Ice making machine

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ice making machine such as an ice making machine of the down-flow type.

2. Discussion of the Prior Art

Disclosed in Japanese Patent Publication No. 3067175 is an ice making machine of the down-flow type in which ice making water in a water tank falls along upright ice making plates in operation at an ice making mode and is circulated into the water tank to be used as washing water. If the ice making water is circulated into the water tank in a contaminated condition, the ice making plates will be washed by the contaminated water, resulting in insufficient washing of the ice making plates.

SUMMARY OF THE INVENTION

It is, therefore, a primary object of the present invention to provide an ice making machine the ice making plates of which are sufficiently washed with fresh water in operation.

According to the present invention, the object is accomplished by providing an ice making machine which comprises a water tank for storing an amount of ice making water, an upright ice making plate arranged above the water tank, and a water sprinkler located immediately above the ice making plate to spray ice making water supplied from the water tank to the ice making plate so that the ice making water falls along the ice making plate, in which the ice making water sprayed to the ice making plate during operation at an ice making mode is frozen and formed into ice cubes in the course of falling along the ice making plate, characterized in that the ice making machine includes drainage means for draining the ice making water from the water tank, water supply means for supplying washing water into the water tank, and control means for activating the drainage means after finish of operation at a defrost mode and for activating the water supply means after the ice making water has been drained from the water tank, wherein the washing water supplied into the water tank under control of the control means is sprayed by the water sprinkler for washing the ice making plate.

In a practical embodiment of the present invention, there is provided an ice making machine which comprises a water tank for storing an amount of ice making water, an upright ice making plate arranged above the water tank, and a water sprinkler located immediately above the ice making plate to spray ice making water supplied from the water tank to the ice making plate so that the ice making water falls along the ice making plate, in which the ice making water sprayed to the ice making plate during operation at an ice making mode is frozen and formed into ice cubes in the course of falling along the ice making plate, characterized in that the ice making machine includes operation means for washing, drainage means for draining the ice making water from the water tank, water supply means for supplying washing water into the water tank, and control means for activating the drainage means when the operation means for washing is operated and for activating the water supply means after the ice making water has been drained from the water tank, wherein the fresh water for washing supplied into the water tank under control of the control means is sprayed by the water sprinkler for washing the ice making plate.

In another practical embodiment of the present invention, there is provided an ice making machine which comprises a water tank for storing an amount of ice making water, an upright ice making plate arranged above the water tank, and a water sprinkler located immediately above the ice making plate to spray ice making water supplied from the water tank to the ice making plate so that the ice making water falls along the ice making plate, in which the ice making water sprayed to the ice making plate during operation at an ice making mode is frozen and formed into ice in the course of falling along the ice making plate, characterized in that the ice making machine includes an ice storage cabinet for storing an amount of ice cubes released from the ice making plate during operation at a defrost mode, detection means for detecting an amount of the ice cubes stored in the ice storage cabinet, drainage means for draining the ice making water from the water tank, water supply means for supplying fresh water for washing into the water tank, and control means for activating the drainage means in response to a detection signal from the detection means when the ice storage cabinet is filled with ice cubes and for activating the water supply means after the ice making water has been drained from the water tank, wherein the fresh water for washing is supplied into the water tank when the water supply means is activated under control of the control means and is sprayed by the water sprinkler for washing the ice making plate.

In the practical embodiments, it is preferable that the ice making machine further includes a guide duct for guiding the ice making water falling from the ice making plate during operation at an ice making mode and for guiding the ice cubes released from the ice making plate during operation at a defrost mode, a water passage duct located at an intermediate portion of the guide duct for circulating the ice making water guided by the guide duct into the water tank, and ice crush means mounted within the guide duct for rotary movement and driven by an electric motor, wherein the ice crush means is driven by operation of the electric motor under control of the control means when the ice making machine is operated at the ice making mode and when the fresh water for washing supplied into the water tank in operation of the water supply means is sprayed by the water sprinkler.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a schematic illustration of a first embodiment of an ice making machine in accordance with the present invention;

FIG. 2 is a block diagram of an electric control circuit for the ice making machine shown in FIG. 1;

FIG. 3 is a flow chart of a control program executed by a microcomputer shown in FIG. 2;

FIG. 4 is a flow chart of an ice making routine shown in FIG. 3;

FIG. 5 is a flow chart of a defrost routine shown in FIG. 3;

FIG. 6 is a flow chart of a washing routine shown in FIG. 3;

FIG. 7 is a block diagram of an electric control circuit in a second embodiment of the present invention;

FIG. 8 is a flow chart of the main portion of a control program executed by a microcomputer shown in FIG. 7;

