WO2016000751A1

WO2016000751A1 - Portable coffee machine with improved coffee brewing performance and energy efficiency

Info

Publication number: WO2016000751A1
Application number: PCT/EP2014/063892
Authority: WO
Inventors: Yavuz Sahin; Emre Ozturk; Sevim AYDIN; Georg MILDE
Original assignee: Arcelik Anonim Sirketi
Priority date: 2014-07-01
Filing date: 2014-07-01
Publication date: 2016-01-07
Also published as: TR201507707A1

Abstract

The present invention relates to a portable coffee machine (1) comprising a brewing chamber (2) for holding ground coffee (3a) or a coffee pod (3b), a hot water preparation unit (4) including a container (5) for storing water (6), a heater unit (7) for heating the water (6) inside the container (5), and means for conveying the hot water (6) inside the container (5) via a conduit (8) from the container (5) to the brewing chamber (2), and thermal insulation material arranged to thermally insulate the hot water preparation unit (4).

Description

PORTABLE COFFEE MACHINE WITH IMPROVED COFFEE BREWING PERFORMANCE AND ENERGY EFFICIENCY

The present invention relates to an electrical coffee machine, in particular an electrical coffee machine which is portable.

Several techniques for brewing coffee are commonly known. In order to meet the preferences and needs of different customers, various electrical coffee machines are available on the markets which brew coffee in accordance with one of the commonly known techniques. An important quality criterion for these various electrical coffee machines is their energy efficiency. A commonly known technique to improve the energy efficiency of a coffee machine is to utilize thermal insulation material in order to insulate its hot water preparation unit from the outside.

US 2010/0098823 A1 discloses an electrically operated portable espresso machine. This espresso machine comprises a boiler which has a heater, a brewing chamber which is connected to the boiler through a fluid passage, and an electrically driven piston which feeds, via the fluid passage the hot water inside the boiler into the brewing chamber. The heater is wrapped around the boiler so as to heat the water. The boiler is thermally insulated from the outside.

In general, in the absence of the thermal insulation material in a coffee machine, the hot water inside the hot water preparation unit would rapidly give off its heat to the outside. Consequently, the heating process would prolong and, in turn, the heater would require more electric power, thus, the energy consumption would increase. In addition due to the prolonged heating process, the coffee brewing performance would degrade. Therefore, in the absence of the thermal insulation material, or in case of an insufficient thermal insulation, the consumer satisfaction may easily decrease.

An objective of the present invention is to provide a portable coffee machine which overcomes the aforementioned drawbacks of the prior art in a cost effective way and which has an improved coffee brewing performance and an improved energy efficiency.

This objective has been achieved by the portable coffee machine as defined in claim 1. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.

In the portable coffee machine of the present invention, the water preparation unit includes phase change material which is arranged in heat exchange with the water inside the container. At least part of the electrical heater unit is arranged next to the phase change material so as to directly heat the phase change material.

The phase change material (PCM) used in the present invention is a storage for large amount of latent heat. The phase change material used in the present invention changes from the solid state to the liquid state as it absorbs heat and changes from the liquid state to the solid state as it releases heat. The PCM used in the present invention has a melting point which is substantially equal to the ideal water temperature for brewing coffee.

In an embodiment, the heater unit has two separate electrical heater subunits which are arranged to heat the phase change material and the water inside the container respectively. When operating the portable coffee machine, the PCM is initially heated so as to undergo a complete phase change from the solid state to the liquid state by operating the respective heater subunit. Subsequently, the water is heated to the ideal temperature for brewing coffee by operating the respective heater subunit. Thus, the two heater subunits are sequentially operated. In particular, by virtue of this configuration, the phase change material can be heated with priority. Thereby, the latent heat storage capacity of the PCM can be maximally utilized so as to store a target amount of latent heat prior to heating the water to the ideal coffee brewing temperature. The present invention is not limited to the sequential operation of the two heater subunits. The two heater subunits are alternatively concomitantly operated.

In a version of the above embodiment, the container is cylindrical shaped and the PCM is at least circumferentially wrapped around the cylindrical shaped container. In this embodiment, the heater subunits are annular shaped and arranged directly on the underside of the PCM and the container respectively.

In an alternative version of the above embodiment, the heater subunit on the underside of the container is alternatively disc shaped.

