Ratholing is a term used to describe extreme cases of funnel flow where the material nearer the walls is completely stationary and only the central material is discharged . Due to the cohesive strength of fine dry fly ash, the material is a great source of friction. Arching, ratholing, caking, segregation and flooding are some of the commonly encountered flow problems in the handling of fine powders. The Circle Feeder is used to reliably discharge all types of granular materials. Ratholing is influenced by the bin/hopper geometry and outlet size the material is fed through. 9 b, although the variation of the blend flow was larger compared to the total powder flow in case study 1. caking and powder flow speed dependency (PFSD) test, of spray-dried bee pollen enriched milk powder (packed in ALP, BOPP/LDPE, and PET/Al. Discharge of powder from a hopper or bin is a common operation in solid dosage form manufacture. This can disrupt your production line. mechanical interlocking of large particles forming an arch 2. . Most flow problems are connected with the funnel flow pattern and can be avoided if the hopper is designed for mass flow (Johanson, 2002, Purutyan et al. We Resolve Storage Structure Ratholing. ), and dry, uniformly-sized larger materials will be free flowing. The energy requirements are very dependent on the bulk solids or powder flowability properties, including cohesion and internal shear angle. flow using an avalanching powder system and comparing it to the methods of determining Carr’s compressibility index and the critical orifice diameter approach. Silo discharge solutions for powder bridging and ratholing. ). 3. Calculating the hopper wall angle is and the critical outlet diameter is critical in preventing arches from forming and if you want the powder to flow. The material that is. The way bulk powders flow impacts on the design of. Royal, T. 24hr Emergency Service. , answered a few questions from Powder & Bulk Solidson common powder handling and flow issues and how operators can take steps to fix or prevent. Effective feeder design not only enhances the flow within bins, hoppers, and stockpiles but also positively. Flow difficulties at the blending step often manifest as slow/no discharge or ratholing. Check out this expert article on Powder Handling in Encapsulation from Right Stuff Equipment, experts in solid dose processing & packaging machinery. Understanding the rheological properties of the. 1. Materials interlock or bond together to form an arch above the outlet, blocking any flow. doi: 10. 456 inches. 26. No matter the design or the materials stored, silos are susceptible to material flow issues caused by blockages. As a consequence of this, the so-called ratholing phenomenon can occur. Polimak Bin Activators are used in several industrial applications to efficiently discharge dry solid materials in powder or granular form from upstream equipment, thereby, reducing bulk material bridging or ratholing while promoting mass. Of course the outlet of the hopper has to be large enough to prevent bridging above the feeder. Keep in mind that the mass-flow bin design process is iterative. Even high viscous material can be fed through the feeder and discharger smoothly. Besides that, powder flow can be determine by the angle of repose make by the powder itself when poured onto a flat surface throughout the hopper. Note that this method does not work well if the bulk material is a powder that can compact easily. In this case, powder discharge from hopper is not predictable. LEARN MORE Powder Cone Valve System. Lower the total height requirement. 2. 2 Mass flow bins sufficient cohesive strength that its critical rathole diameter (the flow channel diameter at Flooding and ratholing problems can be which a rathole becomes. Typical component concentrations in. 4 Flow FactorsCohesive arching, jamming, particle segregation, and ratholing are all common occurrences during the production cycle. The primary focus of this chapter is to provide guidance in designing bulk solids (powder) handling equipment to provide consistent, reliable flow, and the required product uniformity by minimizing segregation. Discharge of powder from a hopper or bin is a common operation in solid dosage form manufacture. Typically, they are used when flow by gravity alone will not work or when it is impractical to provide the design that is required for reliable flow. Keywords: live bottom, cohesive, powder, hopper design. Maintaining reliable powder flow of each ingredient to a continuous blending system is essential for its performance. This was attributed to the fact that the poor flowability of APAP could cause ratholing and high flow variations, especially when the powder. On Wednesday, September 21, 2022 at 2 p. 4. 