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1

Effect of spiral vanes width on the separation performance of a hydrocyclone

Liu Peikun, Wang Xiaoguo, Jiang Lanyue, Zhang Yuekan, Yang Xinghua, Li Xiaoyu, Wang Hui

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 6

art. no. 173563

EN

Aiming at the problem of “entrainment fine particles in underflow” of hydrocyclone in grinding and classification process, a hydrocyclone with spiral vanes (the SV hydrocyclone) was proposed. The CFD techniques were used to study the pressure field, velocity field, turbulence field, particle field and classification efficiency of hydrocyclones with spiral vanes of different widths. The results show that the pressure drop, axial velocity, tangential velocity, turbulence intensity of SV hydrocyclone are reduced in different degrees compared with conventional hydrocyclone, and the reduction becomes more obvious with the increase of vane width. In the case of a vane width of 0.04D, the underflow recovery rate of 5μm and 10μm fine particles was reduced by 16.2% and 15.7%. The selection of spiral vanes with small widths is beneficial to improve the separation accuracy of fine particles and reduce the cut particle size.

2

Determining the Separation Performance of the Knelson Concentrator

Oney Ozcan, Samanli Selcuk

Inżynieria Mineralna

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2020

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no. 1, vol. 1

87--92

EN

This study was aimed at determining the separation performance of the Knelson concentrator in Zonguldak fine coal (-1+0.15 mm). The experiments were carried out in the Knelson concentrator under the following optimal parameters determined in previous studies; water flow rate of 3.14 L/min., bowl speed of 459 rpm, solids ratio of 23.87%, and feed flow rate of 1.50 L/min. A series of tests were conducted at optimal test parameters to obtain enough samples for float and sink analysis. Clean coal and tailing products were subjected to float and sink analysis. Based on this analysis, partition curve for coal cleaning process was generated. The cut-point of the separation was obtained at the specific gravity of 1.72 [g/cm3]. The probable error (Ep) value, which signifies the efficiency of the process, was calculated as 0.11 These results indicated that Knelson concentrator is very effective in separating fine coal.

PL

Celem tego badania było określenie jakości rozdziału materiału w separatorze Knelson dla drobnouziarnionego węgla z Zonguldak (-1+0,15 mm). Doświadczenia przeprowadzono w separatorze typu Knelson przy zastosowaniu optymalnych wartości parametrów, które otrzymano w poprzednich badaniach, tj. przepływ wody 3,14 l/min, prędkość misy 459 rpm, zawartość fazy stałej 23,87% oraz przepływ nadawy 1,50 l/min. Przeprowadzono serię testów przy optymalnych parametrach testowych w otrzymania odpowiedniej ilości dla analizy densymetrycznej. Czysty węgiel oraz odpady poddano takiej analizie, na podstawie której wygenerowano krzywą rozdziału dla procesu czyszczenia. Ziarno podziałowe rozdziału otrzymano przy gęstości właściwej 1,72 [g/cm3]. Wartość rozproszenia prawdopodobnego (Ep), która oznacza skuteczność procesu została określona jako 0,11. Wyniki te wskazały, że separator Knelson jest bardzo efektywny przy rozdziale drobnouziarnionego węgla.

3

Potential design improvements of a reverse flow mini-cyclone with a tangential inlet

Dziubak T.

Chemical and Process Engineering

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2018

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Vol. 39, nr 1

15–-31

EN

This paper presents an effect of general dimensions of a reverse flow mini-cyclone with a tangential inlet on its separation efficiency. Several mini-cyclone design modifications are presented and evaluated for use in the air filtration systems of motor vehicles. Local design improvements of three components of a reverse flow mini-cyclone with a tangential inlet D-40 of an air filter fitted in an all-terrain vehicle engine were introduced. An asymmetric curvilinear shape of an outlet port was used instead of a symmetrical shape. An outlet vortex finder inlet port shape was streamlined, and a cylindrical outlet vortex finder of the cyclone was replaced with a conical one. Experimental evaluation of the effects of the design improvements of mini-cyclone on its separation efficiency and performance as well as flow resistance was carried out. Separation efficiency of the cyclone was determined using the mass method as a product of dust mass retained by the mini-cyclone and supplied to the mini-cyclone in a specified time. Separation performance of the cyclone was determined as the largest dust particle dz =dzmax in a specific test cycle in the cyclone outlet air stream. A polydisperse PTC-D test dust used in Poland, a substitute for AC-fine test dust was used. Dust concentration at the mini-cyclone inlet was kept at 1 g/m3. The size and total number of dust particles in the air stream at the outlet of the original mini-cyclone and at the outlet of the improved mini-cyclone was determined using a particle counter.

