high quality fine powder air cyclone separator

micron separator air classifier | hosokawa micron powder systems

The Micron Separator Air Classifier is a mechanical centrifugal air classifier, using flow through technology, providing precise, efficient, and reliable separations of materials. The Micron Separator is unique in the field of fine powder classification as it can be retrofitted to many popular grinders, such as the Mikro Pulverizer Hammer & Screen Mill.

The machinery is able to classify particles by balancing the centrifugal force of the rotor and the centripetal force of the air. Material to be separated is pulled through by the fan into the inlet duct and up to the rotor, where the two opposing forces classify it. Finer particles are more susceptible to centripetal forces whereas coarse particles are more prone to centrifugal force. These forces flow coarse materials down the inside wall of the machine, emptying out the materials in the coarse particle discharge, while finer particles travel through the air current into the rotor and then discharged through the upper outlet duct. There are 12 motor options to suit all classification needs. The Micron Separator Air Classifier are perfect for applications in the food, chemical, and cosmetic industries.

Due to heavy market demands for multipurpose technology, the Micron Separator is unsurpassed with its broad applications range, boosted productivity when paired with a grinding unit, and precise classifications of even the finest particles.

The machinery is able to classify particles by balancing the centrifugal force of the rotor and the centripetal force of the air. Material to be separated is pulled through by the fan into the inlet duct and up to the rotor, where the two opposing forces classify it. Finer particles are more susceptible to centripetal forces whereas coarse particles are more prone to centrifugal force. These forces flow coarse materials down the inside wall of the machine, emptying out the materials in the coarse particle discharge, while finer particles travel through the air current into the rotor and then discharged through the upper outlet duct. There are 12 motor options to suit all classification needs. The Micron Separator Air Classifier are perfect for applications in the food, chemical, and cosmetic industries.

Due to heavy market demands for multipurpose technology, the Micron Separator is unsurpassed with its broad applications range, boosted productivity when paired with a grinding unit, and precise classifications of even the finest particles.

cyclone separators - an overview | sciencedirect topics

Cyclone separators (used for solidsgas, solidsliquid, and gasliquid separation tasks), in contrast to centrifuges, are mechanically simple; relatively cheap to purchase, install, and run; are compact compared with noncentrifugal (gravity) separators; and require little maintenance.

gassolids separation, mainly for separating product fines from the air leaving spray dryers and fluidized bed dryers, both to increase yield and to minimize air pollution. This is the commonest application of cyclones.

gasliquid separation, mainly for the in-line deaeration of milk (essential for maintaining the efficiency of downstream centrifugal separators), and for separating the concentrate leaving an effect of a multiple-effect evaporator from the water vapor (steam) evaporated from the product in the effect. In the latter application, clean separation prevents bubbles of steam being retained in the concentrate (ultimately diluting the concentrate when they condense on cooling) and carryover of concentrate into the steam side of the next effect, or into the condenser.

The cyclone is a vertical body with a cylindrical upper part and a conical lower part. The solidsair mixture enters tangentially at the top of the cylinder. The linear motion of the mixture is converted to rotational motion by the flow of the air around the curved wall of the cyclone; the cyclone wall provides the centripetal force required to make the air rotate.

As soon as the air starts rotating, the fines particles, which are free to move relative to the air, move toward the wall, as there is no centripetal force being applied to them to keep them in orbits about the cyclones axis. When they hit the wall, they are separated from the air, and slide to the bottom of the cyclone under the influence of gravity. They are removed via a rotary valve.

The centrifugal effect is thus produced by the shape of the cyclone itself, the way the mixture to be separated enters the cyclone, and the velocity of the mixture (which is generated by a fan in the case of dryer air, or by a pump, or by a pressure difference).

Separation of the particles in the way described above is not instantaneous; a sufficiently long residence time is attained by the way the air flows through the cyclone. The air moves in a spiral path down the cylindrical part and then the conical part of the cyclone, then flows inward toward the cyclones axis, and finally upward into a coaxial tube by which it leaves at the top of the cyclone.

The solids (e.g., milk powder particles) in the solidsair mixture entering a cyclone invariably exhibit a particle size distribution; particle size ranges from very small to relatively large. Separating efficiency can be expressed in terms of the diameter of the limit particle, the smallest particle that can successfully be separated. A simplified analysis of the flow pattern inside the separator, which incorporates eqn [1], leads to the following expression for the limit diameter:

where dLis the limit diameter (m), the viscosity of the continuous phase (Pas), Q the volumetric feed rate (m3s-1), vT the maximum tangential velocity of the particle (ms-1), particle the density of the particle (kgm-3), and air the density of the continuous phase (kgm-3).