In another version of the above embodiment, another annular shaped heater is additionally arranged on the top of the PCM. When operating the portable coffee machine the heater subunits on the top of the PCM and on the underside of the PCM are simultaneously operated until the PCM undergoes a total phase change from the solid state to the liquid state. Subsequently, the operations of the latter heater subunits are terminated and the heater subunit on the underside of the container is operated until the water reaches an ideal temperature for brewing coffee. By virtue of this configuration, the phase change material can be heated more rapidly and homogenously, and the latent heat storage capacity of the PCM can be effectively utilized. The present invention is not limited to the sequential use of the heater subunits. The heater subunits are alternatively concomitantly used.

In another alternative embodiment, the heater unit is alternatively arranged between the phase change material and the container. By virtue of this configuration, the phase change material and the water can be heated simultaneously, and the latent heat storage capacity of the PCM can be effectively utilized. In this embodiment, the container and the PCM are not limited to a particular shape. In a version of this embodiment, the container is cylindrical shaped and the PCM is circumferentially wrapped around the container so as to enclose the annular shaped heater unit.

In another alternative embodiment, the container has two sub-containers which are separated by a gap which accommodates two layers of PCM which sandwich the heater unit. By virtue of this configuration, the phase change material can be heated with priority. Thereby, the latent heat storage capacity of the PCM can be effectively utilized.

In a version of this embodiment, the sub-containers are fluidly connected by a channel or the like.

In another embodiment, the portable coffee machine has a valve for controlling the flow of the hot water into the brewing chamber. This valve is preferably a one way valve to prevent any backflow.

In another embodiment, the portable coffee machine is operable with electric power supplied from the mains power source, or optionally with the electric power supplied from its rechargeable battery unit, for instance when the mains power source is disconnected. In a version of this embodiment, the user interface unit of the portable coffee machine also allows to activate/deactivate the battery operation.

In another embodiment, the water preparation unit includes a temperature sensor for sensing the temperature of the water inside the container and two separate heater units, one for heating both the water inside the container and the PCM with the electric power to be supplied from the mains power source, and the other one for merely heating the water inside the container with the electric power to be supplied from the rechargeable battery unit, for instance when the mains power source is disconnected.

In a version of this embodiment, the latter of the above two heater units is preferably a Peltier element which maintains the temperature of the water inside the container at an ideal temperature for brewing coffee, for instance when the mains power source is disconnected.

In another embodiment, the portable coffee machine visually indicates the temperature of the water inside the container.

In another embodiment, the portable coffee machine has a support for a mug.

In another embodiment, the mug of the portable coffee machine has a rechargeable battery unit which is directly or inductively connectable to a charging unit of the portable coffee machine. The mug of the present invention has a temperature sensor and an auxiliary heater unit, in particular a Peltier element for heating the coffee inside the mug, on the basis of the sensed temperature the coffee inside the mug by using the electric power to be supplied from its own rechargeable battery unit.

In another embodiment, the mug of the portable coffee machine maintains the temperature of the coffee at an ideal drinking temperature.

With the present invention, a portable coffee machine has been provided which has an improved coffee brewing performance and energy efficiency. With the present invention, particularly by virtue of the phase change material, the hot water inside the container can be prevented from rapidly cooling and can be kept substantially at an ideal temperature for brewing coffee for a relatively long period, for instance when the heating process is interrupted. With the present invention, particularly by virtue of the relative position of the heater unit, the latent heat storage capacity of the PCM can be effectively utilized. Thereby, a reheating process of the water inside the container can be either obviated or shortened as much as possible, and the coffee brewing process can be expedited. Thereby also the energy efficiency has been increased. With the present invention, a quick brewing process can be granted throughout each use of the coffee machine. Thereby, a consumer satisfaction can be increased.

Additional advantages of the portable coffee machine of the present invention will become apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:

Figure 1 – is a partial schematic view of a portable coffee machine and a mug according to an embodiment of the present invention,

Figure 2 – is a partial schematic vertical cross sectional view of a water preparation unit of the portable coffee machine according to an embodiment of the present invention,

Figure 3 – is a partial schematic vertical cross sectional view of the water preparation unit of the portable coffee machine according to another embodiment of the present invention,

Figure 4 – is a partial schematic vertical cross sectional view of the water preparation unit of the portable coffee machine according to another embodiment of the present invention,

Figure 5 – is a partial schematic vertical cross sectional view of the water preparation unit of the portable coffee machine according to another embodiment of the present invention.