5 % Hang-Up Indices CONSOLIDATION TIME 0 HR 16 HR Arching Index (AI) 1. • Separate paddle propulsion possible. The API AeroFlow® automated flowability analyzer was tested using 6 pharmaceutical excipients. Ratholing: can occur in a bin when the powder empties through a central flow channel, but the material at the bin walls remains stagnant and leaves an empty hole (rathole) through the material, starting at the bin outlet (Fig. Consequently, meas-urement of the wall friction characteristic of a. Andrew W. Avoid powder flow problems by gaining a better understanding of flow patterns and bin design. When bulk solids build up into an arch or dome-like shape over the hopper’s outlet and block the flow, it’s called arching or bridging. Ratholes develop most often in conical hoppers that are not steep enough to produce flow at the walls. the powder flows at the place of the smallest flow resistance. In the characterization of the powder flow, all predictions previously formulated were effectively understood. Even high viscous material can be fed through the feeder and discharger smoothly. It is the only flow aid that can handle. 2. flow rate through an orifice compressibility index and hausner ratio angle of repose shear cell. Powder flow can also vary from lot-to-lot, which needs to be understood during R&D. to 2:15 p. This type of flow pattern is indicative of uniform, first-in-first-out flow, where ratholing, erratic flow, segregation, and flooding problems are mitigated. 2 Mass flow bins sufficient cohesive strength that its critical rathole diameter (the flow channel diameter at Flooding and ratholing problems can be which a rathole becomes. To achieve this, a flow agent should adhere to the surface of particles of solids as shown in Figure 2. Ratholing definition: Present participle of rathole . 1 Shear strength. b. The 2-in. Preventing Flow Stoppages in Powder Handling Processes. This method may be used for all powders, dairy and non-dairy products. Ratholing occurs when material empties out through a flow channel above an outlet. The powder flowability is defined as the ability of a material in the form of particles to flow in a desired manner when used in specific equipment [33]. Powder & Bulk Processing. 2002). 3. Why are my powders are not flowing efficiently? In ratholing, a vertical flow channel develops above the hopper outlet and, once emptied, remains stable. This is often not taken into account and can result in arching or ratholing in storage bins or silos, blockage of chutes, flooding of hoppers and other problems that may affect the performance of the plant. Posted by Control Concepts USA on September 13, 2022 7:13 pm. 487 and 1. Funnel-flow bins lead to ratholing when the non-flowing solid consolidates sufficiently to remain stable after the channel has emptied out, and to flushing of powders as the layers slough off the top of the non-flowing mass and hit the bottom of the channel, or as aerated material rushes through a rathole. Jenike & Johanson is presenting the following AIChE sponsored courses June 18-20 at the Canadian Management Centre in Toronto:Flow of Solids in Bins, Powder Bulk Solids is part of the Informa Markets Division of Informa PLCRat-holing problem: * is one of common powder flow problems * When powders are released via a butterfly or slide valve, flow takes place directly above the container outlet. Silos and hoppers are particularly prone to this issue if the. n 1. 327. pharmacopeial methods to characterise powder flow. Rotoflo is designed to help with material handling ensuring that silo discharge is free-flowing and controlled when handling a number of diverse materials. Obstruction to flow due to bridging arises when a stable arch forms over the hopper outlet, which prevents material from being discharged . Despite being a simple test of compressibility, it can be useful for identification of powder flow behavior. The gravy mix was scooped into the trough, and the. Arching/Bridging & Ratholing. Tired of hammering on equipment, engineers thus began the development of flow aids for bulk solids. The outlet is the smallest flow channel through which the bulk material should move. A bin experiencing ratholing will have limited live (i. Of course the outlet of the hopper has to be large enough to prevent bridging above the feeder. With. W. This type of flow pattern is indicative of uniform, first-in-first-out flow, where ratholing, erratic flow, segregation, and flooding problems are mitigated. m. com. 2017). , “Increase Powder. 1. Buildup in the Silo is an Indication of Ratholing. Some of these conditions include:. In this case, the hopper walls are steep and smooth enough to ensure flow along them. The powder flow is measured using an X-ray-based mass flow meter (SETXvue XP-300, Enurga, Inc. In silos and hoppers it’s often the cause of flow problems like ratholing and bridging. Pivotal work on the development of the theory of bulk solids flow began in earnest in the early 1950s, when. As occurrences of bulk powder flow issues are strongly affected by the flow pattern during discharge. include arching (when the powder forms a cohesive bridge over the outlet) and ratholing (when the powder flows out only from the. Consequently, meas-urement of the wall friction characteristic of a. The most common causes of these issues are: Improper storage; Poorly selected binder that is too cohesive with the API;. Mass flow eliminates ratholing and maximizes the pers with planar geometries (e. The flowability factor is a easy way to quantitatively select substances with regard to their flowability. 