Equation [3] shows that it is possible to separate even very small particles in a cyclone if the entry velocity, vT, is high; if the cyclone is long (tall); and if it is possible to distribute the flow of feed over a number of smaller cyclones rather than a big one (because dL is directly related to volumetric flow rate, Q). Though the value of the recovered solids (e.g., milk powder fines) has to be balanced against the capital and operating costs of a battery of cyclones, air pollution control may be an overriding factor.

In practice, it is often found that the exhaust air contains a small percentage of particles with diameters larger than the limit diameter. The reason for this is probably that small particles impinge on larger ones and push them into the exhaust air.

On the other hand, a considerable proportion often more than 50% of particles with diameters lower than the limit value are successfully separated in the cyclone. These are particles that have reached the vicinity of the wall shortly after entering the cyclone. From there they are carried down and out by a secondary stream of air produced by frictional forces at the wall.

The separating efficiency of cyclones falls off dramatically in solidsair separation for particles below about 10 m in diameter. For this reason, cyclone exhaust streams may need to be bag filtered to ensure that the emission standards aimed at protecting the environment are not exceeded. Cyclones may be entirely replaced by bag filters in milk powder manufacture.

As aforementioned, conventional spray dryers show limited collection efficiency for sub-micron and nanoparticles. The cyclones used in conventional spray dryers employ centrifugal forces to achieve particle separation. However, finer particles agglomerate within the turbulent flow field of the cyclone (Mothes and Lffler, 1984). The limited particle collection efficiency impacts the productivity and commercialization of nanoparticle production by conventional spray dryers.

Different from the cyclone separators in conventional spray dryers, electrostatic precipitator (ESP) in nanospray dryers does not depend on the mass of particles (Lee etal., 2011). ESP applies electrostatic force to separate the particulate product from the gas stream (Mizuno, 2000). In an ESP, a stainless steel cylindrical electrode functions as the particle collecting anode and a grounded star electrode placed within the cylinder acts as the cathode (Fig.4). Sequential steps in the working of an electrostatic precipitator are:

Application of high voltage creates the electric field between the oppositely charged electrodes of ESP. Efficiency of the electrostatic precipitator bears a direct correlation with the strength of the applied electric field. Next step is the corona discharge phenomenon, wherein corona is the electrically active region of the gas stream. Corona is created when the magnitude of the applied electric field generated in the preceding step is high enough to accelerate the free electrons removed by it from the gas molecules. Corona discharge produces positively charged gas molecules and free electrons. These free electrons are speeded up to cause further ionization and this sequence of phenomena is termed as the electron avalanche (Helfritch, 1993).

When the drying gas flows between the cathode and anode, the particles in it are ionized by the charged ions. The charged particles are collected at the boundary between the corona glow and collection electrode, where negative ions are produced from the gas particles released during the corona generation step. When exposed, these negative ions induce dipoles within the uncharged particles in the gas stream. During the above event, while the particle itself remains neutral, the positive and negative charges within the particle gather in separate zones. The positive charges within the particle become concentrated within it in a region which remains in proximity to the approaching negative ion. At this point, it will retain some electrical charge from the ion to confer a net negative charge on the neutral particulate. This is the pre-requisite for the action of electrostatic forces to deviate and separate the particles from the gas stream.

Finally, particle collection is achieved by the applied electric field through the movement of charged particles toward the oppositely-charged electrode. The particles deposited on the internal wall of the electrode cylinder are removed using a rubber spatula or rappers that vibrate the collection surface to aid in the recovery of particles. The ESP is capable of collecting nanoparticles at exceptional yields even for small batch quantities in the range of 30500mg (Brki etal., 2011; Lee etal., 2011; Li etal., 2010; Schmid etal., 2011).

The schematic illustrations depicting the construction and working principle of nanospray dryer and conventional spray dryer are presented in Fig.5A and B, respectively. The differences between the lab scale nanospray dryer and conventional spray dryer are listed in Table1.

