This document discusses mixing theory and equipment used for mixing. It begins by defining mixing and classifying mixing into types including mixing of solids, liquids, immiscible liquids, and semisolids. For mixing of solids, it describes factors that influence mixing and mechanisms of mixing including convective, shear, and diffusive mixing. It then discusses various types of mixing equipment for solids including tumblers, V-cone blenders, double cone blenders, ribbon blenders, sigma blenders, and planetary mixers. The document also briefly covers mixing of fluids and equipment used such as propellers and turbines.
This document discusses size reduction, which is the process of reducing drugs into smaller pieces or fine powder. It defines size reduction and lists its purposes. Factors that affect size reduction include hardness, fiber content, elasticity, melting point, and hygroscopicity. Common size reduction methods are cutting, compression, impact, attrition, and shear. Equipment used for size reduction includes cutter mills, roller mills, hammer mills, and ball mills. Cutter mills use knives to cut materials while roller mills use compression between rollers. Hammer mills rely on impact from hammers and ball mills use impact and attrition from balls within a rotating cylinder.
This document provides information about mixing in pharmaceutical processes. It defines mixing as a process that combines two or more components so that each particle is in contact with particles of the other ingredients. Ideal mixing occurs when the quantity of materials is the same in all parts of the system. The objectives, types, mechanisms, equipment, and flow patterns involved in liquid and powder mixing are described in detail. Different types of impellers like propellers, turbines, and paddles used for mixing are also explained.
Filtration is a process that separates solids from liquids or gases using a porous medium. As the suspension passes through the medium, solids are retained while the liquid or gas passes through. Key factors that affect the filtration rate include properties of the fluid and solids, concentration of solids, filter area, and resistance of the filter medium and cake buildup. The two main types of liquid filtration are cake filtration, where particles build up on the surface of the medium, and deep bed filtration, where particles penetrate the medium pores to remove fine particles from dilute suspensions. Proper filter selection depends on required filtrate quality, throughput, and operating costs. Common industrial filters include bag, plate and frame, pressure leaf,
Mixing is a general term that includes stirring, beating, blending, binding, creaming, whipping, and folding. In mixing, two or more ingredients are evenly dispersed in one another until they become one product.
The forced circulation evaporator uses a pump to circulate liquid through steam-jacketed tubes at high pressure, preventing boiling. This superheated liquid exits the tubes into a flash chamber where the sudden pressure drop causes flashing to vapor. A deflector separates the vapor from the concentrated liquid, which returns to the pump for further evaporation. Forced circulation provides efficient heat transfer, separation of phases, and suitability for concentrating thermolabile or high viscosity substances, though the equipment has higher costs due to powering the pump.
The studies influence techniques of filtration, its various types, and theories involved in the rate of filtration. This topic useful for physical pharmacy students and other concerned with filtration.
The document discusses various methods of size reduction or comminution. It describes different types of mills used for size reduction including hammer mill, ball mill, colloid mill, and fluid energy mill. The objectives of size reduction are to reduce particle size, increase surface area, improve handling and flow of powders. Factors affecting size reduction include hardness, toughness, moisture content and specific mills are described such as how a cutter mill uses cutting blades and a ball mill uses grinding balls to reduce particle size.
This document discusses size reduction, which is the process of reducing drugs into smaller pieces or fine powder. It defines size reduction and lists its purposes. Factors that affect size reduction include hardness, fiber content, elasticity, melting point, and hygroscopicity. Common size reduction methods are cutting, compression, impact, attrition, and shear. Equipment used for size reduction includes cutter mills, roller mills, hammer mills, and ball mills. Cutter mills use knives to cut materials while roller mills use compression between rollers. Hammer mills rely on impact from hammers and ball mills use impact and attrition from balls within a rotating cylinder.
This document provides information about mixing in pharmaceutical processes. It defines mixing as a process that combines two or more components so that each particle is in contact with particles of the other ingredients. Ideal mixing occurs when the quantity of materials is the same in all parts of the system. The objectives, types, mechanisms, equipment, and flow patterns involved in liquid and powder mixing are described in detail. Different types of impellers like propellers, turbines, and paddles used for mixing are also explained.
Filtration is a process that separates solids from liquids or gases using a porous medium. As the suspension passes through the medium, solids are retained while the liquid or gas passes through. Key factors that affect the filtration rate include properties of the fluid and solids, concentration of solids, filter area, and resistance of the filter medium and cake buildup. The two main types of liquid filtration are cake filtration, where particles build up on the surface of the medium, and deep bed filtration, where particles penetrate the medium pores to remove fine particles from dilute suspensions. Proper filter selection depends on required filtrate quality, throughput, and operating costs. Common industrial filters include bag, plate and frame, pressure leaf,
Mixing is a general term that includes stirring, beating, blending, binding, creaming, whipping, and folding. In mixing, two or more ingredients are evenly dispersed in one another until they become one product.
The forced circulation evaporator uses a pump to circulate liquid through steam-jacketed tubes at high pressure, preventing boiling. This superheated liquid exits the tubes into a flash chamber where the sudden pressure drop causes flashing to vapor. A deflector separates the vapor from the concentrated liquid, which returns to the pump for further evaporation. Forced circulation provides efficient heat transfer, separation of phases, and suitability for concentrating thermolabile or high viscosity substances, though the equipment has higher costs due to powering the pump.
The studies influence techniques of filtration, its various types, and theories involved in the rate of filtration. This topic useful for physical pharmacy students and other concerned with filtration.
The document discusses various methods of size reduction or comminution. It describes different types of mills used for size reduction including hammer mill, ball mill, colloid mill, and fluid energy mill. The objectives of size reduction are to reduce particle size, increase surface area, improve handling and flow of powders. Factors affecting size reduction include hardness, toughness, moisture content and specific mills are described such as how a cutter mill uses cutting blades and a ball mill uses grinding balls to reduce particle size.
The document discusses size reduction techniques. It defines size reduction as reducing substances to smaller particles through mechanical means like milling. The objectives of size reduction include improving drug dissolution and absorption. Size reduction is achieved through mechanisms like cutting, compression, impact and attrition. Factors that affect size reduction include the material properties, product requirements, and safety and economic considerations. Common equipment for size reduction discussed are hammer mills, ball mills, fluid energy mills, edge runner mills, and end runner mills.
