Analysis of the precipitation reactor-separation equipment system. Continuous reactor and the rotary vacuum filter operating at the selected negative pressure drop

1981 ◽  
Vol 46 (10) ◽  
pp. 2364-2370 ◽  
Author(s):  
Otakar Söhnel
Keyword(s):  
Pressure Drop ◽  
Negative Pressure ◽  
Continuous Reactor ◽  
Vacuum Filter ◽  
Continuous Precipitation ◽  
Derived Relations ◽  
Filtration Area ◽  
Separation Equipment ◽  
Unit Output ◽  
Rotary Vacuum

An analysis has been performed of the continuous precipitation reactor - rotary vacuum filter system (operating at the selected negative pressure drop) on the basis of the unit output. Filtration area necessary for separation of the product from the precipitation reactor is a function of the mean residence time of suspension in the reactor, concentration of the precipitating solutions, porosity of the filtration cake and the filtration negative pressure drop. Application of the derived relations is demonstrated on the continuous precipitation of Mg(OH)2.

Research on the Pressure Field and Production Ability of Compound Hydrocyclone

2008 ◽  
Author(s):  
Feng Li ◽  
Minghu Jiang ◽  
Lixin Zhao
Keyword(s):  
Pressure Drop ◽  
Pressure Field ◽  
Waste Water Treatment ◽  
Tangential Velocity ◽  
Liquid Density ◽  
Free Vortex ◽  
Overflow Pipe ◽  
Separation Equipment ◽  
Relationship Of ◽  
The Relationship

Compound hydrocyclone is an important separation equipment in oilfield waste water treatment. In order to grasp the equipment separation characteristics, its pressure field and production ability research is becoming more and more important. In the process of pressure or pressure drop deduced, the hydrocyclone’s vortex field is divided into two parts: semi-free vortex area and compulsive vortex area. In the free vortex area, the pressure and the pressure drop are all deduced by the tangential equation, the pressure gradient equation and the relationship equation of tangential velocity in the hydrocyclone body and the velocity of the rotary crib. In the compulsive vortex area, the pressure and the pressure drop are deduced by the velocity equation and the hydrocyclone’s separation equation. As to the respect of the production ability, it is fixed on the relationship of the inlet flow-rate, overflow pipe diameter, the main diameter of the compound hydrocyclone, pressure drop and the inlet liquid density. The research indicates that the pressure or the pressure drop are all connected with compound hydrocyclone’s diameter, rotary crib’s running velocity and diameter of the maximum tangential velocity track face. As the results of the research, the ascertained key operators, pressure and the pressure drop, the hydrocyclone’s production ability can provide designing consult for the hydrocyclone designers.

Evaluation of Air Filtration Options for an Industrial Gas Turbine

2015 ◽  
Author(s):  
Christopher A. Perullo ◽  
Josh Barron ◽  
Dale Grace ◽  
Leonard Angello ◽  
Tim Lieuwen
Keyword(s):  
Pressure Drop ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
High Efficiency ◽  
Air Filtration ◽  
Unit Output ◽  
Almost All ◽  
The Cost ◽  
The Impact ◽  
Unit Performance

Gas turbines ingest large quantities of air during operation. As a result, large quantities of foreign particles ranging in size from smoke (0.01 to 1.0 micron) to pollen (10 micron) enter the unit and can contribute to both fouling and erosion depending on particle size. Fouling and erosion both lead to reductions in unit output and efficiency resulting in increased operational cost. Operators have historically combatted fouling through a combination of online water washes, more effective off-line water washes, and air filtration. As is the case with almost all engineering problems, the trade-off between the cost and effectiveness of these methods must be evaluated. Online washing is somewhat effective but has led to first stage blade erosion and unit trips in some cases. Off-line washing is more effective at cleaning the unit, but requires the unit to be shut down for extended periods of time. Air filtration can help prevent foreign particles from entering the unit, but higher efficiency filters are generally associated with a larger inlet pressure drop, leading to decreased unit output; this is balanced against reduced fouling rates. These tradeoffs between the costs associated with higher efficiency filters and the frequency of compressor washing need to be evaluated on a plant-by-plant basis to determine the best combination of air filtration and compressor washing programs. This paper presents a field study carried out to determine the effectiveness of high efficiency filters in preventing compressor fouling. Fourteen units at four sites were monitored over a 9 month to 3 year time period to determine the changes in unit performance and the impact of water washes on unit performance for both pre and final filters of lower and higher efficiency ratings. Results to date indicate that higher efficiency filters are effective at reducing the need for off-line water washes and potentially reduce life-cycle cost. Reduced output from the higher pressure drop, high efficiency filters is offset by the better performance retention offered from reduced fouling rates.

