Patent Application
20090260252
The present invention relates to equipment for processing plastic materials. More particularly, the present invention relates to an infrared dehumidifier for plastic or other materials.
Various and different processes are used at present for manufacturing finished and semi-finished products from plastic materials, the most common of which are injection molding, blow molding and extrusion.
The raw plastic material is typically provided in granular form and, in order to ensure a high quality of the finished and semi-finished products, humidity must be avoided from the raw plastic material. Accordingly, the plastic material is conveyed through a dehumidifier before feeding into a plasticizing screw.
Infrared dehumidifiers are known and basically consist in devices for eliminating or reducing the humidity in the plastic material through the action of infrared heating lamps. Such infrared dehumidifiers typically include a material feed duct, a material outflow duct, and a container communicating with the feed and outflow ducts, the inside of which is provided with a screw, preferably with increasing pitch, and with one or more infrared heating lamps positioned inside the container and integral with it.
This screw rotates around its longitudinal axis and causes the material to move forward. At the same time, the infrared heating lamps cause the plastic material to become heated, dehumidified and prepared for the following processing step.
In order to improve the reliability of the dehumidifying process, a new type of infrared dehumidifier has been developed and constructed.
An infrared dehumidifier according to the present invention includes, as main parts, a drum positioned on a support frame and one or more infrared heating lamps, arranged inside the drum and configured for dehumidifying and preheating the material.
The drum is hollow, rotates around a substantially horizontal main axis, and is provided with a series of projections on its inner surface.
The material moves through the drum, remaining therein for a time sufficient to allow the material to become dehumidified by the action of the infrared heating lamps.
In one embodiment of the invention, the drum is substantially cylindrical in shape and rotates around a longitudinal axis due to the presence of one or more guides, positioned outside of the drum, and of motion transmission devices.
In another embodiment of the invention, the cross section of the drum has the shape of an arc of a circle and is positioned inside the support frame, such that the open portion of the drum faces upwards. Differently from the previous embodiment, the drum does not perform a 360° rotation, but oscillates, that is, rotates partially in an alternate pattern around its main axis.
In a preferred embodiment of the invention, the projections on the inner surface of the drum are substantially linear and arranged longitudinally on the inner surface of the drum, or, in an alternative embodiment, are arranged in a helical pattern, in order to favor the advancement of the material toward the outlet.
The support frame includes a material feed duct and a duct receiving the outflow of the material toward processing machines or a storage system, and further includes one or more movable elements or hinges for closing or opening the drum.
Such closing or opening elements, if required, can be equipped with one or more translating guides for ensuring an easy access to the drum and for facilitating maintenance.
The movable elements or hinges for closing or opening the drum are configured to allow maintenance and replacement of the infrared heating lamps.
In a method of use of an infrared dehumidifier constructed according to the principles of the present invention, the granulated material travels through the feed duct and is introduced in the drum, where the infrared heating lamps entirely or substantially remove the moisture from the material. The rotating or oscillating movement of the drum causes the exposure of a larger surface of the material to the dehumidifying action of the heating lamps. The treated granules advance toward the outflow duct and are conveyed toward the machines processing the granulated material.
An infrared humidifier according to the present invention may also include an inclination device applied to the support frame, that is, a device suited for raising one side of the support frame or of the drum, thereby inclining the drum and thus favoring the advancement of the material toward the outflow duct.
The inclination of the support frame by means of the inclination device may be adjusted and interrupted when required, thus ensuring a better regulation of the advancement of the material through the drum.
The main advantage of an infrared dehumidifier constructed according to the principles of the present invention resides in facilitating access to the drum by means of the movable elements that open or close the drum.
The drum is preferably cylindrical in shape but also may have a variety of other cross sections, for example may be oval or elliptic, in both cases being rotatable on a guide.
These and other advantages have been achieved through the construction of an infrared dehumidifier constructed according to the principles of the present invention, for example, through an infrared dehumidifier having a rotary hollow drum with one or more infrared heating lamps provided therein.
Features of exemplary infrared dehumidifiers according to the present invention will be described in detail in the following detailed description, with reference to the enclosed drawings depicting non-limiting examples.
a depicts a side perspective view of an exemplary infrared dehumidifier according to the present invention and
a depicts a cross section of an exemplary infrared dehumidifier according to the present invention and
Detailed descriptions of embodiments of the invention are provided herein. It should be understood, however, that the present invention may be embodied in various forms. Therefore, the specific details disclosed herein are not to be interpreted as limiting, but rather as a representative basis for teaching one skilled in the art how to employ the present invention in virtually any detailed system, structure, or manner.
With reference to the embodiment depicted in
In an exemplary embodiment of the invention illustrated in
In this embodiment, projections (B1) are formed as substantially linear elements having an outer surface (B11) that is convex and having an inner surface that is contiguous and integral with the inner surface of drum (B).
Projections (B1) are made integral with drum (B) by means of one or more fastening elements such as screws or bolts.
A support frame (A), configured in this embodiment as substantially parallelepiped in shape, includes a material feed duct, a duct for the outflow of the material toward one or more resin processing machines and two or more movable elements (A1, A3) for closing or opening the drum (B), which are provided with translating guides (A2) to facilitate maintenance operations.
Each of movable elements (A1, A3) for closing or opening the drum (B) is arranged at the level of each of the open bases of rotary drum (B).
In particular, one of movable elements (A1) communicates with the material feed duct, while another one (A3) communicates with the outflow duct. In the preferred embodiment of the invention, infrared heating lamps (C) are coupled to movable elements (A1, A3) through fastening elements such as screws or bolts.
Thus, the granulated material travels through the feed duct and is introduced in rotary drum (B), where infrared heating lamps (C) provide energy for dehumidifying the granulated material. The rotary motion of drum (B) causes a larger surface of the material to the exposed to the dehumidifying action of heating lamps (C). The granules treated according to this process are successively conveyed to the machines processing the resin.
With reference to
In one embodiment of the invention, inclination device (D) includes or is a hydraulic piston.
b illustrates another embodiment of drum (B) of an infrared dehumidifier according to the present invention. In this embodiment, drum (B) has a cross section in the shape of an arc of a circle and is positioned within support frame (A), such that the open portion of drum (B) faces upwards. Differently from the previous embodiment, drum (B) as shown in
While the invention has been described in connection with a number of embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the scope of the invention.
With reference to the above description and the attached drawings, the following claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| VE2007A000080 | Oct 2007 | IT | national |
