Powder Filters Research Articles

ОЧИСТКА ПРОМЫШЛЕННЫХ СТОЧНЫХ ВОД АДСОРБЦИОННЫМИ МАТЕРИАЛАМИ НА ОСНОВЕ РЕДКОЗЕМЕЛЬНЫХ ФЕРРИТОВ-ГРАНАТОВ Sm3Fe5O12

One of the main global threats in the 21st century is the pollution by industrial enterprises (dyes and heavy metals) of the world’s fresh water resources. The main danger is posed by contaminated industrial wastes, which are so loaded with industrial waste that they cannot be used in the future, as well as dumped without purification due to toxicity, aggressiveness and other negative properties. Methods of chemical oxidation, ion exchange, nanofiltration, sedimentation, flotation, etc., used for industrial wastewater treatment, are ineffective, i.e. cleaning is carried out partially or not at all. The purpose of the work is to development of new materials with high adsorption properties by changing and selecting the optimal synthesis parameters for creating filters for industrial wastewater treatment. Object of study. Industrial waste water. Research methods. Nanostructured powders based on Sm3Fe5O12, used as filters for industrial wastewater treatment, are synthesized by the hydrothermal method. The features of the surface topology, structure, shape and size of the particles of the samples are investigated by the methods of scanning electron microscopy and atomic force microscopy. The chemical and phase composition of the research objects was determined using X-ray diffraction (XRD) phase analysis. The adsorption properties of the samples were investigated using spectrophotometry. Results and discussion. The obtained results of the research carried out make it possible to solve a number of problems arising from environmental pollution in general and the treatment of industrial wastewater, in particular, through scientifically based recommendations for the creation of powder filters as an adsorbent, which is used as nanostructured powders of samarium iron garnets. Conclusions. It was found that an empirical study of the characteristics of the topology of these materials is necessary, since the adsorption properties are associated with structural inhomogeneities. Because only with the help of the directed formation of a certain micro / nanostructure of powders can a set of characteristics be obtained in them that make them suitable for industrial use. 1. It was determined that the use of SEM and SPM methods made it possible to study the general structural features of the entire surface of objects at low magnifications, as well as to study in detail at maximum magnifications any surface area. The transition from low magnifications to maximum magnifications was carried out without additional effort. 2. The determining role of the amount of alkali NaOH used in the process of hydrothermal synthesis in influencing the structural and adsorption properties of the resulting powder is shown. It was found that with an increase in the amount of alkali, a decrease in the amount of impurity materials, such as hematite Fe2O3, is observed, as a result of which the adsorption capacity of the materials under study increases.

Treatment of Industrial Water by Nano Technology

Nanotechnology: - It is one of the modern scientific achievements where nanotechnology isavailable, namely the engineering and art of nano scale material treatment (100 nanometers.The ability to manufacture new Nano materials used to treat surface water, groundwater andindustrial wastewater contaminated with toxic metal ions, organic and inorganic substances as wellas microorganisms.In this research, we discussed the use of Nano materials, or nearby, to remove the dissolved oilpollutants from the industrial wastewater of the South Refinery Company, where we used multitubesof carbon nanotubes. The function of the tubes can be described as a particle filter, Hold largeparticles of contaminants that are difficult to pass through the tube tunnel). We also used activatedcarbon powder and carbon filters near pore nanoparticles

Innovative Rough Beer Conditioning Process Free from Diatomaceous Earth and Polyvinylpolypyrrolidone.

In large-sized breweries, rough beer clarification is still carried out using Kieselguhr filters notwithstanding their environmental and safety implications. The main aim of this work was to test an innovative rough beer clarification and stabilization process involving enzymatic treating with Brewers Clarex®, centrifuging, rough filtering across 1.4-μm ceramic hollow-fiber membrane at 30 °C, and fine filtering through 0.45-μm cartridge filter. When feeding an enzymatically-pretreated and centrifuged rough beer with permanent haze (HP) of 2 or 14 European Brewery Convention unit (EBC-U), its primary clarification under periodic CO2 backflushing yielded a permeate with turbidity of 1.0–1.5 EBC-U at a high permeation flux (2.173 ± 51 or 593 ± 100 L m−2 h−1), much greater than that typical of powder filters. The final beer was brilliant (HP = 0.57 ± 0.08 EBC-U) with almost the same colloidal stability of the industrial control and an overall log reduction value (~5.0 for the selected beer spoilage bacterium or 7.6 for the brewing yeast) in line with the microbial effectiveness of current sterilizing membranes. It was perceived as significantly different in flavor and body from the industrial control at a probability level of 10% by a triangle sensory test, as more likely related to the several lab-scale beer-racking steps used than to the novel process itself.

