JPH07289437A - Coffee liquid extractor - Google Patents

Abstract

PURPOSE:To prevent the generation of scale in a coffee liquid extractor. CONSTITUTION:One end of an aluminum water pipe 12 is connected to a lower opening of a tube 14 made of a polycarbonate resin. When the extracting operation is carried out 10-odd times, a scale component separated from water heated by a heater 4 adheres to the internal surface of the tube 14. Under such a condition, when the internal surface of the tube 14 is immersed with the hot water by a new extracting operation, a part of a polymer chain of the surface of the resin is cut under a chemical reaction of the water so that a week interface layer is formed near an interface by a lowering in cohesive force or with a decomposition product. In this case, the water acts as plasticizer to lower the cohesive force which is adhesion force near the interface thereby causing peeling-off of a scale.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coffee liquid extractor, and more particularly to a coffee liquid extractor capable of preventing scale buildup on the inner surface of the conduit of the coffee liquid extractor.

[0002]

BACKGROUND OF THE INVENTION Coffee liquor extractors are usually
After the water replenished in the tank is introduced into the heater and heated, the heated water is poured into the dripper loaded with the coffee powder, and the coffee liquid is extracted. However, due to the hardness component of the supplied water, calcium carbonate or the like precipitates from the heated water as a scale component and adheres to the inner surface of the conduit of the coffee liquid extractor as a scale. Therefore, the temperature of the conduit in the heater rises due to the heat insulation effect of the scale,
The amount of steam generated increases. Therefore, the amount of heating water poured into the dripper decreases, and the time required for extraction increases. Also,
The overheat prevention mechanism of the heater operates and the circuit may be interrupted during extraction.

In order to prevent the above-mentioned scale, US Pat. No. 4,300,870 "Pump chamber for suppressing the formation of deposits" has a discontinuity, for example, a triangular or square cross section, on the inner surface of the conduit in the heater. Fins are installed. In this case, the scale of the heater portion can be prevented, but the scale on the downstream side cannot be prevented.
Also, as a means to remove the scale adhering to the inside of the conduit of the coffee liquid extractor, replenish the tank with water to which a small amount of vinegar or citric acid has been added, and perform the heating extraction step without loading the coffee powder. Are asking the user. The weak acid acts to dissolve calcium carbonate, but in order to wash out the acid remaining in the conduit, it is necessary to carry out the above heat extraction step with fresh water about three times, which complicates the operation.
Further, in hard water areas, the above operation needs to be performed once a month, which makes the operation very complicated.

An object of the present invention is to prevent the generation of scale in a coffee liquid extractor.

[0005]

A coffee liquid extractor according to the present invention comprises a water supply unit, a heating unit for heating water supplied from the water supply unit, and a coffee liquid produced by pouring heated water produced by the heating unit. And a conduit for guiding water (hot water) from the water supply part through the heating part to the coffee liquid extraction part. At least a part of the inner surface of the conduit is provided with an ester structure.

[Chemical 1] It is composed of a heat-resistant synthetic resin having

Examples of the synthetic resin having an ester structure in the present invention include a polycarbonate resin, an unsaturated polyester resin, a polyethylene terephthalate resin, a polyurethane resin, an epoxy resin, and an epoxy resin fixed with an acid or an acid anhydride. The heat resistance of the heat-resistant synthetic resin in the present invention means not only heat resistance to hot water but also heat resistance that does not deform even under the heating temperature in the heating part, and the heat deformation temperature is 90 to 100 ° C. or more. Is desirable. Further, it is desirable that this synthetic resin has acid resistance against citric acid and the like used during washing. Further, the conduit line from the water supply unit to the coffee liquid extraction unit may have the inner surface thereof lined with the above resin.

[0007]

In the coffee liquid extractor of the present invention, the water supplied from the water supply section is heated by the heating section. This heated water is sent to the coffee liquid extraction section to extract the coffee liquid. When the above extraction operation is repeated, the hardness component of the water supplied on the inner surface of the conduit from the water supply section to the coffee liquid extraction section adheres as a scale. Especially, it appears remarkably in the hot conduit from the heating section to the coffee liquid extracting section. If the inner surface of the conduit is made of a synthetic resin having an ester structure, the scale is unlikely to adhere to the conduit due to the following action.