The reference signs appearing on the drawings relate to the following technical features.

Portable coffee machine
Brewing chamber

3a. Ground coffee
3b. Coffee pod
4. Hot water preparation unit

5. Container
5a. Sub-container
5b. Sub-container

6. Water

7. Heater unit
7a. First heater subunit
7b. Second heater subunit
7c. Third heater subunit

8. Conduit

9. Phase change material
9a. Layer (PCM)

9b. Layer (PCM)

10. Valve

11. Mug

12. Support

The portable coffee machine (1) comprises a brewing chamber (2) for releasably holding ground coffee (3a) or a coffee pod (3b), and a hot water preparation unit (4) which includes a refillable container (5) for storing water (6), an electrical heater unit (7) for heating the water (6) inside the container (5), and means for conveying the hot water (6) inside the container (5) via a conduit (8) from the container (5) to the brewing chamber (2), and thermal insulation material (not shown) which is arranged to thermally insulate the hot water preparation unit (4) from the outside (Fig. 1 to 5).

In the portable coffee machine (1) of the present invention, the hot water preparation unit (4) includes phase change material (9) which is arranged in heat exchange with the water (6) inside the container (5). At least part of the heater unit (7) is arranged next to the phase change material (9) so as to directly heat the phase change material (Fig. 1 to 5).

In an embodiment, the phase change material (9) is wrapped on at least part of the container (5). In this embodiment, the heater unit (7) has a first heater subunit (7a) and a second heater subunit (7b). Each of the first heater subunit (7a) and the second heater subunit (7b) can be separately controlled. The first heater subunit (7a) is arranged to directly heat the phase change material (9). The second heater subunit (7b) is arranged to directly heat the container (5). The container (5) is made from a material which has a relatively high thermal conductivity (Figs. 2 to 3).

In a version of this embodiment, the container (5) is cylindrical shaped. The phase change material (9) is annular shaped and circumferentially wrapped around the lateral surface of the container (5). The first heater subunit (7a) is annular shaped and arranged directly on the underside of the phase change material (9). The second heater subunit (7b) is annular shaped and also directly arranged on the underside of the container (5) (Figs. 2 to 3).

In an alternative version of this embodiment, the second heater subunit (7b) is alternatively disc shaped (not shown) and directly arranged on the underside of the container (5) (Fig. 2 to 3).

In another version of this embodiment, the heater unit (7) has, in addition, a third heater subunit (7c). The third heater subunit (7c) can be separately controlled. The third heater subunit (7c) is annular shaped and arranged directly on the top of the phase change material (9) (Fig. 3).

In another alternative embodiment, the phase change material (9) is wrapped on at least part of the container (5). In this alternative embodiment, the heater unit (7) is arranged between the phase change material (9) and the container (5) (Fig. 4).

In a version of this alternative embodiment, the container (5) is cylindrical shaped. The phase change material (9) is annular shaped and circumferentially wrapped around the lateral surface of the container (5) (Fig. 4).

In another alternative embodiment, the container (5) has two sub-containers (5a,5b) each for storing water (6). In this alternative embodiment, the phase change material (9) is provided in form of two layers (9a,9b) which are respectively wrapped on the mutually facing outer surfaces of the sub-containers (5a,5b). The heater unit (7) is arranged between the two layers (9a,9b) (Fig. 5).

In another embodiment, thermal insulation material (not shown) which is arranged to thermally insulate the hot water preparation unit (4) from the outside comprises polyurethane foam material and/or one or more than one vacuum insulation panel (VIP) (Fig. 1 to 5).

In another embodiment, the portable coffee machine (1) comprises a valve (10) for controlling the flow of the hot water (6) through the conduit (8). The valve (10) is located downstream of the container (5) and upstream of the brewing chamber (2) (Fig. 1 to 5).

In another embodiment, the portable coffee machine (1) comprises an electric power unit (not shown) for connecting to the mains power source, a first battery unit (not shown) for receiving one or more than one rechargeable battery, a charging unit (not shown) for recharging each battery in the first battery unit with the electric power to be supplied from the electric power unit, a user interface unit (not shown) for receiving user inputs, and a first control unit (not shown) for controlling the electric power unit, the first battery unit, the charging unit, the user interface unit, and the hot water preparation unit (4). In this embodiment, the portable coffee machine (1) is operated with the electric power supplied from the electric power unit when it is connected to the mains power source. The portable coffee machine (1) is operated with the electric power supplied from the first battery unit when it is disconnected from the mains power source (Fig. 1 to 5).