FIG. 9 is a flow chart of a control program executed by a microcomputer in a third embodiment of the present invention;

FIG. 10 is a schematic illustration of a fourth embodiment of the present invention;

FIG. 11 is a block diagram of an electric control circuit in the fourth embodiment;

FIG. 12 is a flow chart of a control program executed by a microcomputer shown in FIG. 11;

FIG. 13 is a flow chart of a defrost routine shown in FIG. 12; and

FIG. 14 is a flow chart of a washing routine shown in FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First Embodiment

FIG. 1 illustrates a practical embodiment of a large size ice making machine of the down-flow type for industrial use, and FIG. 2 illustrates an electric control circuit E of the ice making machine. As illustrated in FIG. 1, the main body B of the ice making machine is assembled within an upright housing 10 which is composed of a housing body 10a provided at its bottom with a guide duct 10b. The guide duct 10b is inclined downward from the bottom opening 11 of housing body 10a to introduce ice making water or washing water falling from the interior of housing body 10a.

The main body B of the ice making machine includes an ice making mechanism composed of a plurality of upright ice making plates 20 made of aluminum which are arranged in parallel to each other within the housing body 10a. The ice making plates 20 each are integrally formed with refrigerant passages extended transversely in parallel from its upper portion to its lower portion and communicated in series with each other. In the ice making machine, an evaporator is composed of the refrigerant passages.

In the main body B of the ice making machine, a sprinkler 30 is assembled within the housing body 10a at a position located above the ice making plates 20 so that ice making water or washing water spouted from nozzles 31 of the sprinkler 30 falls along the surfaces of upright ice making plates 20. An ice crusher 30a is mounted within the guide duct 10b for rotary movement. The crusher 30a is driven by an electric motor to crush ice plates released from the ice making plates 20 into the guide duct 10b during operation at a defrost mode and to discharge crushed ice blocks into an ice storage cabinet (not show) placed under the guide duct.

A water tank 40 arranged under the housing body 10a is supplied with brine from a source of salt water (not shown) through a brine water supply conduit 40a provided thereon with a brine supply valve 40b of the normally closed type. The water tank 40 is supplied with tap water for washing from a source of tap water (not shown) through a conduit 40c provided with a tap water supply valve 40d of the normally closed type. The water tank 40 stores therein an amount of ice making water, washing water or crushed ice blocks introduced into the guide duct 10 from the housing body 10b and discharged from a discharge duct 12 mounted to an intermediate portion of guide duct 10b. The discharge duct 12 is extended toward the interior of water tank 40 from the intermediate portion of guide duct 10. The source of salt water is arranged to supply sea water as the brine into the water tank.

The ice making water or washing water in water tank 10 is supplied to the sprinkler 30 during operation of a water pump 40f disposed in the water supply conduit 40e. During operation of the ice making machine at a drain mode, the ice making water or washing water in water tank 40 is drained by operation of a drainage pump 40h disposed in a drain conduit 40g.

A freezing circuit 50 assembled with the main body B of the ice making machine includes a compressor 50a whose inlet port is communicated with an outlet port of the evaporator integral with the ice making plates 20 through a conduit 51. The compressor 50a is driven under control of the computer to compress the refrigerant circulated from the evaporator through a conduit 51 and to discharge the compressed refrigerant of high temperature under pressure into a condenser 50b.

The condenser 50b condenses the compressed refrigerant from compressor 50a and causes the condensed refrigerant to flow into an air-liquid separator 50c through a conduit 53. The air-liquid separator 50c separates the condensed refrigerant into air and liquid and causes the refrigerant of liquid phase into an electromagnetic line valve 50d of the normally closed type through a conduit 54. When opened, the line valve 50d causes the refrigerant of liquid phase from air-liquid separator 50c to flow into an expansion valve 50e through a conduit 55. When closed, the electromagnetic line valve 50d interrupts the flow of refrigerant of liquid phase into an expansion valve 50e. The expansion valve 50e converts the refrigerant of liquid phase from electromagnetic line valve 50d into circulation refrigerant of low temperature under low pressure in accordance with a heated degree of the refrigerant at the outlet portion of the evaporator and causes the circulation refrigerant to flow into the inlet portion of the evaporator through a conduit 56.

The evaporator is arranged to cool each ice making plate 20 with the circulation refrigerant supplied from expansion valve 50e and to circulate the circulation refrigerant into the compressor 50a through the conduit 51. The evaporator also acts to heat each ice making plate 20 with hot gas supplied from a hot-gas valve 50f of the normally closed type as described later and to circulate the hot gas into the compressor 50a through the conduit 51.