4

Capillary column coated with geminal ionic liquids as stationary phases for gas chromatographic separation

Jiang R., Yang S., Luo A.

Acta Chromatographica

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2017

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Vol. 29, no. 1

25--43

EN

Four geminal ionic liquids (GILs), namely, 1,4-bis(1,1′-butyl-3,3′- methylene- imidazolium)-benzene bis[(trifluoromethyl)sulfonyl]imide (BBMIB-NTf2), 1,4- bis(1,1′-butyl-3,3′-methylene-imidazolium)-benzene tetrafluoroborate (BBMIB-BF4), 1,4- bis(1,1′-butyl-3,3′-methylene-imidazolium)-benzene hexafluophosphate (BBMIB-PF6), and 1,4-bis(1,1′-methyl-3,3′-methylene-imidazolium)-benzene bis[(trifluoromethyl) sulfonyl] imide (BMMIB-NTf2), were synthesized. They were statically coated onto the inner walls of fused-silica capillary columns and used as stationary phases for gas chromatography. The evaluation of BBMIB-NTf2, BBMIB-BF4, BBMIB-PF6, and BMMIB-NTf2 as stationary phases is reported here for the first time. These new stationary phases exhibit efficiencies of at least 2.3 × 103 plates per meter. Abraham solvation parameter model was used to evaluate the solvation characteristics. The system constants indicated that the dipolarity/polarizability and the hydrogen-bond basicity play a major role among five molecular interactions between stationary phases and solute molecules. A fundamental understanding into the solvation characteristics of these GILs can be used as a guide to choosing the appropriate geminal ionic liquids for specific applications in various fields. The chromatographic separation performance was evaluated by a Grob test mixture, n-alkanes, alcohols, and aromatic isomers. Furthermore, the thermal stability was tested. The present results demonstrate that these geminal ionic liquids stationary phases possess excellent chromatographic separation performance and good thermal stability (at least up to 270 °C) and may be applicable as gas chromatography stationary phases for more application.

5

Dry beneficiation and cleaning of chinese high-ash coarse coal utilizing a dense-medium gas-solid fluidized bed separator

He J., Tan M., Zhu R., Luo Z.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

662--675

EN

Dry dense-medium fluidized bed separation provides a new alternative approach for coal beneficiation and cleaning. An indicator of segregation degree Sash was proposed to evaluate the stratified performance of coal samples by bed density. Fluidization stability of the bed was greatly enhanced by mixing a certain amount (21.53%) of fine magnetite powder (< 0.15 mm) into the fluidized media, which indicated a uniform density distribution as well as slight fluctuations in bed. It was found that the favorable density-segregation performance of 3–13 mm coarse coal occurred with a static bed height of 80 mm and a superficial gas velocity of 11.84 cm/s. The optimal segregation degree values of 0.67, 0.74 and 0.76 were obtained for 3–6, 6–10 and 10–13 mm coal samples, respectively. Low-ash clean coal with yields of 50.79, 56.83 and 61.24% were effectively acquired by the dry separation for various coal size fractions, respectively. Probable error values of 0.07, 0.055 and 0.05 g/cm3 were achieved, indicating good separation performance.

6

The effects of dust extraction on multi-cyclone and non-woven fabric panel filter performance in the air filters used in special vehicles

Dziubak T.

