EP1052030B1 - Air jet sieve for grain size analysis and corresponding screen element - Google Patents

Abstract

The filter has a housing, a filter insert selected from a number with different mesh pitches, a slot nozzle beneath the filt bottom, a drive for the slot nozzle, an air feed to the nozzle, an air outlet via the housing from the chamber beneath the filte bottom and a controller. The filter machine has a sensor (2) for automatic identification of the inserted filter (4) using codin the insert. The coding can be stored on a writable memory medium. An Independent claim is also included for a filter insert.

Description

The invention relates to an air jet sieve according to the preamble of claim 1 and a sieve set for an air jet sieve.

In the grain size analysis by means of a Luftstrahlsiebmaschine after the state The technique (for example, according to DE 44 19 153 A1), the screenings on the screen fabric abandoned, by means of a rotating below the screen mesh slot Gas jet from bottom to top blown through the mesh and the on the Sieve screening material swirled up. The fines of the screenings are from Gas jet entrained and through the mesh from top to bottom in the Transported space below the sieve insert and from there, from the Screening machine discharged. The coarse fractions that are larger than the Mesh size of the respective sieve insert, the sieve can not pass and remain on the mesh after sieving.

GB-A-2321528 describes a sensor on a screening machine which serves the purpose of read a barcode on the screen, creating a central control of the screening machine the Scree. and thus knows which sieve is being weighed. This The procedure is to avoid errors by double weighing the same sieve.

The Patent Abstracts of Japan, vol. 07, No. 366 (P-1571) & JP 05054042 A describes Method and device for automatic inspection of powdered articles by means of a scale and at least one barcode reader.

To determine a grain size distribution curve, several sieves must be used be performed with different screens of different mesh size. For this purpose, the remaining after the first screening on the screen coarse fraction, the sieve residue, subjected to further screening. The first sieve used a first mesh size is removed from the air jet screening machine and a second sieve used with a coarser mesh size. The sieve residue off the first sieving is given up to the second sieve and a second sieving carried out. The sieve residue remaining from the second sieving becomes then fed to a third screening. As needed, many can Screenings in the respective desired particle size steps with the various Seven different mesh sizes are performed. After each done Sieving the sieve residue must be weighed to the To determine Komgrößenverteilungskurve.

To the repeatedly required determination of the Siebrückstandes by To facilitate sieving and weighing has been described in the prior art DE 44 19 153 A1 developed an air jet screening machine, which is an independent, automated weighing of sieve residue. This was in the Luftstrahlsiebmaschine integrated a balance that after each sieving the Lift sieve together with sieve residue and weigh. By comparison this weighing result with the weight of the empty sieve can reduce the amount of Siebrückstandes be determined. In this screening machine, however, only the Weight of the sieve can be determined on further characteristics of the Sieve insert can not be closed reliably from the weight.

To provide meaningful, correct results for the determination of To be able to obtain the size distribution curve, it is very important that all Parameters, according to the test specification, are reliably adhered to. The manual operation of the air jet screening machine and in particular the manual Replacement of the sieve inserts, however, carries the risk of accidental Sieve confusion with respect to e.g. the required mesh size. Therefore, one is reliable test equipment monitoring necessary. This happens so far exclusively by the operator of the air jet screening machine.

In order for analysis screening machines generally the analysis security against Increase incorrect operation, the invention proposes a automated detection of various parameters of the sieve insert enable. In particular, the mesh size of each used Sieve insert are automatically detected by the screening machine.

This object is achieved according to the invention by the air jet sieve according to claim 1 and by the sieve insert according to claim 4 and claim 9 solved.

Advantageous developments of the invention are the subject the relevant dependent claims.