The climbing film evaporator uses long, narrow steam-jacketed tubes to heat and evaporate liquid. As the preheated liquid rises through the tubes, bubbles form and coalesce into larger bubbles that trap liquid and rise as well. This forms a liquid film on the tube walls that rapidly vaporizes. The mixture of vapor and entrained liquid is then separated by an entrainment separator at the top, with vapor exiting and concentrated liquid collected below. Climbing film evaporators are well-suited for heat-sensitive and foaming liquids due to their short contact time and ability to break foam. However, they are also expensive to construct and maintain.
This document discusses size reduction, which is the process of reducing substances into smaller pieces or particles through mechanical means. It describes the objectives and mechanisms of size reduction and factors that affect the process. Several common size reduction machines are also outlined, including their principles, construction, uses, advantages, and disadvantages. Size reduction is an important pharmaceutical process that improves properties like dissolution rate and bioavailability by increasing surface area.
Working principle of compression machinePrashikHumane
The document discusses the working principle of compression machines used in pharmaceutical manufacturing. It describes the main components of compression machines including hoppers, dies, punches, and cam tracks. It explains the compression cycle which involves filling the die, weight adjustment, compressing the powder, and ejecting the tablet. Key process parameters that affect tablet quality such as filling depth, compression force, and turret speed are also summarized.
This document discusses various methods of size reduction. It defines size reduction as reducing the size of larger particles into smaller particles of a desired size and shape using external forces. The objectives of size reduction are listed as increasing surface area, separating constituents, achieving intimate mixing, improving handling characteristics, and facilitating disposal of solid wastes. Common size reduction mechanisms are impact, compression, attrition, and cutting. Factors that affect size reduction include properties of the materials, energy requirements, and theories like Rittinger's, Bond's, and Kick's. Common size reduction equipment discussed are hammer mills, ball mills, fluid energy mills, edge runner mills, and end runner mills.
Granulation is a process that converts small particles into larger agglomerates called granules. There are two basic types of granulation: dry granulation, which uses mechanical compression or compaction; and wet granulation, which uses a granulation liquid like a binder or solvent to form wet masses. Common granulation methods include slugging, roller compaction, fluidized bed granulation, and melt granulation. Granulation is a key unit operation in manufacturing pharmaceutical tablets and capsules to improve flow properties and uniformity.
Mixer Machines Mixer Machines are used in a number of different applications and industries in order to produce a final product that is the result of mixing or combining two or more materials.
Mixing and homogenization are important processes used to combine substances. There are several types of mixtures that can be formed including positive, negative, and neutral mixtures. The main objectives of mixing are to create a uniform mixture, promote chemical reactions, and disperse solids or liquids. Various equipment is used for mixing powders, liquids, and semi-solids depending on the application and properties of the substances. Key factors like particle size and shape, proportions, and densities must be considered to ensure proper mixing.
Filtration is a physical, biological or chemical operation that separates solid matter and fluid from a mixture with a filter medium that has a complex structure through which only the fluid can pass
This document discusses size reduction, which is the process of decreasing the size of particles through mechanical means. It defines size reduction and describes various factors that affect the process, such as hardness, moisture content, and material structure. Several common size reduction methods are also outlined, including hammer mills, ball mills, roller mills, and colloidal mills. The key theories relating to energy input and particle size are explained as well. Overall, the document provides an overview of size reduction techniques and considerations.
Industrial pharmacy
Mixing
Introduction
Importance of mixing
Types of mixtures
Fluid mixing, its mechanisms and types of fluid mixers
Semi-solid mixing, mechanism and equipments used
Solid mixing, mechansims ans types of solid mixing equipments
Introduction
Importance of mixing
Types of mixtures
Fluid mixing, its mechanisms and types of fluid mixers
Semi-solid mixing, mechanism and equipments used
Solid mixing, mechansims ans types of solid mixing equipments
Granulation is done to improve the flow and compression properties of powder mixes by preventing segregation and reducing toxic dust. It increases convenience of transport. Granulation works through adhesion, cohesion, and interfacial forces between particles when a liquid is added to form bridges or films between them. There are three main types of wet granulation equipment: shear granulators, high speed mixer/granulators, and fluidized bed granulators.
Mixer Machines Mixer Machines are used in a number of different applications and industries in order to produce a final product that is the result of mixing or combining two or more materials.
The presentation describes mixing of solid, liquid and semisolid pharmaceutical dosage forms. It includes mechanisms of solid and liquid mixing, interparticle interactions-segregation, factors affecting mixing, applications of mixing and various equipments used for mixing of pharmaceuticals.
Filtration is the process of separating solids from liquids or gases using a porous medium that allows the fluid to pass through but retains the solid particles. Key factors that affect the filtration process include particle size, quantity of suspended matter, and characteristics of the fluid. Common filtration methods include vacuum filtration using leaf or rotary filters, pressure filtration using plate and frame presses, and centrifugal filtration. The selection of the appropriate filtration method, medium, and equipment depends on the process requirements and properties of the slurry being filtered.
The sigma blade mixer consists of a double trough shaped stationary bowl with two sigma shaped blades fitted horizontally in each trough. The blades are connected to a fixed speed drive and rotate to create high shear and kneading actions through their intermeshing motion. Powders are introduced into the trough from the top and the body is covered during mixing to prevent dust or evaporation. The sigma blade mixer is commonly used for mixing dough ingredients through its ability to thoroughly blend materials with minimal dead space at a fixed speed.
This document discusses mixing and blending in the pharmaceutical industry. It defines mixing as a unit operation aimed at reducing non-uniformity in a material's properties. The main goals of mixing are producing a uniform blend and ensuring each component is in contact with the others. Mixing can involve single or multiphase systems and the types of mixtures are positive, negative, and neutral. Key mixing mechanisms for liquids include bulk transport, turbulent flow, laminar flow, and molecular diffusion. Common mixing equipment uses impellers or paddles to induce flow. Problems in mixing include segregation which depends on particle properties. Proper equipment selection considers material properties and processing factors.
This document discusses mixing of solids in the pharmaceutical industry. It defines mixing as a process that randomizes particles within a system. There are various types of mixing including mixing of solids, liquids, and semisolids. Mixing of solids can occur through mechanisms like convection, shear, and diffusion. Several factors influence solid mixing like particle properties, proportions, and equipment used. Common equipment for small-scale solid mixing includes tumbler blenders, V-cone blenders, ribbon blenders, and sigma blenders which use mechanisms like tumbling and shear to achieve mixing. Larger scale continuous mixers also exist. Statistical parameters can assess the degree and uniformity of mixing.
