DE102008001104A1 - Closed fully perforated coating drum - Google Patents

Abstract

The invention relates to a drum, a device and a method for coating tablets. The drum (1) for coating tablets has a circumference formed by an outer wall (3) and an inner, wholly or partially perforated wall (2). There are provided means (6, 7) for the suction of air emerging from the perforation (4). An apparatus for coating comprises such a drum.

Description

The The invention relates to a device and a method for the coating of tablets.

The publication WO 2005/123267 A1 discloses a device for coating tablets comprising a horizontally mounted rotatable drum. The drum has perforated segments. The drum comprises a discharge opening and a closable opening provided on an end face of the drum. Through the closable opening tablets are placed in the drum. The tablets are coated in the drum. The discharge opening is part of the circumference of the drum. If the discharge opening is at the bottom, the drum can be easily emptied through this opening due to gravity.

in the Inside the drum, a mixer can be provided. This is such that, with opposite rotation compared to Direction of rotation during mixing or coating the in the drum tablets located to the front of the door includes, for example, so tablets to be able to remove through the lateral opening.

Seen from the front side with the lateral opening is at one of the publication WO 2005/123267 A1 known device introduced via a first feed the applied to the tablets coating agent in the drum. In particular, aqueous or organic solvents provided with suspensions or paints are placed over the first supply line into the interior of the mixing vessel. Inside, the coating agent exits via at least one downwardly directed nozzle. The nozzle is designed so that the suspension is sprayed inside the drum. The suspension gets so misty on the tablets. The mixing vessel is slowly rotated about the horizontal axis.

typically, The drum rotates at up to 25 revolutions per minute.

Contemporaneous or cyclically conditioned (i.e., tempered, dried and filtered) air into the interior of the mixing drum initiated a second feeder. The air is warmed up a perforated plate down evenly. Of the Airflow causes the coating agent deposited on a tablet is dried. For this purpose, the perforated plate in the state of Technique above the nozzle and rectified with the nozzle. By this arrangement it is achieved that the air flow evenly down in the direction of the mix, ie flows in the direction of the tablets. In this case, aerosolized suspension also flows in the direction of the tablets. A suspension then also passes due to the air flow especially reliable on the tablets.

Of the Air flow passes through the perforation of the drum segments a suction device off again. The perforation is in one Embodiment distributed over the circumference of the drum. For example, four of the same size, over the circumference distributed segments can provide the perforation be.

In one from the publication WO 2005/123267 A1 known advantageous embodiment, the supply of coating material for the tablets takes place via an end face of the drum and the supply of air via the opposite end face.

So far not expressly stated otherwise may be the features known from the prior art individually or in combination features as described below Be invention.

While of the coating inevitably occurs in the drum dust, the passes unhindered through the perforation and the surrounding Housing dirty. The dust load leads to a correspondingly large cleaning effort of the coating device.

It Object of the present invention, the dust pollution at Avoid devices for coating tablets.

to Solution of the task is a drum for coating provided by tablets whose circumference with an inner and outer Wall is provided. The inner wall has perforations. The Drum includes means for the extraction of air from the perforation emerges. Dust is sucked out together with the air. The dust can now be separated from the extracted air and disposed of become. A dust load and an associated very expensive Cleaning the housing of the device for the Coating of tablets and parts in it, can to be avoided.

The Means for sucking out of the perforation Air preferably comprises at least one suction opening, which is arranged adjacent to the periphery on an end face of the drum. The opening can be with a fan or similar Means be connected to air from the area between the inner and to suck the outer wall.

The invention is based on Figures explained in more detail.

1 shows a drum 1 for coating tablets. The circumference of the drum is through an inner wall 2 and an outer wall 3 educated. In 1 For example, two segments of the outer wall are not shown to look at the underlying segments of the inner wall. The inner wall 2 is with a perforation 4 Mistake. Between the inner wall and the outer wall there are partitions at regular intervals 5 separating the space between inner and outer wall into individual chambers 10 (please refer 2 ). Air can not get from one chamber directly to an adjacent chamber due to the partitions. Enter air through the perforation 4 through in one of the chambers, the chamber is preferably shielded by walls so that the air only through a lateral suction opening 6 can be passed on. This construction makes it possible to extract air from the individual chambers in a controlled manner via the openings. It can thus be avoided that air flows uncontrolled and undesirable out of the drum to the outside. For example, if air in the drum down in the direction of tablets, so the air is preferably led out only above underlying perforated segments out of the drum so as to be suitable and effectively coat. Air is extracted from a chamber during rotation of the drum only when it is at the bottom. It is thus ensured that air flows in the intended manner.

At the in 1 In the embodiment shown, the drum comprises a suction opening per chamber 6 as well as a channel 7 , through which the air is sucked out of the respective chamber.