The hot-gas valve 50f is disposed in an intermediate portion of a bypass conduit 57 connected to each intermediate portion of conduits 52 and 56. When opened, the hot-gas valve 50f causes the compressed refrigerant from compressor 50a to flow as the hot gas into the inlet portion of the evaporator through an upstream portion of conduit 52, bypass conduit 57 and a downstream portion of conduit 56. When closed, the hot-gas valve 50f interrupts the flow of hot gas into the evaporator.

A hot water tank 60 is provided to store an amount of hot water and contains a intermediate bent portion 51a of conduit 51 and an intermediate portion 52a of conduit 52 immersed in hot water stored therein. The hot water in tank 60 is warmed by the compressed refrigerant of high temperature under high pressure flowing through the intermediate portion 52a of conduit 52 from compressor 50a. The circulation refrigerant flowing through the intermediate portion 51 of conduit 51 is warmed by the hot water in tank 60 and evaporates. This effects to prevent recirculation of the refrigerant at liquid phase into the compressor 50a.

Hereinafter, the electric control circuit E will be described with reference to FIG. 2. The electric control circuit E includes an operation switch 70 which is operated to start activation of the ice making machine. A water level sensor 70a is provided to detect the level of ice making water in the water tank 40, and a timer 70b is provided to start time measurement when reset under control of the microcomputer 80.

The microcomputer 80 is provided in the electric control circuit to execute a control program shown by a flow chart in FIGS. 3 to 6. During execution of the control program based on outputs of water level sensor 70a and timer 70b, the computer 80 executes processing for control of the crusher 30a, brine supply valve 40b, tap water supply valve 40d, water pump 40f, drainage pump 40h, compressor 50a, electromagnetic line valve 50d and hot gas valve 50f through driving circuits 90, 90a-90g. When the operation switch 70 is operated, the computer 80 initiates to execute the control program memorized in its ROM.

The driving circuit 90 is activated under control of the computer 80 to rotate the crusher 30a in a counterclockwise direction in FIG. 1. The driving circuit 90a is activated under control of the computer 80 to open and close the brine supply valve 40b. The driving circuit 90b is activated under control of the computer 80 to open and close the tap water supply valve 40b. The driving circuit 90c is activated under control of the computer 80 to drive the water pump 40f. The driving circuit 90d is activated under control of the computer 80 to drive the drainage pump 40h. The driving circuit 90e is activated under control of the computer 80 to drive the compressor 50a. The driving circuit 90f is activated under control of the computer 80 to open and close the electromagnetic line valve 50d. The driving circuit 90g is activated under control of the computer 80 to open and close the hot gas valve 50f.

When the operation switch 70 is operated to activate the ice making machine, the computer 80 initiates to execute processing of an ice making routine 100 of the control program as shown in a flow chart of FIG. 3. In processing of the ice making routine 100, the electromagnetic line valve 50 is opened by activation of the driving circuit 90f under control of the computer 80 at step 110 of FIG. 4. After processing at step 110, the hot gas valve 50f is closed by activation of the driving circuit 90g under control of the computer 80 at step 120. Subsequently, the compressor 50a is driven by activation of the driving circuit 90e under control of the computer 80 at step 130 of FIG. 4 to compress the refrigerant circulated into conduit 51 from the evaporator so that the compressed refrigerant of high temperature under high pressure flows into the condenser 50b through conduit 52.

The compressed refrigerant is condensed by the condenser 50b and separated into air and liquid at the air-liquid separator 50c. When the refrigerant of liquid phase from separator 50c flows into the expansion valve 50e through the electromagnetic line valve 50d, the expansion valve 51 converts the refrigerant of liquid phase to refrigerant of low temperature under low pressure and causes it to flow as circulation refrigerant into the evaporator. Thus, the ice making plates 20 are cooled by the circulation refrigerant flowing into the evaporator, and the circulation refrigerant circulates into the compressor 50a.

After processing at step 130, the water pump 40f is driven at step 140 by activation of the driving circuit 90c under control of the computer 80 to supply the ice making water from the water tank 40 to the sprinkler 30 through the conduit 40e. The ice making water is sprayed to the ice making surfaces of plates 20 from nozzles 31 of the sprinkler 30 and falls along the ice making surfaces of plates 20. Thus, the ice making water circulates into the water tank 40 through the discharge passage 12 of the guide duct 10b.

