JPH06253754A - Steam generator - Google Patents

Abstract

PURPOSE:To obtain a stream generator, capable of bringing water into contact with the surface of a heating plate, made of an Al metallic plate and heat-treated in an aqueous solution containing NaHCO3 and a Ca salt, instantaneously generating steam and simply and safely performing the reprocessing and having a good efficiency of steam generation. CONSTITUTION:This steam generator such as a steaming treatment type cooking apparatus for carrying out the steaming treatment of a frozen or a dried product. In this steam generator, a box-shaped internal space is divided into an upper and a lower parts at the vertical central position with a perforated plate 5 and a tray 6 can be fitted and inserted from the transverse direction through an opening 10 provided in the sidewall of a steaming treatment chamber 4. Furthermore, a water feed pipe 7 is fitted, inserted and fixed from the outside in the lower part and a heating plate 8, heat-treated in an aqueous treating solution prepared by mixing sodium hydrogencarbonate with calcium and a calcium salt is installed in the base. The surface of the heating plate 8 is heated with a heater embedded in the interior of the heating plate 8 and brought into contact with water fed from the water feed pipe 7 so as to instantaneously generate steam. Thereby, the reprocessing is simply and safely carried out with a good efficiency of the steam generation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam generator, such as a steam-heat-type cooking device, for steam-heating a frozen product or a dried product.

[0002]

2. Description of the Related Art Conventionally, a cooking device for rapidly steaming heat treatment of frozen and dried food has been known. For example, a so-called steamer used in general households is widely known, and for commercial use, a sealed container. A cooking device is known in which food is placed on the perforated plate inside, water is sprayed onto a heating plate provided below the perforated plate to generate steam, and the steam is brought into contact with food through the perforated plate. (For example, Japanese Examined Japanese Patent Publication 58-50727
issue).

[0003] In such a steam-heat treatment type cooking apparatus used for business, specifically, the bottom of, for example, a drawer type tray for storing foods for steam-heat treatment is formed of a perforated plate, and this tray is formed. A container body with an opening for inserting a heating plate, a heating plate embedded with a heating device such as a heating wire provided at the bottom of the inserted tray, and a water supply for spraying and dripping water on the heating plate. It is usually equipped with a tube.

In this apparatus, food is put in a tray and inserted into the container body, and water is sprayed while the heating plate is heated to a predetermined temperature to instantaneously generate steam. A steaming heat treatment is performed in which they are brought into contact with each other, and heating and hydration are simultaneously performed.

And, such a steam heat treatment type cooking device,
Especially for equipment used for business use,
It is required to be suitable for repetitive work, and from this viewpoint, for example, an aluminum casting with good thermal conductivity is generally used as the heating plate, and the processing chamber is sealed from the outside air to prevent waste due to the dissipation of generated steam. It is usual to adopt a structure such as.

[0006]

A steam generator represented by the above steam-heat-treatment type cooking apparatus is as follows.
With the recent increase in the so-called food service industry and the like, the demand for it has increased, and more and more sophisticated devices have been required.

Therefore, the inventors of the present invention have made extensive studies from such a point of view and completed the present invention.

[0008] That is, in order to speed up the processing of the steam-heat treatment type cooking device, it is desirable that the sprayed water quickly becomes steam and that the generated steam efficiently contact the food. Therefore, as a result of studying the improvement of a heating unit for converting water into steam, it was found that the efficiency of steam generation is greatly improved by corroding the surface of the heating plate with a strong acid, and Japanese Patent Application No. 2-60489 (Japanese Patent Laid-Open No. 60489/1990). 3-260076
No.) already proposed.

By the way, the heating plate treated by this technique can repeatedly generate steam with a sufficiently high capacity, but its function deteriorates as the elapsed time becomes longer, and finally it becomes the same as the untreated one. It was observed that the ability deteriorated over time.