36 3 Wall Friction Angle 24. Unload and produce good faster in your production process. Valves & Actuators. offers powder testing services (flowability, friction, time consolidation, strength as used for comparative tests, silo design for flow and silo design for strength) and solves practical problems in the field of bulk solids handling (silo design for flow to avoid problems like arching, segregation, ratholing) on the basis of the mechanical properties. Powder Rheology. Wall friction, internal friction and bridging properties determine the applicable hopper angle and opening diameter. Reduce costs in manual labor for unsticking materials from bins or hopper walls. Frequently powders that are deemed easy flowing exhibit flow problems such as bridging, ratholing, or erratic discharge. Arching; b. Definitions: Bin: Any upright container for storing bulk solids. Before. Avoid silo problems, such as bridging, funnel flow, ratholing, arching, segregation and product decay. ”. From the test results, you can follow Andrew Jenike's analyses to predict flow behavior in hoppers, e. Silo and hopper ratholing is an issue which causes the compaction of materials on silo and hopper side walls, which results in a severely restricted material flow. The advantages for handling powders and bulk solids via fluidization instead of traditional deaerated gravity flow include: Elimination or reduction of arching (bridging) or ratholing problems Powder Cone Valve System. Still, the material at the bin walls remains stagnant and leaves. Hey Guys! Today I'm going to show you how to replace a bad cv joint (Constant Velocity Joint) step by step. Flow aid devices are internal or external devices that are used to assist in discharging materials from a bin, hopper, or silo. Problems with Hoppers • Ratholing/Piping and Funnel Flow • Arching/Doming • Insufficient Flow • Irregular flow • Inadequate Emptying • Time Consolidation. This is indicated in hopper calculations as “Free Flow” or “0. Comparison of the flow properties of eight commercial dairy powders5. Why are my powders are not flowing efficiently?Ratholing occurs when discharge takes place only in a flow channel located above the outlet. More than 70% of all products contain ingredients that are handled in bulk solid form at some point during the production process. Unload and produce good faster in your production process. Also in the case of funnel flow, asymmetry is of no help when ratholing has to be avoided. Ratholing. As the level of material in the flow channel drops, a resistance to further flow into. R. Powder flow obstruction during hopper/bin discharge, such as arching or ratholing, remains an outstanding risk and cannot be reliably diagnosed using the existing flow function coefficient-based method. 89-0. pharmaceutical tablets, detergents, ceramics, powder metallurgy etc. Flow obstructions occur when the forces opposing motion exceed the forces promoting. However, determining the physical properties under normal operating conditions is essential. Core or Ratholing Flow: The material starts flowing from the top surface in the form of a cylinder at the central portion of the hopper and all the material surrounding this central hole upto the wall is stagnant. The purposes of this investigation were to develop a method to evaluate flow properties of powders from avalanching tests and to detect similarities and relationships between these data and conventional powder flow properties. The behavior is irregular and often catastrophic for achieving regular powder flow. AirSweep breaks up material blocks and sweeps the vessel walls clean. Ratholing is a flow obstruction is a no-flow condition obstruction that can cause erratic that prevents material discharge discharge. Another method to improve flow is. The API AeroFlow automated flowability analyzer was tested using 6 pharma. 0 feet Ratholing Index (RI) 10. Air pads may be needed to move the first material and merely gravity or small vibrations can be sufficient for the second. Feeding, Weighing, Scaling 2. Ratholing. 10). The frequency of the vibration needs careful consideration as it could affect the flow ability of the powder. • Easy to clean due to detachable components. 4. Bridging is the name given to the self- created arch that develops just above the outlet of a bulk material silo or hopper as it empties. Provided here is a review of shear-cell testing and how the technique can be used to predict arching, ratholing and other behaviors. their manufacture are in powder form. The system is designed to help prevent powder bridging and ratholing in silos and hoppers. m = 0 for a rectangular outlet m = 1 for a circular outlet. downtime and degraded product quality. Prevent segregation with mass flow. As the level of fly ash in the flow channel drops, a resistance to further flow into this channel occurs due to. Mixing & Blending. 