Lubricant-Derived Ash Properties and Their Effects on Diesel Particulate Filter Pressure-Drop Performance

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Alexander Sappok ◽  
Victor W. Wong
Keyword(s):  
Performance Evaluation ◽  
Pressure Drop ◽  
Effective Means ◽  
Engine Performance ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Loading System ◽  
Filtration Area ◽  
Underlying Mechanisms

Diesel particulate filters (DPFs) have seen widespread use in on- and off-road applications as an effective means for meeting increasingly stringent particle emission regulations. Over time, incombustible material or ash, primarily derived from metallic additives in the engine lubricant, accumulates in the DPF. Ash accumulation leads to increased flow restriction and an associated increase in pressure-drop across the particulate filter, negatively impacting engine performance and fuel economy and eventually requiring periodic filter service or replacement. While the adverse effects of ash accumulation on DPF performance are well known, the underlying mechanisms controlling these effects are not. The results of this work show ash accumulation and distribution in the DPF as a dynamic process with each stage of ash accumulation altering the filter’s pressure-drop response. Through a combined approach employing targeted experiments and comparison with the existing knowledge base, this work further demonstrates the significant effect ash deposits have on DPF pressure-drop sensitivity to soot accumulation. Ash deposits reduce the available filtration area, resulting in locally elevated soot loads and higher exhaust gas velocities through the filter, altering the conditions under which the soot is deposited and ultimately controlling the filter’s pressure-drop characteristics. In this study, a novel accelerated ash loading system was employed to generate the ash and load the DPFs under carefully controlled exhaust conditions. The ash loading system was coupled to the exhaust of a Cummins ISB diesel engine, allowing for accelerated ash loading and DPF performance evaluation with realistic exhaust conditions. Following DPF performance evaluation, the filters were subjected to a detailed post-mortem analysis in which key ash properties were measured and quantified. The experimental results, coupled with the ash property measurements, provide additional insight into the underlying physical mechanisms controlling ash properties, ash/soot interactions, and their effects on DPF performance.

Lubricant-Derived Ash Properties and Their Effects on Diesel Particulate Filter Pressure Drop Performance

2009 ◽  
Author(s):  
Alexander Sappok ◽  
Victor W. Wong
Keyword(s):  
Performance Evaluation ◽  
Pressure Drop ◽  
Effective Means ◽  
Engine Performance ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Loading System ◽  
Filtration Area ◽  
Underlying Mechanisms

Diesel particulate filters (DPF) have seen widespread use in on- and off-road applications as an effective means for meeting increasingly stringent particle emissions regulations. Over time, incombustible material or ash, primarily derived from metallic additives in the engine lubricant, accumulates in the DPF. Ash accumulation leads to increased flow restriction and an associated increase in pressure drop across the particulate filter, negatively impacting engine performance and fuel economy, and eventually requiring periodic filter service or replacement. While the adverse effects of ash accumulation on DPF performance are well known, the underlying mechanisms controlling these effects are not. The results of this work show ash accumulation and distribution in the DPF as a dynamic process with each stage of ash accumulation altering the filter’s pressure drop response. Through a combined approach employing targeted experiments and comparison with the existing knowledge base, this work further demonstrates the significant effect ash deposits have on DPF pressure drop sensitivity to soot accumulation. Ash deposits reduce the available filtration area, resulting in locally elevated soot loads and higher exhaust gas velocities through the filter, altering the conditions under which the soot is deposited and ultimately control the filter’s pressure drop characteristics. In this study, a novel accelerated ash loading system was employed to generate the ash and load the DPFs under carefully-controlled exhaust conditions. The ash loading system was coupled to the exhaust of a Cummins ISB diesel engine, allowing for accelerated ash loading and DPF performance evaluation with realistic exhaust conditions. Following DPF performance evaluation, the filters were subjected to a detailed post-mortem analysis in which key ash properties were measured and quantified. The experimental results, coupled with the ash property measurements, provide additional insight into the underlying physical mechanisms controlling ash properties, ash/soot interactions, and their effects on DPF performance.

Modeling Airborne Virus Concentrations in Filtered Swine Barns with Negative-Pressure Ventilating Systems

2018 ◽  
Vol 61 (3) ◽  
pp. 1089-1099
Author(s):  
Kevin A. Janni ◽  
Montserrat Torremorell ◽  
Larry D. Jacobson ◽  
Carmen Alonso ◽  
Brian P. Hetchler
Keyword(s):  
Particulate Matter ◽  
Pressure Drop ◽  
Virus Particle ◽  
Negative Pressure ◽  
Reduction Factor ◽  
Respiratory Syndrome Virus ◽  
Fan Performance ◽  
Infiltration Rates ◽  
System Pressure ◽  
Filter Area

Abstract. Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically significant pathogen in the swine industry that can spread through the air. Many swine gestation and farrowing barns with negative-pressure ventilating systems filter the inlet air to manage airborne PRRSV transmission using MERV 8 pre-filters in series with either MERV 14 or MERV 16 filters. Recent research reported air infiltration rates for a new 3,000-sow gestation/farrowing swine barn at several static pressure levels. The barn infiltration data and supplier-provided airflow versus pressure drop data for the filters, a fan, and an evaporative cooling pad were used to model steady-state virus particle concentrations inside a well-mixed barn. Other model inputs included the inside temperature, design ventilating rate, a fan performance factor, filter area, a filter airflow reduction factor due to particulate matter accumulation, and ambient virus particle concentration distributions. For the conditions used, model results indicated that higher barn virus concentrations were obtained with lower mechanical ventilating rates and higher barn infiltration rates. Improved fan performance reduced the number of fans needed but had little impact on barn virus concentrations. Increasing the filter area reduced the pressure drop that the fans had to overcome at higher ventilating rates and correspondingly reduced the unfiltered infiltration rates and barn virus concentrations. Reduced airflow due to particulate matter accumulation on the filters increased the system pressure drop, increased the number of fans running, and increased the barn virus concentrations. Model results indicated that filter combinations that reduced overall virus penetration reduced barn virus concentrations by 57% to 80% for the conditions modeled. More work is needed to assess the model results and the importance of the adjusted factors for other barn and equipment conditions. Keywords: Biosecurity, Filtered barn, Infiltration, Model, Swine, Ventilation, Virus.

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