FEATURES & OPTIONS
Hayes & Stolz has over 60 years of experience in developing mixing technology. Our extensive knowledge of various applications in diverse industries uniquely qualifies us to recommend the right features and options to enhance the performance of our mixers and improve mixing productivity. Every Mixer is custom designed and manufactured specifically for the customer’s application.
All mixer main shafts are constructed from a solid steel shaft precision machined to exacting tolerances.
Cross arms (ribbon support arms) are solid steel round bars secured with welded collars eliminating welds on the main shaft. (Note: See food grade/sanitary construction for exceptions.)
The continuous double-inner and double-outer ribbon design, standard on most Hayes & Stolz mixers, assures the end-to-end travel and the balance of product across the length of the mixer required for fast, uniform blending.
For center discharge Ribbon Mixers, Hayes & Stolz has developed an outer-only ribbon assembly. The most critical issue for center discharge mixers is how to address the inherent problem of the two separate blending zones created that make homogenous mixing a difficult and prolonged process. The new design enhances cross-over of product between the two zones and incorporates gravity to assist in the mixing process.
Manufacturing processes for mild steel ribbon assemblies tend to induce stresses into the final assembly that must be addressed in order to minimize fatigue. The solid main shafts on Hayes & Stolz ribbon assemblies are cross-drilled with through holes and fitted with solid steel cross arms for mounting the ribbons. The through holes in the main shaft are special-machined and treated to relieve induced stress in the shafts. Manufacturing procedures for welding of the ribbon assemblies have been developed to further reduce heat induced stress.
Ribbons for the assemblies are rolled to both pitch and diameter on a proprietary ribbon rolling machine developed by Hayes & Stolz. This process eliminates stress placed on the cross arms caused by using traditional rolling methods. The process also produces ribbons with a uniform diameter, thus giving uniform clearance between the ribbon and the mixer tub wall.
On Ribbon Mixers with a Commercial Finish slotted holes are used for the shaft seal attachment bolts and the bearings are furnished with shims. As the ribbon diameters decrease due to wear, shims can be removed and the ribbon assembly lowered in order to maintain the proper ribbon-to-tub-wall clearance. (Note: See food grade/sanitary construction for exceptions.)
All mixer main shafts are constructed from a solid steel shaft precision machined to exacting tolerances.
Cross arms (paddle support arms) are of fabricated steel and secured to the main shaft with bolted and keyed hubs, eliminating welds on the main shaft. (Note: See food grade/sanitary construction for exceptions.)
The use of paddle assemblies in single shaft horizontal batch mixers is a proven tradition and sometimes considered “old technology”. Hayes & Stolz, through an aggressive R&D program, has developed the next generation of paddle assemblies with enhanced performance. The new paddle assemblies are calculated and designed for the most optimum combination of speed; length to width ratio; and paddle area, pitch and spacing. Unlike most paddle mixers that have only outer paddles, the inner and outer paddle arrangement, standard on most Hayes & Stolz mixers, assures the end-to-end mixing and the balance of product across the length of the mixer required for fast, uniform blending.
For center discharge mixers Hayes & Stolz has developed a new outer-only paddle assembly. The most critical issue for center discharge mixers is how to address the inherent problem of the two separate blending zones created, making homogenous mixing a difficult and prolonged process. The new design enhances cross-over of product between the two zones and incorporates gravity to assist in the mixing process.
One of the main advantages of Paddle Mixers is the ease of maintenance. Paddles are typically much easier to clean than ribbons. The paddle arms are slotted allowing for easy adjustment of the outer paddle-to-tub-wall clearance. As the paddles wear they can be moved in order to maintain the optimal clearance between the paddle and the mixer wall. Both the outer and inner paddles can be easily unbolted and replaced as needed. The outer paddles have hard-faced leading edges or can be manufactured of abrasion-resistant steel for longer life. (Note: See food grade/sanitary construction for exceptions.)
Mixer covers are often a complex part of the mixer design. Covers not only provide the protection required by OSHA from the moving parts; they also provide the means for containing/controlling dust from the mixing process; they provide for methods of ingredient addition; and they often provide access for inspection and cleaning. H&S mixer covers can be custom designed to allow for the best integration with the customer’s operation.
Mixer covers can be furnished fully bolted, fully hinged or with a combination of bolted and hinged cover sections. They can also be provided with any of a number of options to suit the application.Flanged Inlets for Dry Ingredient or Liquid Addition
Flanged inlets are custom located, furnished square or round, and with sizes and bolt patterns to match the customer’s filling equipment.
Duct Pickup Ports
The mixer cover can be equipped with dust pickup ports for connecting to plant dust control system. Ports are custom located and furnished with sizes and bolt patterns to match the customer’s equipment.
Bag Dump Station
Bag Dump Stations are custom manufactured as an integral part of the cover or as bolt-on units. Hinged lids and safety grates are standard. Dust pickup ports, bag slitting devices and other custom features are available to suit the customer’s requirements.
