Agitated Nutsche filter (ANF) is a filtration technique used in applications such as dye, paint, and pharmaceutical production [1] and waste water treatment. [2] Safety requirements and environmental concerns due to solvent evaporation led to the development of this type of filter wherein filtration under vacuum or pressure can be carried out in closed vessels and solids can be discharged straightaway into a dryer.
A typical unit consists of a dished vessel with a perforated plate. The entire vessel can be kept at the desired temperature by using a limpet jacket, jacketed bottom dish and stirrer (blade and shaft) through which heat transfer media can flow. The vessel can be made completely leak-proof for vacuum or pressure service. Its used for Multiple Processes like Solid Liquid Separation, Agitating / Washing, Resuspending / Mixing Extraction, Crystallizing, Drying can be performed within a closed system [3]
The filter disc is the bottom porous plate of the nutsche filter. The filter disc retains the solids and lets the liquid/ gas passing through. It is the main filtration component of the nutsche filter.
Types of the filter disc:
A multipurpose agitator is the unique feature of this system. The agitator performs a number of operations through movement in axes both parallel and perpendicular to the shaft. [5]
A hydraulic power pack or hydraulic power unit is a unit attached to the ANF's agitator system, discharge valve and bottom removal (for cleaning). It consists of an oil tank on which a pump is provided for circulating high-pressure oil through a control valve system and to hydraulic cylinders. These cylinders are provided for vertical movement of the agitator, discharge product and sometimes detach the bottom to clean the filter before changing the product. Operating pressure of the oil varies from 2 kg/cm2 to 80 kg/cm2 (200 kPa to 8 MPa).
Agitated Nutsche filters can be fabricated in materials like Hastelloy C-276, C-22, stainless steel, mild steel, and mild steel with rubber lining as per service requirements. Recently, agitated Nutsche filters have been fabricated out of polypropylene fibre-reinforced plastic (PPFRP). Also, Nutsche filters made from Borosilicate glass 3.3 find use in applications where visibility of process are important along with chemical inertness.
Agitated Nutsche filters are used widely in the production processes of pharmaceutical, chemical and laboratory industries, among others. They are manufactured as agitated Nutsche filter dryers (ANFD'S) for the filtration and drying in the same unit of active pharmaceutical ingredients (API) and chemical compounds.
Filtration is a physical separation process that separates solid matter and fluid from a mixture using a filter medium that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filter medium are described as oversize and the fluid that passes through is called the filtrate. Oversize particles may form a filter cake on top of the filter and may also block the filter lattice, preventing the fluid phase from crossing the filter, known as blinding. The size of the largest particles that can successfully pass through a filter is called the effective pore size of that filter. The separation of solid and fluid is imperfect; solids will be contaminated with some fluid and filtrate will contain fine particles. Filtration occurs both in nature and in engineered systems; there are biological, geological, and industrial forms. In everyday usage the verb "strain" is more often used; for example, using a colander to drain cooking water from cooked pasta.
Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water. Clothes are instead soaked in a water-free liquid solvent. Perchloroethylene is the most commonly used solvent, although alternative solvents such as hydrocarbons, and supercritical CO2 are also used.
Microfiltration is a type of physical filtration process where a contaminated fluid is passed through a special pore-sized membrane filter to separate microorganisms and suspended particles from process liquid. It is commonly used in conjunction with various other separation processes such as ultrafiltration and reverse osmosis to provide a product stream which is free of undesired contaminants.
Powder metallurgy (PM) is a term covering a wide range of ways in which materials or components are made from metal powders. PM processes are sometimes used to reduce or eliminate the need for subtractive processes in manufacturing, lowering material losses and reducing the cost of the final product. This occurs especially often with small metal parts, like gears for small machines. Some porous products, allowing liquid or gas to permeate them, are produced in this way. They are also used when melting a material is impractical, due to it having a high melting point, or an alloy of two mutually insoluble materials, such as a mixture of copper and graphite.
In industrial process engineering, mixing is a unit operation that involves manipulation of a heterogeneous physical system with the intent to make it more homogeneous. Familiar examples include pumping of the water in a swimming pool to homogenize the water temperature, and the stirring of pancake batter to eliminate lumps (deagglomeration).
A Büchner funnel is a piece of laboratory equipment used in filtration. It is traditionally made of porcelain, but glass and plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a fritted glass disc/perforated plate separating it from the funnel. The Hirsch funnel has a similar design; it is used similarly, but for smaller quantities of material. The main difference is that the plate of a Hirsch funnel is much smaller, and the walls of the funnel angle outward instead of being vertical.
A Rotary Vacuum Filter Drum consists of a cylindrical filter membrane that is partly sub-merged in a slurry to be filtered. The inside of the drum is held lower than the ambient pressure. As the drum rotates through the slurry, the liquid is sucked through the membrane, leaving solids to cake on the membrane surface while the drum is submerged. A knife or blade is positioned to scrape the product from the surface.