If the capacity is lowered, it may be considered that the capacity is restored by reprocessing by corrosive treatment with the above strong acid. However, since this apparatus is used in restaurants and the like, There are practical problems with using powerful drugs such as strong acids. Therefore, development of another method has been desired.

From this point of view, the present inventor can provide a steam generator having a high steam generation efficiency, and at the same time, can perform reprocessing safely when the capacity is deteriorated. The present invention was developed to provide a generator.

[0012]

The features of the steam generator of the present invention which achieves the above-mentioned object are that a steam generator for instantly generating steam by bringing water into contact with the surface of a heating plate made of aluminum metal. In the above, the water contact surface of the heating plate is the one that is heat treated with a mixed aqueous solution of sodium hydrogen carbonate and a calcium salt.

For the heating plate, a cast product of an aluminum alloy having good heat conductivity can be generally preferably used.

The surface treatment of the heating plate is generally performed by roughening the surface by shot blasting, and then dipping the heating plate in a treatment aqueous solution in which sodium hydrogencarbonate and required salts are mixed and heating. You can do it by doing.

As the treatment aqueous solution, an aqueous solution containing sodium hydrogen carbonate alone does not improve the water vapor generation efficiency as is clear from the following test examples, and it is necessary to use an aqueous solution mixed with the above-mentioned other salt or the like. Is.

In the above, as the calcium salt, calcium carbonate, calcium sulfate, or a mixture thereof can be preferably used, and the concentration of the aqueous solution obtained by mixing these with sodium hydrogen carbonate depends on the steam generation of the treated heating plate. Although it can be appropriately selected depending on the degree, it is usually 0.1 to 1% when calcium sulfate is mixed with an aqueous solution of 0.1 to 1%, preferably 0.4 to 0.5% of sodium hydrogen carbonate. %, Preferably 0.3-0.6%, and when calcium carbonate is mixed, it is 0.1-1%, preferably 0.3-0.6%. Even when these calcium sulfate and calcium carbonate are mixed together, the total concentration of these is 0.1
˜1%, preferably 0.3 to 0.6%.

The heat treatment method carried out by immersing the heating plate in the treatment aqueous solution prepared as described above is not particularly limited, but for example, the heating plate is heated to 100 ° C. and the treatment liquid is applied thereon. It is also possible to evaporate the water by applying.

[0018]

In the steam generator of the present invention, it is presumed that microscopic unevenness is formed on the surface of the heating plate. With the above configuration, steam can be efficiently generated. The steaming of food can be done quickly.

Further, when the effect is reduced, reprocessing is simple, and since the aqueous solution used is safe, it can be safely and easily performed on site.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A steam generator of the present invention will be described below with reference to the illustrated embodiment constructed in a cooking device.

Embodiments FIGS. 1 to 3 are for explaining a steam heat treatment type cooking apparatus incorporating a steam generator. In these drawings, reference numeral 1 is a main body accommodating control devices such as heating control. And a steam heat treatment chamber 4 is provided on the upper part thereof. A knob 2 for controlling the heating temperature and a power switch 3 are provided on the front surface of the main body.

As shown in FIG. 3, the steam treatment chamber 4 is divided into upper and lower parts by a perforated plate 5 at the upper and lower central positions of a box-shaped internal space, and the tray shown in FIG. 6 is adapted to be laterally inserted through an opening 10 provided in a side wall of the steam heat treatment chamber, a water supply pipe 7 is externally inserted and fixed to a lower portion, and a heating plate 8 is further provided to a bottom portion. Has been. As shown in the figure, the tray 6 is provided so that the bottom surface has a large number of small holes so that vapor from below can flow into the tray. In addition, by opening and closing an electromagnetic valve (not shown) on the steam water supply pipe 7,
A plurality of spray ports are provided so that water can be sprayed onto the entire surface of the heating plate 8 at a predetermined timing. Reference numeral 9 denotes a heater embedded inside the heating plate 8.