In another embodiment, the means for conveying the hot water (6), includes an air pump (not shown) which pressurizes the air above the hot water inside the container (5) (Fig. 1 to 5).

In another embodiment, the hot water preparation unit (4) comprises, in addition, a first auxiliary heater unit (not shown) for heating the water (6) inside the container (5), and a first temperature sensor (not shown) for sensing the temperature of the water (6) inside the container (5). In this embodiment, the first control unit is further adapted to operate, on the basis of the temperature of the water (6) inside the container (5) either the heater unit (7) with the electric power to be supplied from the electric power unit when the electric power unit is connected to the mains power source, or the first auxiliary heater unit with the electric power to be supplied from the first battery unit when the electric power unit is disconnected from the mains power source (Fig. 1 to 5).

In a version of this embodiment, the first control unit is adapted to operate the first auxiliary heater unit so as to maintain the temperature of the water (6) inside the container (5) within a first predetermined range when the electric power unit is disconnected from the mains power source (Fig. 1 to 5). In this embodiment, the first predetermined range corresponds to an ideal water temperature for brewing coffee.

In another version of this embodiment, the first auxiliary heater unit comprises a Peltier element (not shown).

In another embodiment, the portable coffee machine (1) further comprises an indicating means (not shown) for visually indicating the temperature of the water (6) inside the container (5) (Fig. 1 to 5).

In a version of this embodiment, the indicating means comprises one or more than one light emitting diode (not shown).

In an alternative version of this embodiment, said indicating means alternatively comprises a display (not shown).

In another embodiment, the portable coffee machine (1) further comprises a support (12) for placing a mug (11) to be filled with the coffee dripping from the brewing chamber (2) (Fig. 1 to 5).

In another embodiment, the portable coffee machine (1) further comprises a mug (11) which includes a second battery unit (not shown) for receiving one or more than one rechargeable battery, wherein the second battery unit is directly or inductively connectable to the charging unit of the portable coffee machine (1), and wherein the first control unit is further adapted to recharge each battery of the second battery unit with the electric power to be supplied from the electric power unit, a second auxiliary heater unit (not shown) for heating the coffee inside the mug (11) with the electric power to be supplied from the second battery unit or optionally from the portable coffee machine (1), a second temperature sensor (not shown) for detecting the temperature of the coffee inside the mug (11), and a second control unit (not shown) which is adapted to operate the second auxiliary heater unit on the basis of the temperature of the coffee inside the mug (11) (Fig. 1).

In another embodiment, the second control unit is adapted to operate the second auxiliary heater unit so as to maintain the temperature of the coffee inside the mug (11) within a second predetermined range (Fig. 1). The coffee inside the mug (11) has preferably an initial temperature of 90°C to 95°C. After a while the temperature drops to the ideal drinking temperature. In this embodiment, the second predetermined range corresponds to the ideal drinking temperature.

In another embodiment, the second auxiliary heater unit comprises a Peltier element (not shown).

With the present invention, a portable coffee machine (1) has been provided which has an improved coffee brewing performance and energy efficiency. The portable coffee machine (1) of the present invention is not limited to brew a particular type of coffee, and is intended for brewing different types of coffee including filter coffee, espresso or the like by adapting various pressure, temperature, and throughput values for the hot water (6).

Claims

A portable coffee machine (1) comprising

- a brewing chamber (2) for holding ground coffee (3a) or a coffee pod (3b),

- a hot water preparation unit (4) comprising a container (5) for storing water (6), a heater unit (7) for heating the water (6) inside the container (5), and means for conveying the hot water (6) inside the container (5) via a conduit (8) from the container (5) to the brewing chamber (2) and