1. Mixing is defined as a process that randomizes particles within a system. It can involve solids, liquids, or semi-solids.
2. Common mixing equipment for solids includes tumblers, V-cone blenders, double cone blenders, ribbon blenders, and sigma blenders. Each uses different mechanisms like tumbling or shear to mix materials.
3. Liquids can be mixed using propellers, turbines, or paddles attached to an impeller inside a container. Propellers produce longitudinal movement while turbines and paddles induce turbulent flow for effective mixing.
The document discusses size reduction techniques. It defines size reduction as reducing substances to smaller particles through mechanical means like milling. The objectives of size reduction include improving drug dissolution and absorption. Size reduction is achieved through mechanisms like cutting, compression, impact and attrition. Factors that affect size reduction include the material properties, product requirements, and safety and economic considerations. Common equipment for size reduction discussed are hammer mills, ball mills, fluid energy mills, edge runner mills, and end runner mills.
The climbing film evaporator uses long, narrow steam-jacketed tubes to heat and evaporate liquid. As the preheated liquid rises through the tubes, bubbles form and coalesce into larger bubbles that trap liquid and rise as well. This forms a liquid film on the tube walls that rapidly vaporizes. The mixture of vapor and entrained liquid is then separated by an entrainment separator at the top, with vapor exiting and concentrated liquid collected below. Climbing film evaporators are well-suited for heat-sensitive and foaming liquids due to their short contact time and ability to break foam. However, they are also expensive to construct and maintain.
This document discusses size reduction, which is the process of reducing substances into smaller pieces or particles through mechanical means. It describes the objectives and mechanisms of size reduction and factors that affect the process. Several common size reduction machines are also outlined, including their principles, construction, uses, advantages, and disadvantages. Size reduction is an important pharmaceutical process that improves properties like dissolution rate and bioavailability by increasing surface area.
Working principle of compression machinePrashikHumane
The document discusses the working principle of compression machines used in pharmaceutical manufacturing. It describes the main components of compression machines including hoppers, dies, punches, and cam tracks. It explains the compression cycle which involves filling the die, weight adjustment, compressing the powder, and ejecting the tablet. Key process parameters that affect tablet quality such as filling depth, compression force, and turret speed are also summarized.
This document discusses various methods of size reduction. It defines size reduction as reducing the size of larger particles into smaller particles of a desired size and shape using external forces. The objectives of size reduction are listed as increasing surface area, separating constituents, achieving intimate mixing, improving handling characteristics, and facilitating disposal of solid wastes. Common size reduction mechanisms are impact, compression, attrition, and cutting. Factors that affect size reduction include properties of the materials, energy requirements, and theories like Rittinger's, Bond's, and Kick's. Common size reduction equipment discussed are hammer mills, ball mills, fluid energy mills, edge runner mills, and end runner mills.
Granulation is a process that converts small particles into larger agglomerates called granules. There are two basic types of granulation: dry granulation, which uses mechanical compression or compaction; and wet granulation, which uses a granulation liquid like a binder or solvent to form wet masses. Common granulation methods include slugging, roller compaction, fluidized bed granulation, and melt granulation. Granulation is a key unit operation in manufacturing pharmaceutical tablets and capsules to improve flow properties and uniformity.
Mixer Machines Mixer Machines are used in a number of different applications and industries in order to produce a final product that is the result of mixing or combining two or more materials.
Mixing and homogenization are important processes used to combine substances. There are several types of mixtures that can be formed including positive, negative, and neutral mixtures. The main objectives of mixing are to create a uniform mixture, promote chemical reactions, and disperse solids or liquids. Various equipment is used for mixing powders, liquids, and semi-solids depending on the application and properties of the substances. Key factors like particle size and shape, proportions, and densities must be considered to ensure proper mixing.
Filtration is a physical, biological or chemical operation that separates solid matter and fluid from a mixture with a filter medium that has a complex structure through which only the fluid can pass
This document discusses size reduction, which is the process of decreasing the size of particles through mechanical means. It defines size reduction and describes various factors that affect the process, such as hardness, moisture content, and material structure. Several common size reduction methods are also outlined, including hammer mills, ball mills, roller mills, and colloidal mills. The key theories relating to energy input and particle size are explained as well. Overall, the document provides an overview of size reduction techniques and considerations.
Industrial pharmacy
Mixing
Introduction
Importance of mixing
Types of mixtures
Fluid mixing, its mechanisms and types of fluid mixers
Semi-solid mixing, mechanism and equipments used
Solid mixing, mechansims ans types of solid mixing equipments
Introduction
Importance of mixing
Types of mixtures
Fluid mixing, its mechanisms and types of fluid mixers
Semi-solid mixing, mechanism and equipments used
Solid mixing, mechansims ans types of solid mixing equipments
Granulation is done to improve the flow and compression properties of powder mixes by preventing segregation and reducing toxic dust. It increases convenience of transport. Granulation works through adhesion, cohesion, and interfacial forces between particles when a liquid is added to form bridges or films between them. There are three main types of wet granulation equipment: shear granulators, high speed mixer/granulators, and fluidized bed granulators.
Mixer Machines Mixer Machines are used in a number of different applications and industries in order to produce a final product that is the result of mixing or combining two or more materials.
The presentation describes mixing of solid, liquid and semisolid pharmaceutical dosage forms. It includes mechanisms of solid and liquid mixing, interparticle interactions-segregation, factors affecting mixing, applications of mixing and various equipments used for mixing of pharmaceuticals.
Filtration is the process of separating solids from liquids or gases using a porous medium that allows the fluid to pass through but retains the solid particles. Key factors that affect the filtration process include particle size, quantity of suspended matter, and characteristics of the fluid. Common filtration methods include vacuum filtration using leaf or rotary filters, pressure filtration using plate and frame presses, and centrifugal filtration. The selection of the appropriate filtration method, medium, and equipment depends on the process requirements and properties of the slurry being filtered.
The sigma blade mixer consists of a double trough shaped stationary bowl with two sigma shaped blades fitted horizontally in each trough. The blades are connected to a fixed speed drive and rotate to create high shear and kneading actions through their intermeshing motion. Powders are introduced into the trough from the top and the body is covered during mixing to prevent dust or evaporation. The sigma blade mixer is commonly used for mixing dough ingredients through its ability to thoroughly blend materials with minimal dead space at a fixed speed.