An automated comparison of the sieve insert actually used with the Value of the mesh size of the actually required sieve insert in one associated control device, provides the use of the correct sieve insert for sure. If the operator mistakenly chose a wrong sieve insert, so He is by appropriate signals on the screening machines on the error and is prompted the correct sieve insert in the screening machine use. The information obtained from the identified sieve insert may also be e.g. recorded for logging in a memory device and another evaluation, e.g. in an electronic calculator, be supplied.

To the main criterion, the mesh size of each sieve insert automatically each sieve carries a machine-readable signature, from which at least the nominal mesh size is removable. It can further specific data or information of the sieve in the be stored machine-readable signature. In the screening machine is a sensor attached, which can read the signature. The read by the sensor Data and information can be further processed in an evaluation unit, and based on this information the desired actions are initiated. So can occur when detecting a wrong screen by the sensor and the Evaluation unit generates a warning that is due to the Siebverwechslung points.

In addition to the nominal mesh size, other specific data of the Sieves are stored on the signature of the sieve frame, e.g. the manufacturer, the production date, the mesh shape and / or the DIN number of the sieve, and for control purposes e.g. the cleaning intervals.

In an advantageous embodiment of the invention, the machine-readable Signature of the screen frame not only readable by the sensor, but also writable and / or overwritable. So additional information on the Signature of the screen frame stored and retrieved later. This can e.g. the number of sieve use, the implementation of cleaning and / or Control operations or the date of the last sieve use. All this information is stored in the respective sieve insert.

In a variation of a screen according to the invention with machine-readable Signature, the sieve is identified only by a serial number. The Evaluation of the sieve insert is then based on the serial number regarding all relevant data, e.g. the mesh size in a separate unit, such as e.g. in a microcontroller control and / or database. Each serial number specific data sets (mesh size, number of uses, Date of use, manufacturer's information, mesh shape, etc.) assigned, the physically stored and stored separately from the sieve insert.

The practical implementation of the machine-readable signature is the current one According to the art in many ways possible. Functional is here between overwritable, non-rewritable and partial to distinguish overwritable signatures. Depending on the application and individual needs, the best solution can be selected.

The economically feasible with the currently reasonable effort Machine readable and / or writable signatures are as follows Described.

barcode:

On the outside of the screen frame are horizontal stripes on a part or on the entire circumference of the screen frame are arranged and stand out clearly and in contrast from the screen frame. The barcodes can also be printed on a sticker on the outside of the screen frame is glued on. If the sieve insert is inserted into the screening machine, it will feel Sensor (laser) located on the inner circumference of the bowl-shaped housing Screening machine is mounted, the barcode contactless.

Pin code:

Located on the outside of the screen frame or at the bottom of the collar several pins. One of the pens is different from the other pens by its diameter or length, thus giving the correct position for decoding. Each pin protrudes when inserting the sieve insert into the Screening machine in a hole in the housing of the screening machine. In every hole the presence of a pin is checked by a sensor. By the Presence or omission of individual pins can generate a code, which can be read by the sensors in the housing.

Transponder Chip:

A small chip in a glass case will be at one point of the screen frame attached. The chip can by irradiation and by means of a writing and Reader by radio transmission without auxiliary energy targeted information save and spend.

Magnetic stripe:

On the outside of the screen frame is a magnetic strip over the circumference attached, which is located on a located in the housing of the screening machine reading and Writing instruments can be read or written. In a special inexpensive embodiment, the magnetic strip is mounted on a card. The card is attached by a chain or string to the sieve insert. The magnetic stripe card carries the individual information of the Sieve insert to which it is attached. During the screening, the magnetic card is in to introduce a reader on the screening machine, only then can the screening process to be started.

Chip cards:

Similar to the application of cards with magnetic stripes can also use cards with an integrated chip can be used in the same way. The reading and Describing the map is done not on magnetic but on electronic way.

Fig.1 zeigt eine erfindungsgemäße Siebmaschine in einer Gesamtansicht.

Fig.2 zeigt einen vergrößerten Teilschnitt der erfindungsgemäßen Siebmaschine.

