EP0533881B1 - Semolina purifying machine with closed air circuit - Google Patents

Abstract

PCT No. PCT/CH92/00071 Sec. 371 Date Dec. 11, 1992 Sec. 102(e) Date Dec. 11, 1992 PCT Filed Apr. 4, 1992 PCT Pub. No. WO92/18257 PCT Pub. Date Oct. 29, 1992.A semolina cleaning apparatus allows basic operations as in the prior art with complete visual surveillance of operation, but with an outwardly closed product guidance. In this way, entry and exit of dust is completely prevented during normal operation as well as when removing samples. Accordingly, it is possible to operate an individual apparatus as well as an entire group of semolina cleaning apparatuses with circulating air. The air intake can be effected from above.

Description

Technical field

The invention relates to a semolina cleaning machine, the material being cleaned by means of a plurality of oscillating sieve layers forming a cleaning compartment and separated via product discharges for the sieve repulsion and under the sieve layers with a plurality of adjustable discharge nozzles for transferring the sieve diarrhea into two or more collecting channels into the desired fractions becomes.

State of the art

• ein offener Prozessablauf mit Sicht auf das Produkt in den jeweiligen Behandlungsstufen;
• die Möglichkeit innerhalb der kritischen Arbeitsabläufe Produktmuster zur sensorischen Bewertung oder für eine analytische Prüfung entnehmen zu können;
• dem Müller Korrekturen bezüglich der Maschineneinstellung und des Produktflusses zu ermöglichen.

In addition to the roller mill and the plan sifter, the semolina cleaning machine has become a main machine, which together have the characteristic features of milling technology. These are:

• an open process flow with a view of the product in the respective treatment stages;
• the possibility to take product samples for sensory evaluation or for an analytical test within the critical work processes;
• to enable the miller to make corrections to the machine settings and product flow.

In the semolina cleaning machine, the principle of the fluid bed, on the one hand, and the classic sieving, on the other, are combined with a shaking movement of the sieve.

The usual sieving process works without air through the sieve; in contrast, a fluid bed with a strong air flow is created in such a way that the material assumes a fluid-like, flowable state. Very specific laws apply in the fluidized bed, whereby the separation into large and small parts is only the best known effect. The main task of the semolina cleaning machine is the extraction of semolina and haze, various granulations and the reading out of all shell parts which have a darker, often brownish color. Furthermore, with the semolina cleaning machine, grinding products with different qualitative properties can be separated.

In German patent no. 29 181 from 1884, a semolina cleaning machine with a completely closed system has become known. A twin ventilator sucks the air out of the machine head, which has filter cloth cleaning, and returns it along the product collecting area to the lower side of the sieve. The air supply duct is arranged on the side and the diarrhea chamber is thus arranged on the side in a closing manner. Compared to the newer state of the art, there is only a very poor control option for the operation of the semolina cleaning machine, which would no longer be suitable, especially with cleaning compartments having multiple screen layers.

EP-A-155 527 and EP-A-155 537 further describe a modern semolina cleaning machine in which the necessary air is supplied from outside via side inlet slots via an open cleaning box. The product is accessible through the open plaster box and conditionally sanitation is provided.

• Das Stärkekorn darf für Griess-Produkte, die bestimmt sind für die Teigwarenindustrie nicht mechanisch beschädigt werden, da sonst die Teigwarenqualität verschlechtert wird.
• Der Kleber darf für Backmehle zum Beispiel durch örtliche Hitze nicht beschädigt werden.
• Die äusseren Schalenteile müssen möglichst grossflächig erhalten und ausgesondert werden.

The mill grinding, in the sense of modern high-milling, has the peculiarity that not only a certain granulation must be achieved, but that there are some key points to be considered, particularly with regard to the regrind

• The starch grain must not be mechanically damaged for semolina products that are intended for the pasta industry, otherwise the pasta quality will deteriorate.
• For example, the glue for baking flours must not be damaged by local heat.
• The outer shell parts must be preserved and separated out as far as possible.