Investigation of the Dependences of the Attenuation Properties of Cryogenic Metal-Powder Filters on the Preparation Method

We fabricated low-pass metal powder filters for use in low-noise measurements at cryogenic temperatures and investigated their attenuation characteristics for different wire-turn densities, metalpowder shapes, and preparation methods at frequencies up to 20 GHz. We used nominally 30-μmsized stainless-steel 304L powder and mixed it with low-temperature binders. The low-temperature binders used were Stycast 2850FT (Emerson and Cumming) with catalyst 23LV and GE-7031 varnish. A 0.1-mm insulated copper wire was wound on preformed powder-mixture bobbins in the shape of a circular rod and was encapsulated in metal tubes with the powder mixture. All the fabricated powder filters showed a large attenuation at high frequencies with a cut-off frequency near 1 GHz. For filters of the same wire length, a lower wiring density showed a larger attenuation, which implies that the amount of powder in close contact with the wire determines the attenuation. Filters made of a powder/varnish mixture showed significantly larger attenuations than those of a powder/stycast mixture, and the attenuation improved with increasing powder ratio in the mixture. The low-temperature thermal conductivities of a 2 : 1 powder/Stycast mixture and a 5 : 1 powder/varnish mixture showed similar values at temperatures up to 4.2 K.

Towards a Kieselguhr- and PVPP-Free Clarification and Stabilization Process of Rough Beer at Room-Temperature Conditions.

A novel Kieselguhr- and PVPP-free rough beer conditioning process at room temperatures was set up. By submitting precentrifuged rough beer to commercial preparation Brewers Clarex ® and then to membrane clarification at 30 °C across a ceramic 1.4-μm hollow-fiber membrane module, it was possible to obtain a clear and stable beer with a throughput (1306 ± 72 L/m2 /h) by far higher than that (250 to 500 L/m2 /h) characterizing the current powder filters. The haze development due to chilling, sensitive proteins, and alcohol adding was by far lower than that observed when microfiltering PVPP-pretreated rough beer.

Beer Clarification by Novel Ceramic Hollow-Fiber Membranes: Effect of Pore Size on Product Quality.

In this work, the crossflow microfiltration performance of rough beer samples was assessed using ceramic hollow-fiber (HF) membrane modules with a nominal pore size ranging from 0.2 to 1.4 μm. Under constant operating conditions (that is, transmembrane pressure difference, TMP = 2.35 bar; feed superficial velocity, vS = 2.5 m/s; temperature, T = 10°C), quite small steady-state permeation fluxes (J* ) of 32 or 37 L/m2 /h were achieved using the 0.2- or 0.5-μm symmetric membrane modules. Both permeates exhibited turbidity <1 EBC unit, but a significant reduction in density, viscosity, color, extract, and foam half-life with respect to their corresponding retentates. The 0.8-μm asymmetric membrane module might be selected, its corresponding permeate having quite a good turbidity and medium reduction in the aforementioned beer quality parameters. Moreover, it exhibited J* values of the same order of magnitude of those claimed for the polyethersulfone HF membrane modules currently commercialized. The 1.4-μm asymmetric membrane module yielded quite a high steady-state permeation flux (196 ± 38 L/m2 /h), and a minimum decline in permeate quality parameters, except for the high levels of turbidity at room temperature and chill haze. In the circumstances, such a membrane module might be regarded as a real valid alternative to conventional powder filters on condition that the resulting permeate were submitted to a final finishing step using 0.45- or 0.65-μm microbially rated membrane cartridges prior to aseptic bottling. A novel combined beer clarification process was thus outlined.

