high frequency screen of green

high frequency sizing screens

Widely used in fine wet screening applications, these high frequency screening machines comprise of up to five individual screen decks positioned one above the other operating in parallel. The stacked design allows for high-capacity units in a small footprint. The flow distributor splits the feed stream evenly to the individual polyurethane screen decks (openings down to 45 pm) where feeders distribute the stream across the entire width (up to 6 m) of each screen. Dual vibratory motors provide uniform linear motion to all screen decks. The undersize and oversize streams are individually combined and exit toward the bottom of the Stacked Sizer. Repulp sprays and trays arc an optional addition in between screen sections, which allow for increased screen efficiency.

By classifying by size-only, screens compared to hydrocyclones, give a sharper separation with multi-density feeds (for example, in PbZn operations), and reduce overgrinding of the dense minerals. Operations that replaced hydrocyclones with stackedhigh frequency screening machines in closing ball mill circuits can result in a decrease in the circulating load from 260% to 100% and 10 to 20% increase in circuit throughput.

The high capacity Stacked Sizing/screening machine consists of up to five decks positioned one above the other and all operating in parallel. Its use together with urethane screen surfaces as fine as 75 microns (200 mesh) has made fine wet screening a practical reality in mineral processing operations worldwide. The application of this technology in closed circuit grinding is demonstrated with specific application examples.

Screening is the process of separating particles by size and fine screening typically refers to separations in therange of 10 mm (3/8) to 38 microns (400 mesh). Fine screening, wet or dry, is normally accomplished with highfrequency, low amplitude, vibrating screening machines with either elliptical or straight-line motion. Various types ofwet and dry fine screening machines and the factors affecting their operation have been discussed previously.In fine particle wet screening, the undersize particles arc transported through the screen openings by the fluid andthe fraction of fluid in the slurry will therefore affect the efficiency of the separation. From a practical standpoint, the feed slurry to a fine screen should be around 20% solids by volume to achieve reasonable separation efficiency. Asmost of the fluid passes through the screen openings rather quickly, the fine screening process can be completed in ashort screen length. Therefore screen width, rather than screen area, is an important design consideration for fine wet screening.

Recognition of this concept led to the development of multiple feed point fine wet screening machines, or example, the Multifeed screen consists of three screen panels mounted within a rectangular vibrating frame and is actually three short screens operating in parallel. Each screen panel has its own feed box and the oversize from each panel flows into a common launder and then to the oversize chute. Similarly, the undersize from each of the three panels flows into the undersize hopper. The popular 1.2 m (4 ft) wide by 2.4 m (8 fl) long version has a total effective width of 3.0 m (10 fl) In general, multiple feed point machines have been shown to have 1.5 to 2 times more capacity than a single feed point machine of equivalent size and screen area.

Expanding further on this concept, the Stacked screening machine was introduced in 2001. With a capacity considerably greater than any other type of fine wet screening machine previously available, the Stack Sizer has up to five vibrating screen decks operating in parallel for a total effective width of 5.1 m (17 ft). The decks are positioned one above the other and each deck has its own feed box. A custom-engineered single or multiple-stage flow distribution system is normally included in the scope of supply to representatively split the feed slurry to each Stacked screen and then to the decks on each machine. Ample space is provided between each of the screen decks for clear observation during operation and easy access for maintenance and replacement of screen surfaces. Each screen deck, consisting of two screen panels in series, is equipped with an undersize collection pan which discharges into a common launder with a single outlet. Similarly, the oversize from each of the screen decks collects in a single hopper with a common outlet large vibrating motors rated at 1.9 kW (2 5 HP) each and rotating in opposite directions produce a uniform high frequency linear motion throughout the entire length and width of all screen decks for superior oversize conveyance.

As mentioned above, the fluid passing through the openings carries the undersize particles through the screen openings. The screening process is essentially complete when most of the fluid has passed through the openings. Any remaining undersize particles adhere to the coarse particles and are misdirected to the oversize product An optional repulping system is available for the Stack Sizer in which spray water is directed into a rubber-lined trough located between the two panels on each deck With this feature, oversize from the first panel is reslurried and screened again on the second panel. This repulping action maximizes the correct placement of undersize particles and its use will depend upon the particular objective of the screening machine.

To date, 1000s of screening machines are in operation at mineral processing plants worldwide. Dry mass flow capacity typically ranges from 100 to 350 t/h. This is roughly equivalent to 3 or 4 of the older style Multi-feed screens discussed above Like all screening machines, capacity depends upon many factors such as screen panel opening, weight recovery to oversize, the amount of near-size particles, particle shape, and slurry viscosity.

