Stainless steel corrugated pipe for earthquake and noise reduction project of boiler room of Yunnan Honghe Tobacco Factory
Shanghai Dongfeng Pump Valve Factory is a stainless steel bellows product of Yunnan Honghe Cigarette Factory's boiler room shock and noise reduction project, also known as stainless steel metal expansion joint. It is durable, high temperature resistant, high pressure resistant, anti-corrosion, and environmental protection. It has replaced the unhealthy factors caused by the valve, such as unsanitary, easy aging, unstable pressure resistance, easy delamination and tearing, and blasting, and has solved the worries in the operation of the system. Stainless steel corrugated pipe for the anti vibration and noise reduction project of boiler room. Introduction:
From the perspective of structure, Yunnan stainless steel bellows are made of two materials, namely, strip and pipe, which can form annular bellows and spiral bellows. Just because the corrugated pipe formed with strip always has a certain length of brazing or fusion welding buckles and valves, these places often accumulate the residue of the working medium, and precipitate the cleaning test and mechanical impurities in the working medium to pollute the inner cavity. Therefore, its use reliability is relatively poor. The annular corrugated pipe is a pipe of special geometric shape whose outer edge of several annular diaphragms is tangent to several concave centripetal semicircle rings, and the inner edge is tangent to several concave vest semicircle rings. Its blank is mainly pipe material. This kind of corrugated pipe has the advantages of large flexibility, good elasticity, simple manufacturing, small rigidity, etc. It is suitable for making large and medium diameter metal hoses that bear general working pressure and have high requirements for flexibility. The spiral corrugated pipe is a pipe of special geometric shape whose outer edge of the spring wound membrane of a certain length is tangent to the spring wound concave centripetal semicircular ring, and the inner edge is tangent to the spring wound concave vest semicircular ring. This type of corrugated pipe has high strength, high rigidity, simple manufacturing, etc. It is suitable for making metal hoses with high and medium pressure, medium and small diameters that have general requirements for flexibility and high requirements for strength.
Introduction to noise control in boiler room:
Generally speaking, noise is disorderly, discordant, annoying and unnecessary. It is a kind of sound wave, which is mainly generated by physical and chemical processes such as object vibration and impact, and radiates in all directions in the form of waves in the medium. The boiler noise affects the quiet working and living environment of the surrounding residents and damages people's health, especially the small and medium-sized boilers located in densely populated urban residential areas and factory and mining workers' living areas, which pollute the environment and interfere with people's work, study and life, often causing disturbing events and disputes. Boiler noise has become one of the current urban noise sources, therefore, the prevention and control of boiler noise is increasingly important. How to choose simple equipment with less investment and achieve better noise reduction effect and longer service life is one of the current important topics.
Noise hazard:
The impact and harm of noise on human body can generally be divided into labor protection and environmental protection. The former refers to endangering people's health and causing the discovery of various diseases, and the latter refers to disturbing the quiet environment and affecting people's normal life and work. The main harm of noise to human health is: loss of hearing, resulting in noise induced deafness; It leads to excitation and balance of cerebral cortex, damage of cerebrovascular function, and neurasthenia; Damage the cardiovascular system, cause digestive system disorder, and affect endocrine; Disturb people's normal life, rest, language conversation and daily work and study, distract people's attention and reduce work efficiency. Research shows that the noise level of 30~40dB is a relatively quiet normal environment, and more than 50dB will affect sleep and rest. Due to insufficient rest, fatigue cannot be eliminated, and normal physiological functions will be affected to some extent. 70dB of noise will interfere with the conversation, causing confusion and distraction, affecting the normal work efficiency. In a word, the noise in the boiler room is a serious source of noise pollution. If effective control is not carried out, it will affect and harm the on-site personnel and surrounding residents.
Introduction to metal expansion joint structure of cigarette factory:
Guizhou metal expansion joint is generally composed of bellows, mesh sleeve and valve. Corrugated pipe is the body of metal expansion joint in cigarette factory, playing a flexible role; The net sleeve plays the role of strengthening and shielding; The valve serves as a connection. For different use requirements, they are connected in different ways: bellows, mesh sleeve and valve are connected by welding, which is called welding type; The connection in the form of mechanical clamping is called mechanical clamping; In addition, the above
The combination of the two methods is called hybrid.
1. Install sound insulation cover or sound insulation room for noise source equipment such as boiler room blower and induced draft fan; Sound insulation enclosure or sound insulation room is mainly used for The ground shall be subject to sound insulation treatment.
2. Damping treatment shall be carried out for mechanical and electrical equipment such as blower and induced draft fan
3. Vibration reduction treatment for pipeline system in boiler room
4. The maintenance structure of the boiler room is subject to vibration isolation and sound absorption treatment
Source of noise in boiler room:
The noise in the boiler room mainly comes from the aerodynamic noise of the blower and induced draft fan, as well as the mechanical noise of the casing, pipe wall, pneumatic motor bearing, the noise generated by the vibration of water pump, coal feeder, dust remover and other equipment, and the combustion noise of the boiler. The dissipative muffler is mainly used to attenuate the noise transmitted along the pipe with distance by virtue of the sound absorption material or structure embedded on the inner wall of the pipe, so as to achieve the purpose of noise elimination. It is mainly used to control medium and high frequency noise. The reactive muffler does not have sound absorption performance directly. It mainly uses the sudden expansion and contraction of the pipe section to make the noise transmitted along the pipe reflect to the sound source at the abrupt change, so as to achieve the purpose of noise elimination. It is mainly used to control low and intermediate frequency noise.