The heating plate is formed of a cast aluminum alloy surface-treated as follows.

In the steam-heat-treatment type cooking apparatus having the above-mentioned structure, various heating apparatus having different surface treatment conditions were prepared, and the state of steam generation was tested. For comparison,
An apparatus in which the heating plate was surface-treated with an aqueous solution having a composition other than the aqueous treatment solution used in the present invention was prepared, and the state of steam generation was tested.

Test sample (1) The surface of a circular aluminum plate having a diameter of 13 cm was roughened by sandblasting, then 0.5% sodium hydrogen carbonate (NaHOH) and 0.3% calcium sulfate (CaSO 4
_The test plate (1) was obtained by immersing in 200 cc of the mixed aqueous solution of ₄ ) so that the surface of the heating plate was sufficiently immersed and heating at 180 ° C. to evaporate water.

Similarly to test samples (2) to (6) , after sandblasting an aluminum plate, the treatment solution was changed to that shown in Table 1 below and the same treatment was carried out to obtain test samples (2) to (6). It was

Comparative Samples (1) to (5) For comparison, after sandblasting an aluminum plate in the same manner, the same treatment was carried out by changing the treatment aqueous solution to that shown in Table 1 below, and the comparison samples (1) to (5) 5) got

[0028]

[Table 1]

Water vapor generation test The test sample and the comparative sample prepared as described above were used as a heating plate of the steaming chamber of the apparatus described in FIGS. 1 to 3, and the heating plate was heated to 190 ° C. Water of 20 cc was repeatedly and intermittently sprayed from the water supply pipe 7 at intervals of 10 seconds, and the time taken for the dropped water to evaporate and to lose water was measured, and the results are shown in FIG.

From these test results, in the case where the heating plate surface-treated with the treatment aqueous solution according to the present invention was used, compared with the case where no chemical surface treatment was performed (comparison sample (1) treated with city water) It was confirmed that the vaporization rate of water vapor was high and its persistence was also high. Further, the heating plate surface-treated with the treatment aqueous solution containing only sodium hydrogen carbonate was insufficient in steam generation immediately after the treatment.

[0031]

As described above, according to the steam generator of the present invention, the steam generation efficiency is high. For example, when the steam generator is applied to a steam heat treatment type cooking apparatus, the steam heat treatment of food can be performed quickly. There is an effect that can be.

Also, when the reprocessing is carried out, since the processing aqueous solution used is safe, it can be easily carried out, and since a powerful drug such as a strong acid is not used, it can be easily and at the site of use. The effect is that it can be safely reprocessed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall outline of a steam-heat treatment type cooking device to which the present invention is applied,

FIG. 2 is a perspective view of a tray that is inserted into a steaming / heat treatment chamber of a cooking apparatus main body for storing food,

FIG. 3 is a cross-sectional view of a steam heat treatment chamber,

FIG. 4 is a diagram showing the results of a steam generation test using a heating plate surface-treated with various treatment aqueous solutions.

[Explanation of symbols]

 1: Main body part 4: Steaming / heat treatment room 5: Perforated plate 6: Tray 7: Water supply pipe 8: Heating plate 9: Heater 10: Opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Koizumi 2590-1, Tsuruma, Fujimi-shi, Saitama Patio KOSUGI B-203 (72) Inventor Hiroo Sato 1-13 Tomiie-cho, Kanagawa-ku, Yokohama Kanagawa Prefecture Sukai Heights Tokai 1101

Claims (2)

[Claims] 1. A steam generator for generating water vapor instantaneously by bringing water into contact with the surface of a heating plate made of aluminum metal, wherein the water contact surface of the heating plate is a mixture of sodium hydrogen carbonate and calcium salt. A steam generator characterized by being heat treated in the treated aqueous solution. 2. The steam generator according to claim 1, wherein the calcium salt is at least one of calcium carbonate and calcium sulfate.