In contrast to centrifuges, cyclone separators are mechanically simple, relatively cheap to purchase, install, and run, are compact and require little maintenance. In the dairy industry, cyclone separators are used for gas-solid and gas-liquid separations. The key example of cyclone separation of gas-solid mixtures is the separation of powder particles from the outlet air from spray dryers and fluidized bed dryers, both to increase yield and to minimize air pollution. Examples of gasliquid separation in the dairy industry include the in-line deaeration of milk (essential for maintaining the efficiency of downstream centrifugal separators), and for separating the concentrate leaving an effect of a multiple-effect evaporator from the water vapor (steam) evaporated from the product in the effect (Pisecky etal., 2012). In the latter application, clean separation prevents bubbles of steam being retained in the concentrate (ultimately diluting the concentrate when they condense on cooling) and carryover of concentrate into the steam side of the next effect, or into the condenser. In addition, so-called hydrocyclones can be used for solid-liquid separations. One key example is the separation of solids from waste streams.

Cyclone design is shown in Fig.1. The principles of design and operation can be understood by considering fines recovery from dryer air. The cyclone is a vertical body with a cylindrical upper part and a conical lower part. The solidsair mixture enters tangentially at the top of the cylinder. The linear motion of the mixture is converted to rotational motion by the flow of the air around the curved wall of the cyclone; the cyclone wall provides the centripetal force required to make the air rotate. As soon as the air starts rotating, the fines particles, which are free to move relative to the air, move toward the wall. When they hit the wall, they are separated from the air, and slide to the bottom of the cyclone under the influence of gravity and are removed via a rotary valve. The air moves in a spiral path down the cylindrical part and then the conical part of the cyclone, then flows inward toward the cyclone axis, and finally upward into a coaxial tube by which it leaves at the top of the cyclone (Pisecky etal., 2012).

Separating efficiency can be expressed in terms of the diameter of the limit particle, the smallest particle that can successfully be separated. A simplified analysis of the flow pattern inside the separator, which incorporates Eq. (1), leads to the following expression for the limit diameter:

where dL is the limit diameter (m), the viscosity of the continuous phase (Pas), Q the volumetric feed rate (m3s1), vT the maximum tangential velocity of the particle (ms1), particle the density of the particle (kgm3), and air the density of the continuous phase (kgm3). The maximum tangential velocity occurs at the radial position DT/2 (Fig.1).

Eq. (3) shows that it is possible to separate even very small particles in a cyclone if the entry velocity, vT, is high; if the cyclone is long (tall); and if it is possible to distribute the flow of the feed over a number of smaller cyclones rather than a large one (because dL is directly related to volumetric flow rate, Q). Though the value of the recovered solids (e.g., milk powder fines) has to be balanced against the capital and operating costs of a battery of cyclones, air pollution control may be an overriding factor. In practice, it is often found that the exhaust air contains a small percentage of particles with diameters larger than the limit diameter. The reason for this is probably that small particles impinge on larger ones and push them into the exhaust air. The separating efficiency of cyclones falls off dramatically in solidsair separation for particles below the limit diameter (m) (Eq. (3)). For this reason, cyclone exhaust streams may need to be bag filtered to ensure that the emission thresholds aimed at protecting the environment are not exceeded (Pisecky etal., 2012).

In the past, the primary device used to collect solute was a cyclone separator. When a peak was detected, a valve diverted the effluent into a specific cyclone separator. The pressure of the fluid emerging from the detector was reduced until two phases formed. The fluid was then impinged onto the inside wall of a relatively large closed cylinder at an oblique angle. Any liquid (modifier or solute) tends to run down the wall while any gas phase tends to swirl around cyclone-like and exit out the top of the cylinder. The cylinder could be replaced with a cone tapering down to a small hole at the bottom, or consist of a number of connected cylinders, each smaller in diameter than the previous one.

The pressure in a cyclone separator is only slightly lower than the pressure at the end of the column (i.e., 60 or 70bar versus 100bar) and the density of the gaseous phase can be relatively high, making it straightforward to recycle the fluid. The use of binary mobile phases make this somewhat more difficult but not impossible.

Cyclone separators work very well in situations where large amounts of the same material need to be purified. For situations where only small amounts of many different solutes need to be purified, they tend to be big and bulky, and require significant time and solvent to clean.

The oldest form of fraction collection used in SFC involved momentum or cyclone separators. After the detector, the fluid temperature or pressure was manipulated so that two phases form: one a gas and the other a liquid. Polar solute molecules tend to remain in the liquid phase.

In some of the earliest semiprep to prep-scale SFC work by Perrut,71 using pure CO2, the temperature was increased until two phases formed. In some cases, the pressure was also decreased but not substantially. The flow was then diverted into one of a row of cyclone or momentum separators. These cyclones are fairly masses devices with an inner diameter several orders of magnitude larger than the ID of the tube feeding the device. These devices have walls thick enough to not rupture at up to the maximum pressure the pump can deliver. The large increase in volume slows down the fluids when they enter the cyclone. The inlet flow tangentially impacted the wall of the cyclones. The heavier liquid phase coalesced and ran down the wall. The lighter vapor phase was allowed to exit out the top of the device, where it was cooled, liquefied, and recycled to the inlet of the pump.

