Inlet Filter Research Articles

Experimental study on the optimal performance of gas turbine (GT) inlet air filtration system for offshore application

An experimental study on the optimal gas turbine inlet air filtration system performance for offshore applications is presented. The objective is to conduct a comparative real-time data analysis for an offshore selection of optimal filtration system. Different filtration configurations were set up in a wind tunnel under simulated offshore environmental settings. The considered filter grades (A, B, C, D, E and F) align with the ASHRAE filter class (F7, H12, E11, E10, G5 and F9). Offshore contaminants weighing 1000 g, ranging between 0.05 and 20 µm, were used based on ASTM standards. The contaminants were loaded between 20 and 100% mass. The results indicate that the accumulated contaminant across the filter elements at 100% loading for A, B, C, D, and E filters ranged between 205.36 and 318.02 g. Similarly, the pressure differential change across the filters A–B, D–E, B–C, E–F, and filter housing inlet–outlet were estimated at 19.02 kPa, 16.9 kPa, 2.54 kPa, 2.86 kPa, and 2.25 kPa, respectively, while the particle removal efficiency for A, C and D filters were highest calculated at 53%, 58.22% and 51.69%, respectively. The result proved significant, with an overall improvement in the compressor output at 205 kW for a pressure change of 2.25 kPa at the filter housing outlet used to establish the optimal performance. The filter elements recorded decreased efficiency across the compressor stages due to mass accumulation on the media surface area. The study inferred that a 3-stage filtration with filter combination A–B (F7–H12), D–E (E10–G5), and B–C (H12–E11) is suitable for an inlet filtration system for GTs operating within the studied offshore environment.

Experimentation and Mathematical Modelling of Process Parameters for Prevention of Infectious Disease Caused by Staphylococcus aureus Bacteria in Indoor Environment.

Performance optimization using process parameters of an indoor air filtration system is a requirement that has to be established through experimental and analytical means for increasing machine efficacy. A closed casing containing a motor-driven blower is placed in a glass-encapsulated control volume. Air flows axially through an inlet filter and is thrown radially by the blower. In the radial path, air is treated with free radicals from the UVC-irradiated nano-TiO2 coated in the inner wall of casing. A known quantity of Staphylococcus aureus bacteria is populated (Courtesy: EFRAC Laboratories) in the glass-encapsulated control volume. The bacterial colony count is measured at different time intervals after the machine is switched on. Machine learning approaches are applied to develop a hypothesis space and the hypothesis based on best R2 score is used as a fitness function in genetic algorithm to find the optimal values of input parameters. The present research aims to determine the optimum time for which the setup is operated, the optimum air flow velocity in the chamber, the optimum setup-chamber-turning-radius affecting the air flow chaos, and the optimum UVC tube wattage, which when maintained yields the maximum reduction in bacterial colony count. The optimal values of the process parameters were obtained from genetic algorithm using the hypothesis obtained from multivariate polynomial regression. A reduction of 91.41% in bacterial colony count was observed in the confirmation run upon running the air filter in the optimal condition.

Assessment of PCDD/Fs formation and emission characteristics at a municipal solid waste incinerator for one year

Municipal solid waste incineration (MSWI) has become a predominant emission source of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). Research focusing on the impact of operating conditions, environmental changes, and operating time on the generation and emissions of PCDD/Fs has not been resolved. To this end, this study tracked and investigated the PCDD/Fs and 17 congener emissions of a typical grate incinerator (800 t/d) continuously for one year. Results showed that the PCDD/Fs concentration at the boiler outlet, stack inlet, and bag filter, including normal and abnormal operation conditions, ranges from 2.11E-02–41.86 ng I-TEQ/Nm3, 7.00E-04–6.76 ng I-TEQ/Nm3, and 1.12–2.90E+03 ng I-TEQ/Nm3, respectively. The 2,3,4,7,8-P5CDF has the highest contribution in all samples, in which a proportion of TEQ ranged from 30 % to 77.73 %. Moreover, by applying the correlation analysis between PCDD/Fs and operating parameters, the emission characteristic is mainly affected by incinerators and boilers during the normal period, and it is affected by the whole MSWI process under abnormal conditions. In addition, the PCDD/Fs emission from the MSWI plant gradually increases from spring to winter. This study is beneficial for supporting the control of PCDD/Fs emission reduction and assisting the operators to optimize the relevant operating parameters of the MSWI plant to achieve a stable and up-to-substandard emissions during the operation period.