Noise control measures:
The propagation process of noise usually includes three links: sound source, propagation medium and receiver. Noise control should also start from these three links The first is to reduce the noise of the noise source, the second is to control the noise from the transmission path, and use sound absorption, sound insulation, vibration reduction and other technologies to reduce the noise. The third is to protect the receiver. 1. Reduce noise from the sound source. Improve the structural form of the fan, select the best blade type, determine the reasonable speed, improve the machining accuracy and assembly quality, and configure the low-noise pneumatic motor. 2. Protect the recipient. Personal protection shall be provided for operators exposed to noise hazards, such as wearing sound proof earplugs, sound proof earmuffs, sound proof helmets, etc. 3. Control the noise transmission path. ⑴ Sound insulation. The whole fan unit is sealed with a sealed sound insulation cover by using a sound insulation cover. Because the whole fan unit is sealed, the sound insulation cover also effectively controls the noise radiated from the fan housing, motor foundation vibration and other parts. Generally, the fixed sealed sound insulation cover can reduce the noise by 20~30dB. The sound insulation cover is composed of cover plate, damping material and sound absorption layer. The cover plate can be made of 3mm steel plate. In order to improve the sound insulation performance of the resonance area, the steel plate must be coated with a certain damping layer, and the cover is lined with a sound absorption layer to reduce the reverberation generated in the cover. This is an economical and applicable treatment measure for those boiler rooms that have no single fan room. Sound insulation fan room shall be built to seal the fan noise in the room and prevent it from spreading. The fan room is generally bricked, and the mortar joints between the bricks should be full without gaps. Sound insulation measures shall be taken. In addition to selecting appropriate sound insulation materials, the main thing is to seal the doors and windows of the sound insulation room. The doors and windows of the room shall be built into sound insulation doors and windows according to the requirements of sound insulation technology. ⑵ Vibration isolation. The unbalanced operation of the fan will cause foundation vibration, which will radiate noise after being transmitted to the floor and wall. The so-called vibration isolation is to change the rigid connection between the fan and the foundation into an elastic connection to reduce the transmission of sound waves in the solid. For example, designing anti vibration foundation or installing shock absorber, installing vibration isolation pad for vibration isolation are all effective methods. In addition, soft connection is used between the air inlet and outlet of the fan and the pipeline for vibration isolation, which reduces the transmission of vibration energy and achieves the purpose of vibration isolation and noise reduction. ⑶ Damping. Noise can be radiated through the pipe wall and casing. Damping the pipe wall or casing is to use some coatings with high internal loss and friction, such as asphalt, soft and other polymer materials, to coat the pipe wall or casing, so that the vibration energy is consumed by the damping materials and becomes heat energy. Apply asphalt on the pipe wall, and then tightly wrap a layer of asphalt felt to achieve a certain effect. ⑷ Sound absorption. Laying porous sound absorption materials (such as ultra-fine glass wool) on the walls and sheds of the fan room can reduce the reverberation sound indoors. Its surface is fixed with metal wire mesh. At the same time, according to the principle of perforated panel resonance sound absorption structure, perforated panels made of perforations with a certain aperture and perforation rate are installed on the surface layer that has a certain thickness from the metal wire mesh. If the fan room is too large, if the room is too high, the sound absorption screen can be set near the fan or on the fan face, and the local treatment method can also achieve good results. (5) Muffler. Practice has proved that the sound source of the blower and induced draft fan is mainly the aerodynamic noise radiated from the inlet and outlet of the fan. Therefore, the control of noise in the boiler room focuses on the control of aerodynamic noise at the inlet and outlet of the blower and induced draft fan. It is an important measure to install silencers on the inlet and exhaust pipes of the fan (which do not hinder the gas flow and can eliminate aerodynamic noise) to reduce the fan noise at present. Mufflers are generally installed at the inlet and outlet of the blower and the outlet of the induced draft fan. However, if the noise control requirements are very strict, silencers can also be installed at the inlet and outlet according to the specific situation on site. Installing muffler is a main technical measure that can not only allow airflow to pass through, but also effectively reduce aerodynamic noise. According to the principle of noise elimination, there are generally two types of mufflers: resistive mufflers and reactive mufflers.
Introduction to Yunnan Honghe Cigarette Factory:
Honghe Cigarette Factory was established in 1985, trial produced in 1987, and formally obtained the Tobacco Production and Operation License in 1988. Qiu Jiankang is the legal representative of the enterprise. There are 1167 on-the-job employees, with an average age of 33. It has supporting threshing and redrying, silk making, dry ice expansion, package rolling equipment and automatic logistics system; The assets reached 5.9 billion yuan; The annual production capacity exceeds 1.3 million boxes. There is one center (business center) and three headquarters (manufacturing, machinery and electrical). It has complete facilities, complete functions, beautiful environment and personalized working, living and entertainment conditions. Emphasizing the development of technology, we have completed the transformation from bringing principle to local innovation, and then to comprehensive technological innovation with enterprises as the main body. In 2002, the Red Tobacco Information Project was put into trial operation. The goal of this project is to enable enterprises to achieve a high degree of information and automation - information driven operation, and information generated by operation. Since 1993, it has realized single brand production and is a national tobacco industry enterprise producing single brand.