This document discusses mixing and blending in the pharmaceutical industry. It defines mixing as a unit operation aimed at reducing non-uniformity in a material's properties. The main goals of mixing are producing a uniform blend and ensuring each component is in contact with the others. Mixing can involve single or multiphase systems and the types of mixtures are positive, negative, and neutral. Key mixing mechanisms for liquids include bulk transport, turbulent flow, laminar flow, and molecular diffusion. Common mixing equipment uses impellers or paddles to induce flow. Problems in mixing include segregation which depends on particle properties. Proper equipment selection considers material properties and processing factors.
This document discusses mixing of solids in the pharmaceutical industry. It defines mixing as a process that randomizes particles within a system. There are various types of mixing including mixing of solids, liquids, and semisolids. Mixing of solids can occur through mechanisms like convection, shear, and diffusion. Several factors influence solid mixing like particle properties, proportions, and equipment used. Common equipment for small-scale solid mixing includes tumbler blenders, V-cone blenders, ribbon blenders, and sigma blenders which use mechanisms like tumbling and shear to achieve mixing. Larger scale continuous mixers also exist. Statistical parameters can assess the degree and uniformity of mixing.
1. Mixing is defined as a process that randomizes particles within a system. It can involve solids, liquids, or semi-solids.
2. Common mixing equipment for solids includes tumblers, V-cone blenders, double cone blenders, ribbon blenders, and sigma blenders. Each uses different mechanisms like tumbling or shear to mix materials.
3. Liquids can be mixed using propellers, turbines, or paddles attached to an impeller inside a container. Propellers produce longitudinal movement while turbines and paddles induce turbulent flow for effective mixing.
This document discusses mixing theory and equipment used for mixing in the pharmaceutical industry. It begins by defining mixing and classifying mixing into different types including mixing of solids, liquids, and semisolids. It then describes various mechanisms of mixing solids including convective, shear, and diffusion mixing. Key factors that influence mixing of solids like particle properties and interparticle forces are explained. Common equipment for mixing solids in small and large scale are then outlined including tumble blenders, V-cone blenders, double cone blenders, and those with mixing blades. Parameters for effective mixing and evaluating mixing are also summarized.
This document discusses mixing theory and equipment used for mixing. It begins by defining mixing and classifying mixing into types including mixing of solids, liquids, and semisolids. It then describes various mechanisms of mixing like convective mixing, shear mixing, and diffusion mixing. It provides details on factors influencing mixing of solids and statistical parameters used to evaluate mixing. The document also classifies and describes various types of mixing equipment used for solids and liquids along with their principles, construction, working, advantages and applications.
1. The document discusses different types of mixing operations used in food processing, including mixing of solids, liquids, and semisolids.
2. It describes various factors that influence mixing like particle size, shape, density, and surface properties.
3. Several common mixing equipment are outlined, including tumbler mixers, V-cone blenders, double cone blenders, ribbon blenders, and sigma blade mixers. Each have advantages and limitations for certain mixing applications.
The document discusses mixing and homogenization. Mixing is defined as combining two or more substances to form a uniform mixture. It can be done to liquids, powders, or semi-solids using various types of equipment like propeller mixers, double cone mixers, and planetary mixers. Homogenization is converting a non-uniform mixture into a uniform colloidal mixture by reducing particle size, using equipment like hand homogenizers, Silverson mixer homogenizers, and colloidal mills. The key principles and processes involved in mixing and homogenization are explained.
This document discusses different types of mixers and mixing processes. It defines mixing as a unit operation that results in randomization of particles within a system. There are three types of mixtures - positive, negative, and neutral - based on how their components mix and separate. Mixing is commonly used in pharmaceutical formulations to prepare powders, liquids, semi-solids and other dosage forms. Factors like particle size and shape, moisture levels, and material properties influence mixing effectiveness. Common mixers include double cone blenders, V-cone blenders, and those with added agitation blades. Each has merits like handling capacity but also limitations depending on material flow properties.
Amidst the verdant foliage, a **lush bush** unfurls its vibrant petals, each a crimson stroke against the canvas of the sky. The gentle sunlight** weaves through leaves, illuminating this botanical masterpiece. 🌼
This document discusses different types of mixing operations used in pharmaceutical manufacturing. It describes mixing of powders, liquids, and semi-solids. For powder mixing, it outlines factors that affect mixing like particle size and shape. Common mixers discussed include double cone blenders and agitated powder mixers. For liquid mixing, mechanisms like bulk transport and turbulent transport are described. Equipment like propeller mixers and turbine mixers are used. Semi-solid mixing involves dispersion in a base using mixers like triple roller mills and planetary mixers.
This document discusses mixing in the manufacture of cosmetics. It defines mixing and describes factors that influence the mixing process. The objectives and mechanisms of mixing are explained. Positive, negative and neutral mixtures are defined. Methods for mixing solids, fluids and semi-solids are outlined. Common mixing equipment for each type is described, including twin shell blenders, double cone blenders, propellers, turbines, and paddles.
This document discusses mixing in pharmaceutical manufacturing. It defines mixing as a process that randomizes particles within a system. The objectives of mixing include achieving a physical mixture, promoting chemical reactions, and heat and mass transfer. Mixing can involve solids, liquids, or semi-solids and occurs through mechanisms like convection, shear, and diffusion. Proper mixing is important to ensure a homogenous product, while segregation should be avoided. Various mixing equipment and considerations for mixer selection are also outlined.
This document discusses mixing in pharmaceutical applications. It defines mixing as putting together components so that particles are in contact with each other. The objectives of mixing are to achieve uniform composition and promote reactions. Mixing is used in processes like granulation, direct compression, and capsule filling. Factors like particle properties, proportions, and equipment used can affect mixing. The mechanisms of solid, liquid, and semisolid mixing are explained. Different mixing equipment and their workings are also presented.
Presentation tablet production madhu k sMadhu Honey
The document discusses the key equipment and processes used in tablet production, including size reduction equipment, mixers, granulators, dryers, tablet presses, and quality control equipment. It describes the main methods of tablet formulation as direct compression, dry granulation, and wet granulation. For wet granulation specifically, it outlines the steps of milling, weighing, mixing, wet massing using high-shear or fluid-bed granulators, drying granules, screening, lubricating, and compressing into tablets.
Mixing, the seemingly simple act of combining various components, plays a pivotal role in numerous scientific and industrial processes. From stirring milk in your coffee to homogenizing nanoparticles in pharmaceuticals, understanding mixing mechanisms and types is crucial. This note delves into the world of mixing, exploring its depths within 3000 words.