Development of new technology for tar removal in IGCC

The hot gas purification process is essential in integrated gasification combined cycle (IGCC), and the technology used therein exhibits high system efficiency and has a low environmental impact. The main purpose of this research is to develop a filtration system that can be used in a near-industrial environment. By controlling the moving granular bed filter in the moving bed mode, this operation could generate a cooling effect and condense the tar in the filter media by incorporating the characteristics of the dew point temperature of tar. Tar could then be collected by the gas sampling system at the gas exhaust end, and the tar removal efficiency could be obtained by comparing the inlet and outlet concentrations. The test parameters were used to explore the influence of tar removal efficiency of medium- and high-temperature granular bed filters by changing the inlet velocity, temperature, and filter media mass flow rate. Test results show that the tar removal efficiency decreased with increasing temperature and velocity. When the concentration of the tar module was 50 g/Nm3, the gas velocity was 1.8 m/s, and the filter media mass flow rate was 300 g/min. The removal efficiency could reach 98.3% at a temperature of 200 °C. In addition, the test results indicate that the removal efficiency led to an optimized filter media mass flow rate at different inlet velocities. These results are expected to lay a foundation for advanced purification technology in the future.

Outdoor Microplastic Analysis Using Inlet Filters from an NOx Regulatory Air Quality Monitoring Device

Atmospheric microplastics (MPs) are a ubiquitous environmental contaminant of emerging concern. Sampling methods provide information relating to surface area concentration and MP characteristics, without direct comparison with routinely measured standard air quality parameters. This study analysed 6 active air samples generated by a local authority as part of their routine air quality monitoring activities. Continuous sampling totalled 10 months, within the city centre of Kingston-upon-Hull. By using μFTIR analysis, levels of total particles detected using the NOx inlet filters ranged from 5139 ± 2843 particles m−2 day−1, comprising 1029 ± 594 MPs m−2 day−1. The controls displayed a mean level of 2.00 ± 3.49 MPs. The polymers nylon (32%) and polypropylene, PP (22%) were the most abundant. Small fragments of 47.42 ± 48.57 μm (length) and 21.75 ± 13.62 μm (width) were most common. An increase in MP levels during April 2020 coincided with an increase in PM10 levels. This study used robust procedures to measure MPs in the air by exploiting existing air quality monitoring equipment. Knowing the levels, types, and characteristics of MPs can inform toxicity studies to provide more environmentally relevant exposures, which is urgent now that MPs have been reported in human lung tissue.

Numerical Investigation on the Atomization Characteristics of An Aerosol Spray Nozzle

Inlet air filtration of ships and coastal installations is mainly used to filter out salt aerosol particles, so researches on the inlet filter needs to simulate spray aerosol state in the marine environment. The sea salt aerosol particles have multiple sizes, thus salt aerosol generator should have the ability to produce salt aerosol particles of various diameters. This paper investigates the factors that affect the particle diameter of a salt aerosol generating device. Numerical simulations on the two-phase flow in a salt aerosol nozzle are conducted and the influence of air inlet pressure and droplet mass flow rate on the particle diameter is discovered. The results show that the particle diameter of the aerosol nozzle decreases with the air inlet pressure increasing and the droplet mass flow rate decreasing.