In such a manner as described above, the ice making machine is operated at the ice making mode such that the ice making water is frozen by the evaporator and formed into ice plates on the ice making surfaces in the course of falling along the ice making surfaces of upright plates 20. When the level of ice making water in water tank 40 lowers less than a lower limit level, the computer 80 determines a “Yes” answer at step 100a of FIG. 3 in response to a detection signal from the water level sensor 70a and causes the program to proceed to a defrost routine 200 shown in FIG. 5. In the defrost routine 200, the computer 80 executes processing for stopping the water pump 40f at step 210. With this processing, the water pump 40f is stopped under control of the driving circuit 90c to stop the supply of ice making water from the water tank 40 to the sprinkler 30.

After processing at step 210, the hot gas valve 50f is opened by activation of the driving circuit 90g under control of the computer at step 220, and the electromagnetic line valve 50d is closed by activation of the driving circuit 90f under control of the computer at step 230 to interrupt the refrigerant from the air-liquid separator 50c to the expansion valve 50e. Thus, the compressed refrigerant from compressor 50a flows as hot gas into the evaporator through the hot gas valve 50f such that the ice plates formed on the ice making plates 20 are molten by the hot gas and released from the ice making plates to be introduced into the guide duct 10b.

After processing at step 230, the crusher 30a is driven by activation of the driving circuit 90 under control of the computer at step 240 such that the ice plates introduced into the guide duct 10b are crushed by operation of the crusher and introduced into an ice storage cabinet (not shown). During such operation of the ice making machine at the defrost mode, the ice plates formed on the ice making plates are crushed and stored in the ice storage cabinet. When the temperature of refrigerant at a position near the outlet portion of the evaporator rises more than a predetermined temperature for completion of the defrost, the computer determines a “Yes” answer at step 200a in response to a detection signal from a temperature sensor (not shown) placed at the position near the outlet portion of the evaporator.

When the “Yes” answer is determined at step 200a, the computer executes at step 300 processing for stopping the compressor 50a and for driving the drainage pump 40h. With this processing, the compressor 50a is stopped, and the drainage pump 40h is driven by activation of the driving circuit 90d under control of the computer to drain the ice making water remained in the water tank 40 after operation at the ice making mode. When the level of ice making water becomes the lowest level, the computer 80 determines a “Yes” answer at step 300a in response to a detection signal from the water level sensor 70a and executes processing for stopping the drainage pump 40h at step 300b. Thus, the drainage pump 40h is stopped under control of the computer to finish drainage of the ice making water from the water pump 40.

Subsequently, the computer renews a measurement data C to C=C+1 on a basis of a measurement data C=0 at step 700. This means that the processing at step 100 to 300b has been once executed in operation at the ice making mode and the defrost mode. Since the measurement data C at this stage is still less than a predetermined number of times Co, the computer determines a “No” answer at step 500 and executes processing for opening the brine supply valve 40b at step 800. With this processing, the brine supply valve 40b is opened by activation of the driving circuit 90a so that the brine from the source of salt water is supplied as ice making water to the water tank 40.

When the level of ice making water in water tank 40 rises up to an upper limit level, the computer determines a “Yes” answer at step 800a in response to a detection signal from the water level sensor 70a and executes processing for closing the brine supply valve 40b at step 800b. With this processing, the brine supply valve 40b is closed to stop the supply of brine to the water tank 40. Thereafter, the processing for operation at the ice making mode and the defrost mode, for draining the ice making water from water tank 40, and for supplying the ice making water to the water tank 40 is repeatedly executed while the “No” answer is determined at step 500. Thus, the ice blocks of brine are stored in the ice storage cabinet.

During such operation of the ice making machine as described above, the ice making water in water tank 40 is drained at each finish of operation at the defrost mode, and the water tank 40 is supplied with fresh brine as the ice making water in operation at the subsequent ice making mode to produce ice plates of the fresh brine. When the measurement data C is renewed at step 500 more than the predetermined number of times Co, the computer determines a “Yes” answer and executes at step 600 processing of a washing routine shown in FIG. 6.

During processing of the washing routine 600, the tap water supply valve 40d is opened by activation of the driving circuit 90b under control of the computer at step 610 so that the water tank 40 is supplied with tap water for washing. When the level of tap water for washing in water tank 40 rises up to the limit level, the computer determines a “Yes” answer at step 610a and executes processing for closing the tap water supply valve 40d at step 610b. Thus, the tap water supply valve 40d is closed by activation of the driving circuit 90b under control of the computer to stop the supply of tap water into the water tank 40.

After processing at step 610b, the water pump 40f is driven by activation of the driving circuit 90c under control of the computer at step 620 to supply the tap water for washing to the sprinkler 30 through the water supply conduit 40e. Thus, the tap water for washing is sprayed from the nozzles of sprinkler 30 toward each upper portion of ice making plates 20 and falls along the ice making plates 20. In such an instance, the tap water for washing is discharged through the discharge passage 12 of guide duct 30b and circulated into the water tank 40.

