The invention relates to a filter device for a plastic melt or another highly viscous fluid, comprising a housing with an inlet plate and a discharge plate. At least one spacing element and a screen wheel which can be rotated by a drive device are arranged between the inlet plate and the discharge plate. The inlet plate and the discharge plate are clamped against each other with the inclusion of the spacing element via at least three housing clamping elements. An engagement point of the drive device on the screen wheel is arranged outside of the pretensioning surface. When viewed in the rotational direction, an angle α larger than 110° and smaller than 160° is formed on the screen wheel between a first line that extends between the pretensioning surface centroid on which a resulting frictional force F.sub.R acts and the center of the screen wheel and a second line between the center and the engagement point on which an advancing force Fv acts.

On a rotary screen filtering device for medium to high-viscosity fluids, which comprises a rotary screen mounted for rotation in a housing, which screen has at least one screen element through which fluid can flow, the rotary screen, in the region of its sealing faces and the intermediate plates are fabricated or machined together so that they are of identical height. A gap width compensation layer is then inserted between the inlet plate and the intermediate plate and/or between the outlet plate and the intermediate plate. The package of plates is then pretensioned by means of screw bolts in such a manner that all the plates lie firmly against one another up to a maximum permissible operating pressure. Lubrication gaps of defined width are created between the sealing faces and the opposing inner faces of the inlet and outlet plates.

A method and an apparatus manufactures and tests workpieces. The apparatus is mountable on or includes a system for mixing or melting materials. The apparatus includes application units and a replacement system that is designed to automatically replace application units in respect of the position or function thereof.

In one example, an apparatus for filtering a fluid (e.g., a plastic melt having impurities) includes a housing which has at least one inlet for introduction of the fluid and an outlet for delivery of the fluid and a cavity formed in the housing by wall portions of the housing for receiving a sieve support, and a sieve support which is arranged moveably in the cavity of the housing and has a longitudinal axis for receiving at least one filter element for filtering the fluid. The sieve support externally has a plurality of integrally formed raised portions and/or raised portions and/or recesses are formed at wall portions of the housing, that delimit the cavity, such that provided between the wall portion and the sieve support are a plurality of gaps/cavities, by means of which a slight fluid flow is enabled in operation. Another example concerns a valve arrangement.

The invention relates to a melt filter (1) for filtering plastic melts, comprising a screen rotor (3) which is arranged such that it can be rotationally driven between two housing plates (2) and which has recesses (5) along a circular path (4) for receiving exchangeable filter elements (6), and comprising a melt channel (7) which penetrates the housing plates (2) in the region of the circular path (4) and is associated with the screen rotor (3). In order to create advantageous conditions, it is proposed that the screen rotor (3) comprises two axially spaced rotor cheeks (9) which are provided opposite one another with filter elements (6) through which the plastic melt can flow and towards which the melt channels (7) of the two housing plates (2) open out, wherein at least one collecting chamber (10) for plastic melt filtered by the filter elements (6) is provided in the screen rotor (3) between opposing filter elements (6), and wherein a flow channel (11) opening out of the screen rotor (2) in the region of the rotor axis (8) is provided for discharging filtered plastic melt from the collecting chamber (10).

The invention relates to a filter device for a plastic melt or another highly viscous fluid, comprising a housing with an inlet plate and a discharge plate. At least one spacing element and a screen wheel which can be rotated by a drive device are arranged between the inlet plate and the discharge plate. The inlet plate and the discharge plate are clamped against each other with the inclusion of the spacing element via at least three housing clamping elements. An engagement point of the drive device on the screen wheel is arranged outside of the pretensioning surface. When viewed in the rotational direction, an angle α larger than 110° and smaller than 160° is formed on the screen wheel between a first line that extends between the pretensioning surface centroid on which a resulting frictional force F.sub.R acts and the center of the screen wheel and a second line between the center and the engagement point on which an advancing force F.sub.V acts.

A filtering device for highly viscous media, in which filtering device a rotatably mounted screening wheel which has a plurality of screening cavities is arranged between a front housing element and a rear housing element. According to the invention, a plurality of screening cavities lying beside one another, through which flow can pass jointly, are combined into at least one filter group. To this end, on both sides beside the filter group, a closed blocking segment is provided on the screening wheel which segment, when positioned in associated blocking regions of the housing, is sealed off with respect to the housing elements on both sides of the screening wheel. The blocking regions in the housing are in each case larger than or as large as a screening cavity together with a sealing web surrounding the same.

A continuous screen changer, including: an external shell having an internal cavity, and an internal drum. The external shell is provided with a feed port, a screen changing port, and a discharge port. The internal drum is provided with at least four filter screen mounting grooves and material flow passages correspondingly communicating with the filter screen mounting grooves. A sealing wall hermetically connected with the internal cavity is formed between each two adjacent filter screen mounting grooves. Whichever of the filter screen mounting grooves is opposite to the feed port rotates to be opposite to the screen changing port in a rotation process, and whichever of the filter screens is on said filter screen mounting groove opposite to the screen changing port is changed at the screen changing port

A method and an apparatus manufactures and tests workpieces. The apparatus is mountable on or includes a system for mixing or melting materials. The apparatus includes application units and a replacement system that is designed to automatically replace application units in respect of the position or function thereof.

Disclosed are a continuous screen changer, a screen changing device, and an extruder. The continuous screen changer includes an external shell with an internal cavity and an internal drum; the external shell is provided with a feed port, a screen changing port and a discharge port. The internal drum is provided with at least four filter screen mounting grooves and material flow passages correspondingly communicating with the filter screen mounting grooves, and a sealing wall hermetically connected with the internal cavity is formed between each two adjacent filter screen mounting grooves. After entering the internal cavity along the feed port and being filtered by a filter screen, materials flow out of the discharge port along the material flow passages. The filter screen mounting groove rotates to be opposite to the screen changing port, and the filter screen on the filter screen mounting groove is changed at the screen changing port. The continuous screen changer can implement continuous and uninterrupted change of the filter screens, so that the apparatus to which the continuous screen changer is applied can continuously work.