Removal of Radioactive Gas by Zeolite Filter From Nuclear Power Plants

During the normal operation of nuclear power plants, some radioactive wastes are produced in the form of particles or aerosol gas in the reactor building. Particulate radioactive aerosols can be produced in a wide variety of particle sizes, possibly in combination with non-radioactive aerosols. Emission of corrosion products and fission products that are activated by the effect of nuclear rays generate aerosols from two sources. These; are created by the adsorption of gases generated by radioactive decay and volatile radionuclides formed during the fission process on the present suspended material. The most important volatile radionuclides that form the gaseous radioactive waste produced during the normal operation of nuclear power plants are halogens, noble gases, tritium, and carbon-14. The composition and amount of radioactivity present in the various airborne waste streams depend largely on the reactor type and release path. All gaseous waste from nuclear power plants must be treated before discharging into the atmosphere. In this paper, radioactive radon gas was used to represent the radioactive gases generated from nuclear power plants and natural zeolite was used as adsorbent material for radon removal. A series of experiments were conducted to measure the performance of the filter made in the zeolite. First of all, an approximate particle distribution size in the range of 1 to 3 mm was obtained by grinding natural zeolite. The ground material was then compressed in cylindrical adsorbent moulds of 35 mm diameter and 10 mm height. After the moulds were filled with the material, they were dried by heating to 110 ° C for 24 hours. At the end of the heat treatment, the adsorbent beds were cooled and connected to the test apparatus. RAD7 radon test device was used in the experiments. The RAD7 is a portable instrument that uses a solid-state alpha detector to measure radon gas concentrations in the range of 4.0-750,000 Bq / m3. The sampler of the RAD7 device works by drawing an air sample from an inlet filter into a 0.7 L sample cell covered with an electrical conductor. At the centre of the hemisphere, the cell is a planar silicon detector implanted with an ion to measure radioactivity. As result of the experiments, it shows that the zeolite filter absorbs 85% radioactive radon gas and can be used as an air filter in nuclear power plants.

3D-printed activated charcoal inlet filters for oxygen concentrators: A circular economy approach

As of May 2021, the current COVID-19 pandemic is still plaguing the world, challenging all the countries and their health systems, globally. In this context, conditions typical of low-resource settings surfaced also in high-resource ones (e.g., the lack of essential medical equipment, of resources etc.), while exacerbating in the already resource-scarce settings, because of COVID-19. This is the case of oxygen concentrators that are one of the first-line medical devices for treating COVID-19 patients. Since the beginning of 2020, their demand has been rapidly growing worldwide, aggravating the situation for low-resource settings, where the availability of devices providing oxygen-enriched air was already scarce. In fact, due to their delicacy, the lack of spare parts and of an appropriate health technology management system, oxygen concentrators can often be found broken or not working properly in these settings. The underlying problems have deep roots. The current regulatory frameworks and standards, which are set by high-income countries, are too stringent, and do not take into account the limited resources of poorer settings. Thus, they are often inapplicable in such settings. One of the main issues affecting the oxygen concentrators, is that related to the filters, which are designed to filter out dust, particles, bacteria, and to be used in medical locations complying with international standards (e.g., the air filtration level in a surgical theatre in Italy is at 99.97%). When used in low-resource settings, which do not comply with these standards and face several challenges (e.g., dust), these filters have a much-reduced lifespan.For these reasons, this paper aims to present the redesign of the inlet filter of an oxygen concentrator, which is used to prevent gross particles to enter the device. The redesign is based on a reverse engineering approach, and on the use of 3D-printing along with activated charcoal. After testing the filtration efficiency with a particle counter, the filter design has been refined through several iterations. The final prototype performs particularly well when filtering particles above 1 μm (with a filtration efficiency of 64.2%), and still has a satisfactory performance with any particle size over 0.3 μm (with a filtration efficiency of 38.8%). Following the United Nations Sustainable Development Goals, this project aims to empower local communities, and start a positive trend of self-sustained supply chain of simple spare parts for medical devices, leveraging on frugal engineering, 3D-printing, locally produced activated charcoal, and circular economy.

