4  SPECIFIC PRINCIPLES TO COVER EXCEPTIONS AND ADDITIONS TO THE DESIGN, CONSTRUCTION AND CLEANING OF ALL BAKERY EQUIPMENT, AS DEFINED IN SECTION 3.

4.1  DESIGN REQUIREMENTS FOR HANDLING AND STORING DRY INGREDIENTS EQUIPMENT

4.1.1 Design Requirements for All Systems

4.1.1.1 Mild steel bins shall have a food grade protective coating on product zone surfaces.

4.1.1.2 Product entry and discharge openings connected to the attendant conveying equipment shall be sealed and shall be accessible for cleaning.

4.1.1.3 Vents shall be protected against entry of foreign material and shall be provided with readily removable filters to exclude particles of 5 microns or larger.

4.1.1.4 Permanent lighting fixtures shall not be installed within the product zone. If interior lighting is required, externally mounted fixtures shall be used with shatter-proof transparent panels or disks, flush mounted.

4.1.1.5 Level controls shall be accessible for cleaning and inspection.

4.1.1.6 All discharging surfaces shall be adequately sloped or equipped with mechanical means to cause discharge of product.

4.1.1.7 Equipment designed for outside installation shall be suitably covered to prevent entry of water and foreign material.

4.1.1.8 The attachment mechanisms for holding inspection port covers, access doors, and other removable accessories shall have no loose parts.

4.1.1.9 Air activator assemblies shall be accessible for cleaning and inspection.

4.1.1.10 Screw conveyor housings shall be hinged at the top cover and drop bottoms or removable so that the area around the helical flights can be cleaned from the outside. Sufficient clearance shall be provided between the bottom of the screw housing and the floor to permit sufficient exposure of the screw for cleaning or the screw must be removable for cleaning. The screw housing shall be dust-tight and readily accessible for cleaning.

4.1.1.11 Continuous welding on both sides of the spiral flight shall be used for fastening the spiral to the shaft unless the spiral flight is designed to provide at least 1 inch (25mm) clearance between the shaft and the spiral.

4.1.1.12 Screw housings in bin bottoms shall be open along their entire length and expose at least one-half of the circumference of the screw. Fixed supports or plates in such openings shall have a width not greater than two-thirds the pitch of the screw.

4.1.2 Specific Design Requirements for Mechanical Conveying Equipment

4.1.2.1 Buckets shall be of seamless construction. Spaces between buckets and chain or carrier belts shall not be less than ¼ inch (6mm).

4.1.2.2 Drag-chain conveyors shall not be permitted.

4.1.3 Specific Design Requirements for Pneumatic Conveying Equipment

4.1.3.1 Straight runs of pneumatic conveyors, valves and rotary feeders shall comply with the provisions of Sections 3.1 and 3.2 except that piping, tubing, valves or feeders which are self-purging shall be exempt for the requirements of accessibility.

4.1.3.2 The entire pneumatic conveyor system shall be dust and watertight.

4.1.3.3 Vent openings shall be protected with filters.

4.1.3.4 Air supply for blowers or compressors shall be filtered to exclude particles of 5 microns or larger.

4.1.4 Specific Design Requirements for Sifters

4.1.4.1 Separate conveying air systems shall be provided before and after an atmospheric sifter in the system.

4.1.4.2 Sifters shall permit continuous discharge of tailings through dust-tight connections to an enclosed container.

4.1.4.3 Sifters shall employ no rubbing action to facilitate product flow.

4.1.4.4 Sifter screen frames shall be designed to prevent replacement in an improper position and shall be readily removable for cleaning

4.1.4.5 Sifter screens shall be minimum mesh to allow passage of product.

4.1.5 Specific Design Requirements for Weigh Hoppers

4.1.5.1 A removable flexible connection shall be provided between the inlet to the hopper and the product delivery equipment

4.1.5.2 Scale beam or dial housings shall be closed or constructed with an open bottom so as not to form a dirt-collecting pocket.

4.1.6 Specific Design Requirements for Dump Bins

4.1.6.1 The bag rest shelf shall either be readily removable or there shall be a minimum of 2 inches (50mm) open space between the shelf and the housing. It shall be a minimum of 2 inches (50mm) lower than the edge of the dump opening of the bin or housing.

4.1.6.2 Protective grids shall be readily removable.

4.1.6.3 Covers or doors shall be provided to enclose the product zone.

4.1.6.4 Skirts or aprons shall not be used as exterior trim.

4.1.7 Specific Design Requirements for Storage and Portable Bins

4.1.7.1 Cages used for bin cleaning shall be designed and constructed of round metal except for the floor, which may be constructed of flat bars installed on edge.

4.1.7.2 Auxiliary agitators shall be designed and constructed to be smooth, crevice-free and readily accessible.

4.1.7.3 Access openings shall be provided in all storage bins. The openings shall be at least 18 inches (460mm) in its smaller dimension and shall have exterior rims raised at least 1 inch (25mm). Covers or filters for all openings shall be designed to permit ready replacement and sealing. Bins shall have an access opening not more than 48 inches (1.25 meter) above the discharge opening.

4.1.8 Specific Design Requirements for Transport Vehicles

4.1.8.1 If the vehicle is pneumatically discharged, the air supply shall be filtered so as to remove particles of 5 microns or larger, and the filters shall be accessible for inspection and cleaning.

4.1.8.2 Discharge piping and unloading hoses shall comply with provisions of Section 4.1.3 of this standard.

4.1.8.3 Discharge piping and unloading hoses shall be equipped with caps.

4.1.8.4 Unloading hoses, if carried, shall be carried in an enclosed space, which is accessible and completely drainable.

4.1.8.5 Rail car unloaders shall comply with Sections 4.1.2 and 4.1.3 of this standard, whichever is appropriate.

4.1.8.6 Air relief assemblies shall be accessible for inspection and cleaning.

4.1.8.7 All joints in bulk railroad cars shall be welded and made smooth. Joints between the sides and hopper sheets are exempted from the requirement for butt welding.

4.1.8.8 The delivery vehicles shall be constructed of a non-corrosive, food grade material or coated on the interior surface (food contact surface) with an appropriate food grade non-toxic material.

4.1.9 Specific Design Requirements for Reclaiming Systems

4.1.9.1 Ingredient reclaiming systems shall be designed and constructed to be cleanable or readily accessible.

4.1.9.2 Dust shall be collected and contained for easy disposal.