2 pcf Bin Density Index (BDI) 40. Ratholing synonyms, Ratholing pronunciation, Ratholing translation, English dictionary definition of Ratholing. Example of powder ratholing in a hopper. Materials interlock or bond together to form an arch above the outlet, blocking any flow. The nozzle releases highly pressurized air pulses to promote on-demand, first in and first out flow. steeper than. Many consumer products, such as detergent or soap, can be prone to poor flow due to arching or ratholing during routine storage and handling. The powder flow function is a plot of unconfined yield strength versus major principal. Powder flow characteristics and vessel design vary tremendously. Many of these flow issues can be traced back to improper discharger or feeder designs. That’s why. On the other hand, NP0 produced mass flow behaviour even for the narrowest orifice diameter of 2 mm. Many of these flow issues can be traced back to improper discharger or feeder designs. Based upon mathematical models, Jenike developed design charts to determine which flow pattern is to be expected during gravity discharge from a bin or hopper. Angle of repose. Rotoflo is designed to help with material handling ensuring that silo discharge is free-flowing and controlled when handling a number of diverse materials. The reason for this is that when a result in a flooding condition at the outlet. The cell has a fixed shearing rate of 7 mm min −1 and external and internal diameters of 164 and 120 mm, respectively. Our comprehensive line of feeding technology can provide: high and low feed rates, batch, continuous, high. Arches come in two types: interlocking arches, built up of large, mechanically. The primary measure of powder flowability is the powder flow function - which gives a measure of the amount of strength the material retains at a stress free surface following consolidation to a given stress level. Flow difficulties at the blending step often manifest as slow/no discharge or ratholing. Funnel flow silos are usually more cost effective to construct, costing between 20-30% less than mass flow silos, but are not suitable for all materials. The hopper design can play a role in this as those with sharp angles and rough surfaces can inhibit powder flow. Bulk Material. 6 Therefore, a material that has poor powder flow needs to be pre-processed before attempting direct. 3485 Empresa Drive San Luis Obispo, CA 93401 Tel: 805-541-0901. 4 Flow FactorsArching, ratholing, caking, segregation and flooding are some of the commonly encountered flow problems in the handling of fine powders. This can disrupt your production line. One of the recommended types of flow aids is called Mechanical Agitation. In most cases, the vessel or bin can be attached to a vibrator, which shakes the vessel to pack the powder together. The simplest way of explaining the flow function is with the uniaxial unconfined failure test shown in Figure 4, which measures the. One of the recommended types of flow aids is called Mechanical Agitation. Material Flow Solutions, Inc. In order to achieve mass flow, tion hoppers) are shown in Figures 5 and 6, respectively. Systems supplied by PTSA often include silos, hoppers, and other storage vessels. 2 pg 266. ratholing, flooding, and inadequate flow rates, and more. The obstruction to flow would have a significant impact on the overall CM process as it. Ultrasonic excitation minimizes static friction forces and allows bulk solids to flow more continuously and efficiently. Process Control & Automation. The typical problems encountered are either a cohesive arch or ratholing. /d. 3’, meaning that an 18. Problems associated with ratholing are flooding, substantial variation of density in product, and eventually no-flow. ) the powders are filled into closed cavities; this is followed by compaction using rigid punches and finally the product is ejected from the die. Efficiency– As explained earlier ratholing powder flow can be likened to creating a “funnel effect”,meaning silos and hoppers cannot be used to their full storage capacity. Common problems include ratholing, arching in silos during discharge, blockage of pipes during powder transport,. C - For flow, D> y or ff y (a) powder has a yield stress greater than c/ff no flow occurs. outlet dimensions to avoid arching and ratholing. Process Control & Automation. 11. Typical powder flow issues found in the hopper are ratholing, bridging and segregation. Various powder flow properties, such as cohesion, unconfined yield strength,. bulk solid materials exhibit in bins and silos. 3. described ratholing and powder bridging in a small-scale feeder for fine, cohesive and compressible powders (Santos et al. Solution: Reduce Movement. The reason for this is that when a powder becomes deaerated in the stagnant region of a funnel flow bin, it usually developsFlow function is only half of the solution because it’s a measure of powder cohesiveness: Powder flows if: Ì % = σ1/ffc The external stress arising from gravity, (a. It allows users to measure the dynamic flow and shear properties of powders as well as quantifying bulk properties such as density, compressibility and permeability. For example, testing on a Flodex™ may show that a neat API powder has flowability of 26 mm, with a round tabletDischarge of powder from a hopper or bin is a common operation in solid dosage form manufacture. In advance of her appearance at this year’s Powder Show Toronto running from June 4-6 at the Toronto Congress Center in Canada, Tracy Holmes, the president of Jenike & Johanson, Ltd. was used to control the flow of powder. How to prevent solids and powder flow stoppages with proper feeder design FREE | October 18,. At this point,. Powder Mix Segregation. Mass flow exhibits a first-in-first-out flow sequence, allowing the product at the bottom (coarser or heavier particles) to discharge first. Home; Blog; Case Studies; 770-255-1322. 