Unlike ingredient dust collected at a Bag Dump or Mixer, Flour dust can and typically is “reused”, assuming sanitary collection points, components, and operation! Thus the primary equipment is similar to a proper bakery dust collection system. To automate the reuse of the flour some added components are necessary, but well worthwhile in most cases:

• Positioning the cyclone over the primary flour duster and adding a Rotary Airlock to the discharge immediately delivers flour back for reuse when appropriate
• A regenerative blower, airlock, duct, and receiver (such as a cyclone over the zig zag duster) will automatically deliver flour back to one or more use points
• Economical vacuum loaders can transfer reclaimed or new flour up to 50’, eliminating the spillage and safety /sanitation concerns of operators reaching up and over operating equipment to refill the flour use points

CSI purchases and integrates components that minimize the risk of a deflagration and reduce dust accumulations; the client is ultimately responsible for operational safety and code compliance. A variety of combustion detection and extinguishing devices are available to safely collect dust. The following items are commonly used in bakery applications:

Typically a baghouse will have a blow out panel to allow pressure to safely vent should static electricity or another ignition source initiate combustion. If located in a personnel exclusion zone with no combustible materials, that may be the extent of this component. For example, a layout with the the baghouse adjacent to an exterior wall may save additional hardware and significant expense.

In the event the vent is located indoors, a Quench tube vents the gasses through a mesh assembly to cool them, preventing injury or further damage

Equally important is a means to stop expanding gases from flowing through the collection duct and causing a “secondary explosion” at the dust collection points. Bakers have found that an Isolation Flap Valve, which slams shut due to the shock wave, is best. As with most things, not all are created equal! A variety of materials are available, some have less aerodynamic drag, and most importantly if you plan to reuse the dust, sanitation quality varies

Also, isolation valves require a section of reinforced duct (varying from 5’ to 30’ depending on diameter and layout) between it and the baghouse. As with the valve itself, cost goes up dramatically with the diameter, so a well-designed, efficient, properly sized system will be less expensive here as well!

Typically the above components have electrical relays to estop the equipment (and production line) in the event of a failure or deflagration. Other solutions include chemical suppression in the baghouse and/or duct and require periodic inspections at significant expense. Regardless, it is imperative that the baker maintain documentation as to the system requirements, maintenance, and operator training. In addition to the suppression and safety apparatus, CSI will ensure that the ducting design achieves the OSHA/NFPA mandated velocity to prevent the accumulation of dust inside, and balance the air flow for proper dust collection from all locations. Any alteration to the ducting or collection points may affect this and should be evaluated before proceeding!

Attention to detail is invaluable whether considering upgrades or new production lines to gain substantial savings. Key features and available CSI aftermarket components include the following:

• Collection hoods must “fit” the locations, be sanitary, sturdy, and have the proper configuration to capture the dust with the minimum possible CFM!
• Air bars are required to fluidize dust in pan molds and on top of product. For food safety we typically provide a .01 micron coalescing air filter along with solenoid and pressure regulator.
• Replacing “T’s” and lengthy flex hose with rigid duct, sweep elbows and expanding laterals will improve airflow and help achieve the mandated air velocity in each leg. Flexible hoses (other than short lengths necessary at the hood connection) waste energy, cannot be cleaned, and are not code compliant. Lastly, CSI duct will be properly bonded, grounded, and resistance verified at installation.
• Adding a cyclone to “pre-filter” the dirty air prior to the baghouse will greatly improve its performance and maintenance requirements.
• “Bag houses” larger than 8 cubic feet must be replaced or retrofitted with combustible dust protective equipment. For low maintenance and long filter life with less compressed air we utilize vertically mounted bag or cartridge filters with a conservative air/cloth ratio (< 5:1).

While the components are simple, the control logic on dust collection systems is critical! The dust collector must be functioning before the process line starts, and safely interrupt production if the collection system faults for any reason. State of the various combustible dust safety devises must be monitored. For further energy savings the system should stop after production finishes, but only after the shutdown sequence and filter blow down process is completed. And of course the controls must meet local and NEC code requirements as well as corporate specifications.

CSI will coordinate with 3^rd party vendors or provide controls meeting these requirements, including PLC preference and UL certified upon request. The customer can choose between numerous options:

• Operator control via pushbuttons, touch screen, or integrated with makeup equipment
• Allen Bradley or Automation Direct PLC and Inverters
• Painted or Stainless steel enclosures

While seemingly simple, electrical controls on dust collection systems are critical! The dust collector must be functioning before the process line starts, and safely interrupt production if the collection system faults for any reason. State of the various combustible dust safety devises must be monitored. For further energy savings the system should stop after production finishes, but only after the shutdown sequence and filter blow down process is completed. And of course the controls must meet local and NEC code requirements as well as corporate design guidelines.

CSI will provide controls meeting all of these requirements, including PLC preference and UL certified upon request. The customer can choose between numerous options:

• Operator control via pushbuttons, touch screen, or integrated with makeup equipment
• Allen Bradley or Automation Direct PLC and Inverters
• Painted or Stainless steel enclosures

Our goal is your complete satisfaction while providing the most economical and efficient equipment possible! To accomplish these ideals we must work together on the layout, component selection, installation, and operator training.

CSI equipment incorporates decades of bakery knowledge and endeavors to make every system as safe as it is productive!

This includes the following:

• Isolated and lockable disconnect
• Layout and component selection considerations
• Detailed operator manual with safety instructions
• Bolted and or interlocked machine guarding
• Graphical safety and ArcFlash warning stickers