Eksploatacja i Niezawodność

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2016

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Vol. 18, no. 3

348--357

EN

Common impurities found in the inlet air to the internal combustion engine of motor vehicles are characterized. Dust concentrations in the air were analysed for different operating conditions of a motor vehicle. It is shown that the most common and the most harmful air impurity for the technical machinery is a mineral dust from roads. The benefits of using the inertial filter (multicyclone) as a first stage of air filtration, including extended engine life are presented. The methods of dust extraction from a dust collector of the air filter multi-cyclone are shown. The necessity of regular ejection dust extraction from the multi-cyclone dust collector is shown. A dust extraction rate m0 is defined and its effects on the cyclone separation efficiency and flow resistance are shown. The test method and the test conditions for a two-stage filter in multi-cyclone - non-woven fabric filter element configuration are developed. The characteristics of the separation efficiency and flow resistance of the cyclone and the non-woven fabric filter were determined as a function of dust mass supplied with the inlet air to the two-stage filter for three different extraction rates and without dust extraction from the multi-cyclone dust collector. The separation efficiency and flow resistance were determined for a multi-cyclone and a non-woven fabric filter without dust extraction from the multi-cyclone dust collector and with or without periodical maintenance. The benefits of periodical cleaning of the dust collector were shown.

PL

Scharakteryzowano zanieczyszczenia powietrza wlotowego silnika spalinowego pojazdu mechanicznego. Przeanalizowano wartości stężenia pyłu w powietrzu dla różnych warunków eksploatacji pojazdów. Przedstawiono korzyści w postaci wydłużenia czasu eksploatacji silnika wynikające ze stosowania filtru bezwładnościowego (multicyklonu), jako pierwszego stopnia filtracji powietrza. Pokazano metody usuwania pyłu z osadnika multicyklonu filtru powietrza. Wykazano konieczność bieżącego, poprzez ejekcyjne odsysanie, usuwania pyłu z osadnika multicyklonu. Zdefiniowano stopnień odsysania pyłu m0 oraz wykazano jego wpływ na skuteczność filtracji i opory przepływu cyklonów. Opracowano metodykę i warunki badań filtru dwustopniowego pracującego w układzie: multicyklon-włókninowy wkład filtracyjny. Wyznaczono charakterystyki skuteczności filtracji i oporów przepływu multicyklonu oraz włókniny filtracyjnej w zależności od masy pyłu dostarczonej wraz z powietrzem wlotowym do filtru dwustopniowego dla trzech wartości stopnia odsysania m0 = 5%, m0 = 10%, m0 = 20% oraz bez odsysania pyłu z osadnika multicyklonu. Wyznaczono charakterystyki skuteczności filtracji i oporów przepływu multicyklonu oraz włókniny filtracyjnej bez odsysania pyłu z osadnika multicyklonu i z okresowym obsługiwaniem oraz bez obsługiwania. Wykazano konieczność okresowego czyszczenia osadnika pyłu.

7

Ocena czyszczenia ziarna żyta w nowym, rotacyjnym urzadzeniu czyszczacym

Krzysiak Z

Mechanik

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2013

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R. 86, nr 2CD

PL

W pracy przedstawiono analizę separacji oraz skuteczności i wydajności czyszczenia ziarna żyta w nowym, rotacyjnym urządzeniu czyszczącym. Budowę urządzenia oparto na rotacyjnym sicie stożkowym, w którym proces przesiewania jest wspomagany pneumatycznie. Analiza skuteczności czyszczenia wykazuje jego poprawne działanie w szerokim zakresie prędkości obrotowej sita stożkowego. Przy konstrukcji urządzenia zastosowano systemy inżynierskie CAx, które wykorzystano do wykonania opatentowanego wzoru użytkowego.

EN

The paper analyzes separation, effectiveness and performance of corn grain cleaning in the innovative rotary cleaning device. The device construction is based on rotary conical sieve with pneumatically-assisted separation process. The systems engineering techniques CAx were used to construct the device, i.e. to develop utility model patent. The analysis of separation effectiveness has demonstrated its appropriate operation within a broad range of rotational speed of the conical sieve. The systems engineering techniques CAx were used to construct the device, i.e. to develop utility model patent.