Low-pressure steam cooker

Abstract

A low-pressure steam cooker comprises a base plate and low-pressure hood. The base plate has a base surface and cooking product surface opposite the base surface. The cooking product surface has a hood bearing surface having a peripheral raised retaining edge and at least one water trough for holding water. The low-pressure hood has a dish-shaped hood volume and a mounting rim, the contour of which is shaped complementary to the contour of the retaining edge of the base plate, so that the mounting rim is enclosed by the retaining edge when the mounting rim is seated on the hood bearing surface. The base plate and low-pressure hood are each formed of a non-glazed ceramic material. The surfaces of the mounting rim and the hood bearing surface facing each other are formed so that a steam outlet gap remains therebetween, at least in sections.

Claims

1. Low-pressure steam cooker comprising: a base plate having a base surface and a cooking product surface laying opposite it, wherein the cooking product surface has a hood bearing surface having a circumferential, raised retaining edge, and wherein the cooking product surface has at least one water trough for holding water; a low-pressure hood having a dish-shaped hood volume and a mounting rim, the contour of which is shaped complementary to the contour of the retaining edge of the base plate, so that the mounting rim is enclosed by the retaining edge when the mounting rim is seated on the hood bearing surface; wherein the base plate and the low-pressure hood are each formed of a non-glazed ceramic material, the ceramic raw material of which was admixed with granite meal; wherein the water trough has a water absorption volume in the range of 1% to 2% of the hood volume; and wherein the surfaces of the mounting rim and the hood bearing surface facing each other are formed in such a way that a steam outlet gap remains between them, at least in sections.

2. Low-pressure steam cooker according to claim 1, where the base plate and its retaining edge as well as the mounting rim of the low-pressure hood each have a circular outer contour, wherein the outer diameter of the mounting rim is slightly smaller than the inner diameter of the retaining edge.

3. Low-pressure steam cooker according to claim 1, wherein the water trough is formed by a communicating channel system in the cooking product surface.

4. Low-pressure steam cooker according to claim 3, wherein the channel system of the water trough comprises a plurality of concentrically extending channel sections and a plurality of radial extending channel sections.

5. Low-pressure steam cooker according to claim 4, wherein the bottom lines of the concentrically extending channel sections and the radially extending channel sections extend in a lower plane, the cooking product surface extends in a middle plane and the upper edge of the retaining edge extends in an upper plane, wherein these three planes extend parallel to each other and wherein the middle plane is positioned closer to the lower than to the upper plane.

6. Low-pressure steam cooker according to claim 1, wherein the mounting rim and the hood bearing surface (04) have a surface roughness with an average roughness Ra>100 μm.

7. Low-pressure steam cooker according to claim 1, wherein the low-pressure hood has an outwardly directed support surface on its upper side opposite the mounting rim.

8. Low-pressure steam cooker according to claim 1, wherein base plate and low-pressure hood consist of a waterproof ceramic material.

9. Low-pressure steam cooker according to claim 8, wherein the ceramic material contains microwave-absorbing components, in particular dark micaceous minerals.

10. Low-pressure steam cooker according to claim 1, wherein titanium oxide was admixed to the ceramic raw material during the manufacture of the base plate and the low-pressure hood.

Description

DESCRIPTION OF THE DRAWINGS

[0029] Further advantages and details of the invention will be apparent from the following description of a preferred embodiment, with reference to the drawing. Wherein:

[0030] FIG. 1 shows a top view of an embodiment of a base plate of a low-pressure steam cooker according to the invention;

[0031] FIG. 2 shows a perspective view of a low-pressure hood of a low-pressure steam cooker;

[0032] FIG. 3 shows a cross-sectional view of the low-pressure steam cooker.

DETAILED DESCRIPTION OF THE INVENTION

[0033] FIG. 1 shows a simplified top view of a disc- or plate-shaped base plate 01 of a low-pressure steam cooker according to the invention. The base plate 01 has a base surface 02 (FIG. 3) and a cooking product surface 03 laying opposite the base surface. In the embodiment shown, the cooking product surface 03 is formed by numerous sections which preferably lie in a common middle plane. The cooking product surface has a hood bearing surface 04 in the outer area having a circumferential, raised retaining edge 05. The base plate has, for example, a diameter D.sub.G=24 cm, a height H.sub.G=1.5 cm and, with these exemplary dimensions, a weight of about G.sub.G=1,080 g.

[0034] The cooking product surface 03 has at least one water trough, which in the embodiment shown is formed by concentrically extending channel sections 06 and radial extending channel sections 07, which are in communication with each other. Preferably, all channel sections are formed with the same depth and their bottom lines thus extend in a common lower plane. The water trough 06, 07 serves to hold water during the cooking process. The water trough advantageously has a volume V.sub.M=30 ml.

[0035] FIG. 2 shows a dish-shaped low-pressure hood 10 in a perspective view, which low-pressure hood forms the second component of the low-pressure steam cooker. The low-pressure hood 10 has, for example, a hood volume V.sub.H=1,700 ml, a diameter D.sub.H=20.5 cm, a height H.sub.H=9.5 cm, and, with these dimensions, for example, a weight G.sub.V=1,170 g.

[0036] The low-pressure hood 10 has a mounting rim 11 in the plane of its opening, the contour of which is shaped complementary to the contour of the retaining edge 05 of the base plate 01, such that the mounting rim 11 is enclosed by the retaining edge 05 when the mounting rim of the low-pressure hood is seated on the hood bearing surface of the base plate (FIG. 3).

[0037] The base plate 01 and the low-pressure hood 10 are each formed in one piece from a non-glazed ceramic material, the ceramic raw material of which is admixed with granite meal. Even with modified dimensions, the water absorption volume V.sub.M of the water trough is about 1% to 2% of the hood volume V.sub.H, preferably 1.5% to 1.9%, particularly preferably 1.764%. The water absorption of the sintered granite ceramic is similar to that of porcelain or alternatively porcelain stoneware and is preferably <0.5%. The ceramic should have a high heat capacity such that there is uniform transfer of heat to the food to be cooked. Moreover, good heat storage serves to keep the food warm for a long time after cooking. Depending on its composition, the heat capacity of granite ceramics is up to approx. 1.2 J g.sup.−1 K.sup.−1. In this manner, a higher heat storage capacity than steel is provided. The granite ceramic is excited by microwave radiation and is thereby heated. On the other hand, granite ceramic does not absorb so much of the microwave radiation that the effect on the food would be too small. The granite meal added to the ceramic raw material contains quartz, feldspar and mica. In particular, the dark micaceous minerals contained absorb microwave radiation, and the material heats up much more strongly than with white porcelain.

[0038] FIG. 3 shows a cutaway view of the low-pressure steam cooker in assembled form as it is used for cooking food. It can be seen that the mounting rim 11 of the low-pressure hood is seated on the hood bearing surface 04 and is enclosed around the outer periphery by the retaining edge 05. The surfaces of the mounting rim 11 and the hood bearing surface 04 facing each other are formed in such a way that, preferably by increased surface roughness, a steam outlet gap 15 remains between them, at least in sections, through which gap the water vapor produced during heating can escape. To allow the steam generated during use to escape, the hood must not seal tightly with the base plate. This is ensured by the use of coarse mass components in the ceramic. The components have sizes of up to 2 mm. As a result, the contact surface is always designed in such a way that water vapor of a pressure of more than 1 bar can escape.

[0039] It is also visible in FIG. 3 that the low-pressure hood 10, on its upper side opposite the mounting rim has an outwardly directed support surface 16. The support surface 16 is used when the low-pressure hood is used as a dish after the cooking process.