Study on the fabrication of low-pass metal powder filters for use at cryogenic temperatures

We fabricated compact low-pass stainless-steel powder filters for use in low-noise measurements at cryogenic temperatures and investigated their attenuation characteristics for different wire lengths, shapes, and preparation methods up to 20 GHz. We used nominally 30-micrometer-sized SUS 304L powder and mixed with Stycast 2850FT by Emerson and Cumming with catalyst 23LV. A 0.1 mm insulated copper wire was wound on preformed powder-mixture spools in the shape of a right-circular cylinder, a flattened elliptic cylinder and a toroid, and the coils were encapsulated in metal tubes or boxes filled with the powder mixture. All the fabricated powder filters showed a large attenuation at high frequencies with a cut-off frequency near 1 GHz. However, the toroidal filter showed prominent ripples corresponding to resonance modes in the 0.5-m-long coil wire. A filter with a 2:1 powder/epoxy mixture mass rate and a wire length of 1.53 m showed an attenuation of -93 dB at 4 GHz and the attenuation was linearly proportional to the wire length. As the powder-to-epoxy ratio increased, the high-frequency attenuation increased. An equally-spaced single-layer coil structure was found to be more efficient in attenuation than a double-layer coil. Geometry of the metal filter-case affected noise ripples with the least noise in a circular-tube case.

Erratum: "Printed circuit board metal powder filters for low electron temperatures" [Rev. Sci. Instrum. 84, 044706 (2013)

Erratum: "Printed circuit board metal powder filters for low electron temperatures" [Rev. Sci. Instrum. 84, 044706 (2013)

Printed circuit board metal powder filters for low electron temperatures

We report the characterisation of printed circuit boards (PCB) metal powder filters and their influence on the effective electron temperature which is as low as 22 mK for a quantum dot in a silicon MOSFET structure in a dilution refrigerator. We investigate the attenuation behaviour (10 MHz-20 GHz) of filter made of four metal powders with a grain size below 50 μm. The room-temperature attenuation of a stainless steel powder filter is more than 80 dB at frequencies above 1.5 GHz. In all metal powder filters, the attenuation increases with temperature. Compared to classical powder filters, the design presented here is much less laborious to fabricate and specifically the copper powder PCB-filters deliver an equal or even better performance than their classical counterparts.

플라즈마 용사를 이용한 복합세라믹 미세필터 연구

본 논문은 세라믹과 금속파우더를 이용한 복합소재를 플라즈마 용사 방식으로 개발한 결과를 수록하였다. 사용된 세라믹 파우더는 Al₂O₃+40TiO₂ 이고 입자 크기는 20㎛, Al₂O₃ 98+파우더의 입자 크기는 45㎛ 를 사용하였다. 20㎛, 30㎛ 및 50㎛ 금속필터 입자는 SIKA-R 20IS, 30IS 및 50IS(소결금속필터)을 사용 했으며, 75㎛ 금속필터 입자는 5 겹 소결메쉬 필터를 사용헀다. 용사 공정으로 가공된 복합 필터는 세라믹 파우더의 종류, 크기 및 코팅 두께에 따라 성능의 차이를 보였으나, 전반적으로 필터링 가능 능력은 향상되었다.

Porometry, porosimetry, image analysis and void network modelling in the study of the pore-level properties of filters

We present fundamental and quantitative comparisons between the techniques of porometry (or flow permporometry), porosimetry, image analysis and void network modelling for seven types of filter, chosen to encompass the range of simple to complex void structure. They were metal, cellulose and glass fibre macro- and meso-porous filters of various types. The comparisons allow a general re-appraisal of the limitations of each technique for measuring void structures. Porometry is shown to give unrealistically narrow void size distributions, but the correct filtration characteristic when calibrated. Shielded mercury porosimetry can give the quaternary (sample-level anisotropic) characteristics of the void structure. The first derivative of a mercury porosimetry intrusion curve is shown to underestimate the large number of voids, but this error can be largely corrected by the use of a void network model. The model was also used to simulate the full filtration characteristic of each sample, which agreed with the manufacturer's filtration ratings. The model was validated through its correct a priori simulation of absolute gas permeabilities for track etch, cellulose nitrate and sintered powder filters.

Improved powder filters for qubit measurements

We designed and fabricated miniature low-pass metal powder filters suitable for noise-sensitive measurements at cryogenic temperatures. In comparison with previous powder filters, our filters have a much better frequency response and significantly smaller dimensions (0.7 cm(3) including the plugs) and can also be used as hermetic feedthroughs at low temperatures. Their transmission characteristics are smooth, contain no ripples, and have a steep decay above the cutoff frequency. At 4.2 K the cutoff frequency of a single filter is f(c)=1 MHz and the roll-off is -50 dB per decade. All of the fabricated filters have identical frequency responses at 4.2 K and their characteristics are reliably reproducible.

