DE2326676B2 - Storage stone for heat storage stoves - Google Patents

Description

surfaces was provided and at points 1 to 6 under the in F i g. The installation conditions shown in FIG. 2 within an externally insulated heat storage furnace housing were measured.

From the F ig.l and 2 it can be seen that the magnesite storage stone with groove-shaped recesses 7 is provided on its upper side, in the respective in FIG. 1 tubular electrical, not shown Heating elements 8 are inserted during assembly. By stacking several Storage stones are then created from FIG. 2 can be seen inner storage core, which is surrounded by air ducts 9 through the side recesses are formed on the individual storage stones. The memory core assembled in this way becomes then surrounded by an outer insulating layer 10, which is usually made of stone with an additional glass barrel insulation can be composed.

A magnesite storage stone of the following composition was used for the measurement:

MgO 92%

Al O ₃ 1%

F ^e 2 ^ 3 I / o

CaO 3%

^{p n}
I 2

This magnesite brick had a density of 3.0 kg / cm ³ .

This storage stone, corresponding in its appearance to roughly light bricks, was assembled in the assembled building State according to FIG. 2 charged with night power under normal conditions, and over the full available charging time of around 8 hours. The memory then has an amount of heat absorbed of about 38,500 kcal, and the temperature distribution on the measuring points is the following:

810 ° C 730 ⁰ C 710 ⁰ C 700 ⁰ O 68O ⁰ C 685 ° C

The same experiment was carried out with the same heating elements and the same remaining composition of the storage heater with storage stones of the same analysis (magnesite), but with a black Baked enamel was provided on all outer surfaces, as is customary for coloring hotplates is used. After the same charging time of 8 hours and the same heat content of about 38 500 kcal, the temperature distribution was as follows:

Measuring points

12 3 4 5 6

- / 6 $ ° q 720 ° C 705 ° C 695 ⁰ C 68O ⁰ C 690 ⁰ C

This temperature distribution shows that apparently due to the better heat dissipation from the heating element, a more uniform distribution and a rise in the temperature inside the storage stone has occurred if a dark coloring of the outer surfaces and at least the surfaces in the area of the heating elements is provided. The decisive factor is especially the Aosinken the temperature at the heating element by about 45 ⁰ C over the test version without coloring. This lower temperature on the heating element makes it possible to heat the entire storage core by around 40 to 45 ° C more, so that the total heat content of the storage can be correspondingly higher.

The coloration thus surprisingly results in a considerable increase in the heat capacity by storage heater achieved without the need for expensive resources or new and expensive storage materials λ must be considered.

1 sheet of drawings

Claims (4)

26076 * to improve memory charging. Claims- These known storage stones, however, in turn have the disadvantage that their production is relatively 1. Speichersteiü for heat storage stoves, which is expensive and that memit because of the use Recesses for receiving electrical 5 TaUischer molded bodies, for example made of aluminum heating elements is provided and where the minimum can exist, the costs are too high took to improve the heat output by being increased. Also the dimensional stability and the heating elements to the storage stone mass. Durability of such composite storage stones are met, characterized by a can compared to the usually built up Speim at least be lower in the area of the heating elements (8), because the different looks black coloring. expansion coefficients for the structure of the storage 2. Storage stone according to claim 1, the materials used from stone to internal tension magnesite consists, characterized in that the gene and thus also to break the storage stones Coloring is applied as a color layer (11). being able to lead. 3. Sp safety stone according to claim 2, characterized in that the object of the present invention is therefore indicates that the color layer (11) is based on all to create a memory stone, although External surfaces of the storage stone is applied. just like this well-known design, the heat dissipation 4. Storage stone according to claims 2 and 3, promotes from the heating elements to the stone volume, characterized in that the color layer (11) is constructed in such a way that temperature changes a black stoving enamel is provided, as it is 30 and in particular also high peak temperatures Usually used for coloring hotplates without impairing the physical properties will. shafts and especially the strength properties of the stone can lead. The initiation is, proceeding from the knowledge, _a5 that in the previously known, relatively light magnesite bricks, the absorption capacity is not utilized, characterized by a black coloring provided at least in the area of the heating elements. By The invention relates to a storage stone for this measure, through the dismantling of the previous heat storage furnace, which is provided with recesses for receiving electrical heating elements as inevitable in such stones, heat gradient either a lowering of the temperature and the measures to improve the temperature on the heating element or a corresponding heat transfer from the heating elements to the storage increase in the thermal capacity of the storage stone are initially taken. It is known to be rich for warmth. This embodiment also brings storage stoves, especially for electric night-time 35 in an extremely simple way, the surprising effect of electricity storage stoves, ceramic storage stones to use the heat output from the heating elements material, the content of MgO in the storage stone mass apparently much better a decisive Role for heat storage is going on, and it's got measurement capability. For example, so-called shows that with the same electrical heating-up brick with 50% MgO and forsterite bricks with 40 power, the temperatures on the heating element got about 50% MgO, but the heat capacity ^{could be kept 45 0} C lower than with magnesite bricks with 90% or blast furnace bricks, in which such a coloring is not exceeded by pre-magnesite bricks with 95% MgO. was dealt. It has proven to be extremely simple and blast furnace ragnesite has proven to be advantageous for use for heating if the storage stone from storage furnace is too expensive, so that today there is generally 45 magnesite and the coloring as a color layer is only magnesite stones with about 90% MgO as storage is upset. which are used on all outer surfaces of the Speisteine for night storage heaters. chersteins is applied. These stones have the advantage of a high storage, a black, temperature-resistant and tradable color layer and can be found in the desired manner as usual stoving varnish as particularly advantageous with the recesses for the production of the through holes, such as those used for coloring hotplates or. Like. Ventilation openings and with the recesses for which is used. Equip the initially described advantageous absorption of the heating elements. Adherent results were achieved with a magnesite. The endeavor is now to achieve the heat content storage stone with an MgO content of 92%, a charged storage stove as high as possible. It is conceivable that similarly good results will also be obtained. It has been shown, however, that the 55 storage heating elements, which are already dark by default, are the weakest point, because material with similar physical properties is usually not hotter than round like magnesite for material reasons separately a -800 ⁰ C can be. The accumulator charge needs to be colored. Due to the maximum temperature of the heating elements, such materials are not yet known today.
Limits are set because it is due to the heat gradient remaining in the known 60 In the drawing, the arrangement of the temperature storage stones is indicated between measuring points on a storage stone, with the heating elements and the adjacent storage unit measuring once with an uncolored stone and once not possible to bring more heat away from the heating elements into the stone with a magnesite element colored with stoving varnish. storage stone has been carried out. It has therefore also already become known (DT-Gbm 65 In FIG. 1 there is a perspective illustration 17 07 480), good heat-conducting, metallic molded body position of a storage stone made of magnesite is shown, embed in relatively cheap heat storage materials, once without coloring and once with a thereby the thermal conductivity of the storage mass to black enamel layer on all exterior