Refrigeration – Processes – Congealing flowable material – e.g. – ice making
Reexamination Certificate
2000-07-17
2001-09-04
Tapolcai, William E. (Department: 3744)
Refrigeration
Processes
Congealing flowable material, e.g., ice making
C062S158000, C062S233000
Reexamination Certificate
active
06282909
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to ice making methods and apparatus that have adaptive controls for addressing diverse operating and ambient conditions.
BACKGROUND ART
Commercial experience has revealed that productive ice-making systems and functional components may not adapt to diverse ambient conditions or internal operating conditions. One particular type of commercial ice making machine sensing system involves optoelectronic IR (infrared) emitters and detectors used to detect beam blockage in several sensing applications. An optoelectronic IR beam blockage sensor apparatus may detect falling ice pieces during the ice harvesting operation, a level of ice in the ice storage bin representative of a bin full condition, and low or high levels of water in the ice-making sump reservoir to provide signals respectively used with automatic ice making.
Basic optoelectronic sensing techniques have inherent detriments that impede consistent, reliable, and long-term operation. Optoelectronic emitters and detectors are prone to changes in characteristics as a function of changes in operating voltages, currents, and temperature. Optoelectronic emitters are particularly susceptible to detrimental and permanent changes in emission efficiency with age based upon accumulated operation time under conditions of elevated semiconductor junction temperature and high operating voltage or current.
Prior optoelectronic sensor implementations suffer performance degradations due to relatively slowly changing conditions and parameters including operating temperature, component age, degradation of the emitters, misalignment of optical components, mineral haze accumulation on optical lenses, moisture condensation on optical lenses, fog, ambient levels of IR radiation, and the like. The practical result has been the sensor subsystem causing the ice making system to go into a diagnostic fault and shutdown mode that interferes with ice making operation, often due to dirty lenses, and an error indication merely communicates the need for service.
Previous methods of optoelectronic sensing using DC optocoupling and a fixed DC comparator require high emitter drive and high detector gain to sense falling ice under poor optocoupling conditions. This causes a detrimental condition whereby ambient sunlight potentially “blinds” the optodetector due to output saturation, thus losing the capability to detect relatively small changes in signal level that occur when a slight dynamic optocoupling reduction is caused by a falling ice piece, and reduces capability to distinguish such an event from other ambient conditions and changes in ambient conditions. Detector blinding due to output saturation is cause for the ice making system to go into shutdown to protect itself from potential damage.
False sensing of ice via a previous optoelectronic method was possible because sensing methods implemented quick controller microprocessor interrupts set by a single false detection of an ice obstruction. Electrical noise had the potential to set the interrupt flag, thus causing a false sensing of the presence of ice and the microcontroller algorithm required approximately 200 lines of code and reacted relatively slowly.
A previous problematic optoelectronic sensing system operated pulsed drive of the optoemitter drive circuitry at 120 Hz which is inherently the same frequently as many discharge lamp pulses, electromagnetic fields, and electrical noise producers operating from a 60 Hz power source. Frequency spectra of noise and signal thus have common harmonics that preclude simplified methods to filter out the shared 120 Hz noise fundamental and odd harmonics thereof.
Ice machine methods, systems, and apparatus provide numerous control algorithms for both ice seeding and for harvesting operations. To address significant numbers and ranges of types and sizes of ice, and numerous possible ambient operation conditions for ice-making machines, a proliferation of control algorithms with specific programmed operation parameters would be required in previously known systems, thus resulting in excessive machine service.
Additionally, previous fault diagnostics response algorithms have caused ice-making machines to go into a fault response shutdown condition calling for service due to temporary faults. Such temporary faults are caused by such actions as leaving the ice machine door open so that IR optoelectronic detectors are saturated with ambient IR radiation and temporary loss of supply water pressure. In either of these two unanticipated conditions, the default timeout fault response has been to shutdown operation and indicate need for a service call.
Interrelated complexity of ice machine system operation components including sensors, compressor, heat exchangers, ambient conditions, supply water temperature, supply water quality, and the like typically result in less than optimal performance. Previous ice machine operation system, methods, and components typically result in tradeoffs to favor machine safety versus ice production performance. Furthermore, ice machine controller system hardware has been somewhat distributed and separate, each additional feature causing additional hardware and assembly costs due to increased interface wiring, electrical connectors, multiple independent modular assemblies for control, and the like.
SUMMARY OF THE INVENTION
The present invention overcomes the above-mentioned disadvantages by providing a method and apparatus for increasing ice machine production capability and reliability by enabling a set of cooperating improvements with adaptive controls to an ice production system. In general, system reliability, performance, and cost improvements are enabled by enhancements such as selection of a microcontroller incorporating flash ROM (read only memory) enabling end-configuration programmability. In addition, selection of a microcontroller containing integral EEPROM memory enables greater adaptive algorithm control and operation parameter modification, reprogrammability, and lower controller cost. Furthermore, an improved communication interface capability and an expanded fault diagnostic data storage may provide for simplified service. The system preferably includes operation history monitoring for performance validation. Integrated control assemblies improve control and lower cost, while the adaptive electronic circuits control optoelectronic sensing components. Additional output drive and associated controls hardware control compressor starting, compressor operation, reduction of compressor output pressure, and heat exchanger blower fan speed. Sensors provide inputs in response to detected conditions including water reservoir high level, water reservoir low level, ice thickness, supply line voltage, ice door closed, and compressor output pressure.
Preferably, the apparatus component improvements that enable system improvements and method improvements preferably include: adaptive optoelectronic emitter and/or detector circuitry, preferably for sensing falling ice pieces during harvest operation and sensing the ice bin full status. Preferably, both such functions are performed by a single set of emitter and detector components, although each set may have multiple emitters and detectors. In addition, optoelectronic sensing of reservoir high and low water levels preferably utilize programmed and adaptive software thresholds based upon sampling and averaging. Furthermore, an alternative modification may be to utilize acoustic and/or vibration sensing of falling ice pieces during harvest operation and standing ice present in the ice chute. In another embodiment, ice mold types harvest ice as one large piece that breaks up when it drops, and a water splash curtain swings aside from the dropping of harvested ice. Preferably a simple and low cost magnet and reed switch sensor system for curtain position indicates the ice harvest.
A capacitive electric-field dielectric proximity sensor for ice thickness senses ice proximity to determine an end of cycle based upon a thickness and amount of
Ballast Ronald L.
Newman Todd R.
Shank David
Brooks & Kushman P.C.
Nartron Corporation
Tapolcai William E.
LandOfFree
Ice making system, method, and component apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ice making system, method, and component apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ice making system, method, and component apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2546920