The large surface area of the shell parts, in contrast to the more cubic shape of the flour and semolina parts, is now used in the semolina cleaning machine for their selection. This happens due to the physical forces which push the flat parts upwards in a shaken fluid bed, so that they can be excreted as sieve rejection. Only the flour or semolina parts are sieved in the semolina cleaning machine and these according to size. This process is analogous to a calibration with the aim of a certain grain size spectrum.

All requirements for the optimal functioning of the semolina cleaning machine are met by the very unique concept structure, as it developed from the beginning 100 years ago. The semolina cleaning machine has become a special machine that is used almost exclusively in the field of grain mills. Any significant concept change should result in a change in function. This means that new requirements, such as closing the entire product flow to the outside, for reasons of hygiene, cannot reasonably be solved without at the same time questioning the basic requirement of openness and accessibility to the process.

Presentation of the invention

The object of the invention was now to improve the cleaning of semolina, in particular with regard to ventilation technology and hygiene, but to improve it while maintaining all the essential advantages of the modern open concepts.

The new invention relates to a semolina cleaning machine with a plurality of oscillatingly mounted sieve layers, air supply and air discharge of a product feed, a product discharge for the sieve rejection and, under the sieve layers, a product collecting tray with a large number of adjustable discharge nozzles for the transfer of the sieve diarrhea into two or more Sasunel channels and is characterized in that the product collecting tray with an air supply duct extending over its length forms an outward-closing diarrhea chamber and, together with the sieve layers, form an oscillating unit. Self-cleaning results in particular from the fact that the air supply duct is part of the oscillating unit.

The air supply duct can, if several semolina cleaning compartments. Machines are in operation at the same time, the air supply duct is connected directly as an air return duct of a circulating air system (air circulation), or in the case of a single machine without circulating air, the fresh air in the area of the machine head, preferably at an end part of the semolina cleaning machine, is sucked in via an air grille, i.e. no longer from the Floor area as before.

The semolina cleaning machine according to the invention is characterized in that the exhaust air from at least two cleaning compartments is collected in an air discharge line and sucked off via a separately arranged aspiration, cleaned and returned as supply air under the sieve layers via a supply channel in each case, an overhead inlet to the air supply channel to the side next to it the sieve trays, so that recirculated air from above next to the Sieve trays pass into the flow chamber and thus under the sieve trays.

Surprisingly, it has been possible to significantly improve the main work equipment, namely the air or the ventilation side, by not being able to assign an independent air system or cleaning system to each cleaning compartment, but rather a common air system to much more cleaning compartments, which at the same time means air circulation in the sense of recirculating air allowed.

However, the invention also permits a whole series of particularly advantageous further configurations. For example, the discharge nozzles for the product are preferably arranged on the collecting base and have throttles. The collecting troughs are designed as vibrating troughs, the throttles preferably being designed to be adjustable in cross section. The screen layers, together with the collecting base and the collecting troughs, can each have their own oscillating drive, the collecting troughs preferably also being designed as closed channels and having transparent removal flaps for product samples on the top in the longitudinal direction.

It is also proposed that the air supply duct be arranged over the length of the screen layers and approximately in the central region of the screen layer. In this way, the entire area above the sieves remains free for window elements for visual inspection of the fluid bed.

Another very particularly advantageous embodiment is to arrange a plurality of air quantity adjustment flaps between the air supply duct and the diarrhea.

This makes it possible for the first time to remove the air volume adjustment flaps from the dust chamber and to install them in the clean air section.

A major contribution is made to keeping the semolina cleaning machine clean inside. The air inlet for the air supply duct can be arranged on one end side of the semolina cleaning machine and the supply duct approximately at the same height as the sieve position. The adjustment flaps are on the pressure side of the system.

