Food and Drink Processing Industry Whitepaper
Maintenance Challenges in the Food and Drink Industry
Factories are rarely able to justify the cost of stopping their production for long periods of time, which means engineers often have to work at weekends or at night to perform maintenance on machinery. Regular maintenance is vital to ensure there are no negative impacts on cleanliness or quality of the products being manufactured. This should be done with minimum impact to production and using the most cost effective methods.
In the past, redundant plant equipment was available should there be a failure. For example, if a pump stopped working, a second backup pump would switch on, meaning no loss of production. Nowadays, it is not cost effective to install redundant plant equipment, making it easier to justify the cost of condition monitoring.
Food and drink manufacturing comprises many different industries. It ranges from fruit and vegetable processing, bakeries, grain milling, and dairy processing through to sugar refineries.
The beverage manufacturing sector includes beer, wine and spirits production, as well as soft drinks and mineral water. Factories are under pressure to increase processing efficiency whilst continuing to meet consumer demand for more diversified products.
Equipment Used in Food and Drink Processing
The food and drink industry uses a broad range of equipment in its manufacturing processes, including mixers, centrifuges, pumps, motors, air compressors, ovens, fans, and conveyors.
Maintenance engineers should be aware of the benefits of monitoring vibration levels on this machinery. Vibration monitoring is a cost effective method of predictive maintenance that is becoming increasingly popular. Damage to machines and unplanned factory shutdowns due to failure can be extremely costly.
Typical Approaches to Vibration Monitoring
There are two possible methods for monitoring the vibration of rotating machinery: online monitoring and offline monitoring.
Online Vibration Monitoring
Online monitoring is where the overall vibration level of a machine is continuously monitored, providing full protection twenty-four hours a day, seven days a week.
A common setup for online monitoring is the installation of 4 to 20 milliamp accelerometers from the HS 420 Series, interfaced directly to PLC systems, SCADA platforms, BMS systems, and similar 4 to 20 milliamp input modules. Alarms can be preset to shut down machinery immediately if safe vibration levels are exceeded.
This approach lends itself well to the food and drink processing industry, where PLC systems are commonly used.
Alternatively, a standalone protection system can be installed using 100 millivolt per g accelerometers from the HS 100 Series in conjunction with vibration modules from the HS 500 Series.
The standard AC 100 millivolt per g accelerometers from the HS 100 Series are commonly used to measure bearing condition and out of balance characteristics. One vibration module is required for each accelerometer output, with each module providing two pre programmable trip alarms and a local display.
Modules can be DIN rail mounted or housed in a bespoke industrial enclosure from the HS 580 Series. The vibration modules also provide the option to retransmit outputs to a PLC or similar system, creating a complete online protection solution.
Offline Vibration Monitoring
Where it is difficult to justify the expenditure of a full online monitoring system, a lower cost offline vibration monitoring system can be used.
In this arrangement, fixed accelerometers from the HS 100 Series are connected to a switch or connection box such as the HS SE or HS CE Series. A handheld data collector is then used to take vibration readings, which are downloaded into a database for further detailed analysis.
Data collection can be carried out by a vibration analysis company or by internal maintenance engineers taking regular readings. Analysis of this data over time enables maintenance engineers to build a valuable picture of machine operating conditions and schedule necessary maintenance procedures.
Although offline monitoring is only as effective as the most recent reading, systems can later be expanded into online monitoring. This can be achieved by replacing the switch box with a monitoring station capable of providing in depth vibration analysis using FFT with remote web access.
Examples of Applications in the Food and Drink Industry
Restricted Access Machinery
Health and safety or insurance regulations can influence the type of vibration monitoring setup used. Maintenance workers are sometimes unable to access certain machinery, even when interlock systems are present, as access interrupts production.
This is a clear example where online vibration monitoring provides constant condition information without impacting production.
Fans in Bakeries and Drying Processes
Within bakeries, large fans are commonly used in drying or cooling processes. A build up of debris on the impeller can cause imbalance. Small lumps of debris may detach during operation, leading to additional imbalance in motor shafts and increased vibration.
If this situation is not monitored, there is a risk that impellers may break off and cause serious damage.
Hazardous and Dusty Environments
During the manufacture of flour and sugar, intrinsically safe accelerometers may be required due to the presence of dust or chemicals in the atmosphere.
Hansford Sensors produces a range of intrinsically safe vibration sensors certified for use in Dust Group II environments.
Washdown and Chemical Exposure
If machinery is washed regularly or exposed to chemicals, it is essential to ensure accelerometers are fitted with suitable cabling.
In these applications, a standard AC sensor from the HS 100 Series with an integrated silicon cable and an IP68 sealing rating is recommended. These sensors are available in top or side entry configurations and are submersible up to one hundred metres.
Temperature considerations may also be required in areas involving ovens or refrigeration.
Low Speed Applications
For low speed machinery such as conveyors in bottling plants or canning factories, AC sensors from the HS 100 Series with higher sensitivity of five hundred millivolts per g are suitable to improve signal quality.
Where improved low frequency response is required, the HS 100F Series provides an additional option.
Enclosures and Environmental Protection
When selecting enclosures such as switch boxes, connection boxes, or junction boxes, the operating environment must be considered.
In dusty or wet areas, stainless steel enclosures are recommended to prevent corrosion or damage. These products are designed specifically for harsh industrial environments and with these applications in mind.
Technical Support and Application Expertise
Hansford Sensors has extensive experience in the design and manufacture of industrial vibration sensors for a wide range of applications. Technical advice is available to support correct sensor selection and monitoring system design.
For further advice, contact the technical team on +44 (0) 845 680 1957 or email sales@hansfordsensors.com
