Industrial dishwasher maintenance: the balance between good cleaning and food safety

Industrial dishwashers are designed for the automatic cleaning of dishes and glassware with pressurized water and detergent. In addition to speeding up the cleaning process and guaranteeing thermal disinfection, among their many advantages, they allow for significant water savings, and they enable staff to undertake other tasks.

There are several models of industrial dishwasher (glassware washers, dome or hood dishwashers, pot washers, dishwasher tunnels, etc.), depending on the size and dimensions required, and the type of dishes or utensils for which it is designed.

Their general operation is similar in all cycle dishwashers, except for continuous tunnel dishwashers, which are slightly different.

Filling:

The water enters through the filling/rinsing solenoid valve (except in cases where there are 2 solenoid valves) and it fills the boiler, continuing on to the washing tank, until the tank is filled up to the level of the pressure switch. During filling, the detergent dispenser is activated, in order to apply the set detergent dosage directly into the washing tank.

Heating:

Once the tank is full, or even during filling, both the boiler heating elements, which heat the rinsing water to 80-90ºC, and the tank heating elements, which heat the washing water to 50-60ºC, are activated. This process takes 10 to 20 minutes. During the heating process, some industrial dishwashers allow for cold washing, and some dishwashers do not allow for washing. Some of the dishwashers that allow for washing even automatically increase the cycle time in order to compensate for the lack of temperature.

Washing:

Once the dishes have been placed in the basket, and the basket has been placed in the dishwasher, the washing process begins. During this phase, the washing pump takes in water from the tank and uses either rotating or fixed sprinklers at the top and bottom to project the pressurised water, with the detergent, onto the dishes in a closed circuit. This cycle lasts between 1.5 and 3 minutes.

For this process, Proquimia recommends the ECOCOCONPACK A10, A30 and A50 range of concentrated products. The range of alkaline detergents, such as Licuasol, Licuaclean, Licuafis, Licuajet or Licuaplus, would also be suitable for industrial dishwashers.

Rinsing:

Once the washing phase has finished, the rotating or fixed rinsing sprinklers spray pressurized water with polisher from the boiler. This phase lasts between 10 and 20 seconds and consumes 2-5 litres of water, depending on the industrial dishwasher. During this process, the polisher breaks the surface tension of the water, which causes the droplets to coalesce, forming a thin film that reaches all parts of the dishes. When hot, this film of water evaporates quickly, leaving the dishes dry and free from drip marks. Some examples of polishers, all from Proquimia, are Ecoconpack Abrillantador, Klir, Adisec, Cerofilm or Secosec.

It is important to know that the washing and rinsing water follow different circuits. Whilst the washing water is in the tank, where it is kept at a temperature of 50-60ºC by means of heating elements, following a closed circuit and recirculating towards the sprinklers during the washing cycles, the rinsing water is always clean mains water. It is stored in the boiler, where it is also heated to a temperature of 80-90ºC by means of heating elements, thus guaranteeing the thermal disinfection and rapid drying of the dishes.

Basic cleaning and disinfection standards

After each work shift, it is recommended that the dishwasher be completely cleaned, or at least emptied and refilled. Always washing with the same water in the tank means that the dishwasher becomes progressively dirty, even though a small amount of new water enters during the rinsing phase. To carry out this process, simply remove the cap and wait for the dishwasher to empty completely. Then replace the cap and, once the door is closed, filling will begin (if the dishwasher is on). On models that have drain pump emptying, in addition to removing the plug, the corresponding emptying button must be pressed.

After each shift, or at least once a day, the industrial dishwasher must be completely cleaned according to the following procedure:

• Empty the dishwasher.
• Dismantle the washing and rinsing sprinklers, plugs and filters.
• Apply disinfectant detergent, spraying it on the inside of the tank. Scrub it and leave it to work for at least 5 minutes. Products such as Deosol, Deobact D, Asepvix Conpack Deobact D, Conpack Asepvix or Conpack Desinfectante Plus from Proquimia can be used for this task.
• Manually unblock the rinsing sprinklers, and the washing sprinklers in particular, which may be clogged (you can tap lightly on the sprinklers to loosen the dirt inside)
• Apply disinfectant detergent on the outside of the washing and rinsing sprinklers, and the disassembled parts. Scrub it and leave it to work for at least 5 minutes. Products such as Deosol, Deobact D, Asepvix Conpack Deobact D, Conpack Asepvix or Conpack Desinfectante Plus from Proquimia can be used for this task.
• Put the parts back in place and fill the dishwasher without replacing the drain plug to rise it for a few seconds (on industrial dishwashers with a rinse button, this button can be activated to perform this step)
• Let the rinse water empty (activate the drain pump for emptying on models that have a pump, and run a couple of washing cycles without dishes in order to pass water with detergent through the inside of the washing sprinklers and the pump.
• Empty the dishwasher again.

In this regard, the Catalan Food Safety Agency (ACSA) has just published a brief document which highlights the importance of proper cleaning and appropriate maintenance of industrial dishwashers, in order to ensure food safety in food preparation and serving establishments.

BIBLIOGRAPHIC REFERENCES

ACSA. Catalan Food Safety Agency. (s. f.). Els rentavaixelles industrials. Retrieved 19 April 2021, from https://acsa.gencat.cat/ca/Publicacions/guies-i-documents-de-bones-practiques/documents-de-bones-practiques/els-rentavaixelles-industrials/