JD COOLING | Top Tips
- Always ensure that your tank of water is pre-cooled to the set-point temperature prior to production starting; this should be around +0.75 to +1ºC max (a simple timer can be fitted to allow this to happen automatically)
- Prior to your busy season, make sure that your plant is fully serviced so that it can achieve its maximum potential. Once underway, check weekly the area around your external plant and ensure that the condenser is completely clean and not blocked by seedlings, leaves, paper or packaging. Remove all such blockages carefully so as not to bend the delicate fins on your condenser coils.
- At the start of your busy season, check the speed setting on your conveyor using a coloured tennis or golf ball. Place this on the conveyor just at the entry point of product as it goes under the water drench. Time the period it takes for the ball to exit this drench at the output end of the machine. Depending on product type and size, this time should be 15 – 25 minutes, and never less than 15 minutes for summer crop temperatures. Adjust your belt speed using either the inverter or gearbox control. Most machines would be designed for a crop on belt depth of around 600mm (2 ft) at peak design throughputs. Do not adjust the belt speed for lower throughputs, only adjust according to seasonal trends. For example, for winter crops you could speed up the belt to around 10-minute dwell time for higher tonnage.
- At the start of your season, check the water flow over your coils. This should be set so that the trays have a full level of water (this will vary across the trays, but it should be possible to achieve flow through all of the holes in the trays) and the pumps are delivering their maximum flow without overflowing the intermediate coil distribution trays.
- Check your water condition daily. Chemical treatments need to be carefully controlled to ensure that the cooling coils are not corroded. These may control bacterial counts but the actual water cleanliness is important to water distribution so consider changing your water every two or three days. This may vary according to harvest conditions and water filtration efficiency. The old water from the Hydrocooler can be used to fill pre-washers which will save water and also see that they are filled with cooler water than ambient systems.
- Check your water distribution hourly. The top tray system that feeds the coils can become blocked and this will destroy the design water flow pattern and thereby reduce cooling efficiency from the coils. A squeegee can be used to force through particulates so that they go back into the system and get filtered out, leaving the trays flowing freely at the upper level.
- Cooling coils will become dirty from the recirculating water. A film of slime can build on the coil pipework and this will drastically reduce cooling efficiency from the coils. Coils should be thoroughly cleaned weekly by removing the intermediate water trays and any side covers to allow a pressure lance to be used to remove this slime build-up from the side and top of the coils.
- Use borehole water to fill and top-up your machine wherever possible. Borehole water tends to be lower in temperature than mains or stored water and will reduce the cooling demand on your plant.
- Consider adiabatic cooling for your condenser. During peak conditions it may be possible to increase your cooling capacity by up to 10% by lowering the outside air temperature on to your condenser coil. DO NOT put water directly on to your condenser coil as this will lead to premature corrosion of the coil. Contact JD Cooling for more information on adiabatic cooling for condensers.
- Consider an interim service during your peak season. A properly functioning plant will deliver much better crop quality and can provide massive running cost reductions.