ВЛИЯНИЕ НЕКОТОРЫХ ПАРАМЕТРОВ ЭКСПЕРИМЕНТАЛЬНОГО ПРОТИВООБЛЕДЕНИТЕЛЬНОГО КОМПЛЕКСА «ФИЛЬТР» НА ЭФФЕКТИВНОСТЬ ЗАЩИТЫ ЭНЕРГЕТИЧЕСКИХ УСТАНОВОК ОТ СНЕГА

Unpredictable growth of ice crust on filters installed in air cleaning devices at the inlet to air supply channels to aircraft drives during operation of gas compressor stations in heavy snowfalls can lead to accidents and downtime. To combat ice growths, an experimental complex "FILTER" was developed. The developed experimental complex makes it possible to conduct interdisciplinary studies of the behavior of snow and ice covers on gas-permeable and deformable surfaces of various types, providing gas-dynamic conditions similar to those that occur near air-cleaning devices. These include precipitation in the form of snow, high relative humidity, negative temperatures at which snow and ice cover forms on the inlet filters. Studies have been carried out on the release of an ice crust formed on protective gas-permeable and deformable surfaces of various types. For its destruction, the energy of a gas-dynamic jet was used. The general design scheme of the experimental anti-icing complex "FIL-TER", the results of experiments and their analysis are presented. Thus, on the experimental anti-icing complex, an assessment was made of the effect on the efficiency of protection of a model power plant from an ice crust of the following parameters: air supply pressure to the nozzle (varied in the range 0.1–0.6 MPa), (changed in the range 7.75–13.5 m/s), the diameter of the gas-tight area and the material of the gas-permeable deformable surface. The most effective combination of parameters is determined. It was found that of the considered gas-permeable deformable surfaces, the option with a plastic mesh demonstrated the highest efficien-cy with the following flow parameters: jet pressure P ≥ 0.5 MPa, air flow velocity 13.5 m/s, gas-tight area diameter 50 mm.

Evaluating the Occurrence and Relative Abundance of Mosquitoes in Rainwater Harvesting Systems

Highlights Rainwater harvesting systems can harbor mosquitoes and their larvae. Approximately half of sampled systems were found to contain mosquito larvae. Mosquitoes were more abundant in systems with unscreened openings and multiple inlet filters. Frequent maintenance and eliminating unscreened openings minimize mosquito presence. Abstract. Mosquitoes are associated with the spread of diseases such as the Zika and West Nile viruses. Government and health officials recommend the elimination of standing water to prevent the breeding of mosquitoes that transmit these viruses. Previous research has shown that rainwater harvesting (RWH) systems in high-rainfall regions tend to be underutilized, thereby creating a source of standing water that could potentially harbor mosquitoes and their larvae. As RWH is an important tool for conserving potable water and mitigating stormwater runoff, it is imperative to determine if these systems are contributing to the proliferation of mosquitoes and, if they are, to identify measures to prevent this. The prevalence and relative abundance of mosquitoes were investigated in 64 RWH cisterns throughout Virginia and North Carolina. Mosquito larvae captured during sampling were identified morphologically to genus and species. Of the 64 systems sampled, 47% contained mosquitoes; the predominant species found was Aedes albopictus, a potential carrier of Eastern Equine Encephalitis, LaCrosse Encephalitis, West Nile virus, and Zika virus. Systems with multiple inlet filters, unscreened storage tank openings, and/or heavy foliage in the immediate vicinity were most likely to contain mosquito larvae. Study results indicate that frequent maintenance, the elimination of unscreened tank openings, and the eradication of sources of standing water in the area surrounding a system greatly reduce the likelihood of mosquitoes proliferating in rainwater harvesting systems. Keywords: Container breeding, Mosquito, Mosquito larvae, Rainwater harvesting.

Fine tuning of a PID controller with inlet derivative filter using Pareto solution for gantry crane systems

Gantry cranes are widely used in transporting heavy loads in construction projects and critical industries such as petrochemical industry and nuclear power stations. Their mission should be accomplished with as high accuracy for the trolley positioning, and minimum values of sway oscillation angles as possible. So, the control strategies aim to achieve high productivity (through transporting the trolley with good precision) while considering safety precautions (through eliminating sway oscillations). One of the linear closed loop control methods is using PD and PID controllers. This research provides a non-linear mathematical model for single-pendulum gantry crane with two stable control schemes that depend on PID and PD controllers equipped with inlet derivative filter for every scheme. The two control schemes utilize a PID controller for positioning the trolley and a PD controller for eliminating undesired sway angles of the payload. In the second scheme, the input voltage control signal is always saturated to be positive to preserve the direction of rotation of the driving DC motor. The controllers include up to five gains and two inlet derivative filter coefficients which are tuned using Multi-Objective Genetic Algorithm (NSGA-II) with four different fitness functions and one weighted function to choose a suitable solution from other Pareto solutions. The simulation results are presented to show the superiority of the second scheme precision in trolley transporting with minimum payload sway oscillations.