The Schlenk line is a commonly used chemistry apparatus developed by Wilhelm Schlenk. It consists of a dual manifold with several ports. One manifold is connected to a source of purified inert gas, while the other is connected to a vacuum pump. The inert-gas line is vented through an oil bubbler, while solvent vapors and gaseous reaction products are prevented from contaminating the vacuum pump by a liquid-nitrogen or dry-ice/acetone cold trap. Special stopcocks or Teflon taps allow vacuum or inert gas to be selected without the need for placing the sample on a separate line.
In chemical engineering, biochemical engineering and protein purification, cross-flow filtration is a type of filtration. Cross-flow filtration is different from dead-end filtration in which the feed is passed through a membrane or bed, the solids being trapped in the filter and the filtrate being released at the other end. Cross-flow filtration gets its name because the majority of the feed flow travels tangentially across the surface of the filter, rather than into the filter. The principal advantage of this is that the filter cake is substantially washed away during the filtration process, increasing the length of time that a filter unit can be operational. It can be a continuous process, unlike batch-wise dead-end filtration.
An industrial filter press is a tool used in separation processes, specifically to separate solids and liquids. The machine stacks many filter elements and allows the filter to be easily opened to remove the filtered solids, and allows easy cleaning or replacement of the filter media.
Cannula transfer or cannulation is a set of air-free techniques used with a Schlenk line, in transferring liquid or solution samples between reaction vessels via cannulae, avoiding atmospheric contamination. While the syringes are not the same as cannulae, the techniques remain relevant.
A vacuum ceramic filter is designed to separate liquids from solids for dewatering of ore concentrates purposes. The device consists of a rotator, slurry tank, ceramic filter plate, distributor, discharge scraper, cleaning device, frame, agitating device, pipe system, vacuum system, automatic acid dosing system, automatic lubricating system, valve and discharge chute. The operation and construction principle of vacuum ceramic filter resemble those of a conventional disc filter, but the filter medium is replaced by a finely porous ceramic disc. The disc material is inert, has a long operational life and is resistant to almost all chemicals. Performance can be optimized by taking into account all those factors which affect the overall efficiency of the separation process. Some of the variables affecting the performance of a vacuum ceramic filter include the solid concentration, speed rotation of the disc, slurry level in the feed basin, temperature of the feed slurry, and the pressure during dewatering stages and filter cake formation.
Electrofiltration is a method that combines membrane filtration and electrophoresis in a dead-end process.
The belt filter is an industrial machine, used for solid/liquid separation processes, particularly the dewatering of sludges in the chemical industry, mining and water treatment. Belt filter presses are also used in the production of apple juice, cider and winemaking. The process of filtration is primarily obtained by passing a pair of filtering cloths and belts through a system of rollers. The system takes a sludge or slurry as a feed, and separates it into a filtrate and a solid cake.
Laboratory funnels are funnels that have been made for use in the chemical laboratory. There are many different kinds of funnels that have been adapted for these specialized applications. Filter funnels, thistle funnels, and dropping funnels have stopcocks which allow the fluids to be added to a flask slowly. For solids, a powder funnel with a short and wide neck/stem is more appropriate as it prevents clogging.
A filter drier is a piece of process equipment used during the filtration and drying phase of a pharmaceutical, bio pharmaceutical or chemical process for an active pharmaceutical ingredient (API) or other compounds production. Filter dryers are designed for washing and isolating solids with or without integrated containment systems.
A pusher centrifuge is a type of filtration technique that offers continuous operation to de-water and wash materials such as relatively in-compressible feed solids, free-draining crystalline, polymers and fibrous substances. It consists of a constant speed rotor and is fixed to one of several baskets. This assembly is applied with centrifugal force that is generated mechanically for smaller units and hydraulically for larger units to enable separation.
The peeler centrifuge is a device that performs by rotating filtration basket in an axis. A centrifuge follows on the principle of centrifugal force to separate solids from liquids by density difference. High rotation speed provides high centrifugal force that allows the suspended solid in feed to settle on the inner surface of basket. There are three kinds of centrifuge, horizontal, vertical peeler centrifuge and siphon peeler centrifuge. These classes of instrument apply to various areas such as fertilisers, pharmaceutical, plastics and food including artificial sweetener and modified starch.
A conical plate centrifuge is a type of centrifuge that has a series of conical discs which provides a parallel configuration of centrifugation spaces.
Pile Cloth Media Filtration is a mechanical process for the separation of organic and inorganic solids from liquids. It belongs to the processes of surface filtration and cake filtration where, in addition to the sieve effect, real filtration effects occur over the depth of the pile layer. Pile Cloth Media Filtration represents a branch of cloth filtration processes and is used for water and wastewater treatment in medium and large scale. In Pile Cloth Media Filtration, three-dimensional textile fabrics are used as filter media. During the filter cleaning of the pile layer the filtration process continues and is not interrupted.