Sizers are for high capacity in a short compact machine. Generally you can make good cuts or separations with high efficiency. If you need near absolute 99.9% precision cuts, then a sizer cannot do that, and most inclined screeners also cannot. So that is why it is very important to understand what the separation goal is before selecting a screener. You cannot have high capacity and high accuracy + 99.9 in the same machine! This machine does not exist! A sizer generally can accomplish a similar separation of a single inclined screen in 2 or 3 screens, and 1/3 the length. of course a lot depends on the PSD, and how close the remaining particles are on each side of the desired cut.

high-frequency screen for all kinds of material | fote machinery

High-frequency screen is made up of the vibrator, pulp distributor, screen frame, chassis, suspension springs, screens, and other components. Mineral high-frequency screen has the following merits: high efficiency, low amplitude, high-frequency screening.

High efficiency breaks the tension on pulp, which means the fine grains vibrate strongly on the surface of the screen to help the heavy useful grains separate out. As a result, the fine grains contact with screen frequently and the fine grains which are smaller than the need fall down from the screen pore and leave the grain we need.

As a leading mining machinery manufacturer and exporter in China, we are always here to provide you with high quality products and better services. Welcome to contact us through one of the following ways or visit our company and factories.

Based on the high quality and complete after-sales service, our products have been exported to more than 120 countries and regions. Fote Machinery has been the choice of more than 200,000 customers.

high frequency screen-ore dressing machine - henan fote machinery co., ltd

High frequency screen has high efficiency, small amplitude and high screening frequency. It is an efficient machine widely used for the wet type and dry type screening, classification and dehydration of all kinds of fine particles such as iron, tin, tungsten, tantalum, niobium sand.

High frequency screen has high efficiency, small amplitude and high screening frequency. It is an efficient machine widely used for the wet type and dry type screening, classification and dehydration of all kinds of fine particles such as iron, tin, tungsten, tantalum, niobium sand. When the feeding density and the feeding granularity are proper and the difference of underflow granularity and feeding granularity is smaller than 30%, the screening efficiency can be as high as 70%. The high screening efficiency can greatly reduce the circulating load and the content of qualified particles on the screen, thus improving the processing capacity of the grinding mill.

Timely screening the materials that reach the fineness requirement can improve the output of the grinding mill, reduce the energy consumption and improve the economic benefits. Installing a high frequency screen in the dressing return circuit can screen the coarse ore concentrate and send it to the grinding mill for re-grinding, and the fine particles under the screen are concentrated to improve the taste of the ore concentrate.

High frequency screen has high efficiency, small amplitude and high screening frequency. It is an efficient machine widely used for the wet type and dry type screening, classification and dehydration of all kinds of fine particles such as iron, tin, tungsten, tantalum, niobium sand. When the feeding density and the feeding granularity are proper and the difference of underflow granularity and feeding granularity is smaller than 30%, the screening efficiency can be as high as 70%. The high screening efficiency can greatly reduce the circulating load and the content of qualified particles on the screen, thus improving the processing capacity of the grinding mill.

Timely screening the materials that reach the fineness requirement can improve the output of the grinding mill, reduce the energy consumption and improve the economic benefits. Installing a high frequency screen in the dressing return circuit can screen the coarse ore concentrate and send it to the grinding mill for re-grinding, and the fine particles under the screen are concentrated to improve the taste of the ore concentrate.

high frequency screen or feeder | general kinematics

The GK High-Frequency Screen or Feeder equipped with the innovative, patent-pending Structural Springs, is a fiscally responsible solution for powder and bulk processing. Structural Springs also function as legs to create a simplified design. The smaller natural frequency motor provides a more cost agreeable solution compared to brute force.

high repetition rate intracavity frequency doubled ld side-pumped ceramic nd:yag green laser based on bbo electro-optical q-switch | springerlink

a high repetition rate and high power 532 nm green laser generated by intracavity frequency doubling of a 808 nm laser diode side-pumped ceramic Nd:YAG laser based on BBO electro-optical Q-switch has been demonstrated. in the simple V-folded cavity, the maximum green laser average power 32.6 W was obtained with a pulse width of 58.5 ns at a repetition rate of 10 kHz by using a LBO crystal for frequency doubling, corresponding to a conversion efficiency of 10.9% from diode pumping power to green laser power. An instability of 1.9% was measured over a period of 30 minutes and the beam quality factors were measured to be M 2 x = 3.55, M 2 y = 3.89 at the maximum output power.

Bai, Y., Zhang, C., Fan, J.J. et al. High repetition rate intracavity frequency doubled LD side-pumped ceramic Nd:YAG green laser based on BBO electro-optical Q-switch. Laser Phys. 20, 15851589 (2010). https://doi.org/10.1134/S1054660X10130013

wavelengths and colors of the visible spectrum

The human eye sees color over wavelengths ranging roughly from 400 nanometers (violet) to 700 nanometers (red). Light from 400700 nanometers (nm) is called visible light, or the visible spectrum because humans can see it. Light outside of this range may be visible to other organisms but cannot be perceived by the human eye. Colors of light that correspond to narrow wavelength bands (monochromatic light) are the pure spectral colors learned using the ROYGBIV acronym: red, orange, yellow, green, blue, indigo, and violet.