After finish of the processing at step 620, the timer 70b of the computer is reset at step 620a to start measurement of a predetermined time for washing. Accordingly, the computer determines a “No” answer at step 620b repeatedly during lapse of the predetermined time for washing, and the ice making plates 20 are washed by the tap water for washing during operation of the water pump 40f under control of the computer. Upon lapse of the predetermined time for washing, the computer determines a “Yes” answer at step 620b and executes processing for stopping the water pump 40f at step 620c. Thus, the water pump 40f is stopped by activation of the driving circuit 90c under control of the computer to stop the supply of the tap water for washing to the sprinkler 30.

After processing at step 620c, the drainage pump 40h is driven by activation of the driving circuit 90d under control of the computer at step 630 thereby to drain the circulated tap water for washing from the water tank 40 through the drain conduit 40g. When the level of tap water in water tank 40 lowers less than the lower limit level, the computer determines a “Yes” answer at step 630a in response to a detection signal from the water level sensor 70a and executes processing for stopping the drainage pump 40h at step 630b. Thus, the drainage pump 40h is stopped by activation of the driving circuit 90d under control of the computer to stop drainage of the tap water for washing from the water tank 40.

As is understood from the above description, the water tank 40 is supplied with fresh tap water for washing from the source of tap water through the tap water supply valve 40d after the ice making water was drained, and the ice making plates 20 are washed by the tap water spouted from the sprinkler 40 during operation of the water pump 40f. Accordingly, the water circulation system such as the sprinkler 30, ice making plates 20, guide duct 10b, discharge passage 12 and water tank 40 is washed with fresh tap water. Thus, salt component adhered to the water circulation system during operation at the ice making mode will be cleanly eliminated with the fresh tap water. As a result, the water circulation system is maintained in a clean condition without being corroded by salt component in the ice making water. Since the washing routine 600 is processed at each time when the “Yes” answer is determined at step 500, the water circulation system is automatically washed without any works for washing.

When the processing of the washing routine 600 is finished, the measurement data C is cleared as C=0 at step 700. Thereafter, processing at step 800-800b is executed in the same manner as that at the time when the “No” answer was determined at step 500. Thus, until the level of brine in water tank 40 becomes the upper limit level, the brine supply valve 40b is maintained in an open position to supply the brine to the water tank 40 through the brine supply conduit 40a. After the water circulation system has been washed, the operation at the ice making mode is automatically started.

During operation of the ice making machine, the hot water in tank 60 is warmed by the compressed refrigerant flowing from the compressor 50a to the intermediate portion 52a of conduit 52. Thus, the refrigerant of liquid phase circulated to the compressor 50a from the evaporator vaporizes at the intermediate portion 51a of conduit 51. This is useful to avoid damage of the compressor 50a caused by circulation of the refrigerant of liquid phase.

Second Embodiment

Illustrated in FIGS. 7 and 8 is a second embodiment of the present invention, wherein an operation switch 70c for washing is added to the electric control circuit E to be operated for washing the water circulation system described above.

In this second embodiment, a control program shown by a flow chart in FIG. 8 is substituted for the control program shown by the flow chart in FIG. 3. The other construction is the same as that of the first embodiment. In this second embodiment, the computer executes processing for stopping the drainage pump 40h at step 300b as in the first embodiment. Thereafter, the computer determines at step 500a whether the operation switch 70c for washing has been operated or not. If the operation switch 70c is not operated, the computer determines a “No” answer at step 500a and executes the processing at step 800 and at the following step in the same manner as in the first embodiment. When the operation switch 70c for washing is operated, the computer determines a “Yes” answer at step 500a and executes the processing of the washing routine 600 in the same manner as in the first embodiment. The water circulation system is washed with fresh tap water by processing of the washing routine 600.

Third Embodiment

Illustrated in FIG. 9 is a third embodiment of the present invention, wherein a washing routine at step 600 in FIG. 9 is substituted for the washing routine at step 600 in FIG. 6. The other construction is the same as that in the first embodiment. In this third embodiment, the computer executes processing for closing the tap water supply valve 40b at step 610b as in the first embodiment. Thereafter, the computer executes processing for driving the water pump 40f and for driving the ice crusher 30a at step 620d in FIG. 9. Thus, under control of the computer, the water pump 40f is driven by activation of the driving circuit 90c to supply the tap water for washing to the sprinkler 30 from the water tank 40, and the ice crusher 30a is driven by activation of the driving circuit 90. The tap water for washing is spouted from the nozzles of sprinkler 30 toward the ice making plates 20 and falls along the ice making plates 20 to wash the ice making surfaces of them. The tap water for washing is discharged through the guide duct 30b and circulated into the water tank 40 through the discharge passage 12. In such an instance, the crusher 30a is washed by the tap water falling from the ice making plates 20, while the internal surface of guide duct 10b is washed by the tap water picked up by rotation of the crusher 30a.

