DESCRIPTION

BACKGROUND OF THE INVENTION

Throughout this description the Bond Ultrasonic Nebuliser system will be referred to as "The BUN system"

The BUN system is predominately marketed at the Supermarket sector and other independent retailers as an alternative to traditional refrigerated cabinet drainage.

STATEMENT OF INVENTION

The BUN system was primarily invented as a self contained direct replacement of a heating element and evaporation tray/drip tray that is typically used in refrigerated display cabinets to evaporate waste water discharged after the cabinet has completed a defrost cycle.

The BUN system was invented and tested as an energy efficient means of dealing with the problem of water displacement throughout the refrigerated display cabinet market. This includes Multi deck, Half Glass Door, Well, Full Glass Door, Roll in cabinets, Deli counters on remote and integral appliances, low and high temperature.

ADVANTAGES

Heaters traditionally fitted to refrigerated cabinets for evaporation purposes are based around 900 watt to 1 kilowatt. The BUN system operates using 10% of the energy required to run these traditional rod heaters. INTRODUCTION TO DRAWINGS

Figure 1 shows a basic example of the atomisation chamber construction venting to atmosphere.

Figure 2 shows a basic example of the atomisation chamber construction venting to atmosphere with the addition of an ultra violet light.

Figure 3 shows a basic example of the atomisation chamber construction being ducted back over the condenser coil.

Figure 4 shows a basic example of the atomisation chamber construction being ducted back over the condenser coil with the addition of an ultra violet light.

Key to reference letters on drawing:

(A) Cabinet drainage (B) Atomising chamber (C) Atomising chamber inlet

(D) To atmosphere (E) Atomising chamber (F) Ultraviolet light outlet vent

(G) Float switch (H) Nebulised water (I) Direction of Air flow particles

(J) Fan (K) Atomising chamber (L) Transducer drive drainage outlet circuit board

(M) Transducer (N) Transformer (O) Atomising chamber inlet vent

(P) Power supply (Q) Duct

DETAILED DESCRIPTION

The BUN system uses a vessel as an atomisation chamber (C) to collect the water that is discharged through the atomising chamber inlet (B) from the refrigerated display cabinets drainage system (A) during the cabinets defrost period. The water discharged from the cabinet is melted ice (demineralised water) that has formed on the evaporator coil during normal operation.

The atomising chamber (C) used to collect the water is sized accordingly against the drainage output (A) requirement of the refrigerated display cabinet.

The base of the atomising chamber (C) has a series of ultrasonic transducers (M) mounted to it. The number of transducers (M) used in each unit is proportional to the size of the atomising chamber (C) and the cabinets drainage (A) output.

A float switch/water level sensor (G) is also attached to the base of the atomising chamber (C), ensuring that the transducers (M) always have adequate water coverage and are only in operation when required.

Once the float switch (G) has been activated by an adequate amount of water the power supply (P) energises the drive circuit boards (L) via the transformer (N). The drive circuit boards (L) now energise the transducers (M) and the process of nebulisation begins .

During the process of nebulisation a low wattage blow fan (J) creates air turbulence (I) across the top of the atomising chamber (C) which causes the nebulised water particles (H) to vent out of the atomising chamber (C) through the outlet valve (E) and evaporate into the atmosphere (D) quickly and efficiently.

The nebulised water particles (H) can be directed through the condenser coil of the refrigerated cabinet for increased performance and improved life expectancy of the compressor unit. The base of the atomising chamber (C) is fitted with a small drainage outlet (K) for maintenance purposes.

Dependent on the type of refrigerated cabinet the system is fitted to the fan (J) can be replaced with a draw blade to extract the nebulised water particles (H) through a duct (Q) and then on to the condenser. This arrangement is shown in Figures 3 and 4.

Figure 2 and 4 show the addition of an ultraviolet light (F) which provides ultraviolet sterilisation to any stored water.

TECHNICAL UNDERSTANDING OF HOW IT WORKS

The BUN system uses ultrasonic nebulising modules and transducers to create nebulising. These modules are electronic oscillator circuits that power the transducers at high frequency. The transducers are matched at their resonant frequency and generate a mechanical vibration. Water inside the atomisation chamber is in direct contact with the vibrating faces/plates of the transducers. This causes the water to vibrate. Because of its mass, the water is unable to follow the high frequency oscillation of the transducers and cavitation occurs. When this process begins below the surface of the water, refracted capillary waves are generated, throwing off a cool dense cloud/mist of water particles.

To prevent the evaporated water particles from condensing back to a liquid form, a low wattage fan is used to blow out the evaporated water through a vent or is drawn through a ducting system, out of the atomising chamber.

The dense cloud/mist of nebulised water particles created as a result of nebulising has a cooling effect which if harnessed can be re-directed to flow across the face of the condenser coil. This cooling effect will help the condenser reject the heat gained from the load within the refrigerated area. This will therefore due to the pressure/temperature relationship of the refrigerant reduce the discharge pressure from the compressor, therefore prolonging its life and reducing its running cost.