2. Poor flowability of powders in a hopper means that flow obstruction due to arching occurs or uneven flow causes ratholing. Bridges of powder can form in your containers preventing flow. Ratholing/ funneling 5 Inconsistent flow 3 Electrostatics Flowability Compaction . ) (Ganesh et al. c. g. 2. Consolidations can therefore be undone. This was attributed to the fact that the poor flowability of APAP could cause ratholing and high flow variations, especially when the powder. Bridging, ratholing, arching and comparable behaviors are the bane of powder handling and formulating. Where less desirable properties are present, poor powder flow can: lead to challenges during blending (no discharge or ratholing), 4 difficulties when discharging the powder into the hopper 5 or issues regarding weight uniformity in the tablet. The critical arching dimension, of 5. 1 Importance of powder flow in the pharmaceutical industry 6 1. Robert Sedlock. Mass-flow bin. shear strength (σ f ), bulk density (ρ b) and add three further factors: hopper wall angle (β c ), outlet size (D crit) and Hausner ratio (H. The final potential issue is erratic flow, in which flow alternates between ratholing and arching (see Figure 1). a. Factors that affect the flow behavior are discussed. A better approach to predicting flow behavior is to take the characteristics of wall friction (φ w ). The field of bulk solids handling was developed due mainly to the work of Dr. 2 Flowability indicators used in industries 7 1. The flow properties of a bulk solid can have a significant impact on process efficiency and the success of the end product. 4. Powder-container design affects discharge rate, cleanability, and powder flow. What Can Cause A. was used to control the flow of powder. Circle Feeder is the premier choice feeder that can prevent the segregation during mass flow discharging. This article describes a study scientists conducted to resolve a powder-binding problem that developed during the scale-up—from proof-of-concept scale to pilot. , 2003). Powder flow obstruction during hopper/bin discharge, such as arching or ratholing, remains an outstanding risk and cannot be reliably diagnosed using the existing flow function coefficient-based method. There are two main reasons why no-flow conditions happen: arching and ratholing. In the pharmaceutical industry, powder flow assessment methods are of great interest for the development and manufacture of solid dosage. Segregation Ratholing (Fig. Once the central flow channel has emptied, all flow from the silo stops. Particle size distribution (PSD) estimation by sieving of the two powders was performed according to Ph. powder becomes deaerated in the stagnant region of a funnel flow bin, it usually develops 2. Bulk solids and powders frequently encounter various flow challenges, including bridging, ratholing, flooding, and inadequate flow rates, and more. rathole, bridging and segregation to occur. The hopper design plays a role in this as hoppers with sharp angles and rough surfaces can inhibit powder flow. This can lead to ratholing and bridges. Gravity Flow. Powder ratholing: the powder flows only within a channel, the powder around this channel, or rathole, do not flow In clear, there is much less or not at all flow out of the hopper ! Note that other flow issues exist, showing different symptoms but are somehow less common and not detailed in this page. The most common and serious problem is no-flow, due to arching or ratholing [6], [7]. Powder blockage in silos. Expanded flow silos and stockpiles are recommended for storing large quantities of non-degrading materials and for modifying existing funnel-flow silos to correct problems caused by arching, ratholing and flushing. A Brookfield Powder Flow Tester, equipped with Powder Flow Pro software for automated instrument control and data acquisition, was used to test this name brand baby formula. This is different from avalanche testing where a rather unconsolidated powder bed rotates inside a rotating drum and therefore, the powder bed properties are evaluated in a practically free flow. 2. Ratholing can lead to costly powder flow problems. These problems can result in limited live capacity. It is therefore imperative to know your powder properties in order to design the desired silo. Movement speeds up material segregation. Arching, ratholing, caking, segregation and flooding are some of the commonly encountered flow problems in theAlso in the case of funnel flow, asymmetry is of no help when ratholing has to be avoided (Fig. The goal of the design process is the determination of the hopper wall inclination necessary for mass flow and the minimum outlet size to prevent flow problems due to arching or ratholing. Ratholing of powders can occur in a container (silo, hopper, IBC, mixer vessel) when the powder empties through a central flow channel. Forty years ago, Jenike [Gravity Flow of Bulk Solids, Bulletin 108, Utah Engineering Station, 1961] and Johanson [Flow Indices in the Prediction of Powder Behavior, Pharmaceutical Manufacturing. Figure 3: Stagnant, cohesive powders can form a stable rathole in funnel flow. 125” to 0. Use the following guidelines for impacting vibrators: Wall Thickness of 0. 