Part 1: Unveiling the Mixing Landscape
1.1 Demystifying Mixing:
Mixing refers to the process of bringing different components into close contact to achieve uniformity. The degree of mixing, characterized by homogeneity or dispersion, is influenced by several factors like viscosity, density differences, and mixing methods.
1.2 Classifying the Mixers:
A plethora of mixing methods exist, each suited for specific applications. Here are some key categories:
Bulk Mixing: Aims for complete homogeneity throughout the entire volume, commonly used in liquids and pastes. Techniques include stirred tanks, blenders, and extruders.
Dispersive Mixing: Focuses on distributing smaller particles or droplets uniformly within a continuous phase. Homogenizers, colloid mills, and sonication are frequently employed.
Laminar Mixing: Utilizes repeated folding or stretching operations to achieve layering and eventual homogenization. Microfluidic devices and some bakery processes use this principle.
Turbulent Mixing: Introduces chaotic eddies and high shear forces to rapidly break down concentration gradients. Stirred tanks with impellers, jet mixers, and fluidized beds are examples.
1.3 Factors Affecting Mixing:
Several factors impact the efficiency and effectiveness of mixing:
Properties of the Materials: Viscosity, density differences, and particle size significantly influence mixing behavior.
Mixing Geometry and Flow Patterns: The shape and configuration of the mixing vessel and the resulting flow patterns determine mixing intensity and uniformity.
Mixing Time and Intensity: The duration and intensity of mixing are crucial for achieving the desired level of homogeneity.
External Forces: Application of additional forces like heat, ultrasound, or magnetic fields can enhance mixing in specific scenarios.
Part 2: Delving into Specific Mixing Types:
Understanding specific mixing types helps in selecting the most effective method for each application:
Stirred Tank Mixing: This versatile method uses rotating impellers to generate flow and achieve moderate to high shear mixing. Variations include impeller design, tank geometry, and baffles.
Fluidized Bed Mixing: Solids are suspended in a gas stream, creating a fluid-like behavior and enabling efficient mixing of granular materials.
Jet Mixing: High-velocity jets inject material into the mix, promoting rapid dispersion and homogenization. Used in pipelines and reactors.
Microfluidic Mixing: Utilizes microchannels to manipulate flow patterns and achieve precise mixing at small scales, oft
Mixing is a key process in pharmaceutical manufacturing that involves combining ingredients in a uniform manner. There are several types of mixers that employ different mechanisms like shear, convection, and diffusion to achieve mixing. Factors like particle size and shape, proportions, viscosity, and temperature can influence the mixing process. Common applications of mixing in pharmaceuticals include granulation, direct compression tableting, and capsule filling. The selection of an appropriate mixer depends on factors like the materials involved, the scale of production, and desired mixing action.
Mixing: Objectives, applications & factors affecting mixing,
Difference between solid and liquid mixing,
mechanism of solid mixing, liquids mixing and semisolids mixing.
Principles, Construction, Working, uses, Merits and Demerits of Double cone blender
Principles, Construction, Working, uses, Merits and Demerits of twin shell blender
Principles, Construction, Working, uses, Merits and Demerits of ribbon blender
Principles, Construction, Working, uses, Merits and Demerits of Sigma blade mixer
Principles, Construction, Working, uses, Merits and Demerits of planetary mixers
Principles, Construction, Working, uses, Merits and Demerits of Propellers
Principles, Construction, Working, uses, Merits and Demerits of Turbines
Principles, Construction, Working, uses, Merits and Demerits of Paddles
And
Principles, Construction, Working, uses, Merits and Demerits of Silverson Emulsifier.
This presentation contains all information on mixing and different mixing equipment used in food industry. The different equipment includes those for solids, liquids and semi solids. It consist of tumbling mixers, rotational screw mixers, agitators, impellers, paddle mixers, planetary mixers and so much more.
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
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Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
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2. Mixing is defined as a process that tends to
result in a randomization of dissimilar particles within a system.
• The term MIX means to put together in one mass.
• The term BLENDING means to mix smoothly and inseparably
together during which a minimum energy is imparted to the bed.
• The terms MIXING and BLENDING are commonly used
interchangeable in the pharmaceutical industry.
3. Classification of mixing
A. Mixing of solids
B. Mixing of liquids
C. Mixing of immiscible liquids
D. Mixing of semisolids
4. A. Mixing of solids
• In the manufacture of tablets or granules normally a number of additives are
added. Therefore mixing of powder becomes essential part of the process.
• Mixing is considered as a critical factor, especially in case of potent drugs and
low dose drugs where high amounts of adjuvants are added.
• The diverse characteristics of particles such as size shape volume surface area
density porosity flow charge contribute to the solid mixing.
• Depending on their flow properties solids are divided into two classes as
cohesive and non cohesive.
5. Interparticleinteractions&
segregation
1.Inertialforces:
These forces hold neighboring particles in fixed relative
position.
E.g.: Vander Waal forces, electrostatic forces, surface forces.
Surface forces:
Cohesive forces and frictional forces results in surface-surface
interactions which resist the movement of particles, hence they should
be minimal.
.
These depend on surface area, surface roughness, polarity, charge,
moisture.
6. Segregation
• Poor flow properties.
• Particle size difference.
• Difference in mobilities.
• Differences in particle density and shape.
• Transporting stage.
• Dusting stage.
It may occur even after mixing.
7. 2. Gravitational forces
• Improve the movement of two adjacent particles or groups of
particles
• When particle-particle collisions occur , exchange of momentum is
achieved continuous exchange or distribution of momentum
between transitional and rotational modes is necessary for effective
mixing
• Efficiency of momentum transfer depends on
Elasticity of the collisions
Coefficient of friction
Surface area of contact
Centrifugal forces
8. Mechanism of mixing of solids
1. Convective mixing/Macro mixing:
Inversion of the powder bed using blades or paddles or
screw element, in which large mass of material moves from one
place to another.
2. Shear mixing:
In this type, forces of attraction are broken down so that
different
each particle moves on its own between regions of
components and parallel to their surface.
3. Diffusion mixing/Micro mixing:
Involves the random motion of particle within the
powder bed, thereby particles change their position relative to one
another.
9. • In the solid-solid mixing operations , four steps are involves.