It is also proposed to reconnect the air discharge to the air supply duct via a separator and a fan. But this made it possible for the first time to operate the semolina cleaning machine as a closed system and with circulating air. This is not only an important contribution to the hygiene in the mill, it also completely eliminates a source of dust that previously appeared to be almost imperative in miller process technology. If the vibrating troughs are placed under slight negative pressure, there is no disruption to the operation and no more dust escaping when samples are taken. In this way, several semolina cleaning machines can now advantageously be connected to a common air discharge line. However, several semolina cleaning machines are preferably connected to a common air return line in recirculation mode. This enables several semolina cleaning machines to be connected to a common dust separation unit and operated with circulating air.

For the mastery of the entire air system, it is further proposed to provide the entire air circulation system with an exhaust air line, so that at least the upper area of the semolina cleaning machine can be placed under negative pressure with respect to the surroundings.

Brief description of the invention

die Figur 1

einen Längsschnitt durch eine Griessputzmaschine;

die Figur 2

die Ansaugseite mit einem Querschnitt II - II der Figur 1;

die Figur 3

die Absaugseite mit einem Querschnitt III - III der Figur 1;

die Figur 4

schematische Ansaugseite und Absaugseite im Verbund mit Umluft;

die Figur 5

eine Gruppe von 3 Griessputzmaschinen sinngemäss zu der Figur 4;

die Figur 6

eine Längsansicht der Griessputzmaschine.

The invention will now be explained in more detail with the aid of some exemplary embodiments. Show:

the figure 1

a longitudinal section through a semolina cleaning machine;

the figure 2

the suction side with a cross section II - II of Figure 1;

the figure 3

the suction side with a cross section III - III of Figure 1;

the figure 4

schematic suction side and suction side combined with circulating air;

the figure 5

a group of 3 semolina cleaning machines analogous to Figure 4;

the figure 6

a longitudinal view of the semolina cleaning machine.

Ways of Carrying Out the Invention

In the following, reference is now made to FIGS. 1 and 6.

A semolina cleaning machine 1 is supported on a bracket 2 and has a fixed head part 3. The material is fed in via a product inlet 4 and an inlet cascade, and is passed directly to the uppermost sieve layer 5 'of the sieves 5. The screens 5 are vibrated together by a vibration exciter 30.

The material obtained via the sieve layers 5 ', 5'',5''' as a push-off at the deep end is discharged via product discharge channels 6 ', 6'',6''' and in FIG. 1 via a common product discharge channel 6. The sieve diarrhea reaches a product collecting tray 7 and via a plurality of transfer channels 8, 8 ', 8''etc. and via respective throttles 9 into one of two collecting channels 9 or 9. 9 'of which the goods are either passed on via a drain pipe 10 or 11 depending on the product quality. All vibrating parts have a spring element 12 as a support. In the upper, middle part of the semolina cleaning machine, an air discharge nozzle 13 is arranged, from which the dust-containing air via a dust separator 14, a fan 15 and an air return line 16, and via a flap box 17 as a cleaned fresh air flow via an air supply duct 18 into a product diarrhea 19 (FIG . 2) arrives. It is important that the flow layer on the uppermost sieve layer 5 can be checked with the eye via windows 20 as before. In Figure 2 (as in the following Figures 3-5), the semolina cleaning machine by two identical machines, respectively. shown as a double machine, as is common for semolina cleaning machines. It is essential, however, that the air supply duct 18 is provided in two for targeted control or air flow for each half of the machine. In the case of recirculated air, however, the air supply and route are common. The transition from the air supply duct 18 into the diarrhea chamber 19 can be adjusted by means of air regulating slide 20 via handwheels 21. The two collecting channels 9 and 9 'each contain different products, what with small circles, respectively. Points is indicated. The fixed head part 3 is held on a central support 2 '. Each cleaning compartment with sieve layers 5, product collecting base 7 and air supply duct 18 forms an oscillating unit which can be connected as a double unit and which is connected to the fixed machine parts via flexible sleeves 33.

