Fairmount Minerals is one of the largest producers of industrial sand in the United States. Its Illinois based subsidiary, Wedron Silica, has been in operation for over 100 years, producing high-purity, round-grain silica sand. This sand is mined from the St. Peters Sandstone which is a 200 million-year-old sand deposit that runs from Minnesota to Oklahoma.

A total of 60 people manage the production of approximately 10,000 tons of sand each day. The biggest application segment is the fracturing sand market. Hydraulic fracturing sands, known as ‘frac sands’, consist almost entirely of quartz or silica sands and are used as proppants in oil and gas wells. Frac sand treatment is the forcing of a concoction of frac sands, viscous gel, and other chemicals down a well to prop open fractures in the subsurface rocks thus creating a passageway for fluid from the reservoir to the well. 

The Wedron Silica plant operates 24 hours a day, 7 days a week. All production is managed through an Ethernet network. This involves hydraulic high pressure mining canons, cameras linked to the control centre with fibre-optics that help to control and adjust truck loading, and the sand drying rooms. Data monitoring and control systems need to be of the highest reliability levels, specifically in such a harsh environment as mining.

”Our data network has been working on Ethernet protocol for ten years, but this is the first time that we have installed a full redundancy ring” says Frank Barnes, Technical Manager at Wedron Silicate. “There were several reasons for choosing Westermo’s Lynx range switches, like the strong harsh environment compliance, the redundancy ring off-the-shelf capability, and the world fastest recovery time of 20 ms. But, we particularly appreciate the easy configuration and monitoring of the switches as well as the no-charge software update. We also had a very close technical collaboration with Gross Automation, Westermo’s distributor for North America”, adds Barnes.

The ring portion of the network consists of eleven of the Lynx 1400-series switches with a further six Lynx 400-series switches on branch runs. The ring switches are located in the plant process buildings and are named for their location. All are mounted in dust tight boxes and powered buy two 24vdc power supplies that are connected to a battery backup. The ring network is kept powered for over two hours in the event of a power outage. All of the control and monitoring information is on Westermo’s network.

Westermo’s Lynx 1400 and Lynx 400 support IMGP protocol (Internet Group Management Protocol), which provides filtering techniques to control the flow of data around the ring in such a way as to optimise the bandwidth, and furthermore, to secure the network operation. IGMP is used by IP hosts to dynamically register membership in Multicast groups to the closest multicast router. Multicast routers periodically send out a “Host Membership Query message” to remain updated on group membership for the local network. In order to efficiently use the bandwidth and cut down on traffic, multicasting is the ideal solution. When data needs to be sent to a large amount of users on the network, the data will be sent simultaneously to the specified users via multicasting, and not just blanketed to all users.

IGMP snooping requires the switch to examine, or snoop, some Layer 3 information in the IGMP packets sent between the hosts and the router. When the switch hears the IGMP host report from a host for a particular multicast group, the switch adds the host’s port number to the associated multicast table entry. When the switch hears the IGMP leave group message from a host, it removes the host's port from the table entry. The Lynx-series has the IGMP Server (router) implemented, which means that no external IGMP server on the network is necessary. It is also integrated with the FRNT feature, which means that the multicast filters will be updated within 20 ms in case of any network failure.

The Lynx switches fully support QoS (Quality of Service) with four priority queues and strict priority scheduling as well as HoL (Head of Line Blocking Prevention). This is also a key issue for process applications such as Wedron’s, because it achieves determinism for real time critical applications.

The Lynx 400 and Lynx 1400 switches have a military design with a full metal housing (IP 40). They operate under a wide temperature range from –40 to +158°F and have a wide DC power range from 19 to 60 VDC. They have no moving parts or electrolytic capacitors, low power consumption with redundancy, are DIN rail mounted and support long cable.