[0008] The scale component adhered to the conduit becomes a scale that is hard to peel off when water is removed from the inner surface of the conduit after the extraction operation is completed, and the scale component does not easily peel off. When the inner surface of the conduit is immersed in hot and cold water by a new extraction operation, a part of the polymer chains on the surface of the synthetic resin containing the ester structure is cut by the chemical reaction of water, and the cohesive force decreases or decomposition products are generated. A weak boundary layer is formed near the interface. At this time, water acts as a plasticizer to reduce the cohesive force, which is the adhesive force in the vicinity of the interface, and the scale is peeled off due to the stress generated by the volume expansion of the synthetic resin. Further, the intermolecular force between the resin and the scale at the interface is cut by the water, and the scale is easily separated. Therefore, the accumulation of scale on the inner surface of the conduit is prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the drawings. The present invention is not limited to this. 1 and 2, a coffee liquid extractor 1 includes a tank 2 as a water supply unit, a base 3 that detachably fixes the tank 2, a heater 4 installed on the base 3 and a dripper 5 as a coffee liquid extraction unit. When,
It mainly comprises a decanter 6 that can be mounted on the heater 4. The tank 2 is a resin box body having a lid 7 on the upper part thereof, and an outlet 2a having a check valve 8 is formed on the bottom part thereof.

The heater 4 includes an aluminum block 9, a sheath heater 11, and an aluminum water pipe 12 as a part of a conduit.
Is embedded and is fixed to the base 3 via a heat resistant member (not shown). Part of the aluminum water pipe 12,
A thermostat (not shown) is attached. One end of the aluminum water pipe 12 is connected to the above-mentioned check valve 8 via a silicon tube 13 as a part of a conduit line. The other end of the water pipe 12 is likewise connected to a lower opening of a tube 14 made of polycarbonate resin as a part of the conduit. Silicon tube 13 has an inner diameter of 8 to 10 m
m, outer diameter 10 to 12 mm, and length 40 mm. The resin tube 14 has an inner diameter of 6 mm, an outer diameter of 8 mm, and a length of 300 m.
It is about m.

The dripper 5 includes a dripper body 15 and
It is composed of a mill 16 installed above the dripper body 15. The dripper body 15 is a hot water case 17
A cylindrical extraction case 18 extending below the tapping case 17 and a filter 19 housed in the extraction case 18.
It is a container made of resin. The upper portion of the tap case 17 is connected to the upper end opening of the tube 14. A water sprinkling hole (not shown) is formed in the lower portion of the hot water discharge case 17, and a filter 19 is arranged below the water sprinkling hole. A peripheral surface and a bottom surface of the filter 19 are formed of a resin net 20 for storing coffee powder. A coffee liquid outlet 21 for guiding the coffee liquid extracted by the filter 18 to the decanter 6 is formed at the bottom of the extraction case 18. The extraction case 18 is supported by a part of the base 3.

The mill 16 is mainly composed of a mill case 22 for loading coffee beans, a cutter 23 arranged at the bottom of the mill case 22, and a motor 24 for rotationally driving the cutter 23. The rotation shaft of the motor 24 penetrates the dripper body 15 and is detachably connected to the cutter 23. The mill case 22 has a mill lid 2 on the top.
5 and has an opening (not shown) communicating with the filter 18 at the bottom. With such a configuration, the coffee beans loaded in the mill case 22 are crushed to a predetermined grain size by the rotation of the cutter 23, and loaded into the filter 18 by gravity from the lower opening or wind force generated by the rotation of the cutter 23. The decanter 6 is arranged below the coffee liquid outlet 21. The decanter 6 is a glass container, and is placed on the upper surface of the block 9 so that the spout 6 a is located directly below the coffee liquid outlet 21.

When coffee liquid is extracted using the coffee liquid extractor 1, water is put in the tank 2 and a predetermined amount of coffee beans is put in the mill case 22. By operating a switch (not shown), the motor 24 is rotated to crush the coffee beans in the mill case 22. The ground coffee beans are automatically loaded into the filter 18. Water that has passed through the check valve 8 and the silicon tube 13 is heated in the energized heater 4 and poured into the filter 18 through the tube 14. The coffee liquid extracted in the filter 18 is collected in the decanter 6 from the coffee liquid outlet 21 and is kept warm by the residual heat of the heater 4 until the extraction is completed.

When the above extraction operation is carried out several tens of times using water having a hardness component, scale components precipitated from the water heated by the heater 4, such as calcium carbonate, calcium phosphate, silica and magnesium silicate, Calcium sulfate adheres to the inner surface of the tube 14. When the water content on the inner surface of the tube 14 disappears at the end of the extraction operation, the adhered scale component strengthens its adhesive force and becomes a scale, which makes it difficult to peel off from the inner surface of the tube 14.