Inside the drum can be a discharge spiral 8th to be available. After coating, the direction of rotation of the drum is changed so that the coated tablets are transported by the helix to the opening present in an end wall. Through the opening through the tablets can now be easily removed. This embodiment avoids a greater technical effort that would otherwise have been required for a removal opening through the inner and outer walls.

2 shows a device for coating tablets with an in 1 shown drum 1 , Air and coating agents are directed in the drum down on the tablets to be coated, and in particular in that of the document WO 2005/123267 A1 known way. Is there a channel? 7 the drum below, so its outer opening is adjacent to an adjacent to the drum suction 9 on, over the air from the corresponding chamber 10 is sucked off. Such a suction opening adjacent to the drum 9 then there is only at the bottom, so as to achieve that air only from a chamber 10 is exhausted when the chamber is below. It manages to suck air together with dust controlled from the drum so that can be effectively coated.

Preferably For example, a suspension used for coating is transferred laterally fed a first side of the drum and the air side on the opposite side. This will achieve that the page from which the operation is carried out by the user, more Space exists compared to the case that through an end wall through suspension and air is supplied.

The Feed and the nozzle, over the suspension must be cleaned from time to time. It is therefore an advantage, this feed from the front, So provide from the operator side. This is the cleaning effort lower. The air supply falls namely a corresponding cleaning effort not or in a clear lower scope. Therefore, the air supply is preferred from the relatively hard to reach back.

In an advantageous embodiment of the device is the suspension below or at the height of the axis of rotation of Drum supplied. The air is wholly or predominantly fed above the axis of rotation of the drum. It can be like that The air coming from above is directed towards bulk material and thereby the atomized suspension in the direction of the mix or transport tablets.

Since the mix, so the tablets roll inside the drum, they are not during the coating on average at the lowest point, but depending on the rotational speed of the drum slightly laterally offset from this lowest point. This is advantageously taken into account in the arrangement of the air supply and the supply of suspension by means for supplying air and suspension are aligned so that the suspension and the air are directed in the direction of this laterally offset point. If a perforated plate for the supply of air and a nozzle for the supply of a coating agent used, the perforated plate and the nozzle are preferably not exactly vertical, but aligned obliquely. The perforated plate is then aligned approximately parallel to the surface which the tablets form during coating. Air and suspension then exit in the same direction from the respective supply means. The exit direction of air and suspension then close with the vertical angle one that is greater than 0 ° and less than 90 °. Regularly, this angle is between 10 ° and 60 °, in particular at 25 ° to 50 ° at conventional speeds of up to 25 revolutions per minute. Accordingly offset from the lowest point of the drum are therefore preferably one or more suction openings 9 provided from the outside to a channel 7 border the drum. In addition, there are preferably no further suction openings 9 ,

air can have an example annular recess fed to the front of the drum. Prefers However, the drum includes a circular at the back Plate rotatably connected to the remainder of the drum. The rotatable connection is preferably designed sealing. While Mixing turns the drum, not the circular one Plate. Through this circular plate, the air is over passed a corresponding line. The technical Range of the device, such as electronic controls, Engines, etc., will then be behind the back of the drum This technical area is thus from the production area separated what for the trouble-free operation is beneficial.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2005/123267 A1 [0002, 0004, 0008, 0018]

Claims (11)

Drum ( 1 ) for coating tablets having a circumference through an outer wall ( 3 ) and an inner, completely or partially perforated wall ( 2 ) and means ( 6 . 7 ) for sucking out of the perforation ( 4 ) escaping air. Drum according to claim 1, wherein the means for sucking off the perforation ( 4 ) exiting air a suction opening ( 6 ) adjacent to the periphery on an end face of the drum ( 1 ) is arranged. Drum according to claim 1 or 2, in which the area between outer and inner wall is in chambers ( 10 ) and each chamber ( 10 ) a suction opening ( 6 ). Drum according to one of the preceding claims, having one or more suction openings ( 6 ), each suction opening ( 6 ) with a channel ( 7 ) is connected for the extraction of air. Drum according to one of the preceding claims with an opening in an end wall for filling the drum with tablets. Drum according to one of the preceding claims, with a discharge spiral mounted inside the inner wall ( 8th ) for the removal of tablets through an opening located in an end wall. Drum according to one of the preceding claims, comprising a rotatable, circular plate in an end wall of the drum ( 1 ). Device for coating a tablet with a drum according to one of the preceding claims and with means for feeding suspension and air into the drum ( 1 ) into it. Device according to the preceding claim with a suction opening ( 9 ) for the extraction of air from the drum, which from the outside to a channel ( 7 ) or a suction opening ( 6 ) borders the drum. Device according to the preceding claim, which does not have suction openings above the axis of rotation of the drum, which outside a channel ( 7 ) or a suction opening ( 6 ) border the drum. Process for coating tablets by placing in a drum ( 1 ) is applied to tablets therein a liquid together with air and the air below the axis of rotation of the drum via one or more channels ( 7 ) is sucked out of the drum.