Fourth Embodiment

Illustrated in FIGS. 10-14 is a fourth embodiment of the present invention, wherein a small size ice making machine of the down-flow type is substituted for the large size ice making machine in the first embodiment. As shown in FIGS. 10 and 11, the small size ice making machine is composed of a main body Ba thereof and an electric control circuit Ea.

The main body Ba of the ice making machine includes a pair of upright ice making plates 20a arranged in parallel and upper and lower sprinklers 30b, 30c. The upper side sprinkler 30b is arranged above the ice making plates 20a to spray ice making water or washing water toward each upper end of the ice making plates 20a from its nozzles 32. The lower side sprinkler 30c is placed between the upper portions of ice making plates 20a to sprinkle defrost water or washing water toward the back surfaces of the ice making plates 20a from its nozzles 33.

The main body Ba of the ice making machine further includes a meshed guide member 20b and an ice storage cabinet 20c and includes a water tank 40 and a water pump 40f as in the first embodiment. The water tank 40 is located under the ice making plates 20a, and the guide member 20b is inclined toward the ice storage cabinet 20c to receive ice blocks formed on the outer surfaces of the ice making plates 20a and introduce them into the ice storage cabinet 20c.

The water tank 40 is provided to store an amount of tap water supplied from a source of tap water through a tap water supply valve 40d. In this embodiment, the tap water is used as ice making water or washing water. The water pump 40f is provided to supply the tap water from water tank 40 to the sprinklers 30a, 30b through a water supply conduit 40e. A drainage pump 40h is provided to drain the tap water from the water tank 40 as in the first embodiment.

The main body Ba of the ice making machine further includes a defrost water tank 40i and a defrost water supply valve 40n of the normally closed type. The defrost water supply valve 40n is disposed in a defrost water supply conduit 40m to supply tap water from the source of defrost water as defrost water to the defrost water tank 40i in its open position. A water supply pump 40k is disposed in a water supply conduit 40j to supply the defrost water from the defrost water tank 40i to the sprinkler 30c in its activated condition.

A washing water supply valve 40q is disposed in a conduit 40p between downstream portions of the water supply conduits 40j and 40e to supply washing water from the water supply pump 40f to the sprinkler 30c through conduits 40e and 40p in its open position. When closed, the washing water supply valve 40q interrupts the supply of washing water to the sprinkler 30c.

The main body Ba of the ice making machine is provided with a freezing circuit 50A which includes the compressor 50a as in the first embodiment for supplying compressed refrigerant to the condenser 50b through a conduit 58. The freezing circuit 50A further includes a coiled evaporator 50g which is disposed between the ice making plates 20a to cool the ice making plates. The evaporator 50g is connected at its inlet portion to an expansion valve 50e through a conduit 56 and at its outlet portion to the compressor 50a through a conduit 59. The other construction of the freezing circuit 50A is substantially the same as that in the first embodiment.

In the electric control circuit Ea, the control program executed by the microcomputer 80 in the first embodiment is modified as shown in a flow chart of FIG. 12. In this modification, the flow chart of FIG. 3 is modified as shown in FIG. 12, the flow chart of FIG. 5 is modified as shown in FIG. 13, and the flow chart of FIG. 6 is modified as shown in FIG. 14. In the electric control circuit Ea, a stored ice detection switch 70d and driving circuits 90h, 90i, 90j are added as shown in FIG. 11, the driving circuits 90, 90a in the first embodiment are removed.

The stored ice detection switch 70d is arranged to detect an amount of ice cubes 20d stored in the ice storage cabinet 20c as shown in FIG. 10. The driving circuit 90h is activated under control of the computer 80 to open and close the defrost water supply valve 40n. The driving circuit 90i is activated under control of the computer 80 to open and close the washing water supply valve 40q. The driving circuit 90j is activated under control of the computer 80 to drive the water supply pump 40k. The other construction of the electric control circuit Ea is the same as that in the first embodiment.