Architecture Design of An Intelligent Monitoring System for Turbine Filtration Device

In order to improve the operation efficiency of the turbine and reduce the failure rate of the equipment, this paper takes the inlet filter device of the turbine as the research object, comprehensively utilizes computer technology, machine learning, computer network and other technologies, and proposes a remote monitoring system of the turbine filter device based on industrial Internet cloud service and C/S architecture. The industrial process monitoring system is designed according to the actual situation of the industrial process. By connecting the system to the industrial Internet cloud service, the remote monitoring of the on-site running state and operation data of the equipment is realized. On this basis, the artificial neural network is proposed to realize the timely diagnosis and treatment of faults, and the operation and maintenance suggestions are put forward to improve the stability of equipment operation, reduce the maintenance cost of equipment, so as to improve the economic benefits of system operation and maintenance.

A failure analysis of a generator unit shutdown due to short circuit of generator positive and negative collector rings

Taking the short circuit faults of the positive and negative collector rings of a 40MW gas turbine generator as an example, the failure process of the generator's positive and negative collector rings is analyzed, the process of failure occurrence is explained, and the cause of the failure is analysed, the main reason for the failure is that the air inlet filter of the collector ring chamber of the generator is damaged and falls off, and the broken and dropped filter screen enters the collector ring chamber with the wind, which causes a short circuit of the positive and negative collector ring. Finally, the corresponding treatment and preventive measures are formulated.

Analysis and Measures For the Influence of Plastic Balls in Drilling Fluid on Cable Formation Testing

Cable formation testing is an important means of reservoir evaluation in Bohai Oilfield, but most directional exploration wells will add solid lubricant plastic balls into the drilling fluid due to engineering needs, and the inlet and outlet filter screen of the derivative subsequent cable formation testing instrument is blocked by plastic balls, which seriously affects the normal operation.In order to overcome the influence of plastic balls on the cable formation test, the main reason for the plastic balls to block the filter screen is analyzed. The idea that the inlet value and the outlet value should be closed before the instrument goes down the well, pump operation should not be carried out before sealing, and pumping should be carried out only after sealing is put forward. Combined with successful cases,the operation method of Sealing, No Opening; Shut Off, Before Release is summarized. The popularization and application of this method can effectively overcome the influence of plastic ball on cable formation test, and the application effect is remarkable.

ASSESSMENT OF THE WASHING EFFECTIVENESS OF ON-PURPOSE DESIGNED ECO-FRIENDLY CLEANER AGAINST SOOT DEPOSITS

The increment of the industrialization processes led to even more release of carbonaceous particulate into the environment. These airborne contaminants are produced by endothermic machines, coal combustion, heating systems, and production plants. Soot particles suspended into the air can overpass the inlet filters (if present) of gas turbines and deposit onto the internal parts of the compressor. This phenomenon, leading to the modification of the aerodynamic surface of the airfoils, is the main responsible for the gas turbine performance losses over time. This detrimental effect can be partially recovered by washing the compressor unit, frequently. In this work, the assessment of the washing effectiveness against soot deposits of an on-purpose designed eco-friendly cleaner is provided. The removal effectiveness of this water-based cleaner is related to the capability to collect soot particles from surfaces, limiting redeposit phenomena over the stages. The experimental investigation has been carried out by injecting soot particles, under controlled conditions, into a multistage test axial compressor. Using image post-processing techniques, carried out over the entire compressor flow path, a quantitative evaluation of the washing capability has been assessed. Compared with demineralized water, the cleaner was found to be effective if high cleaning performances are expected.