26. Differences in densities and flow rate cause the materials to separate on a vibrating conveyor belt, upon free-fall into a bin, or when flowing horizontally into a container. aid, modifying the feeder, or using gas injection. and host "True or False: Bulk Solids Edition" from 1:29 p. Define Ratholing. A bridge forms when wall friction holds up the ends of the arch. Compressibility properties Measure a material’s bulk density as a function of consolidation pressure, which is required in the analysis of bridging, ratholing, and hopper angles. Since funnel flow will result in a first-in, last-out flow sequence, any side-to-side segregation that occurred when the equipment was filled will often be exacerbated 7. 3. Home; Blog; Case Studies; 770-255-1322. How it works. Impact on filling. For each of these bins type, the critical outlet diameter, to avoid arching and ratholing, should be calculated in order to ensure a good flow. 4704, or Email Us. Multi-Craft Services. spoilage, flooding, or ratholing are likely to occur, then a mass-flow discharge pattern should be selected. If the material being handled is cohesive, the material outside of this channel will. Solimar Fluidisers create twice as much aeration action as many lookalikes. Dense phase. 5 Advantages Of In-Home Therapy And Rehabilitation Best Tyre Brands for Your Car NFL COVID PROTOCOLS: OUTBREAK POSTPONES STEELERS-TITANS What’s the Future of the Manufacturing Industry? Best Tyre Brands for Your Car NFL COVID PROTOCOLS: OUTBREAK POSTPONES STEELERS-TITANS What’s the Future of the Manufacturing. A Brookfield Powder Flow Tester equipped with Powder Flow Pro software for automated instrument control and data acquisition was used to test brown gravy mix. offers powder testing services (flowability, friction, time consolidation, strength as used for comparative tests, silo design for flow and silo design for strength) and. As the level of fly ash in the flow channel drops, a resistance to further flow into this channel occurs due to. Erratic flow results when ratholes collapse, causing the powder to arch as it impacts the out-let. 1 Importance of powder flow in the pharmaceutical industry 6 1. The two most common flow problems experienced in a silo, bin or hopper are arching (bridging) and ratholing. Lack of discharge in theFlow-rate limitation and flooding: problems specific to fine powders. 11. • Prevent ratholing, bridging and damage to the material. Powder rheology is the study of the behaviour of powders as bulk assemblies, consisting of solids, liquids and gases. Ratholing is influenced by the bin/hopper geometry and outlet size the material is fed through. Joe will describe uses for liners such as TIVAR 88 and 2B stainless steel along with coatings such as electrostatic powder coatings and Plasite 7122 epoxy coating. 14. For system manufacturers, process engineers, and operators: The timely application of flow enhancing solutions is recommended to prevent quality issues and production interruptions, such as bridging, ratholing and demixing. These flow problems can result in powder caking, production delays, increased operator intervention, or product losses. a cohesive arch when particles bond together ii. PHARMACEUTICAL ENGINEERING. The two most common flow problems experienced in a silo, bin or hopper are arching (bridging) and ratholing. 2. 1991; Holdich. This creates a non-flow regime whereby a discharge aid is needed to re-initiate powder flow from the silo. The powder's flow pattern has a major effect on the development of certain flow problems, especially flooding. (Note: The terms bulk solid, bulk material, and material are used interchangeably. It is a superb discharging device overcoming all manner of powder flow problems. Typical powder flow issues found in the hopper are ratholing, bridging and segregation. Numerous cement plants are plagued with bulk solids flow problems like bridging, ratholing, and flooding, each of which can negatively impact production efficiency. m. Schematic representations of challenges arising on the storage (ratholing during silo storage - a), handling (build up on powder conveying line - b) and applications of high-protein dairy powders requiring rehydration (powder clumping. Purutyan H. Carson, “Fine Powder Flow Phenomena plastic powder, food products, and pharmaceuticals. , useable) capacity, as low as only 10–20% of the bin’s rated storage capacity.