Research of filter materials for dust fractioning

A special place in air pollution with dust emissions is occupied by the production of building materials, using large quantities of dispersed mineral substances as aggregates. The article is devoted to the study of hazardous dust fractions emission when assessing the dustiness of the working area for the production of concrete and reinforced concrete products, since the specific location and operation of the equipment complex is characterized by uneven dust formation in space and time. This reduces the efficiency of the aspiration systems. Based on the analysis of methods and means for assessing dustiness, the use of the gravimetric method is justified, however, to assess the content of the most dangerous dust particles for the human body with a size of 2.5 to 10 microns, a size separation of particles is required. Non-woven synthetic filter materials of various thick-nesses and densities are investigated. It is proposed to carry out sampling in blocks with three filters from different filter materials. The studies were carried out with the help of a specially made portable complex. The most effective filter materials were determined with the help of microscopic analysis. The conducted calibration of the blower performance with an assessment of the measurement accuracy showed relatively small errors in the air sampling, which confirms the feasibility of assessing the dustiness of the filter blocks.

Effect on Efficiency of Lobe Performance in a Roots Blower

A Roots blower is a mechanical device for moving air or other gases. As the flow process is highly complex in roots blower operation, it is necessary to analyses efficiency of lobes and develop the geometry of roots and casing to reduce the flow loss significantly. In the present thesis, the methodology to find near optimum combination of blower operating variables of performance.Roots blower are positive displacement device. In this study, roots blower is used to control the room conditions like temperature, moisture control, mist and transfer low volume intake into the system, increase the power efficiency of the engine. It is reliable, economical and having low maintenance cost.A roots blower performance depends on quality of air intake and geometry used. The quality of air major impact to the lobe arrangement and effect on temperature increase, reduced thickness of lobes and impact on performance of roots blower.

Impeller Blower Performance in Conveying Broiler Litter

Broadcast application is the typical application method for poultry litter, which is a mixture of poultry manure and a bedding material. Applying poultry litter in subsurface bands reduces concentrations of nutrients from the litter in surface runoff water, reduce loss of ammonia to volatilization, and has been shown to increase cotton lint yield, relative to conventional broadcast application. An impeller blower was developed for conveying poultry litter a short distance horizontally and downward to the soil. When relatively dry pine shavings-based broiler litter with a moisture content of 27% w.b. was used, and the impeller speed was 930 r min-1 [14.9 m s-1 (48.9 ft s-1) circumferential speed], the blower performed well conveying litter at a rate of 1.2 kg s-1 (2.6 lb s-1) [0.88 kg dry matter s-1 (1.9 lb dry matter s-1)]. The blower performance was unsatisfactory, however, when relatively moist litter with a moisture content of 45% w.b. was used because the litter adhered to the interior of the blower outlet and clogged the outlet. The blower was mounted beneath a litter hopper, and safety of people in the vicinity of the blower is a concern if the litter contains rocks or other hard objects, and there is no shield to prevent these objects from being flung upward, out of the hopper, from the blower inlet. When the blower was run at 889 ± 14 r min-1 without any litter, so it was conveying only air, as the area of the circular blower inlet increased by a factor of 25 from 0.00051 to 0.0127 m2 (0.79 to 19.6 in.2), the mean outlet air velocity increased by a factor of 4.0 from 3.0 to 12.0 m s-1 (9.8 to 39.4 ft s-1). The blower conveyed dry litter successfully for a single-band implement [1.2 kg s-1 (2.6 lb s-1) mass flow rate at 930 r min-1 impeller speed], for subsurface band application of poultry litter. Mesh chain conveyors, however, perform better for litter moisture contents up to 40% w.b. The mass flow rate of litter, up to 40% w.b. moisture content, can be controlled quite well with mesh chain conveyors (litter mass flow rate coefficients of variation typically 5% or less), but is more difficult to control with this impeller blower. Keywords: Animal waste, Band application, Impeller blower, Manures, Manure application equipment, Pneumatic conveying, Poultry manure, Subsurface banding.

Effect of Impeller Condition on Blower Performance, Case Study: Impeller of K-2201 in Pt. Pertamina RU III

The performance of blower depends on impeller condition. This paper is to discuss the open face impeller condition related to performance based on performance curve provided by the manufacturer. The impeller condition is observed under three different conditions. The first condition is that the impeller area is covered by 3 mm thick of fouling. The second condition is that there is a 1 mm of rubbing on the vane and the third condition is the impeller after being repaired. The datas are taken by the actual operation condition. The observed data is then calculated and plotted on OEM performance curve. The result shows that the first condition has the lowest performance; the produced head is 47% lower than the OEM’s.

A Development of the Fuel Cell System That the Jet-Pump is Applied

A fuel cell system is developed by applying a jet-pump system that performs hydrogen supplying and anode recirculation functions. The jet-pump system made up of an ejector and a proportional valve is designed to substitute conventional ejector-blower hydrogen recirculation system. The impulsive fuel feeding applied to overcome the ejector performance limits in low-power conditions. The fuel supply valve moves like injector to operate ejector at a design point in short time and does not works in remain time of each period. Therefore, average performance of ejector is better than continuous fuel feeding condition. The jet-pump compares aerodynamic performances with the blower and installed in the 100kW fuel cell system also. As a result, 25Hz and duty 75% conditions show above 80% of ejector-blower performance under 10kW emulation condition and three conditions demonstrates better performance over 10kW condition. Applicability of Jet-pump is verified at fuel cell system also. The system integrated jet-pump maintains stable state and shows equal level of ejector-blower applied case in Min. cell ratio and voltage decrease test results.

Active Control of Flow Separation in a Radial Blower

An experimental investigation was undertaken as a proof-of-concept study for active separation control in a radial blower. Acoustic perturbations were introduced into the impeller housing of a small radial blower with fully stalled blades. Increases in the plenum pressure of 35% were achieved and, based on tuft-based flow visualization, it was concluded that the pressure increases were brought about due to excitation and deflection of the leading-edge separated shear layer. Within the parameter range considered here, the optimum dimensionless control frequencies were found to be O(0.5), irrespective of the blade orientation or number of blades. Moreover, the maximum pressure rise was achieved with an investment of only 2% of the fan input power. Backward bladed impeller blades exhibited slightly larger increases in pressure coefficients when compared with their forward bladed counterparts. The dependence of blower performance on reduced frequency was remarkably similar to that seen on flat plate airfoils at similar Reynolds numbers under periodic excitation.

New Design Features of Centrifugal Blower Systems to Improve its Airflow Performance and Power Consumption

A parametric study is carried out to screen the effects of HVAC blower housing volute, scroll, design parameters on its performance. The results of statistic regression analysis, mathematical models and prediction correlation to test data are included and discussed. Blower airflow field is inspected by computational fluid dynamics (CFD) and Laser Doppler velocimetry (LDV) to define its deficiencies. New design features for blower scrolls are developed to resolve the flow deficiencies, in order to minimize the blower energy losses, vibrations and air-rush noise. Flow field improvements are illustrated. Blower performance with the new design features is compared to the performance of the previous design art known as “standard blower” designs. Airflow capacity of the new designs is higher than that of a standard design of one degree larger in size, within the operating range of automotive air-handling systems. Blower efficiency is increased by 3 to 8% over a wider airflow range. The effects of scroll size and exit design on the performance of the new scroll designs are illustrated and discussed.