Fig.3 zeigt eine erfindungsgemäße Siebmaschine mit integrierter Waage.

Fig.4 zeigt eine Ausgestaltung mit Magnetkarte und Kartenleser.

The invention is described below with reference to the drawings.

1 shows a screening machine according to the invention in an overall view.

2 shows an enlarged partial section of the screening machine according to the invention.

3 shows a screening machine according to the invention with integrated balance.

4 shows an embodiment with magnetic card and card reader.

The air jet sieve according to FIG. 1 has a sieve insert 4 inserted into the housing. The sieve insert 4 is provided with a coding 1 on its outer circumference. The coding 1 can be, for example, a barcode or a pen code. As an alternative, the coding 1 can be stored on a writable memory 5 . The writable memory replaces the coding 1 and is attached to the same place of the sieve insert 4 .

The mounted in the housing sensor 2 is connected to the coding 1 or the writable memory 5 in operative connection when the sieve insert 4 is inserted into the housing of the air jet sieve. The registration and further processing of the signal read by the coding 1 or the writable memory 5 takes place in a control device 3 , which generates the desired and predefined actions on the basis of the respective signal.

The partial section shown in Fig. 2 shows the coding 1 and the writable memory 5 together with the sensor 2 and the control device 3 in an enlarged view.

In Fig. 3 , the sensor 2 is replaced by a balance 7 , which identifies the sieve 4 used in its weight. The control device 3 can identify the specific features of the strainer 4 used on the basis of Siebgewichtes.

4 shows a schematic representation of the screening machine, wherein the sieve insert 4 is marked with a magnetic card or chip card 6 and the sieve insert 4 identified by the insertion of the magnetic or chip card 6 in a slot in the housing of the screening machine by a card reader 2 and by the control device 3 can be further processed.

Claims (9)

1. Air jet sieve with a housing, with placed thereon a sieve insert (4) which is selected from a number of test sieves having different mesh widths and can be inserted in the housing, with a slotted nozzle underneath the bottom of the sieve insert (4), with a drive for the slotted nozzle, with an air supply to the slotted nozzle and an air outlet through the housing from the chamber underneath the bottom of the sieve insert (4), and with a control device for operation, characterised in that a sensor (2) is provided through which the inserted sieve insert (4) can be identified automatically by a coding (1) arranged thereon, and information about the mesh width and/or the number of times the sieve has been used and/or the date of use of the sieve and/or the manufacturer and/or the date of production and/or the mesh form and/or the DIN number of the sieve insert (4) is storable in the coding (1).
2. Air jet sieve according to claim 1, characterised in that the sensor (2) is a balance (7) through which the sieve insert (4) is identifiable by its weight.
3. Air jet sieve according to one of the preceding claims, characterised by a control device (3) for further processing of the information from the coding (1) and/or the weight and for generating actions predefined thereby.
4. Sieve insert for an air jet sieve according to one of the preceding claims, characterised in that the coding (1) provided on the sieve insert (4) is a bar code or a pin code.
5. Sieve insert for an air jet sieve according to claim 4, characterised in that the coding (1) is storable in a writable memory (5).
6. Sieve insert according to claim 5, characterised in that the writable memory (5) is a magnetic strip or microchip provided on the sieve insert (4).
7. Sieve insert according to claim 6, characterised in that the coding (1) is storable on a code card (6) connected to the sieve insert (4).
8. Sieve insert according to claim 7, characterised in that the code card (6) is a magnetic card or a chip card.
9. Sieve insert for an air jet sieve according to one of claims 1 to 3, characterised in that information about the mesh width and/or the number of times of use and/or the date of use and/or the manufacturer and/or the date of production and/or the mesh form and/or the DIN number of the sieve insert (4) is storable in the coding (1) and/or the DIN number of the sieve insert (4) and/or the execution of cleaning/checking operations and/or the serial number and/or other manufacturer data is storable.

Images