These are:
1. Expansion of the bed of solids
2. Application of 3-dimensional shear forces to the powder bed.
3. Mix long enough to permit true randomization of particles.
4. Maintain randomization.
10. The law of mixing appears to follow first order,
𝑴 = 𝑨 (𝟏 − 𝒆−𝒌𝒕)
Where M = degree of mixing after time t,
T = time
A and k = constants
A and k depends on the
Mixer geometry
Physical characteristics of the powders and
Proportion of the material being mixed.
11. Degree of mixing
• Ideal mixing or perfect mixing:
• Acceptable mixing:
1. Random mixing
2. Ordered mixing
– Mechanical means of ordered mixing
– Adhesion means of ordered mixing
– Coating means of ordered mixing
13. Statistical
parameters
• Mixing should be continued until the amount of the active drug that
is required is with in ± 3 SD units that of found by assay in a
representative number of sample dose.
Relative standard deviation:
• It replace the S.D as a measure of sample uniformity.
• Useful for comparing the efficiency of two or more mixing operations or
different sample size or different composition.
𝑚𝑒𝑎𝑛 ȳ
𝑝𝑒𝑟𝑐𝑒𝑛𝑡 𝑟𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑆. 𝐷 =
𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑑𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛(𝜎)
𝑋100
Arithmetic mean:
Size distribution is calculated
Arithmetic mean ȳ = 𝑖
𝑛 𝑦
𝑛
Standard deviation:
Used to know the spread of dispersion.
Standard deviation 𝜎 =
𝑛(𝑦𝑖−ȳ)2
(𝑛−1)
14. Mixing indices
• Involves the comparison of SD of sample of a mixture under
study with the estimated standard deviation of a completely
random mixture.
• It can be expressed -
𝑀 = or 𝑀 =
𝜎𝑅 𝜎𝑜 −𝜎
𝜎 𝜎𝑜 − 𝜎𝑅
Where,
M =mixing index
𝜎𝑅=standard deviation of the random blend
𝜎 =standard deviation of the sample blend
𝜎𝑜 =standard deviation of the unmixed powder
15. Factors influencing mixing
• Nature of the surface
• Density of the particles
• Particle size
• Particle shape
• Particle charge
• Proportion of materials
16. EQUIPMENT
Criteria:
1. Powder bed should not be filled for more than 60%
2. Particles should be subjected to movement in three
directions
3. Shearing force should be sufficient to prevent
aggregation.
4. There should be no centrifugal effect
5. Forces should not cause breakage of the particles.
6. The mixing process should be stopped abruptly.
17. Classification of equipment for solid mixing
• Based on flow properties:
1.Free flowing solids:
e.g.: V cone blend , Double cone blender
2.Cohesive solids:
e.g.: Sigma blender, Planetary mixer
• Based on scale of mixing:
1.Batch type(small scale):
e.g.: Mortar and pestle, V cone blender, Double cone blender,
Ribbon blender, Sigma blender, Planetary paddle, Fluidized
mixer
2.Continuous type(large scale):
e.g.: barrel type, zigzag type
18. S.no. Nature of mixer Examples Mechanism of
mixing
1 Batch type Mortar pestle Trituration
2 Tumbling mixers or cylindrical
mixers with no mixing blade
Double cone blender
V cone blender
Tumbling action
3 Tumbling mixer with a mixing
blade
V cone blender double
cone blender
Tumbling action as
well as shearing with
blade
4 Static mixers Ribbon blender
Sigma blender
Planetary paddle
Stationary shell and
rotating blade
5 Air mixers or fluidized mixers Fluidized mixer Air supported
blending
6 Continuous type Barrel type
Zigzag type
Rotating shell with
rotating blade
19. Tumblersorcylindrical blenders
with nomixing blade
• Meant for dry powders
• Equipment consists of a container of any geometric form.
• Container is mounted on special roller so that it can be rotated about any
axis.
• Edge of 27 degrees is good for mixing.
• Efficiency of a tumbler mixer highly depends on the speed of rotation. It
should be critical and optimum.
• Slow rotation- no intense tumbling, No cascade motion, Not enough shear
rates are applied.
• Rapid rotation-sufficient centrifugal action to the powder to the side of
the mixer, more dusting and segregation of fines is possible.
• Rate of rotation depends upon size , shape of the tumbler and nature of
the material to be mixed. Common range is 30-100rpm.
• Mixing is done by tumbling motion, which is accentuated by virtue of the
shape of the container.
20. TwinshellblenderorV cone
blender
• It is V shaped and made up of stainless
steel or transparent plastic.
• Material is loaded through shell hatches
and emptying is normally done through
and apex port.
• The material is loaded approximately
50-60% of the total volume.
• Small models – 20 kg , rotate at 35rpm
• Large models – 1 ton, rotate at 15rpm
• As the blender rotates , the material
undergoes tumbling motion.
• When V is inverted, the material splits
into two portions. This process of
dividing and recombining continuously
yields ordered mixing by mechanical
means.
21. Doubleconeblender
• It consists of double cone on rotating shaft.
• It is usually used for small amount of
powders.
• It is efficient for mixing powders of
different densities.
• Material is loaded and emptying is done
through the same port.
• The rate of rotation should be optimum
depending upon the size, shape of the
tumbler and nature of the material to be
mixed.
• The rate of rotation commonly ranges from
30-100rpm.
• Mixing occurs due to tumbling motion. Double cone
blender
22. AdvantagesofV coneblenderanddoublecone blenders:
• If fragile granules are to be blended, twin shell blender is suitable
because of minimum attrition.
• They handle large capacities.
• Easy to clean , load, and unload.
• This equipment requires minimum maintenance.
Disadvantages ofV coneblenderanddoubleconeblenders:
• Twin shell blender needs high headspace for installation.
• It is not suitable for fine particulate system or ingredients of large
differences in the particle size distribution, because not enough
shear is applied.
• If powders are free flowing, serial dilution is required for the
addition of low dose active ingredients.
24. Advantagesof tumblerswith
blades:
• Baffles areuseful for bothwet anddry mixing.
• Wide range ofshearing forcecan beapplied with agitatorbars permitting
theintimate mixingofvery fine aswell ascoarse powders.
• Serial dilution is notneededwhen incorporating low-doseactive
ingredients.
Disadvantagesoftumblerswith blades:
• Attrition is large, sizereductionoffriable particlesresults.
• Scale-up can prove aproblem, becausegeneralprinciples ofscale-updo
notwork
• Cleaning may beaproblem, becauseagitatorassemblymustberemoved
andthepackingshouldbereplacedfor aproduct changeover
• Potentialpacking(sealing) problemsoccur.
