Abstract: The invention includes a warewasher comprising a wash chamber, a tank at the bottom of said chamber for supplying recirculated heated water through a pump to wash arms in said chamber, a primary water heating system comprising a heat exchange tube entering said tank through a first port or inlet in said tank, traversing the base of the tank, and exiting said tank through a second port or outlet, said tube being at a height in said tank such that the tube is submerged when said tank is filled with water, said tube having a first end and a second end located outside of the tank and providing a passageway between the ends, a gas-fired infrared burner located in said tube adjacent said first end to which an air/gas mixture is supplied and combusted by said burner, at least one secondary labyrinthine heat exchanger in intimate heat transfer relationship with at least one of the walls of said tank below the water level, and controls for automatically operating the heating system in response to a need to increase th

Abstract: The invention is a warewasher comprising a wash chamber, a tank at the bottom of the wash chamber, a heat exchange tube entering the tank through a first port in the tank, traversing the base of the tank, and exiting the tank through a second port. The tube is at a height such that it is submerged when the tank is filled with water. The tube has first and second ends outside the tank, and a gas-fired infrared burner located in the tube adjacent the first end to which a combustible fuel is supplied and combusted by the burner. The combustion products of the fuel are received in the tube and are vented at the second end. By combusting fuel and passing the combustion products through the tube, water in the tank is heated.

Abstract: A commercial warewasher is disclosed, in which racks of soiled ware, such as dishes, are consecutively washed through a machine cycle which includes recirculating wash water over the ware followed by a fresh water spray rinse. A portion of the wash water is drained and a second portion is intentionally retained in the machine during the rinse period after each rack of dishes is washed. The retained portion is thereby combined with the fresh rinse water to provide a volume of water sufficient for pumped wash recirculation for the next rack without cavitation, while enabling usage of a minimum quantity of rinse water required to provide effective rinsing. Reduced water consumption, reduced energy to heat the water and reduced chemical usage (detergents, sanitizers and rinse agents) are all possible in amounts and degrees depending upon the type and design of warewasher with which the method and apparatus is employed.

Abstract: A commercial warewasher consecutively washes racks of soiled ware, such as dishes, through a machine cycle which includes recirculating wash water over the ware followed by a fresh water spray rinse. Part of the wash water is drained and a second portion is retained in the machine after each rack of dishes is washed, then combined with subsequent fresh rinse water spray to provide a volume of water sufficient for pumped wash recirculation for the next rack without cavitation. When a drain valve is opened, water pressure to the wash arm system is reduced, flow through it decreases, and when the pump stops the wash system will drain by gravity to the lowest point in the wash system plumbing. In the meantime the pump discharges wash water until the level of water in the sump and/or its associated outlet pipe reaches the level of the pump impeller eye. The pump begins to cavitate and effectively ceases to pump water.

Abstract: A latch for a warewasher effects manual movement of a bolt between a retracted position which permits the door to be fully closed and an extended position which either latchingly engages a keeper to secure the door in the closed position, or abuttingly engages the keeper to prevent the door from being inadvertently fully closed. In addition to manual operation, the latch is operated by gravity to extend the bolt from its retracted to its extended position as the door of the warewasher is moved from a horizontal opened position to a vertical position. In this way, the bolt of the latch is extended to abut the keeper of a warewasher if the door is simply moved from the horizontal opened position to the vertical position, but may be easily and quickly closed by manual operation of the latch to retract the bolt followed by complete closure of the door, and then extension of the bolt to secure the door in the fully-closed position.

Abstract: A tray accumulator for a soiled ware conveyor comprises a tray rack adapted to be removably supported upon a dolly which is in turn supported upon and moved along a track. The dolly comprises a support frame which may be essentially permanently mounted to track rails, with all dollies being interconnected for movement as a train. The dolly comprises a support frame having front and rear members interconnected by side members, with the tray rack including an offset flange for engaging the rear member of the frame. First and second retaining brackets are secured to the side members of the frame and extend upwardly therefrom, and first and second studs are secured to the outer sides of the tray rack such that the studs fit behind the retaining brackets when the tray rack is mounted on the frame. Side rails are secured to the side members of the dolly support frame to restrain sideward movement of the tray racks relative to the dollies.

Abstract: An endless train of dollies with means for continuously moving them in an oval path and in either direction, each dolly supporting a tray rack that in turn can removably support a plurality of trays in stacked relation. Bus boys load trays of soiled dishes into the tray racks at one station in the endless train of moving dollies. The endless train of moving dollies is positioned adjacent to a second endless train of moving dollies, each dolly in this second train supporting a basket for receiving soiled dishware and trays that a second bus boy standing in a second station positioned between the two endless trains of dollies transfers trays of soiled dishware with their trays from the tray racks to the baskets in the second endless conveyor. The tray racks are of novel construction and each one consists of a U-shaped casing in horizontal cross section.