- thermal insulation material which is arranged to thermally insulate the hot water preparation unit (4) from the outside,

characterized in that

the hot water preparation unit (4) further comprising phase change material (9) which is arranged in heat exchange with the water (6) inside the container (5), wherein at least part of the heater unit (7) is arranged next to the phase change material (9) so as to directly heat the phase change material (9).
The portable coffee machine (1) according to claim 1, characterized in that the phase change material (9) is wrapped on at least part of the container (5), and the heater unit (7) has a first heater subunit (7a) and a second heater subunit (7b), wherein the first heater subunit (7a) and the second heater subunit (7b) can be selectively operated, wherein the first heater subunit (7a) is arranged to directly heat the phase change material (9), and wherein the second heater subunit (7b) is arranged to directly heat the container (5).
The portable coffee machine (1) according to claim 2, characterized in that the container (5) is cylindrical shaped, the phase change material (9) is annular shaped and circumferentially wrapped around the lateral surface of the container (5), the first heater subunit (7a) is annular shaped and arranged directly on the underside of the phase change material (9), and the second heater subunit (7b) is either annular shaped or disc shaped and directly arranged on the underside of the container (5).
The portable coffee machine (1) according to claim 3, characterized in that the heater unit (7) has a third heater subunit (7c), wherein the third heater subunit (7c) can be selectively operated, and wherein the third heater subunit (7c) is annular shaped and arranged directly on the top of the phase change material (9).
The portable coffee machine (1) according to claim 1, characterized in that the phase change material (9) is wrapped on at least part of the container (5), wherein the heater unit (7) is arranged between the phase change material (9) and the container (5).
The portable coffee machine (1) according to claim 6, characterized in that the container (5) is cylindrical shaped, the phase change material (9) is annular shaped and circumferentially wrapped around the lateral surface of the container (5), wherein the heater unit (7) is also annular shaped.
The portable coffee machine (1) according to claim 1, characterized in that the container (5) has two sub-containers (5a, 5b) each for storing water (6), wherein the phase change material (9) is provided in form of two layers (9a, 9b) which are respectively wrapped on the mutually facing outer surfaces of the sub-containers (5a,5b), and wherein the heater unit (7) is arranged between the two layers (9a, 9b).
The portable coffee machine (1) according to any one claims 1 to 7, characterized in that a valve (10) for controlling the flow of the hot water (6) through the conduit (8), wherein the valve (10) is located downstream of the container (5) and upstream of the brewing chamber (2).
The portable coffee machine (1) according to any one of claims 1 to 8, characterized in that

- an electric power unit for connecting to the mains power source,

- a first battery unit for receiving one or more than one rechargeable battery,

- a charging unit for recharging each battery in the first battery unit with the electric power to be supplied from the electric power unit,

- a user interface unit for receiving user inputs and

- a first control unit which is adapted to control the electric power unit, the first battery unit, the charging unit, the user interface unit, and the hot water preparation unit (4).
The portable coffee machine (1) according to claim 9, characterized in that the hot water preparation unit (4) further comprising

- a first auxiliary heater unit for heating the water (6) inside the container (5) and

- a first temperature sensor for sensing the temperature of the water (6) inside the container (5),

wherein the first control unit is further adapted to operate, on the basis of the temperature of the water (6) inside the container (5) either the heater unit (7) with the electric power to be supplied from the electric power unit when the electric power unit is connected to the mains power source, or the first auxiliary heater unit with the electric power to be supplied from the first battery unit when the electric power unit is disconnected from the mains power source.
The portable coffee machine (1) according to claim 10, characterized in that

the first control unit is further adapted to operate the first auxiliary heater unit so as to maintain the temperature of the water (6) inside the container (5) within a first predetermined range.
The portable coffee machine (1) according to any one of claims 1 to 11, characterized in that an indicating means for visually indicating the temperature of the water (6) inside the container (5).
The portable coffee machine (1) according to any one of claims 1 to 12, characterized in that a mug (11) comprising

- a second battery unit for receiving one or more than one rechargeable battery, wherein the second battery unit is directly or inductively connectable to the charging unit of the portable coffee machine (1), wherein the first control unit is further adapted to recharge each battery of the second battery unit with the electric power to be supplied from its electric power unit,

- a second auxiliary heater unit for heating the coffee inside the mug (11) with the electric power to be supplied from the second battery unit, or optionally from the portable coffee machine (1),

- a second temperature sensor for detecting the temperature of the coffee inside the mug (11) and

a second control unit adapted to operate the second auxiliary heater unit on the basis of the temperature of the coffee inside the mug (11).
The portable coffee machine (1) according to claim 13, characterized in that

the second control unit is adapted to operate the second auxiliary heater unit so as to maintain the temperature of the coffee inside the mug (11) within a second predetermined range.