25. Ribbonblender
Principle:
Mechanism of mixing is shear. Shear is
transferred by moving blades. High shear rates
are effective in breaking lumps and aggregates.
Convective mixing also occurs as the powder bed
is lifted and allowed to cascade to the bottom of
the container. An equilibrium state of mixing can
be achieved.
Construction:
• Consists of horizontal cylindrical trough
usually open at the top. It is fitted with two
helical blades, which are mounted on the
same shaft through the long axis of the
trough.
• Blades have both right and left hand twists.
• Blades are connected to fixed speed drive.
• It can be loaded by top loading and emptying
is done through bottom port.
26. Working:
Uses:
Used for mixing of finely divided solids, wet solid mass, and
plastic solids.
Uniform size and density materials can be easily mixed.
Used for solid – solid and liquid – solid mixing.
27. Advantages of ribbon
blender:
• High shearcan beapplied by usingperforated baffles,
which bring abouta rubbing andbreakdown
aggregates.
• Headroomrequires less space.
Disadvantagesofribbonblender:
• It is a poor mixer, becausemovementofparticles is two
dimensional..
• Shearing action is lessthan in planetary mixer.
• Dead spotsare observed in themixer, though they are
minimum.
• It hasfixedspeeddrive.
28. Sigmablademixer
Principle – shear. Inter meshing of sigma
blades creates high shear and kneading action.
Construction and working:
• It consists of double tough shaped stationary bowl.
• Two sigma shaped blades are fitted horizontally in
each tough of the bowl.
• These blades are connected to a fixed speed drive.
• Mixer is loaded from top and unloaded by tilting the
entire bowl.
• The blades move at different speeds , one about
twice than the other, which allows movement of
powder from sides to centers.
• The material also moves top to downwards and gets
sheared between the blades and the wall of the
tough resulting cascading action.
• Perforated blades can be used to break lumps and
aggregates which creates high shear forces.
• The final stage of mix represents an equilibrium
state.
Sigma blade mixer
29. Usesof sigmablade
mixer:
• Usedin thewet granulation processin themanufacture of
tablets, pill massesand ointments,
• It is primarily usedfor liquid – solid mixing,although itcan
beusedfor solid – solid mixing.
Advantagesofsigmablademixer:
• Sigmablademixer createsaminimumdeadspaceduring
mixing.
• It hasclosetolerances betweenthebladesandthesidewalls as
well asbottomofthemixer shell.
Disadvantagesofsigmablade mixer:
• Sigmablademixer works at afixed speed.
30. Planetarymixer
Principle:
Mechanism of mixing is shear. Shear is
applied between moving blade and stationary
wall. Mixing arm moves around its own axis and
around the central axis so that it reaches every
spot of the vessel. The plates in the blades are
sloped so that powder makes an upward
movement to achieve tumbling action also.
Construction:
• Consists of vertical cylinder shell which can be
removed.
• The blade is mounted from the top of the
bowl.
• Mixing shaft is driven by planetary gear and it
is normally built with variable speed drive.
31. Uses :
• Break down agglomerates rapidly.
• Low speedsare usedfor dry blendingand fastfor wet
granulation.
Advantages:
• Speedofrotation can bevaried at will.
• More useful for wet granulation process.
Disadvantages:
• Mechanical heatisbuildup within thepowder mix.
• It requires highpower.
• It haslimited sizeand isuseful for batch work only.
32. Applications of solid mixing
• Involved in the preparation of many types of
formulations.
• It is also an intermediate stage in the production
of several dosage forms.
– Wet mixing in the granulation step in the production
of tablets and capsules.
– Dry mixing of several ingredients ready for direct
compression as in tablets.
– Dry blending of powders in capsules, dry syrups and
compound powders.
– Production of pellets for capsules.
33. B. Mixing of Fluids
Mechanism:
• Bulk transport: Movement of large portion o a material from one location to
another location in a give system. Rotating blades and paddles are used.
• Turbulent mixing: Highly effective, mixing is due to turbulent flow which
results in random fluctuation of the fluid velocity at any given point within
the system. Fluid velocity at a given point changes in 3 directions (X, Y and Z).
• Laminar mixing: Mixing of two dissimilar liquids through laminar flow, i.e.,
applied shear stretches the interface between them. Suitable for liquids
which require moderate mixing.
• Molecular diffusion: Mixing at molecular level in which molecules diffuse due
to thermal motion.
35. Mixing Device
• Based on shape and pitch , the are classified into 3
types,
»Propellers
»Turbines
»Paddles
36. Propellers
• It consists of number of blades, generally 3 bladed
design is most common for liquids. Blades may be
right or left handed depending upon the slant of their
blades.
• Two are more propellers are used for deep tank.
• Size of propeller is small and may increased up to
0.5metres depending upon the size of the tank.
• Small size propellers can rotate up to 8000rpm and
produce longitudinal movement.
37. Advantagesofpropellers:
Used when high mixing capacity is required.
Effective for liquids which have maximum viscosity of 2.0pascals.sec
or slurry up to 10% solids of fine mesh size.
Effective gas-liquid dispersion is possible at laboratory scale.
Disadvantagesofpropellers:
Propellers are not normally effective with liquids of viscosity greater
than 5pascal.second, such as glycerin castor oil, etc.,
38. Turbines
• A turbine consists of a circular disc to
which a number of short blades are
attached. Blades may be straight or
curved.
• The diameter of the turbine ranges from
30-50% of the diameter of the vessel.
• Turbines rotates at a lower speed than the
propellers (50-200rpm).
• Flat blade turbines produce radial and
tangential flow but as the speed increases
radial flow dominates. Pitched blade
turbine produces axial flow.
Near the impeller zone of rapid currents, high turbulence and
intense shear is observed. Shear produced by turbines can be further
enhanced using a diffuser ring (stationary perforated ring which surrounds
the turbine).
Diffuser ring increase the shear forces and liquid passes
through the perforations reducing rotational swirling and vortexing.
39. Advantages of Turbines:
• Turbines give greater shearing forces
than propellers through the pumping
rate is less. Therefore suitable for
emulsification.
• Effective for high viscous solutions
with a wide range of viscosities up to
7.0 Pascal. Second.
• In low viscous materials of large volumes turbine create a strong
currents which spread throughout the tank destroying stagnant
pockets.
• They can handle slurries with 60% solids.
