Wyniki wyszukiwania - BazTech

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Problem hałasu. Badania akustyczne rozprężania gazu w warunkach laboratoryjnych

Gaj Patryk, Karczewski Jacek, Kopania Joanna

Energetyka Cieplna i Zawodowa

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2022

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Nr 6

28--35

PL

Od czasu wynalezienia silników parowych rosnąca industrializacja powoduje zwiększenie wydajności produkcji zakładów przemysłowych. Jednakże rozwój technologii łączy się również z negatywnymi efektami. Należą do nich zanieczyszczenia lub zakłócenia środowiska pracy, co ma wpływ na nasze codzienne życie. Jednym z nich jest tak zwane „zatrucie hałasem”, czyli zwiększenie średniodobowego poziomu hałasu.

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Influence of shell shape on flow and acoustic parameters of a steam silencer

Gaj Patryk, Sobczak Krzysztof, Kopania Joanna, Wójciak Kamil

Archives of Thermodynamics

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2021

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Vol. 42, no 4

141--154

EN

Steam discharge produces noise due to rapid expansion and a temperature drop of ejected steam. This is why steam silencers are used to change one-stage into multi-stage expansion, which reduces the intensity of pressure and temperature drop during this process and shifts emitted noise into higher frequencies, which are easier to dampen. This paper presents a flow-acoustic numerical model of a steam silencer. It is meant to help to obtain a precise analysis of phenomena occurring in steam silencers and improve the process of designing this type of device. The model described in this paper was based on the parameters of a real working unit manufactured in the Institute of Power Engineering – Thermal Technology Branch. Most of the steam silencers are designed based on construction guidelines that have not been changed for a long time. This restrained an increase in the acoustics efficiency of the steam silencers. An improvement of their flow and acoustic properties allows for the development of smaller, more efficient, and lighter construction. The current version of the model was used for the analysis of flow and acoustic changes which occur after modifying the lower region of a shell of the steam silencer. The proposed modification allowed for a 19% increase in mass flow rate through the silencer and noise reduction in the low-frequency range.

3

The impact of the damper blade position on the generated noise and pressure losses in plenum box with swirl diffusers

Wójciak Kamil, Gaj Patryk, Kopania Joanna, Bogusławski Grzegorz

Vibrations in Physical Systems

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2019

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Vol. 30, nr 1

art. no. 2019103

EN

The article presents the effect of setting the throttle in the plenum box with swirl diffuser on the generated noise and the pressure losses. The sound power levels of the source was determined using the precision method in the reverberation room in accordance with the PN-EN ISO 3741:2011 standard. The examination was carried out for damper blade position set vertically and horizontally for full opening and at a 45 degree angle in both directions. In order to confirm the universality of the conducted experiment, the tests were carried out for two different face swirl diffuser with different shapes of air control blades and holes in the plate and for different flow rates. The multi-criteria optimization methods were used to select the best throttle position.

4

Assessment of sound absorbing properties of composite made of recycling materials

Gaj Patryk, Kopania Joanna, Wójciak Kamil, Bogusławski Grzegorz

Vibrations in Physical Systems

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2019

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Vol. 30, nr 1

art. no. 2019109

EN

In modern world we are searching methods to reuse most of industrial disposals produced during manufacturing. Some kinds of materials, like scraps from acoustic foam, however are not so easily utilized using recycling methods for its primary usage. Disposals produced during the manufacturing process can be compressed and reused as sound absorbing material. The purpose of this article is to examine sound absorbing properties of material made of acoustic foam disposals and compare it with sound protection materials, which are commonly used. Sound absorbing damping were tested using Kundt’s tube and reverberation room examination method. Tests were carried out according to standard PN-EN ISO 354:2005, for reverberation room examination, and according to Bruel&Kjaer electronic instruments technical manual for Kundt’s tube examination.