Coex
Encyclopedia
CoEx is the name of a brewer in a espresso machine
, coffee machine or vending machine
which is able to brew a cup of coffee
as well as an espresso
. It is a mechanism in which with ground coffee and hot water (on pressure in case of espresso), a cup of coffee or espresso can be made, and from which, after the drink has been prepared the coffee residue is removed.
, which moves above the chamber then down to seal it. Hot water is passed through under pressure, coming from the back of the mechanism via the lower piston, through the ground coffee in the cylinder chamber. The brewed coffee (or espresso) leaves the system through a filterscreen in the upper piston, at the front of the system. After brewing the upper piston is pulled out of the cylinder and moved to one side. The lower piston then moves upwards, pushing the coffee residue out of the cylinder chamber. In the last phase the coffee residue is wiped from the brewer toward a waste bucket next to the brewer and the mechanism returns to its start position.
Espresso machine
An espresso machine is used to produce the traditional Italian coffee beverage called espresso.-History:The first machine for making espresso was built and patented by Angelo Moriondo of Turin, Italy, who demonstrated a working example at the Turin General Exposition of 1884. He was granted patent no...
, coffee machine or vending machine
Vending machine
A vending machine is a machine which dispenses items such as snacks, beverages, alcohol, cigarettes, lottery tickets, consumer products and even gold and gems to customers automatically, after the customer inserts currency or credit into the machine....
which is able to brew a cup of coffee
Coffee
Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
as well as an espresso
Espresso
Espresso is a concentrated beverage brewed by forcing a small amount of nearly boiling water under pressure through finely ground coffee. Espresso is widely known throughout the world....
. It is a mechanism in which with ground coffee and hot water (on pressure in case of espresso), a cup of coffee or espresso can be made, and from which, after the drink has been prepared the coffee residue is removed.
The mechanism
Firstly ground coffee is dosed into the cylinder chamber. Then the cylinder chamber is closed by the upper pistonPiston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...
, which moves above the chamber then down to seal it. Hot water is passed through under pressure, coming from the back of the mechanism via the lower piston, through the ground coffee in the cylinder chamber. The brewed coffee (or espresso) leaves the system through a filterscreen in the upper piston, at the front of the system. After brewing the upper piston is pulled out of the cylinder and moved to one side. The lower piston then moves upwards, pushing the coffee residue out of the cylinder chamber. In the last phase the coffee residue is wiped from the brewer toward a waste bucket next to the brewer and the mechanism returns to its start position.
Coffee or espresso
The mechanism distinguish between the way in which coffee or espresso is being prepared. The coffee, which is supposed to be brewed with coarse grinded, lightly burned coffee beans, is made on a low pressure Pressure Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :... of 1[bar], whereas espresso, which is supposed to be brewed with a fine grind, strongly burned coffee beans, is made on a high pressure of 9-10[bar]. The difference in pressure is created by a mechanical switch in the upper piston. As long as the pressure remains low, the force of the spring will keep the switch in place and the holes will remain open. If the pressure increases, the switch will move up and closes the big hole. The pressure will then increase quickly to the pressure level the pump Pump A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps... s are able to deliver. (Those pump are not part of the brewing system, but delivers the hot water under low or high pressure to the system.) In the schematic pictures at the right, those differences are shown. In the picture above, the water pressure in the cylinder filled with coffee is low and the spring is able to keep the switch open. The coffee is able to leave the system fluently, through a filter and through a relatively big hole. In the picture below the water pressure was able to move the switch to the upper position. The big hole is closed and the pressure increases further to the pressure level the pumps are able to deliver. Under pressure the espresso leaves the brewer via the small remaining hole. Capacities
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