Skip to main content

Renin Angiotensin Mechanism.

Filtration: Meta Filter.

 

Meta Filter:

Principle:

  • Mechanism is surface filtration.

  • In this, metal rings contain semicircular projections, which are arranged as a nest to form channels on the edges.

  • This channel offers resistance (strainer) to the flow of solids (coarse particles).

  • The clear liquid is collected into the receiver from the top. 

Construction:

  • Metafilter consists of a series of metal rings.

  • These are threaded so that a channel is formed on the edges.

  • It contains a grooved drainage column on which a series of metal rings are packed.

  • These rings are usually made up of stainless steel and have dimensions of about 15.0 mm internal diameter and 22.0 mm external diameter.

  • Each metal ring has a number of semicircular projections (0.8 mm in thickness) on one side of the surface.

  • The projections are arranged as a nest to form channels on the edges.

  • These rings are tightened on the drainage column with a nut.

  • Meta Filters are also known as edge filters. 

Working:

  • Filters are placed in a vessel

  • Slurry is pumped under pressure or occasionally by applying reduced pressure to the outlet side

  • Slurry passes through the channels formed on the edges between the rings

  • The clear liquid rises up and collected from the outlet into receiver

  • For separation of fine particles, a bed of suitable materials such as kieselguhr is first built up.

  • The pack of rings serves essentially as a base on which the true filter medium is supported. 

Advantages of filter leaf:

  1. Can be used under high pressures, without any danger of bursting the filter medium.

  2. Running cost is low, as separate filter medium is not used. 

  3. Can be constructed from a material that can provide excellent resistance to corrosion and avoid contamination of sensitive products.

  4. It is an extremely versatile filter because fine as well as large both types of particles can be separated.

  5. Removal of cake can be carried out by simply back- flushing with water.

  6. Change over from one batch to another or one product to another is easy.

  7. Sterile products can be handled. 

Disadvantages of meta filter:

  1. It is not a continuous process.

  2. It is used where the proportion of solid in the liquid to be filtered is about  5% or less.

Uses:

  • Meta Filters are usually used for-

  1. Clarification of syrups.

  2. Filtration of injection solutions.

  3. Clarification of insulin liquors.

  4. Filtration of viscous liquids can be achieved by applying pressure.

Labels:

Popular posts from this blog

Rate of Drying Curve.

  Definition Drying is defined as the removal of liquid from a product usually with application of heat. Rate of Drying Curve. Drying process can be divided into three periods Initial Adjustment Period. Constant drying rate period. First falling drying rate period. Second falling rate period. Initial Adjustment Period (A-B): Also called the “ Heating up” period . In this period the substance gets heat and increases in temperature. Drying has not yet started. Constant drying rate period (B-C): During this period the temperature of the solid and the rate of drying remain constant. The moisture evaporating from the surface is replaced by water diffusing from the interior of the solid at a rate equal t o the rate of evaporation.  The moisture content at the end of constant rate (point C) is referred to as the critical moisture content (CMC).  At CMC, dry spots start appearing and drying rate starts falling . First falling drying rate period (C-D): This period is also called the period of
Read more

Heat Exchangers and Heat Interchangers.

  In pharmaceutical industries many types of equipments are used for transfer of heat, they can be classified as follows, Heat Exchangers. Heat Interchangers. Heat Exchangers: These devices are used for transferring heat from a fluid (Hot Gas or Steam) to another fluid (Liquid) through a metal wall. Heat Interchangers: These devices are used for transferring heat from a One liquid to another liquid or one gas to another gas through a metal wall. HEAT EXCHANGERS; The equipment used for heat transferring are known as heat exchangers. Some of the processes that involves heat transfer in pharmaceutical industries are: Preparation of starch paste (in steam jacketed kettle). Crystallization. Evaporation. Distillation.  Classification of heat exchangers On the basis of transfer of heat, heat exchangers are classified as: Direct transfer type:  The hot and cold fluids are separated by a metal wall through which the heat is transferred from hot fluid to cold fluid. E.g. shell and tube heater, 
Read more

Flash Distillation.

  Principle: When a hot mixture is allowed to enter from a high-pressure zone into a low pressure zone, the entire liquid mixture is suddenly vaporized. This process is known as flash vaporization .  During this process, the chamber is cooled.  The less volatile fraction is condensed and the more volatile component remains in the vapor phase .  This process requires time, hence liquid and vapor are kept in intimate contact until equilibrium is achieved. Flash distillation is also called equilibrium distillation because separation of two liquids takes place when liquid and vapor phases are at equilibrium. Equipment used for Flash Distillation: Construction: It consists of a pump, which is connected to a feed reservoir.  Pumps help in pumping the feed into the heating chamber.  The heating chamber is heat supplied by steam.  The other end of the pipe is directly introduced into the vapor-liquid separator through a reducing valve.  The vapor outlet is provided at the top of the separato
Read more