DE2244929A1 - Laboratory baking oven - for investigating characteristics of grains - Google Patents

Abstract

A cylindrical, insulated casing has a hatch in its vertical cylindrical wall closed by a double walled transparent door and has plane top and bottom hot plates thermostatically controlled. Sufficient water to produce saturated steam in the oven chamber is injected automatically on to the bottom hot plate, from an integral subsystem, when the door is closed. The samples of grain/flour are placed on segments of a turntable driven by a sealed shaft through the floor using a stepping motor positioned by a selector switch for rapid loading, unloading and visual inspection.

Description

MICRO OVEN The baking test is a complex evaluation the quality of the grain to be examined or

of flour suitable method used in grain processing and research institutes is widely used.

To carry out the experiments under laboratory conditions Small experimental ovens set some, countering which the following demands be asked: - maintaining the temperature; - the even one Heat distribution in the oven; - ensuring a room with saturated steam fight back the baking.

The first two conditions can be used in the known test ovens should be considered a problem solved, although it is noteworthy that e.g. English Simonsche Oven or the Brabberian Oven (DBR) just bake one Test material of 300-1000 g allows. Ovens used for baking smaller furs are not available nowadays.

With a view to the need for simultaneous review of cereals of various properties and varieties and the fact. that in the Institutes test material is available in small quantities, the manufacture Due to rolls of reduced weight, such ovens are required for baking of test samples of 50-100 g. In case of weight loss namely, the samples are more and more sensitive to the heat distribution in the Baking chamber, which prevents reproducibility.

The most problematic is ensuring a space with saturated steam during the baking period.

The space with the saturated steam is therefore necessary that the moisture In the course of baking the experiment does not wake escaping, as we would otherwise samples with a huge crust, which are unsuitable for further qualification examinations, obtain.

The course of baking is generally as follows: The oven will heated to the given degree of heat (baking temperature) after opening the oven door the already prepared (kneaded and shaped) awakenings are inserted. At the same time there are 4-8 test wakes baked, mostly Heating plates. which can be turned by hand from the outside these are placed on it one after the other.

If possible, the dough pushed into the heated oven must Immediately get into the room with saturated steam to avoid evaporation can, but cannot because of the oven door that is open during insertion be realized.

The critical period can therefore be 1-1.5 minutes, counted from the beginning of baking to the formation of the crust, since afterwards - as a result of the crust formation - the degree of evaporation is lower.

In the case of the known types of ovens, this causes the room with saturated steam ensured that there is an evaporation tray in the oven. The evaporation tray is taken from the oven's baking chamber or from a heater built in for this purpose heated up. In both cases, the evaporation can start as soon as the heater is heated are placed, at the time of insertion there is a room with saturated steam available. On the one hand, however, the saturated steam escapes when the Ttfr is opened, on the other hand, undesirable condensation can occur after the closing of the After the door has been pushed in, the steam redirects the oven the dew point, but the space is weaving in the critical initial period saturated steam not secured.

So there is the task, immediately after being pushed in, after locking the door to create a tier with saturated steam in the oven.

In the case of the micro-oven according to the invention, the object is thereby achieved solved that after the insertion took place and the door is closed by a pipe and vessel system that forms an organic unit with the furnace defined the dew point associated with the given degree of heat Amount of water is left on the heating plate, which is converted into steam there, immediately creating a room with saturated steam. The addition of water is expedient -directly or indirect - controlled by closing the oven door.

With. Respect to it. that the duration of the indulgence the circumstances influenced in no small measure, considered the movement of the baking plate as necessary to accelerate during the pushing in. In this case one must not except Take care that the samples have to stay in the oven for the same time as the Different baking times greatly impair comparability. Although the The order of the shifting can also be adhered to with the exception, whereby If the above assumption is approximated, this operation must be carried out by the individual Skills are made independent.

The task is fulfilled by an automatic. the rapid deployment of the individual segments of the Baok board in front of the door, in a defined position, with at the push of a button, electronically secures; so is the operator busy with the insertion (or exception); with the help of the automatic can Any segment can be put in front of the door in any order.

The invention is to be described in more detail below using an exemplary embodiment explained.

The micro oven shown in the drawing has a cylindrical shape and is provided with a double-walled Isolatinn 5. Within the insulation is the hermetically sealed baking chamber 2, the lower and upper end plates also serve as heating plates 1 and in this arrangement ensure even heat distribution. The turning axis is through the lower heating plate 3 of the drive 7 carried out sealing, the axis protruding into the baking chamber @ on the axis the baking plate 4, which consists of segments, is attached, which is rotated by means of the motor through the axis, whereby the even heat distribution is further increased.

The baking plate rotates during the baking period. To speed up an automatic function is used to insert or exclude the test material Position switch with preselection system, which ensures that the segment of the selected Test material in the center line of 1ir 6 adjusts itself.

The water supply unit serves to secure a room with saturated steam 8, with the help of which water can be dosed onto the lower heating plate; the amount of water is based on the knowledge of the heat quality - with the help of the table belonging to the furnace - certainly. The water is removed from the storage tank before the start of the insertion 14 drained into the vessel 15 provided with a division, of which after closing the door, after the end of the insertion. the water through the tap on the Hot plate pours out. After the end of the Baking the evaporation can be done.

The one with an error is used to ensure the desired degree of warmth 12, the temperature adjuster 10 and a reading device provided thermostat. To push in of the test material and for checking during baking, the oven is equipped with a double-walled, transparent and tightly closing door 6 provided. The review during baking is made easier by internal lighting.

Claims (2)

PATENT CLAIMS 1J laboratory micro-oven, one at the bottom and one at the top with levels Heating plates closed, insulated oven, and one in the oven rotatably arranged segments existing, sealing on the through the lower heating plate has carried out, vertical axis arranged heating plate, furthermore, with one, designed on the cylindrical jacket of the baking chamber, double-walled, transparent door is provided, thereby g e k e n n n z c i c h n e t that the oven one that forms an organic unit with the furnace after the end of the insertion controlled by the door directly or indirectly, to secure a room with saturated Steam required amount of water on the heating plate (1) metering pipe and vessel system (8). 2. Micro oven according to claim 1, thereby g e k e n n z e i c h n e t that this is for the purpose of shortening and standardizing the period of insertion Automatic preselection system placing the desired segment in front of the door (6) (13).