When the operation switch 70 in the fourth embodiment is operated to activate the ice making machine, the computer 80 initiates to execute processing of the ice making routine 100 of the control program as shown in FIG. 12. In processing of the ice making routine 100, the electromagnetic line valve 50d is opened, the hot gas valve 50f is closed, and the compressor 50a and water pump 40f are driven under control of the computer 80 in the same manner shown in the flow chart of FIG. 4. Thus, in the freezing circuit 50A, the refrigerant of high temperature under high pressure from the compressor 50a flows through the condenser 50b, air-liquid separator 50c and expansion valve 50e and is circulated into the evaporator 50g in the form of refrigerant of low temperature under low pressure. In turn, the ice making plates 20a are cooled by the refrigerant circulated into the evaporator 50g, and the refrigerant is circulated to the compressor 50a.

In such operation, the water pump 40f is driven by activation of the driving circuit as in the first embodiment to supply ice making water from the water tank 40 to the upper side sprinkler 30b through the conduit 40e. The ice making water is spouted to the ice making plates 20a from the nozzles 32 of sprinkler 30b and falls along the ice making plates. Thus, the ice making water circulates into the water tank 40.

In such a manner as described above, the ice making machine is operated at the ice making mode such that the ice making water falling along the ice making plates 20a is frozen by the evaporator 50g and formed into ice cubes on the ice making plates. In the course of growth of ice cubes, the ice making water in water tank 40 decreases. When the level of ice making water in water tank 40 lowers less than the lower limit level, the computer 80 determines a “Yes” answer at step 100a of FIG. 3 in response to a detection signal from the water level sensor 70a and causes the program at step 200b to proceed to a defrost routine 200b shown in FIG. 13.

In the defrost processing routine 200b, the water pump 40f is stopped by processing at step 210, the hot gas valve 50f is opened by processing at step 220, and the electromagnetic line valve 50d is closed by processing at step 230 as in the first embodiment. Thus, the compressed refrigerant from compressor 50a flows as hot gas into the evaporator 50g through the hot gas valve 50f. In such an instance, the water pump 40k is driven by activation of the driving circuit 90j under control of the computer at step 250 to supply defrost water from the defrost water tank 40i to the lower side sprinkler 30c through the conduit 40j. The defrost water is spouted to the upper portions of ice making plates 20a from the nozzles 33 of sprinkler 30c and falls along the back surfaces of ice making plates 20a to be circulated into the water tank 40 across the meshed guide member 20b.

In operation at the defrost mode described above, the ice cubes formed on the ice making plates 20a are molten by the defrost water falling along the back surfaces of ice making plates 20a and the hot gas flowing into the evaporator 50g and released from the ice making plates to be stored in the ice storage cabinet 20c.

When the temperature of refrigerant at a position near the outlet portion of evaporator 50g rises more than the predetermined temperature in operation at the defrost mode, the computer determines a “Yes” answer at step 200a in response to a detection signal from the temperature sensor. When the “Yes” answer is determined at step 200a, the compressor 50a is stopped by processing at step 300, and the drainage pump 40h is driven by processing at step 300a to drain the ice making water from the water tank 40 as in the first embodiment.

When the level of ice making water in water tank 40 becomes the lowest level, the computer determines a “Yes” answer at step 300a in response to a detection signal from the water level sensor and executes processing for stopping the drainage pump 40h at step 300b. Thus, the drainage pump 40h is stopped under control of the computer to finish drain of the ice making water from the water tank 40.

Subsequently, the computer determines at step 500a whether the ice storage cabinet 20c has been filled with ice cubes or not. If the answer is “No”, the tap water supply valve 40d is opened by processing at step 800c to supply the tap water as ice making water to the water tank 40 through the tap water supply conduit 40c. When the level of ice making water in the water tank 40 rises more than the upper limit level, the computer 80 determines a “Yes” answer at step 800a in response to a detection signal from the water level sensor 70a and executes processing for closing the tap water supply valve 40d at step 800d. Thus, the tap water supply valve 40d is closed by processing at step 800d to interrupt supply of the tap water to the water tank 40. Thereafter, the defrost water supply valve 40n is opened by processing at step 800e for a predetermined time to supply the tap water as defrost water to the defrost water tank 40i through the defrost water supply conduit 40m.

After processing at step 800e, the computer 80 determines at step 800f whether the ice storage tank 20c has been filled with ice cubes or not. When the ice cubes are not fully stored in the storage cabinet 20c, the computer determines a “Yes” answer at step 800f in response to a detection signal from the stored ice detection switch 70d. Thereafter, the operation at the ice making mode and the defrost mode is repeated by processing at step 500a until the ice cubes are fully stored in the ice storage cabinet 20c.