Some people can see further into the ultraviolet and infrared ranges than others, so the "visible light" edges of red and violet are not well-defined. Also, seeing well into one end of the spectrum doesn't necessarily mean you can see well into the other end of the spectrum. You can test yourself using a prism and a sheet of paper. Shine a bright white light through the prism to produce a rainbow on the paper. Mark the edges and compare the size of your rainbow with that of others.

There is no wavelength assigned to indigo. If you want a number, it's around 445 nanometers, but it doesn't appear on most spectra. There's a reason for this. English mathematician Isaac Newton (16431727) coined the word spectrum (Latin for "appearance") in his 1671 book "Opticks." He divided the spectrum into seven sectionsred, orange, yellow, green, blue, indigo, and violetin keeping with the Greek sophists, to connect the colors to days of the week, musical notes, and the known objects of the solar system.

So, the spectrum was first described with seven colors, but most people, even if they see color well, can't actually distinguish indigo from blue or violet. The modern spectrum typically omits indigo. In fact, there is evidence Newton's division of the spectrum doesn't even correspond to the colors we define by wavelengths. For example, Newton's indigo is the modern blue, while his blue corresponds to the color we refer to as cyan. Is your blue the same as my blue? Probably, but it may not be the same as Newton's.

The visible spectrum does not encompass all the colors humans perceive because the brain also perceives unsaturated colors (e.g., pink is an unsaturated form of red) and colors that are a mixture of wavelengths (e.g.,magenta). Mixing colors on a palette produces tints and hues not seen as spectral colors.

Just because humans can't see beyond the visible spectrum doesn't mean animals are similarly restricted. Bees and other insects can see ultraviolet light, which is commonly reflected by flowers. Birds can see into the ultraviolet range (300400 nm) and have plumage visible in UV.

Humans see further into the red range than most animals. Bees can see color up to about 590 nm, which is just before orange starts. Birds can see red, but not as far toward the infrared range as humans.

the danger of green laser pointers | mit technology review

These devices create coherent green light in a three step process. A standard laser diode first generates near infrared light with a wavelength of 808nm. This is focused onto a neodymium crystal that converts the light into infrared with a wavelength of 1064nm. In the final step, the light passes into a frequency doubling crystal that emits green light at a wavelength of 532nm.

Today, Jemellie Galang and pals from the National Institute of Standards and Technology and the University of Maryland say theyve found worrying evidence that the output of some green laser pointers is much higher and more insidious. They describe one $15 green laser pointer that actually emits ten times more infrared than green light.

Galang and co are under no illusion as to the potential consequences of this. This is a serious hazard, since humans or animals may incur significant eye damage by exposure to invisible light before they become aware of it, they say.

Thats not a good state of affairs. Any ordinary user would be entirely unaware of the problem because infrared light is invisible. However, Galang and buddies describe a simple way for anybody to detect these infrared emissions.

The method is to reflect the the beam off a standard CD which acts as a diffraction grating, and so separates light of different wavelengths. The diffracted light is reflected onto a piece of paper which displays the diffraction pattern. Many webcams are sensitive to infrared light or can be easily modified to detect it. So photographing the paper using such a camera shows the diffraction pattern of the green light and any infrared light produced too.

They also take apart the green laser pointer in question to identify the cause of the problem. The design ought to include an infrared filter that blocks any infrared light that isnt converted to green light. However, the culprit they bought not only did not have the filter, it did not have a slot for such a filter. We thus believe that the absence of the filter in this case was due to a design decision, they say

high-stability single-frequency green laser with a wedge nd:yvo4 as a polarizing beam splitter - sciencedirect

The effect of the large power depletion of the fundamental wave in the phase-matched polarization on the stability of the second-harmonic wave output from an intracavity frequency-doubled ring laser is discussed. It has been demonstrated that the instability resulting from the unbalanced power depletion of the fundamental waves can be eliminated by using a wedge laser rod. The function dependence of the wedge angle and the laser power is concluded. An intracavity frequency-doubled ring laser with a wedge Nd:YVO4 laser crystal and a LBO doubler is designed and built. Comparing with similar lasers but without using the wedge laser crystal, the frequency-conversion efficiency, the power stability and the polarization purity of the second-harmonic wave output from the laser with a wedge laser rod are significantly improved. The single-frequency green laser of 6.5W at 532nm, with the polarization degree more than 500:1 and the power stability better than 0.3% for 3h, was experimentally achieved.