Pilot-Scale Study on the Specific Resistance of Beech Wood Dust in a Pulse-Jet Filter

The specific beech wood dust resistance coefficient values were experimentally determined in the condition of pulse-jet filtration using a pilot-scale baghouse. The experiments were carried out for two variants of the filter medium. One of them had a PTFE (Polytetrafluoroethylene) membrane on the working surface. Three values of filtration velocity and seven levels of dust concentration at the filter inlet were used to determine the variability of the specific resistance coefficient of beech wood dust accumulated on the filter medium. The values of the specific beech wood dust resistance coefficient depend on filter medium finishing and filtration parameters: filtration velocity and dust concentration at the filter inlet. The high concentration of dust at the filter inlet and low filtration velocity should be used, especially in filters with surface finished media, for the reduction in pressure drop, which would affect in a significant reduction of energy consumption.

Investigation of methods for equalizing the flow parameters in the axial compressor intake flare

The problem of ensuring a uniform velocity field at the air inlet to the first stage of the gas turbine compressor SGT5-2000E with an angular inlet path, that contains an inlet filter, a silencer and an angular intake flare, is considered. Based on the mathematical modeling of the flow in this flare, it was found that the maximum speed at the compressor inlet is 36% higher than the average flow rate. It leads to the fact that the range of stable operation of the compressor seriously narrows. To solve this problem, it is proposed to change the intake flare design so that a newly developed effective damper of uneven velocity fields is installed in its flow part. Studies have shown that in this way the nonuniformity coefficient was reduced from the above 36% to 6%.

Life Cycle Cost Analysis of Gas Turbine Air Inlet Filtration System

As an important component of gas turbine, air inlet filtration system is of great significance for ensuring the normal operation of gas turbine. However, it is often difficult to select a suitable air inlet filtration system according to the operating characteristics of the unit and the external environment due to the large number of variables. From the perspective of life cycle cost, the main factors to be considered in the selection of inlet filtration system are discussed, and the corresponding calculation model is proposed. Through the cost calculation of a gas-steam combined cycle unit’s inlet filtration system during the whole life cycle, the influence of the initial cost, operation cost, maintenance cost and gas turbine performance degradation cost on the total cost is analyzed. The results show that the cost of gas turbine performance degradation accounts for 90.44%, and the initial cost only accounts for 0.62% in the total cost. Therefore, in the selection of the inlet filtration system, the system economy should be evaluated from the perspective of full life cycle cost. The calculation model has important guiding significance for the selection and cost calculation of the gas turbine inlet filtration system.

Pleatco Filtration purchases TVS Filters

Pleatco Filtration has bought TVS Filters, a designer and manufacturer of pleated filter cartridges, gas turbine inlet filters and other filtration products for complex industrial air filtration applications.

Effect of underdrain design, media height and filtration velocity on the performance of microirrigation sand filters using reclaimed effluents

Sand filters are commonly used in microirrigation systems to prevent emitter clogging, especially when wastewater is used. However, little is known about the operating conditions required to guarantee a good filtration and a low energy consumption. For this reason, three sand filters with different drainage designs (collector arms, inserted domes and porous medium) using reclaimed effluents were analysed when operating with two sand media heights (0.20 and 0.30 m) and two filtration velocities (30 and 60 m h−1). Each one of these four different operating conditions (combination of two sand media heights and filtration velocities) was tested for 250 h. Filtered and backwashed volumes, energy consumption during filtration and backwashing, inlet and outlet filter pressures, and water quality parameters at filter inlet and outlet were recorded using a supervisory control and data acquisition system. Results showed that porous media underdrain design presented higher turbidity removal efficiencies for most of the tested conditions (38.53, 33.63 and 10.51% at 0.20 m/30 m h−1, 0.20 m/60 m h−1 and 0.30 m/60 m h−1, turbidity removal, with sand media height/filtration velocity, respectively) and dome underdrain only at 0.30 m/60 mh−1 (47.74%). Porous media underdrain also filtered more water volume per electrical energy unit (8.30 m3 kWh−1) than domes and arm collector underdrain (8.18 and 8.07 m3 kWh−1, respectively). In general, filtration velocities of 30 m h−1 showed higher turbidity removals and filtered more water volume per electrical energy unit than 60 m h−1. Media height did not show a clear effect, but smaller media heights did allow energy and material saving.