Perrut's earliest work was with hydrocarbon solutes, where there was little concern of thermally degrading the solutes. Today, the vast majority of SFCs are used in the pharmaceutical industry, where there is a very real concern of thermally degrading compounds.

Many bench-scale separators are similar in design to the ones used by Perrut, but use binary mobile phase mixtures and are generally smaller. Most modern SFCs form two phases by decreasing the pressure, not increasing the temperature. They are usually also heated, but only to avoid a significant decrease in temperature caused by the expansion, which can result in condensation of atmospheric water on the outer surfaces of the equipment. In this arrangement, one cyclone is dedicated to each fraction. Valving switches flow between the cyclones.

Valves on the bottom of the cyclones allow the periodic removal of the collected fractions. However, cleaning of the separators between samples can be time consuming, potentially requiring disassembly and a significant amount of solvent.

With some cyclones, the vapor phase remains at fairly high pressures. This minimizes the energy requirements for condensing or compressing it to feed it back to the pump. However, this also results in a higher concentration of a vaporized modifier, as indicated in Section 8.18.8.1.

During sampling of fumes and dusts, a measured volume of air is drawn through the sampling train and particles are captured by a filter, a cyclone separator followed by a filter, or a multistage cascade impactor (Johnson and Vincent, 2003). The first method (simple filter collection) is called the gravimetric method and measures total particulates (respirable and nonrespirable), with no size separation. The second method uses the cyclone separator as a size-selective presampler to separate coarse dust from the respirable fraction and then captures the respirable dust on a filter, which is gravimetrically analyzed. In the third method, a multistage cascade impactor separates the dust into several fractions, according to the number of stages in the impactor. A convenient, currently popular filter method is the IOM Dust Sampler with a reusable filter cassette, which attaches to a standard sampling pump and separates and measures inhalable and respirable dusts (Kenny etal., 2001). The volume of the air sample may vary from a few liters to several cubic meters, depending on the concentration of metal, the sampling equipment, and the sensitivity of the laboratory analytical method. Often the concentrations, especially those around or below the hygienic standard, are so low that a large air volume and high flow rate are needed before enough metal particles can be collected over a reasonable period of time. The sample size should be large enough to allow rate estimations of concentrations within the magnitude of about a tenth of the hygienic standard to be made.

In these types of dryer, foods are metered into metal ducting and suspended in hot air. In vertical dryers the air flow is adjusted so that lighter and smaller particles that dry more rapidly are carried to a cyclone separator faster than heavier and wetter particles, which remain suspended to receive the additional drying required. For products that require longer residence times, the ducting is formed into a continuous loop (known as pneumatic ring dryers) and the product is recirculated until it is adequately dried (Fig.16.8). Humid air is continuously vented from the dryer and replaced with dry air from the heater. High-temperature short-time ring dryers (or flash dryers) have air velocities from 10 to 40ms1. Drying takes place within 0.53.5s if only surface moisture is to be removed, or within a few minutes when internal moisture is removed. These dryers are therefore suitable for foods that lose moisture rapidly from the surface, are not abrasive and do not break easily. Evaporative cooling of the particles prevents heat damage to give high-quality products.

Pneumatic dryers have relatively low capital and maintenance costs, high drying rates and close control over drying conditions, which make them suitable for heat-sensitive foods. Outputs range from 10kgh1 to 25th1 (Barr and Baker 1997). They are suitable for drying moist free-flowing particles (e.g. milk or egg powders and potato granules), usually partly dried to less than 40% moisture and having uniform particle size and shape over a range from 10500m. They may be used after spray drying to further reduce the moisture content, and in some applications the simultaneous transportation and drying of the food may be a useful method of materials handling (also Chapter 27, section 27.1.2).

