Design specification for noise control in petrochemical industry
1 Scope
This specification specifies the noise control principles, noise control limits and design requirements of sound insulation, sound absorption, noise elimination and isolation in the overall design in petrochemical industry.
This specification is applicable to noise control design for new, renovated and extended construction projects in petrochemical industry, and may serve as a reference for the noise control reconstruction project of the existing production devices.
2 Terms and definitions
For the purposes of this specification, the following terms and definitions apply.
2.1
sound source
object or equipment that produces vibration and has sound radiation
2.2
sound field
area in the medium where sound waves exist
2.3
sound pressure level
twenty times the logarithm to the base 10 of the ratio of sound pressure to reference sound pressure
Note: The reference sound pressure is 20μPa.
2.4
sound level
weighted sound pressure level measured by certain instrument characteristics and weighting characteristics of A, B and C
Note: Those without specifying the instrument characteristics and weighting characteristics used refer to A-weighted sound pressure level.
2.5
A-weighted sound pressure level
sound pressure level measured with A-weighted network
2.6
equivalent [continuous A-Weighted] sound pressure level
[A-weighted] sound level of continuous steady-state sound with the same mean-square [A-weighted] sound pressure as time-varying noise within the specified time
2.7
background noise
any interference that has nothing to do with the presence or absence of a signal in a system where the interference occurs, is checked, measured or recorded
2.8
regenerated noise
noise of airflow generated in pipe or muffler
Note: The regenerated noise is related to the airflow velocity and will reduce the function of muffler or even make it completely ineffective.
2.9
isolation
capability of reducing the system to respond to external excitation through flexible support
Note: In steady state, isolation is expressed by the reciprocal of transfer ratio.
3 Overall design
3.1 General requirements
3.1.1 Noise control design shall run through different design stages of construction projects, and the main work contents shall include:
a) estimation of noise environmental impact in environmental impact assessment, pre-assessment of labor safety and hygiene and pre-assessment of occupational hazards of construction projects;
b) noise environmental impact analysis and noise source intensity control measures and objective requirements in environmental protection clause, labor safety and hygiene clause and occupational health clause;
c) design of various noise control facilities;
d) modification and supplementary design for the parts that fail to meet the design objectives of noise control on completion of the construction project.
3.1.2 In noise control design, measures shall be taken to control the noise from the aspects of technological process design and equipment selection, mainly including:
a) adopt low-noise technological process;
b) low-noise equipment of similar equipment shall be preferred during equipment selection;
c) noise control measures shall be taken in case of high-pressure and high-speed gas emissions.
3.1.3 Personal protective measures shall be taken for posts or workplaces that are difficult to control and still fail to meet the requirements of noise control standards after noise control measures are taken.
3.1.4 Depending on the spectral characteristics, noise intensity and location of high noise sources, measures such as sound insulation, noise elimination, sound absorption, isolation, damping vibration attenuation or comprehensive noise control may be taken.
3.1.5 All noise control equipment or facilities shall not produce secondary pollution. According to the use conditions, fire prevention, corrosion prevention, moisture prevention, gas (steam) flow impact resistance and other requirements shall be considered, and the mechanical processing may be compared with the specification requirements of similar equipment.
3.1.6 New, renovated and extended construction projects shall be provided with full-time or part-time noise monitoring and management personnel, and equipped with necessary equipment and facilities.
3.1.7 Project investment must cover noise control equipment and facilities as well as monitoring instruments and equipment.
Foreword i
1 Scope
2 Terms and definitions
3 Overall design
3.1 General requirements
3.2 Site selection and general layout
3.3 Pipes and valves
3.4 Technology machinery and equipment
4 Noise control design limits
5 Sound insulation design
5.1 General requirements
5.2 Acoustic shield
5.3 Sound insulation operation room
5.4 Sound insulation screen
5.5 Sound insulation bandaging for pipes and valves
6 Sound absorption design
6.1 General requirements
6.2 Selection of sound-absorbing materials and sound-absorbing components
7 Noise elimination design
7.1 General requirements
7.2 Dissipative muffler
7.3 Reactive muffler
7.4 Throttling step-down muffler and jetting muffler
8 Isolation design
8.1 General requirements
8.2 Isolation
Annex A (Normative) Noise control design estimation equation
Annex B (Normative) Allowable sound pressure level of octave band
Explanation of wording in this specification