During such operation of the ice making machine as described above, the ice making water in water tank 40 is drained at each finish of operation at the defrost mode, and the water tank 40 is supplied with fresh ice making water in operation at the subsequent ice making mode to produce ice cubes of the fresh water in a clean condition. When the ice cubes are fully stored in the ice storage cabinet 20c, the computer determines a “Yes” answer at step 500a in response to a detection signal from the stored ice detection switch 70d and executes at step 600a processing of a washing routine shown in FIG. 14.

During processing of the washing routine 600a, the tap water supply valve 40d is opened by processing at step 610 to supply tap water for washing into the water tank 40. When the level of tap water for washing in water tank 40 rises up to the upper limit level, the tap water supply valve 40d is closed by processing at step 610b. Thereafter, the washing water supply valve 40q is opened and the water supply pump 40f is driven by processing at step 620d to supply the tap water for washing from the water tank 40 to the upper side sprinkler 30b through the conduit 40e and to the lower side sprinkler 30c through the conduit 40p, washing water supply valve 40q and conduit 40j.

Thus, the tap water for washing is spouted from the nozzles of upper side sprinkler 30b toward each upper portion of the ice making plates 20a and is spouted from the nozzles of lower side sprinkler 30c toward the back surfaces of ice making plates 20a. The tap water for washing from the upper side sprinkler 30a falls along the ice making surfaces of plates 20a and circulates into the water tank 40 across the meshed guide member 20b. The tap water for washing from the lower side sprinkler 30c falls along the back surfaces of ice making plates 20a and the evaporator 50g and circulates into the water tank 40.

After finish of the processing at step 620d, the timer 70b of the computer is reset at step 620a to start measurement of a predetermined time for washing. Accordingly, the computer repeatedly determines a “No” answer at step 620b during lapse of the predetermined time for washing, and the ice making plates 20a and evaporator 50g are washed by the tap water for washing during operation of the water pump 40f under control of the computer. Upon lapse of the predetermined time for washing, the computer determines a “Yes” answer at step 620b and executes processing for closing the washing water supply valve 40q and for stopping the water pump 40f at step 620e. Thus, the washing water supply valve 40q is closed, and the water pump 40f is stopped to stop the supply of the tap water for washing to the sprinklers 30b, 30c. After processing at step 620e, the drainage pump 40h is driven by processing at step 630-630b to drain the washing water from the water tank 40 as in the first embodiment.

As is understood from the above description, the water tank 40 is supplied with fresh tap water for washing from the source of tap water through the tap water supply valve 40d after the ice making water was drained therefrom, and the ice making plates 20 and evaporator 50g are cleanly washed by the fresh tap water spouted from the upper and lower side sprinklers 30b, 30c during operation of the water pump 40f. Accordingly, the water circulation system such as the sprinklers 30b, 30c, ice making plates 20a, meshed guide member 20b and water tank 40 is washed with the fresh tap water. Thus, contaminants adhered to the water circulation system during operation at the ice making mode are cleanly eliminated with the fresh tap water. As a result, the water circulation system is maintained in a clean condition.

When the ice storage cabinet 20c is filled with the ice cubes, the computer determines a “Yes” answer at step 500a in response to a detection signal from the stored ice switch 70d and executes the processing of the washing routine 600a. Accordingly, the water circulation system is automatically washed without any working for washing during operation of the ice making machine at the ice making mode. This is useful to maintain the ice making machine in a clean condition in a simple manner.

When the processing of the washing routine 600a is finished, the processing at step 800c-800e is executed by the computer to open the water supply valve 40d for supplying fresh tap water into the water tank 20c from the source of tap water until the level of fresh tap water in tank 20c rises up to the upper limit level and to open the defrost water supply valve 40n for supplying defrost water into the defrost water tank 40i. Thereafter, the computer determines a “No” answer at step 800f since the ice storage cabinet 20c is filled with the ice cubes.

In actual practice of the present invention, underground water may be used as the washing water in stead of the tap water. In the embodiments described above, the drainage timing of the ice making water and washing water from the water tank 40 is determined by detection of the water level sensor 70a. In the case that the ice making water and washing water from the water tank may not be fully drained only by detection of the water level sensor, the drainage pump 40h may be driven for a predetermined time after the lowest level of water in the water tank was detected by the water level sensor 70a. In such a case, the timer 70b can be used to measure the predetermined time for activation of the drainage pump 40h.

Although the ice making plates 20 in the above embodiments are made of aluminum to avoid corrosion caused by salt content, the ice making plates may be made of copper or stainless steel in the case where corrosion caused by slat water can be prevented by washing of the water circulation system.

Ice making machine

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

US Classifications

International Classifications

Abstract

Description

Claims

Priority Claims (1)