Since the constituents of the scale decrease in solubility as the temperature rises, they are particularly likely to deposit and adhere to the heater 4 where the temperature is high. When a new extraction operation is performed in this state and the inner surface of the tube 14 is immersed in hot and cold water, the scale easily comes off from the tube 14 made of the polycarbonate resin having the ester structure. It is considered that this is due to the following actions.

That is, a part of the polymer chains on the surface of the polycarbonate resin containing an ester structure is cut by the chemical reaction of water, and a weak boundary layer is formed near the interface due to a decrease in cohesive force or a decomposition product. At this time, water acts as a plasticizer to reduce the cohesive force, which is the adhesive force in the vicinity of the interface, and the scale is peeled off due to the stress generated by the volume expansion of the polycarbonate resin. Further, it is considered that the intermolecular force between the resin and scale at the interface is cut by water. As a result, a scale adhesion preventing effect, which cannot be obtained with Teflon or silicon resin, is obtained.

[Experimental Example 1] The extraction operation was carried out a plurality of times with a coffee extractor, and the increase in the weight of the tube due to the number of extractions and scale adhesion was measured. (Test method) A coffee liquid extractor 1 having the polycarbonate resin tube 14 of the above-mentioned example and a coffee liquid extractor in which the left tube was replaced with aluminum were prepared, and water having a total hardness of 185 and a calcium hardness of 165 was once provided. Per 150
The extraction operation was performed by supplying 0 cc. After the completion of 10 times of extraction operation, the tube was removed and the weight change (difference from the initial value) was measured. The aluminum and polycarbonate resin tubes are installed vertically, and the initial inner diameter is both 6.0 m.
m. When a polycarbonate resin tube was used, the scale flowing out to the filter 19 was collected, dried, and then weighed. The results are shown in Figure 3.

For reference, when the inner diameter of the tube is measured,
In the case of aluminum, it is 4.8 mm after 70 times of extraction operation.
(80%), and the channel area is narrowed to 64%. On the other hand, in the polycarbonate resin tube,
No increase in weight is observed in the 20th and subsequent extraction operations.

[Other Embodiments] In the above embodiment, one end of the aluminum water pipe 12 is connected to the tank 2 via the silicon tube 13, and the other end of the water pipe 12 is connected to the dripper 5 with a polycarbonate resin tube 14. However, it is also possible to connect the tubes 14 made of polycarbonate resin to both ends of the water pipe 12 made of aluminum.
In this case, it is possible to prevent the generation of scale over substantially the entire range of the water conduit of the coffee liquid extractor. Further, the aluminum water pipe 12, which is particularly prone to scale, may be subjected to a lining treatment with a polycarbonate resin or a synthetic resin having the above ester structure. In this case, it is particularly effective when extraction is performed using water containing a large amount of hardness component.

[0020]

According to the coffee liquid extractor of the present invention,
Since the inner surface of the water conduit is made of a synthetic resin having an ester structure, generation of scale in the water conduit of the coffee extractor is prevented when the extraction operation is repeated. This is particularly useful in the water conduit from the hot heating section to the coffee brewing section. In addition, the conventional cleaning of the conduit with citric acid or the like is generally unnecessary, and the operation is not complicated. Furthermore, the temperature rise of the conduit due to the adhesion of scale is suppressed, and the time required for extraction does not increase with repeated use. In addition, the overheat prevention mechanism of the heater does not operate and the circuit is not interrupted during extraction. The above-mentioned effects are remarkable when water containing a large amount of hardness component is used.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a coffee liquid extractor according to an embodiment of the present invention.

2 is a perspective view showing a connected state of tubes of the coffee liquid extractor of FIG. 1. FIG.

FIG. 3 is a graph showing the experimental results of the relationship between the number of extraction operations and scale attachment.

[Explanation of symbols]

1 Coffee liquid extractor 2 Tank (water supply part) 4 Heater (heating part) 5 Dripper (coffee liquid extraction part) 14 Polycarbonate resin tube (conduit line)

Claims (1)

[Claims] 1. A water supply unit, a heating unit for heating water supplied from the water supply unit, a coffee liquid extraction unit for pouring the heated water made in the heating unit to extract coffee liquid, and a heating unit for heating the water supply unit. And a conduit for guiding water (hot water) through the portion to the coffee liquid extracting portion, and at least a part of the inner surface of the conduit is made of a heat-resistant synthetic resin having an ester structure. Liquid extractor.