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ABSTRACT: The VACUCAM? Ejector Mixer is the most effective method to convey and completely wet powdered thickeners easily, quickly, reliably and in a dust free process often achieving levels of solids often unattainable with conventional mixers.
Regardless of process and dry side container issues, only Semi-Bulk completely integrates process systems to eliminate the dusting and unwetted agglomerates so often associated with powerful thickening agents such as polymers, cellulose & gums.
TECHNICAL SUMMARY: To incorporate thixotropes, the VACUCAM? Ejector Mixer is operated in a single pass process mode for the following reasons: solids levels are low enough for this process; less equipment / fewer control complexity means less costly investment; and recirculation through the VACUCAM? Ejector Mixer imparts shear to the mixture, which we wish to avoid with gums and thickening agents.
The single pass however does not always imply water - we could inhale these powders single pass into finished products or interim mixtures as long as 1) shear will not adversely effect the pumped liquid, 2) the viscosity is <5000 CPS and 3) there is sufficient excess liquid to wet out the powder.
Further, if real time process accuracy is desired, we can take the powder from a feeder that matches the powder to the liquid rate, thereby producing the exact solids concentration on a "real time - on line" basis - eliminating the need for a secondary vessel.
PROCESS SEQUENCE: The VACUCAM? Ejector Mixer, when used with thickening agents, is always operated in single pass process mode. That is, we design the system with a convey rate to provide the time necessary to completely inhale the batch amount of powder and wet it out before the batch amount of liquid is pumped through the VACUCAM? Ejector Mixer. In this manner, the instantaneous level of solids during the powder incorporation sequence is higher than the ultimate, or use level of solids. Once the batch weight of powder is conveyed and wetted the fresh liquid continues to run into the batch, diluting the level of solids back to the desired final set point. In this manner, the fresh liquid also performs the added function of completely flushing the VACUCAM? Ejector Mixer and slurry delivery system clean and clear for automated re-start of the next batch.
Slurry Option A is where the VACUCAM? Ejector Mixer is located on an existing process vessel. This tank should have adequate agitation and capacity to maintain a full batch and ensure that the finishing, or "trim" amount of liquid (as outlined above) is completely blended with the slurry produced by the VACUCAM? Ejector Mixer. The limitation of this option is that the dry side feed source must be located within 30 feet horizontally and 40 feet vertically of the VACUCAM? Ejector Mixer.
Slurry Option B was designed to bring the mixing action to the dry side products when the dry side products cannot be located near the VACUCAM? Ejector Mixer. The supply pump presents the pressurized fluid to the slurry skid where the VACUCAM? Ejector Mixer produces a conveying and wetting vacuum to incorporate the powder. The powder feed is as outlined in options A, B, C or D. The deareation tank controls the discharge from the VACUCAM? Ejector Mixer and feeds the skid mounted take-away pump the slurry. The take-away pump, controlled from a level signal in the deareation tank, transfers the slurry product to blend or use vessel(s) with sufficient agitation to ensure mixture stays homogeneous and functionalizes fully. The take-away pump is selected and sized based upon the flow properties of the mixture before and after powder incorporation to adequately deliver the processed products to various end point tanks, through the use of proper valving schemes.
Dry side options: Reference drawing number P2933-01-A
The four common dry side options revolve around how the product is shipped: Air-PalletR Container, paper bags and bulk bags (super sacks).
Dry Option A is for lowest volume users, those with paper bags. The powder is pre-weighed and placed in an aerating hopper, which is either connected to an existing dust collector or is constructed complete with an integral dust collection system. The polished stainless interior with aerating membrane provides complete, uniform and total discharge of the dry product to process. Aeration gas is controlled manually with a supply manifold.
Dry Option B is a bulk bag unloader with surge hopper and vibrating bag pan. A separate (optional) device provides the dust collection. The bulk bag is hoisted onto the unloader frame with either a fork lift or integral hoist and trolley system. The bulk bag is attached to the lower surge hopper utilizing the Quick ClampT mechanism for dust free attachment. Lower hopper options include capacities from 2-20 cubic feet, polished interior / exterior, vibrating screens, de-lumpers / sifters, controlled rate feeders and load cells for loss-in-weight process control.
Dry Option C is a bulk bag unloader with surge hopper and dust collection system. Optional trolley and hoist completes this package for stand-alone functionality. The entire structure is mounted on load cells for loss in weight operation and accuracy similar to the Air-PalletR Container, Option D. Once the batch target weigh is achieved, a sweep valve opens and the powder line is cleared. Powder holding capacity in the lower section hopper is available from 20 to 90 cubic feet.
Dry Option D shows the Air-PalletR Container with an integral dust collector and aeration manifold. This system will automatically batch the powdered product to the slurry process accurate to +/- 1 pound. The Air-PalletR Container capacities are 35, 50 and 100 cubic feet. Upon completion of the convey process, the powder lines are swept clear and the system awaits the next batch signal. Once the Air-PalletR Container is emptied, a new Container is placed on the unload stand and the process continues. The empty Air-PalletR Container is returned to the supplier for refill.
SUMMARY: Semi-Bulk Systems customizes every system for a best-fit solution to address all functional, operational and process requirements. It is important to note any dry side option presented can be combined with either slurry option. For additional reference material see the VACUCAM? Ejector Mixer brochure, continue browsing the Web site, or call us at 800-732-8769.
Click here to open Single pass process CAD drawing schematic.
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Processes