50 Ω characteristic impedance low-pass metal powder filters

We have fabricated several 50 omega characteristic impedance low-pass metal powder filters. The filters are made with bronze or copper metal powder with varying amounts of metal powder in a metal powder/epoxy mixture. Our goal is to make a filter with a characteristic impedance Z = 50 omega at frequencies up to 10 GHz. Using a 78% bronze powder/epoxy mixture in a suitable geometry, we achieved an impedance Z = 54 omega at 4.2 K, with a cutoff frequency fc approximately/= 0.3 GHz and an attenuation A = Vout/Vin=0.0001 (-80 dB) at 10 GHz. We also made several non-50 omega low-pass bronze powder filters with fc = 1 MHz and A = 0.0001 at 10 MHz. Fabrication details and performance data will be presented for both types of filter.

Porosity measurement of stainless steel filters produced by electrical discharge technique

Electrical discharge compaction (EDC) of metal powders is a relatively new process, which combines the advantages of compacting metal powders and fast sintering. In this process, metal powder contained in an electrically non-conducting tube is suddenly subjected to a high voltage. As a result and under suitable conditions, the specimen will consolidate. It is a fast, cheap and reproducible process. In this study, stainless steel powder filters with different shapes and sizes are produced by the EDC process and different aspects of the products are investigated. Porosity measurements of filters are also presented. The porosity of these stainless steel powder filters is found to be comparable with those produced by other techniques.

Attenuation of microwave filters for single-electron tunneling experiments

Two types of microwave filters, metallic powder filters and a filter using a resistive coaxial cable, were tested. Attenuation of the metallic powder filters using copper or stainless steel (SUS304L) was measured at 300 K, 77 K, and 4.2 K, and it was found that SUS304L powder of nominal 30 /spl mu/m grain size gives best result as the microwave filter for single electron tunneling (SET) experiments. Attenuation of a coaxial filter, or Thermocoax with SMA connectors attached at both ends is larger at low temperatures than that at room temperatures, and the temperature dependence of the attenuation does not agree with Zorin's model. The filter arrangement in a cryostat designed for SET experiments, is also reported.

Electric and magnetic properties of a thermoplastic elastomer incorporated with ferromagnetic powders

The electric and magnetic properties of a composite material consisting of a thermoplastic elastomer incorporated with iron powder and nickel-iron alloy powder are investigated. The volume fraction of the powder filters ranges from 0.1 to 0.5. The composites are characterized in terms of their volume and surface resistivities, permittivities and electric loss factors and magnetic permeabilities 0 and magnetic loss factors. With the addition of the ferromagnetic powders, the volume and surface resistivity values of the composites decrease by more than seven orders of magnitude, the permittivity values increase tenfold and magnetic permeability values increase by a factor of about six. The ferromagnetic powders are more effective in contributing the electric and magnetic properties the composite at higher loading levels. The frequency variations of AC electric and magnetic properties are also measured in the range 20 Hz to 1 MHz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Polyethylene-passing powder filters for the long infrared region of the spectrum

Polyethylene-passing powder filters for the long infrared region of the spectrum

Low Temperature Properties of the Reststrahlen Powder Filters in the Far-Infared Region

Low Temperature Properties of the Reststrahlen Powder Filters in the Far-Infared Region

A study of gas permeability and fineness of purification of nonspherical powder filters

1. We have studied the permeability and fineness of purification of filters prepared by ordinary and nozzle compacting from reduced powders of Kh17N2 stainless steel. With satisfactory hydraulic characteristics, the investigated specimens gave a high degree of purification. 2. We evaluated the coefficient of permeability for a dust layer which had settled on the filter.

Metal powder filters for the automatic analysis of pulps of alumina production

1. The working time of an iron cermet filter for waste pulp without regeneration proved to be sufficiently long so that it can be used under industrial conditions. 2. Self-washing was found in cermet filters, which can be used for their regeneration. 3. Cermet filters can be used in the alumina industry for continuous removal of pulp filtrate for automatic analysis.