The product flow can be directed from each individual transfer channel 8, 8 ′, 8 ″, etc. either into the collecting channel 9 or into the collecting channel 9 ′ via an adjusting flap 22. This can be done by swiveling to the right on the left machine or to the left on the right machine. A product sample can be removed from the respective transfer channel by opening removal flaps 23.

FIG. 3 shows the air flow from the diarrhea chamber 19 through the sieve layers 5 ', 5' ', 5' '' and an air extraction chamber 24.

FIG. 4 combines FIGS. 2 and 3, ie represents 2 different cuts, the air discharge on the left and the air supply of a semolina cleaning machine on the right.

FIG. 5 basically shows 3 semolina cleaning machines, each shown as a double machine, in the upper half of the picture the air discharge, in the lower half of the picture the air supply to the same machines. In addition to FIG. 3, FIG. 5 also shows a dust filter 25 and an exhaust air line 26 with a controllable throttle valve 27 for regulating the air pressure conditions in the system.

As indicated in FIG. 6, the solution according to the invention also allows a traditional mode of operation, insofar as it relates to air extraction. The air intake can, however, as indicated by arrows 30, 31, 32, take place from the upper room, that is to say no longer from below, from the area near the floor, which normally has a higher level of dust or bacteria. For this purpose, an air intake grille is attached at the appropriate point.

Claims (8)

1. Semolina purifier or cleaning machine, comprising two cleaning sections and associated air supply and discharge with a head part (3), an air suction exhaust union (13), respective vibratably mounted sieve layers, a product supply, a product discharge for the sieve tailings, likewise a product collecting floor below the sieve layers, with a plurality of adjustable outlet nozzles for transferring the sieve throughs into two collecting channels, a throughfall chamber (19) being formed between the sieve layers and the product collecting floor (7), characterised in that it

   a) has an air supply duct (18) which is connected via a dust separator (14) to a fan (15), an air return conduit (16) with a valve casing (17) and a top inlet leading to the air supply duct (18), to the air suction exhaust union (13), and which extends over the length of the product collecting floor (7) laterally adjacent to sieves (5), and

   b) the air supply duct (18) closes off the throughfall chamber relatively to the exterior, and

   c) the product collecting floor (7), the air supply duct (18) and the sieve layers of a cleaning section form one vibratory unit.
2. Semolina cleaning machine according to claim 1, characterised in that the air inlet for the air supply duct (18) is arranged in the upper region, at one end of the semolina cleaning machine (1).
3. Semolina cleaning machine according to claim 1 or 2, characterised in that the air supply duct is situated approximately at the same height as the sieve layers, and between the air supply duct (18) and the throughfall chamber (19) a plurality of air quantity adjustment valves (20) are arranged.
4. Semolina cleaning machine according to one of claims 1 - 3, characterised in that a common air discharge (13) is arranged, approximately in the central region above a stationary head part (3), for the two cleaning sections.
5. Semolina cleaning machine according to claim 4, characterised in that the air discharge (13) is connected for air circulation operation with recirculating air of the two cleaning sections via the duct separator (14) and the fan (15) to the air supply duct (18) again.
6. Semolina cleaning machine according to one of claims 1 - 5, characterised in that the outlet ducts (8, 8', 8'') are connected to the product collecting floor and have throttlable adjusting valves, the collecting channels (9,9') being constructed as vibratable channels and the adjusting valves (22) being preferably variable as regards the throughflow cross-section.
7. Semolina cleaning machine according to one of claims 1 to 6, characterised in that the sieve layers (5', 5'', 5''') together with the collecting floor (7) and the collecting channels (9, 9' ) have own vibration generator means (30) in each case.
8. Semolina cleaning machine according to one of claims 1 to 7, characterised in that the collecting channels (9,9') are constructed as closed ducts and have at their topside in the longitudinal direction removal flaps (23) for product samples.

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