DOI 10.35776/VST.2021.05.06
UDC 628.356.1:621.61

Ovseichuk B. V., Guseinova Elena, Florian Adam

On the operation of blowers controlled by mechanical blades
under extreme conditions

Summary

Reducing energy costs for air supply to aeration systems of the treatment facilities by using adjustable air blowers is an urgent task. A comprehensive analysis of operating single-stage centrifugal air blowers controlled by mechanical rotating blades under low ambient temperatures typical for Russia is presented. In the process of monitoring, the parameters of the air blowers were monitored (air temperature at the compressor inlet, excess pressure at the compressor outlet, vibration level, lubricating oil temperature, temperature of the impeller shaft bearings, input current consumed of the electric drive motor).

Key words

adjustable air blower , excess pressure , air temperature reduction , measurement diagram , parameters of the air blower operation , input current of the electric motor , isentropic performance factor , rotating blade , centrifugal compressor

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UDC 628.23

Vasilyev V. M., Malkov A. V., PANKOVA G. A., Klementyev M. N.

Detecting the places of corrosive gas emissions from sewers to the surface and conditions of their formation

Summary

Corrosive gas emissions from sewers to the surface happen because of the excess pressure increase in the underroof and shaft space of the sewer. The causes of the pressure increase in the shaft space are considered. The gas amount changing during entering the shaft and removed from it depends on the wastewater flow rate, sewer filling (the height of the gas flow), hydraulic gradient of the sewer, formation of stagnation zones (sludge sedimentation), and temperature. Variation of these parameters and thus the location of corrosive gas emissions to the surface depend on a number of factors that can be divided into several groups: construction, hydraulic, geodesic, operation, random, climatic. Reducing the gas emissions from sewers is possible by: introduction of construction solutions for gaseous medium redistribution; elimination of air blocks, installation of purification filters; avoiding deviations from the design solutions ari­sing during the construction of deep sewers; proper management of wastewater flow at elevation differences; improvement of the sewer operation rules, severization of the requirements to the operating personnel qualification.

Key words

collector , sewerage network , joint movement of liquid and gas , gas emission , excess pressure , ventilation