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EP-3944795-B1 - MILLING SYSTEM FOR GRINDING GRAIN AND GRINDING APPARATUS THAT INCORPORATES IT

EP3944795B1EP 3944795 B1EP3944795 B1EP 3944795B1EP-3944795-B1

Inventors

  • Cunill Sanchez, D. Joel

Dates

Publication Date
20260506
Application Date
20210730

Claims (9)

  1. Milling system for grinding grain or such like, of those that are installed in grinding apparatus, which comprises, at least, one set of two milling discs (13,14) with opposite toothed milling cutter inner faces, wherethrough the grains to grind are made to pass; wherein the milling discs (13,14) are coaxial and have relative rotating movement between them, wherein at least one of the milling discs is made to rotate with respect to the common axis by motorized means, with one of the milling discs having a central inlet opening (22) of the grains to the space between the toothed lower faces and with these milling discs(13, 14) having a separation between opposite toothed surfaces (20,21) of each milling disc, greater in its central area and less in its outer perimeter area, whereby the milling system (10) comprises, in addition to at least one set of two milling discs (13,14), a coaxial disc (11) with one or more ejector blades (16) of the ground product which rotates in conjunction with the rotating milling disc (13), the milling system being characterized in further having a ventilation system, wherein said ventilation system is formed, at least, by one or more openings (17) wherethrough air intake is allowed from the lower part of the milling system (10), wherein the one or more openings (17) are in the base of the disc (11) with ejector blades (16), which connect the lower part of the disc (11) with ejector blades (16) to the installation area of the set (15) of milling discs (13,14), and by an air impeller element (12) which rotates in conjunction with the milling disc (13) and of the ejector blade disc (11), where said impeller element (12) comprises a structure with a coaxial distribution of multiple vanes (18) or blades appreciably radial to said axis of rotation, said air impeller element (12) being positioned between said base of the disc (11) with ejector blades (16) and one of the milling discs (13), creating a driving of air through said openings (17).
  2. Milling system for grinding grain or such like, according to claim 1, wherein the air impeller element (12) is an independent part that is coupled between the disc (11) with ejector blades (16) and one of the milling discs (13), which rotates in conjunction with them.
  3. Milling system for grinding grain or such like, according to claim 1, wherein the air impeller element (312) consists of an element integrated in the disc (311) with ejector blades (316), with them forming a single part, making the openings (317) in their base coincide with the open spaces between vanes or blades.
  4. Milling system for grinding grain or such like, according to claim 1, wherein the air impeller element (212) consists of an element integrated in the milling disc (213) adjacent to the disc (211) with ejector blades (216), with them forming a single piece.
  5. Milling system for grinding grain or such like, according to any of the previous claims, wherein the milling disc (13) adjacent to the disc (11) with ejector blades (16) incorporates a fixing element to the disc (11) with ejector blades (16).
  6. Grinding apparatus, which comprises at least one grain milling system (10) and collection or dispensing of the ground grain, with motorized means to transmit the rotation movement to the grain milling system, characterized in that the grinding apparatus (100) comprises at least one grain milling system (10) such as that disclosed in claims 1 to 5.
  7. Grinding apparatus, according to claim 6, wherein the grinding apparatus (100) comprises one or more air inlet openings (106) from the outside to the inside to the installation area of the grain milling system (10).
  8. Grinding apparatus, according to claim 7, wherein the air inlet opening (106) from the outside to the inside to the installation area of the grain milling system (10) is the grain inlet opening from the grain supply hopper (101) to the grain milling system (10).
  9. Grinding apparatus, according to claim 7, wherein the air inlet opening (106) from the outside to the inside of the installation area of the grain milling system (10) are openings in elements of the grinding apparatus (100) that connect with the grain milling system (10).

Description

The present invention relates to a milling system for grinding grain and/or similar products, preferably coffee grain, which performs the grinding of the grains between two discs with relative movement between them. Likewise, the present invention also relates to a grinding apparatus that incorporates this milling system for grinding. Background of the invention The grinding of seeds to create a ground product is widely known in coffee preparation processes, wherein the grinding of the coffee grain is performed to transform it into a product of a certain size for its preparation. This ground product may be of a larger or smaller particle size, according to the regulation of the grinding milling system used. In conventional coffee grinding equipment, which typically incorporate a ground coffee dispensing system for its use in "espresso" type coffee-makers, the grain is ground by making it pass between two milling cutters by way of coaxial discs, which have a relative rotating movement between them. Each one of these milling cutters has a multitude of teeth on the opposite inner faces, wherein said teeth are appreciably radial. At least one of the milling discs has teeth on its surface with different separation between them and of different height, depending on their position on said surface of the milling disc. This configuration is characterized in that it allows the entry of the whole grain through its central area corresponding to the open area closest to the axis of rotation. This area is the one wherein there is a greater separation between the teeth of the two opposite faces of the milling discs, allowing the whole grains to pass between the two milling discs. The rotation of at least one of the milling discs with respect to the other means that the portions of coffee grain, as they are broken up and due to centrifugal force displace towards the outer perimeter, are ground in areas with teeth closer together and less free height between the milling discs and, therefore, performing a finer grinding. The ground coffee exits the milling discs by their outer perimeter, by the same effect of centrifugal force, and it is carried to the dispensing system. This grain breakage action during the rotation of the milling discs, which is typically performed above 1400 rpm, creates a friction and consequent increase in the milling disc temperature. The increase in this temperature, measured after making 200 coffees according to the conventional portafilter measurements of espresso coffee machines, reaches 40°C which causes a dilation of the two milling discs. This dilation of the milling discs creates a greater clearance between discs and poorer grinding, which also involves a greater consumption of coffee grains to make the same coffees. To resolve this problem, and to be able to maintain the temperature of the milling discs at a suitable operating temperature, which is established at around 28 °C during execution of the grinding for 200 coffees, different solutions are known in the state of the art that introduce auxiliary cooling systems, such as the installation of a circulation of a coolant fluid in the grinding area or from an auxiliary fan to make the cooling air reach the milling discs. These solutions make it necessary to introduce new auxiliary elements and need a more complicated design and a more complicated installation in the grinding apparatus which translates into a greater manufacturing complexity and higher costs. Temperature detection systems are also known in the milling discs that allow a milling control system for grinding grain, the regulation of the rotation speed, decreasing it to reduce the effect of friction that makes the temperature of the milling discs increase. This solution, although it allows controlling and lowering the temperature of the milling discs, so that they work at the most suitable temperature possible, slows the productivity of the milling system, so that the apparatus performance is affected. Grinding systems which provide a ventilation effect in the grinding chamber are known from DE 24 18 473 A1 and JP 2016 043326 A. Description of the invention The objective of the present invention is to provide a milling system for grinding grain or such like, and to provide a grinding apparatus that includes a milling system, which manage to resolve the drawbacks of the state of the art, having other advantages that will be described below. Firstly, it is necessary to clarify certain terms employed, in order that they should not be interpreted as limitative, or that obvious changes of configuration/application might vary the reference employed in the present description without changing the object of the protection. In particular, it is important to make reference to the fact that the upper or lower positions described in this description come from a preferred configuration of vertical axis, so that said discs disposal with vertical coaxial axis means that the terminology of upper