In these types of dryer, foods are metered into metal ducting and suspended in high-velocity hot air. In vertical dryers the airflow is adjusted so that lighter and smaller particles that dry more rapidly are carried to a filter or cyclone separator faster than are heavier and wetter particles, which remain suspended to receive the additional drying required. Pneumatic ring dryers have ducting formed into a continuous loop and the product is recirculated in a high-velocity hot airstream until it is adequately dried (Fig. 14.9). A manifold or internal classifier selectively recirculates semidried food. The manifold uses centrifugal forces that are created by passing the airstream containing the product around a curve to concentrate the product into a moving layer. Adjustable splitter blades return heavier, semidried material into the hot airstream for another pass through the system. The lighter, drier product exits the manifold to the collection system. When used with a disintegrator mill, the system gives control of residence times and particle size, resulting in efficient and uniform drying without heat damage. This selective extension of residence times enables the ring dryer to process materials that were previously regarded as difficult to dry, including pastes, gels, slurries, or sticky materials. Mixing the wet feed with a portion of dry product produces a conditioned material that is fed into the dryer. Pneumatic ring dryers have relatively low capital and maintenance costs, high drying rates and close control over drying conditions, which make them suitable for heat-sensitive foods. Outputs range from 10kgh1 to 25th1 (Barr and Baker, 1997). They are suitable for drying moist free-flowing particles (e.g. milk or egg powders and potato granules), usually partly dried to <40% moisture and having uniform particle size and shape over a range from 10 to 500m. Further information on ring dryers is available at GEA (2016b) and a video animation of the operation of a pneumatic dryer is available at www.youtube.com/watch?v=Z8jI7wma8lE.

High-temperature short-time ring dryers (or flash dryers) have air velocities from 1040ms1. Drying takes place within 0.53.5s if only surface moisture is to be removed, or within a few minutes when internal moisture is removed. These dryers are therefore suitable for foods that lose moisture rapidly from the surface, are not abrasive and do not easily fracture. Evaporative cooling of the particles prevents heat damage to give high-quality products.

In this type of drier, food particles are fed into a fast-moving stream of heated air. They are carried in the air stream through ducting which is of sufficient length to give the required drying time. The dry particles are recovered from the air stream by a cyclone separator or filter. The ducting may be arranged vertically, known as air-lift driers, or horizontally. Relatively high air temperatures are used to reduce the length of the ducting. Expansion chambers may be incorporated into the ducting to facilitate control over the air temperature. Two or more of these driers may be used in series, with fresh air being introduced to each stage. To reduce the length of the ducting a closed-loop or ring drier may be used. The food particles circulate a number of times around the loop until they reach the required moisture content. They are then recovered from the air stream by a cyclone. There is a continuous supply of fresh air and feed to the drier and dried product is discharged continuously. Pneumatic driers are used to dry relatively small particles such as grains and flours and as after-driers on spray drier installations.

high quality fine powder air cyclone separator fabrication,factory,manufacturers china,hot sale

Cyclone is an important gas solid separation equipment in the fields of petrochemical, natural gas, coal-fired power generation and environmental protection have been widely used, compared to other gas-solid separation, ore cyclone recycle separator has a simple structure, no moving parts, high separation efficiency, it is suitable for gas flow big fluctuations, high pressure, high dust conditions and the amount of liquid.

Cyclone separatorsbasic principle is to use centrifugal sedimentation principle separated from the gas out of solid and liquid impurities and dust particles. Gas from the upper portion of the cyclone tangential inlet into the cyclone along the wall so that it rotates at high speed in a spiral path to thebottom, then itis rotated upward after reaching the bottom of the fold, becoming core gasanddischarginginto thegaspipeline. Due to centrifugal force, the gas stream with entrained dust particles in the air flow during rotation of the cyclone gradually moving towards the wall, hit the wall after sliding into the cyclone outlet, and finally fellinto theunder chamber, together with its own weight and moves down to bottom of the cyclone outlet, portion of the gas without solid particles and liquid droplets smaller centrifugal forceflows to upper outlet.

Feature: Simple structure, small footprint, low investment, easy operation and maintenance, pressure loss medium, small power consumption, can be used in a variety of materials can be used for high temperature, high pressure and corrosive gases, and recyclable dry particles.

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1. The design and fabrication are in compliance with the latest related standards and strictly carried out according to ISO 9001 system, so that it can satisfy clients requirement of product traceability.2.Welcome purchasers or their authorized persons to our workshop at any time to do random inspection and supervision during fabrication. And we will support them actively.3.During the equipment installation, we can assign professionals to guide at site and participate in the commissioning.4.In case the problem occurs during running and shall be handled by us at site, we will reach there immediately after receiving notification from the purchaser.5.We will provide the required spare parts timely with favorable price.6.We sell products in the faith of To take clients satisfaction as the standard and provide the lifetime service for our delivered products.

Dehai Boiler is a manufacturer for A-class boiler (power plant boiler, industrial boiler, HRSG, waste-to-energy boiler, biomass boiler etc.) and correlated pressure parts. We supply boiler design, fabrication, installation, repair and maintenance. Dehai has IS...