Motion System Design
Sorting system minds peas and queues

Sorting system minds peas and queues

From peas to plastics, modern high-speed sorting systems classify items of all kinds by color, shape, or size. Faster than the human eye can perceive, MHJ rapid response valves from Festo Corp., Hauppauge, N.Y., – also known as Jet Valves – blow bulk goods into various containers with precision. For example, in one application, the system sorts red and green plastic balls measuring 6 mm in diameter. In real time, rapid MHJ response valves separate the mixed balls into different containers after they have been rolled down a chute.

The SOEC color sensor analyses the colors of the 12-gm balls at the end of the chute. It includes a high switching frequency of 500 Hz and three independently teachable channels. A white LED light source keeps the SOEC independent of external light sources and enables it to guarantee the recognition of objects in the entire working area, so that the sensor maintains its overview even at high speeds.

The sensor then sends a signal to the CPX-FEC control unit, which sets the rapid response valves in motion. PLC standard 24 Vdc/1A outputs enable simple and direct control of versions with integrated electronics. Alternatively, an external two-channel cable current regulator is available, which is particularly well suited for processing industry applications. With a protection class of IP65, the MHJ10 rapid response valves are not sensitive to dust and humidity and can be mounted directly without protection.

At extreme speeds, it's almost impossible to detect the cause of motion sequence faults. Although high-speed cameras can provide answers during commissioning, service, and operation, they're generally expensive. An economical alternative is the SBOC-M/SBOI-M intelligent vision system. This system supports diagnostics and commissioning, as well as function monitoring with a scanning rate of up to 2,000 images per second. The electronic system for recording and storing motion sequences is already integrated in the camera; it needs to be set up via a PC and then operates automatically. When played back in slow motion, the high-speed compact vision system shows the sorting process on a monitor, enabling the process to be diagnosed and corrected. This ensures process security and, ultimately, all parts are sorted with perfect results.

Another application is in the food industry, sorting peas. Whether fresh, dried, or frozen, thousands of peas are spread over a free-fall chute via a feed shaker. Lasers scan the peas for similar color, shape, and structure as they fall towards the inspection zone at a speed of 3 m per second. Peas that are lighter, darker, or bruised are hit via air guns a few msec later and ejected from the falling mass. MHJ jet valves are packed tightly together on the free-fall chute, ensuring that imperfect produce is removed in a fraction of a second.

Visit Festo Corp. for more information.

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