OSHA compliant manways for inspection, maintenance or for cleaning access can be provided in the cover or in the body wall. Manways can also service a dual role as hand-add stations for ingredients. (NOTE: For some mixer sizes, manways create a “Confined Space Entry” condition. Follow your company’s policy for Confined Space Entry.)
Cover Assist Mechanisms
Hayes & Stolz offers options for easy opening of hinged sections. The cover sections can be equipped with a counterweight, gas spring assist or pneumatic cylinder assist. Cover assist mechanisms are designed for OSHA compliance.
For processes that require the addition of liquids, Hayes & Stolz can provide liquid manifolds and/or spray nozzles. Manifold/spray nozzle locations will be determined for optimum performance, directing the liquid(s) onto the material being mixed with minimum spray on exposed mixer components. This is done to minimize build-up on the agitator assembly and mixer body.
The “up first, then down” design of the spray nozzle pipe extensions minimizes “dripping” of liquids into the mixer when the manifold/nozzles(s) are not pressurized.
Liquid manifolds, sized to match the liquid flow rate, can be mounted either inside or outside of the mixer body assembly. When practical, access is provided for nozzle inspection/replacement without removing the mixer cover.
DISCHARGE LOCATIONS AND OPTIONS
The mixer discharge location is generally dictated by the installation requirements for the mixer and the type and location of the equipment the mixer will discharge into. Hayes & Stolz will locate the discharge as required to satisfy these requirements and will also design and manufacture the ribbon or paddle assembly to sweep the product toward the opening promoting full discharge of the mixed product. The most common discharge locations are bottom end (preferred) and bottom center.
Flat Slide or Curved Slide Gates
Hayes & Stolz Flat or Curved Slide Gate discharges are for commercial (non-sanitary) applications, to be located bottom-end or bottom-center of the mixer tub. Slide gates can be furnished in single or multiple-opening arrangements and with manual rack & pinion, pneumatic or electric actuators. Optional open/closed position indicating switches are offered. Note: Curved slide gates match the mixer tub contour eliminating the “pocket” of unmixed product directly above the gate.
Hayes & Stolz Paddle Gate discharges are for commercial or sanitary applications, to be located bottom-end or bottom-center of the mixer tub. Slide gates can be furnished with manual or pneumatic actuators. Optional open/closed position indicating switches are offered.
Full-Length Drop Bottom Discharge
Hayes & Stolz Drop Bottom discharges are for commercial (non-sanitary) applications and consist of double bomb bay style doors that match the mixer tub contour, eliminating “pockets” of unmixed product. The pneumatically actuated doors extend through the endplates eliminating ledges inside the mixer, and the end plate penetrations are manufactured with a beveled edge for a positive door end seal. A formed lip seal where the closed doors meet in the middle and a beveled leading edge on one door keep the seal area free of compacted product prevent leakage.
The bolted door and hinge design has heavy continuous hinges with stainless steel hinge pins. Machined adjustable turnbuckles for door actuation provide for adjustment and over-center locking when doors are closed. Replaceable hardened bushings are installed at all pivoting wear points. Actuating arms have hubs and are keyed to the door shaft.
Optional open/closed position indicating switches and optional door dampening systems are available.
Hayes & Stolz can custom design a weir type discharge where product is discharged through an opening(s) located high on the sidewall or endplate of the mixer or over a “false wall” located inside the unit. Weir type discharges are used to convert batch operation into a continuous mixing line.
Hayes & Stolz can custom design a through-the-endplate type discharge where product is discharged through an opening located low in the endplate of the mixer. Discharges can be furnished with manual or pneumatic actuators. Optional open/closed position indicating switches are offered.
Special Application Discharges (By Other Manufacturers)
- Butterfly Valves
- Ball Valves
- Vortex® Gates (Visit their website)
- Gemco® Valves (Visit their website)
- Roto Disc® Valves (Visit their website)
SURGE BINS AND UNLOADING CONVEYORS
The addition of a surge bin, fitted to the discharge of a mixer, increases the production capacity of the mixing process. The surge bin allows the mixer to be quickly emptied, the next batch of ingredients to be delivered to the mixer, and the mixing process for the new batch to be started, while the mixed product in the surge bin is delivered to downstream processes at the desired rate.
The standard surge bin can be furnished with either a drag type or screw type unloading conveyor, designed to deliver product from the surge bin at a capacity to match the process production requirements; or with a slide gate to control the discharge of the surge bin. The most common is the H&S drag conveyor in either a flat, inclined or bent section configuration. Custom designed surge bins and unloading conveyors are available.
Hayes & Stolz drag type unloading conveyors have UHMW drag flights mounted on heavy steel chain and a full-length removable baffle assembly over the return flights to protect the conveyor components from the impact of material being emptied from the mixer. The baffle assembly also helps feed the material into the path of the drag flights for smooth unloading.
