 attached to the lower end portion of the cylinder 1 via housing section 14. The ice-making water is supplied to the ice-making water tank 9 through a fresh water valve WV2 provided to a water inlet 16 connected with a water tap. The quantity of water in the tank 9 is detected by a first sensor 17a and a second sensor 17b of a water level switch 17 provided to an inner wall 9a of the tank 9. The ice-making water in the tank 9 is supplied to the inlet section 11 of the cylinder 1 through the water inlet pipe 10 and a three way type cleaning valve WV3 provided in the water inlet pipe 10. An overflow pipe 18 provided to the ice making water tank 9 and used for the overflow of ice-making water in the event that the quantity of water supplied from the valve WV2 exceeds the level of the first sensor 17a of the water level switch 17.

The water inlet 16 is directly connected to one valve section of the cleaning valve WV3 through a water supply pipe 19. In the case of using a water-cooled type condenser, water can be discharged through an automatic water supply valve 20.

FIG. 2 shows a control circuit 21 of the auger type ice making machine according to the present invention. The water level switch 17 is connected to a power source P (three phase 200 Volts) through a relay X.sub.1. A cleaning timer 22 connected at one end to the relay X.sub.1 is connected to the water discharge valve WV1. The compressor CM, the geared motor 15 and a cleaning switch S.sub.1 are also connected to the electrical source. The cleaning switch S.sub.1 is provided with an ice storage detecting switch 6a, the supply water valve WV2 and the cleaning valve WV3.

Referring now to the operation of the above described auger type ice making apparatus of the present invention, the power source is turned ON for actuating the freezing section including the compressor CM, as well as the freezing cylinder 1 then being chilled, and the ice products formed in the freezing cylinder 1 are moved upward, as shown in FIG. 1, by the rotating screw edge 2, to be stored in the ice reservoir 6 through the ice discharge duct 5. According to our experiments, when ordinary tap water is used, the concentration of the various substances contained in the ice-making fresh water is elevated in about two hours and reaches a saturation point. Also, as the concentration of various substances becomes higher as when using well water or industrial use water, the time to saturation is shortened, and it becomes saturated because of the high densities. These substances are more likely to be precipitated and settled in the pipes 10, 19 and in the freezing cylinder 1 as the concentration of the substances in the ice-making fresh water increases. Thus, in order to remove these harmful substances, the cleaning timer 22 is operated for a certain time as shown by the timing chart of FIG. 3 and, when the water quantity in the tank 9 has reached an optimum level, that is, when the first sensor 17a of the water level sensor 17 is turned ON, the water supply valve WV2 is closed while the water discharge valve WV1 is opened only during the time that the valve WV2 is closed, whereby the substances settled in the water inlet pipe 10 and on the bottom of the freezing cylinder 1 are flushed by the ice-making water and removed. In this case, the quantity of water used for such cleaning is only that contained in the tank until the second sensor 17b of the water level switch 17 is activated. At this time, the water supply valve WV2 is opened by the operation of said second sensor 17b, the discharge valve WV1 is then closed and the fresh water is supplied until the first sensor 17a is operated, the ice making water having then reached the constant water level A. With the on/off one cycle time a of the water level switch 17, the operating time b of the cleaning timer 22 can be set so as to be (b>2a). In this case, the first cleaning operation is not performed during the first cycle because the operation of the timer 22 is started when the water level in the tank is the lowest level in which said water supply valve WV2 enables the supply of water, i.e., the level detected by the second sensor 17b. However, the cleaning is performed during the next cycle. The cleaning timer 22 is turned OFF after the lapse of a certain time so that the discharge valve WV1 is maintained in the open state to continue the ice-making operation.

As the ice products are stored in the ice reservoir 6 and the ice storage detecting switch 6a is turned ON, the water supply valve WV2 is closed and the water discharge valve WV1 is opened. More specifically, as is apparent from FIG. 2, when ice reservoir 6 is filled with ice, this state is detected by switch 6a and the switch 6a opens (FIG. 2 shows switch 6a in its closed state), automatically causing valve WV2 to close and valve WV1 to open so as to flush out with fresh water the substances settled in the water inlet pipe 10 and on the bottom of the freezing cylinder 1. The cleaning switch Sl is manually switched, then the cleaning valve WV3 is switched, whereby the tap water is directly supplied through the water inlet 16 and supply pipe 19 into the cylinder 1 and discharged through the opened discharge valve WV1 so that the cleaning operation may be achieved.

FIG. 4 shows the overall structure of an auger type ice making apparatus in accordance with a second embodiment of the present invention, the condenser 8 of which is fitted with a fan 8b and thus cooled by air instead of by water as is the above described first embodiment of the present invention. The differences between the apparatus of the second embodiment and the first embodiment shown in FIG. 1 is that the water inlet 16 is a U-shaped tube having one end connected to a tap water cock 16a and a bottom portion connected to an anti-freeze cock 16b and thus the water inlet has no connection with the condenser 8. The operation and result of the auger type ice making apparatus shown in FIG. 4 are substantially similar to those of the preceding embodiment already explained with respect to FIG. 1.

According to the present invention an auger type ice making machine, is provided in which the water supply pipe and the freezing cylinder can be cleaned during the ice making operation without affecting the ice-making operation, whereby the ice-making capacity is not lowered, and scale accumulation in the freezing cylinder as well as the wear of the bearings or mechanical seals can be effectively prevented, thus providing for improved reliability and a smooth and effective ice-making operation for a long time.