Way More Than 200 Per Hour
Dishwasher - Twin Rack/Double Hood
These machines look like a passthrough dishwasher and act the same. They are double the width and the hood is also double in size to accommodate two baskets od dishes at the one time. They can wash double the volume of the equivalent single tank passthrough dishwasher.
Dishwasher – Conveyor
The conveyor dishwasher is designed for higher-volume premises where a fast throughput of a few thousand dishes per hour is necessary. It is physically larger than a standard passthrough dishwasher and is sometimes referred to as a rack conveyor dishwasher. The smallest is equivalent to two or three 500mm² baskets in length and the largest can fill a room at lengths of 5 or 6 metres.
These machines are specified as either a left to right flow or a right to left flow of operation. It is imperative to know this prior to installation as it cannot be changed to suit. The only other option is to change your whole system to work in reverse. The implications of getting this wrong would be with the tabling and sinks, as they would have to be renewed to suit.
With a frontloading dishwasher and a passthrough dishwasher, there is a door to open or hood to lift to insert the basket into the machine. However, with a conveyor machine there is no door or hood to open or lift. The operator pushes the loaded basket into the opening of the conveyor machine and the basket catches onto metal legs or levers. The basket is pulled through automatically on a mechanised conveyor system. There are plastic curtains at the opening and at the clean side of the machine, which cut down on splashing and help retain the hot temperatures within the machine.
Smaller versions of a conveyor dishwasher consist of a single wash tank and a rinse area. The basket is pulled through the wash area and then into the rinse chamber and out the other end.
On larger machines this is more sophisticated. Large machines are great for an outside catering or events company when hundreds of guests attend and the plates can’t be washed on-site at the venue, or even on that same day. The crockery, cutlery, and glasses are packed away and transported back to the caterer’s premises to be washed.
When dirty dishes are stacked together and allowed to dry, they become harder to clean, because both the front and the back of each plate is soiled. In these circumstances, the larger conveyor dishwashers come into their own.
The operator loads the plates into a basket, gives them a quick wet with the pre-spray tap and pushes them into the machine. The first stage is a prewash which soaks the plate and loosens the dirt. The next stage is the actual wash where the soil is further loosened, and combined with detergent, high wash temperature, and long wash contact time. Then the wares move into the rinse chamber.
The rinse takes away any remaining soil and detergent and sanitises the plates with a minimum 82°C rinse water temperature. Rinse aid within the rinse
water starts to disperse water from the surface of the plates. Finally, the conveyor moves the basket into a drying tunnel which ensures that when the plates exit the machine, they are clean, sanitised, dry and ready to be packed away for the next event.
Because the conveyor mechanism is constantly on when the baskets are inserted into the front end of the machine, when they exit the dishwasher, they are pushed along the exit table until they reach the end of the table. In order to prevent the baskets from being forced out when there is no more room for them, and to avoid the conveyor motor from burning out, a stop end switch is fitted to the end of the exit tabling. When a basket bumps into this switch, it signals to the conveyor system to stop. An operator would then unload the baskets until there is room again for more baskets.
Without one of these machines, you would need multiple staff carrying out various roles and the process would be extremely labour intensive, especially when having to dry everything to be packed away again.
Dishwasher – Flight Machine
From a layman’s perspective, a flight dishwasher is similar in design to a conveyor dishwasher although they can be longer in length. The flight machine is more like an actual, continuous conveyor system that runs from one end of the machine to the other and back to the start. Plates are loaded directly onto rows of hard plastic pegs and are drawn into the machine. If you imagine the way that escalators work, where the stairs continuously move in the same direction on a loop system, then a flight dishwasher operates under the same principle.
A flight dishwasher has all the trappings of a large conveyor and sometimes more – prewash, wash, pre-rinse, rinse, and drier. Some of these machines are massive and are used in large-scale operations such as motorway service station restaurants, airports, prisons, and hospitals. The operator stacks the clean wares straight onto trolleys to be taken away. They do not have the ‘inconvenience’ of having to first load a basket or empty a basket of clean dishes at the other side.