• Turbines are suitable for liquids of large volume and high
viscosity, if the tank is baffled.
40. Paddles
• A paddle consists of a central hub with
long flat blades attached to it vertically.
• Two blades or four blades are common.
sometimes the blades are pitched and
may be dished or hemispherical in
shape and have a large surface area in
relation to the tank in which they are
used.
• Paddles rotates at a low speed of
100rpm.
• They push the liquid radially and tangentially with almost no axial action unless
blades are pitched.
• In deep tanks several paddles are attached one above the other on the same
shaft.
• At very low speeds it gives mild agitation in unbaffled tank but as for high speeds
baffles are necessary.
41. Usesof
paddles:
Paddles are used in
the manufacture of antacid
suspensions, agar and pectin
related purgatives, antidiarrheal
mixtures such as bismuth-
kaolin.
Advantagesofpaddles:
Vortex formation is not
impellers because of low speed mixing.
possible with paddle
Disadvantagesofpaddles:
Mixing of the suspension is poor therefore baffled
tanks are required.
42. Factorsinfluencingmixingofliquidsintanks
Material related factors-
– Properties of liquids: physical properties of materials to be
mixed. e.g.: Density, Viscosity and miscibility.
Equipment related factors-
– Shape of impeller: Propeller type, straight, vertical, curved, or pitched.
– Position of impeller: Central, off-center, side entry, vertical or inclined etc.,
– Shape and size of the container: cylindrical or other geometric forms.
Presence or absence of baffles.
– Cost of equipment and its maintenance.
Process related factors-
– Speed of rotation of the impeller.
– Time required for mixing.
– Amount of power that can be expended.
– Ease of operation.
– Batch size.
43. Advantages of liquid mixing
• Liquid mixing promotes heat transfer between liquid
and a heating source. This step is essential in the
crystallization of drug substances. Uniform heat
transfer in the solution yields crystals of same size.
• Liquid mixing is essential in the manufacture of
number of dosageforms.
E.g.:
– Suspensions
– Emulsions
– Solutions
– Aerosols
44. C
. Mixing of immiscible Liquids
Carried mainly in the manufacture of emulsions, and the
equipment used for the preparation of an emulsion is known as emulsifier. Also
known as homogenizer as it results in fine emulsion.
Fine emulsion is prepared in 2 stages.
In 1st stage coarse emulsion is prepared by using one of the following
process:-
– Wedge wood
– Mechanical blender
– Hand homogenizer
– Porcelain mortar and pestle
– Milk shake mixer
– Propeller in a baffled tank
Some times the above equipment directly gives fine emulsion.
Otherwise coarse emulsion is subjected to homogenizer in the 2nd
stage to get fine emulsion by using following process:-
– Silverson emulsifier
– Colloidal mill
– Rapisonic homogenizer
45. Factorsinfluencing selectionof
an emulsifier
1. Quantity of emulsion to be prepared: batch wise or
continuous operation
2. Flow properties of liquids: Newtonian, plastic, pseudo
plastic or dilatant.
3. Temperature maintenance: mixing will
be effective at high temperatures provided the material is
stable.
4. Desired rate of cooling: if elevated temperatures are
applied
47. Silverson mixer -Emulsifier
Principle:
• It produces intense shearing forces and
turbulence by use of high speed rotors.
• Circulation of material takes place through
the head by the suction produced in the
inlet at the bottom of the head.
• Circulation of the material ensures rapid
breakdown of the dispersed liquid into
smaller globules.
• It consists of long supporting columns and
a central portion. Central portion consists
of a shaft which is connected to motor at
one end and other to the head.
• Head carries turbine blades.
• Blades are surrounded by a mesh, which is
further enclosed by a cover having
openings.
48. Uses:
• Used for the preparation of emulsions and creams
of fine particle size.
Advantages:
• Silver son mixer is available in different sizes to
handle the liquids ranging from a few milli liters
to several thousand liters.
• Can be used for batch operations as well as for
continuous operations by incorporating into a
pipeline, through which the immiscible liquids
flow.
• Disadvantages:
• Occasionally, there is a chance is clogging of
pores of the mesh.
49. D. Mixing of semisolids
• Semi solids dosageforms include ointments, pastes, creams, jellies, etc., while
mixing such dosageforms , the material must be brought to the agitator or
the agitator must move the material throughout the mixer.
• The mixing action include combination of low speed shear, smearing, wiping,
folding, stretching and compressing.
• A large amount of mechanical energy is applied to the material by moving
parts. Sometimes a part of the supplied energy appears as heat.
• The forces required for efficient mixing are high and consumption of power is
also high. Hence the equipment must be rugged constructed to tolerate
these forces.
• Some semisolids exhibit dilatant property i.e., viscosity increases with
increase in shear rates. Therefore, mixing must be done at lower speeds.
• The speed must be changed accordingly to thixotropic, plastic and pseudo
plastic materials.
50. Classification of
equipment
• Agitatormixers:
e.g.:- Sigma mixers and Planetary mixer.
• Shear mixers:
e.g.:- Triple roller mill and Colloidal mill.
Selection of mixing equipment for semi
solids
• Physical properties of the materials – density viscosity and
miscibility.
• Economic considerations regarding processing – time required
for mixing and power consumption.
• The cost of equipment and its maintenance.
51. Triple roller
mill
Principle:- High shear , which causes
crushing of aggregates, particles and also
distributes the drug uniformly throughout
the semi solid base.
• It consists of 3 parallel rollers of equal
diameters made up of stainless steel.
• These are mounted on rigid frame
work horizontally.
• The gap between the first 2 rollers is
more than that of the gap between
the last two.
• A hopper is placed in between the first
two rollers.
• A scrapper is attached to the last roller.
• First roller rotates at lower speed
compared to the 2nd similarly 2nd roller
speed is less than the 3rd roller.
52. Advantagesoftriplerollermill
• From the small to the large batch - Three roll mills are ideally
suited for processing the smallest and also very large quantities.
• Excellent temperature control - Three roll mills enable excellent
control of the product temperature, since the product is processed
as a thin film on the roller. This way, the product can be warmed or
cooled off depending on your requirements.
• Avoid contamination - Through the selection of materials for the
rollers and scraper knives, which are available in a broad spectrum
of chrome-plated steel, aluminium oxide, zirconium oxide, and
silicon carbide, it is possible to avoid product contamination due to
metal abrasion.
• Extremely uniform dispersion is obtained.
• low material loss.
• easy cleaning.