With 25 years of experience in the field of design and construction of components and aseptic systems for the chemical/pharmaceutical industry, CO.RA.® manufactures interception, dosage and flow control valves.

The drum dosing system conceived by CO.RA.®. enables the discharge of product inside a polyethylene liner (of various lengths and attached to the structure itself) and the closed cycle preparation of bags by using the liner, while controlling the weight with maximum accuracy, thanks to the scale located under the container (bag, drum).

The standard system is composed of an adaptor interfaced with the machine to be served, a DOUBLE VALVE®, a liner fixing system, an exhaust filter, a dosing terminal complete with display, incorporated keyboard and a loading cell base.

The terminal is provided with a back lit, high contrast liquid crystal digital display of  weight and analog weight range with application icon signaling activities and communication interfaces for DCS Profibus type, Ethernet and RS232 connections. Said terminal can be connected to a multi-strip printer or label maker and a version for hazardous ambients – zone 1/21 (ATEX 94/09/CE) is also available. The maximum dosing accuracy obtainable is +/- 50 gr. 

The DOUBLE VALVE®, is designed to satisfy control, dosing, regulation and mixing requirements during the filling  process of products. It is a dosing valve, completely made of stainless steel AISI 316L, with a silicone gasket that complies with FDA 177.2600 norms and composed of a butterfly with a central rotor. The valve is driven by double acting pneumatic actuators, 90° for the butterfly and 180° for the rotor. The actuators are driven by a control panel interfaced with the weighing system. The DOUBLE VALVE®, is available in the following sizes : 150mm, 200mm and 250mm with 80mm or 100mm rotor and satin finished body and mirror polished butterfly and rotor.

The operating cycle

A Double Valve is installed on the outlet of the machine to be discharged and it is fixed in place by clamps which simplify the assembly and/or disassembly. The operating cycle of the system is divided into two distinct phases: heavy dosing and trickle dosing. During the first phase the butterfly opens to allow the quick discharge of 95% of the product to be dosed until the heavy weight limit is reached. During the second phase the butterfly closes and the rotor (in the center of the butterfly) begins to trickle feed until the total weight of the product is reached.

An empty container is placed on the base of the scale, the liner is pulled until it touches the bottom of the container and the end is closed  by means of a clip in order to form the “bag bottom”. At this point it is necessary to push the start button on the dosing terminal, and once the product has been discharged, place a clip to close the bag and another clip 10 cm above that one in order to create the necessary space to cut the bag. Finally, it is necessary to remove the container from the base and repeat the cycle described above.