Hayes & Stolz offers a variety of seal options for the main shaft penetration through the end plates. The selection of seals that are properly suited for the mixing application is important in order to minimize leakage and reduce premature shaft wear that results in expensive repairs and down time.
The H & S Split Block Seal, for dry mixing in commercial (non-sanitary) applications, consists of a UHMW body, steel front and back plates and two wraps of ˝” braided teflon packing. The split design allows for easy disassembly for cleaning and maintenance.
The H & S Flanged Gland Seal, for dry mixing in commercial (non-sanitary) applications, consists of a steel body, steel back plate and one wrap of ˝” braided teflon packing. Construction materials can be mild steel or stainless steel. The split design allows for easy disassembly for cleaning and maintenance. The body acts as a plunger against the braided packing material allowing for some adjustment as the packing wears.
The H & S Packing Gland Seal (with or without air purge) is designed for dry, slurry or wet mixing in commercial or sanitary applications. The housing and plunger are available of machined stainless steel or UHMW with stainless steel front plate, back plate and pusher plate. For dry applications the seal comes standard with multiple wraps of ˝” braided teflon packing. Stacked v-rings are used for liquid applications. The split design allows for easy disassembly for cleaning and maintenance. The plunger design allows for adjustment as the packing material wears.
H&S can also provide seals of other manufacturers at the customer’s request.
HIGH SPEED CHOPPERS
High Speed Choppers for Horizontal Batch Mixers are through-the-wall dispersion units used for de-agglomerating and high speed dispersion of small lumps and balls that are often difficult to handle during normal mixing. During mixing the ribbons (or paddles) continuously sweep product across the chopper(s). As the rotating chopper blades impact the product at 3600 rpm, lumps and agglomerates are broken up; fibrous materials are ripped apart for size reduction; and/or color pigments can be broken up for more uniform color dispersion. The addition of High Speed Choppers will result in high quality, more thorough mixing and faster mix times for difficult ingredients.
Hayes & Stolz Choppers consist of a 3600 rpm drive motor, precision machined housing and high speed shaft, bearings, coupling, seal, chopper blade and mounting bracket.
Multiple units can be mounted on the same mixer to further enhance mixing performance.
Standard choppers are available with 7˝ or 10 HP motors.
The fabricated chopper housing allows for easy access to internally mounted coupling and bearings.
Hayes & Stolz standard tulip blades are available of stainless steel for both commercial and sanitary/food grade applications or of plasmadized, abrasion resistant carbon steel for highly abrasive applications.
The unique mounting design of the chopper allows for complete removal from outside the mixer.
The mounting bracket is designed to match the radius and contour of the mixer tub wall eliminating any dead pockets in the mixing zone.
Choppers can be adapted to any of the H&S ribbon or paddle mixers for commercial or sanitary/food grade applications. They can also be purchased to retrofit and upgrade most mixers manufactured by others.
(Note: To install in an existing mixer some modifications to the ribbons or paddles will be required to allow clearance for the chopper blade. A hole will need to be precisely located and cut into the tub wall and mounting brackets welded in place.)
Hayes & Stolz has extensive knowledge of numerous mixing applications for many industries and is uniquely qualified to recommend the right features and options to enhance the performance of our mixers and improve mixing productivity.
Some mixing applications require heating/cooling of the product during the mixing process to achieve the desired result or to minimize induced heat from the mixing action. Other applications require insulation of the mixer in order to maintain a product’s temperature range during mixing.
Hayes & Stolz mixers can be furnished with heating/cooling coils or with insulation and steel jackets to satisfy temperature-sensitive mixing applications. Coils can be used with heated water or low-pressure steam for heating, or with chilled water or ambient water for cooling. Jacketed mixers can be furnished with blanket type insulation or spray insulation and with bolted or fully welded jackets. Coils and jackets are available on commercial or sanitary/food grade mixers.
Intensifier bars are steel rods added perpendicular to the mixer’s inner ribbons for de-agglomeration of clumps that are easily broken and do not require the intensity of a High Speed Chopper. They are recommended for mixing or blending applications for liquid, slurry or low- density products, and can be added to commercial or sanitary (food grade) mixers.
Support Structures and Platforms
The installation of a mixing line sometimes requires a support structure to elevate the mixer to clear other equipment, or a work platform around the mixer for maintenance or to hand-add ingredients. Hayes & Stolz has the engineering and manufacturing expertise to help with the design of structures or to manufacture to a customer’s design. Platforms are designed and manufactured with OSHA compliant handrails and with ladders or stairs as required. All structures and platforms are custom designed to the installation requirements.
Hayes & Stolz offers Mixer Control Panels complete with NEMA 4 enclosure, panel disconnect, mixer drive motor starter(s), mixer start/stop push buttons, discharge gate open/close selector switch, and interlocks for cover safety and overload.
Hayes & Stolz is not just an equipment manufacturer. We Deliver Solutions. Contact a qualified Hayes & Stolz Sales Engineer to discuss custom designs of Hayes & Stolz Mixers to meet your specific needs.