Continuous heating of liquid to constant temperature

#The present invention relates to a device and method for the continuous heating of a liquid to a constant temperature. A particular application of this invention is the heating of a liquid such as waiter to a constant and precise temperature to allow, for example, the preparation of food. In particular, this device and this method may be used to advantage for heating water under pressure for making coffee.

#For making coffee, discontinuous water-heating devices in which a given amount of water is heated, then used with the aid of a pump to make the coffee, are known. In such devices, the volume of water available is limited, the heating time is long and it is inevitable that there will be a period of waiting between each making of coffee. In addition, these devices are bulky and expensive.

#There also exist some devices for the continuous heating of water, where the water is heated as it passes along a duct or pipe embedded in a block with a high heat capacity to guarantee constant temperature. The volume of water that can be used is limited by the heat capacity of the block, and in any event the devices needed to regulate the electrical power supply and/or the amount of water delivered are not capable of achieving sufficient temperature precision using economical means. Again, the heating time is long.

#The appended drawings diagrammatically and by way of example illustrates one embodiment of the heating device according to the invention.

#FIG. 1 is a block diagram of the continuous heating device.

#FIG. 2 is a longitudinal section through a device for regulating the flow rate and recirculation of water.

#The device for the continuous heating of a liquid to a constant temperature according to the embodiments illustrated in the drawings utilizes water as an example of the type of liquid that can be heated. A commonplace use of heated water is for preparing heated beverages such as coffee. This device comprises a reservoir 1 of water at ambient temperature, a pump 2 which takes in the water or the liquid contained in the reservoir 1 and a heating unit of heating body 3 through which the pumped water or liquid passes and comprising a user outlet fitted with a valve 4.

#The cold water pump 2 has characteristics suited to the desired use, for example the making of coffee, particularly as regards its “pressure-flow rate” characteristics. This pump may, for example, be of an electromechanical type and has characteristics similar to those depicted in FIG. 7.

#The reservoir 1 is equipped with a non-return valve 5 to prevent any return of water or liquid to the tank 1 via the pipe 6 connecting it to the pump 2.