Mamontov O. Reduction of noise and vibration from compressor installations at workplaces of enterprises of the building industry

The thesis is devoted to developing methods and tools aimed at reducing technological vibration and noise of compressor units at the building industry enterprises. The thesis analyzes the conditions of work at the workplaces of the main production areas of these enterprises. It turned out that increased levels of noise and vibration are the dominant harmful production factors. The most common sources of these factors are compressor plants. The main causes of increased levels of noise and vibration are unbalanced rotors of these installations. The scientific achievements in the field of reducing noise and vibration in sources of origin, as well as in the process of distribution from the source to the object of protection within the production premises are considered. The methods of balancing hard rotors, the methods for calculating noise-absorbing coatings as well as the optimum location of noise sources and workplaces in industrial premises are considered. For the first time, the methods and means of measuring, respectively the static and short-term imbalance of rigid rotors, are developed and patented, which are based on measuring the frequencies (periods) of free oscillations of the "pendular frame-rotor" system. This ensures the safety of the process of measuring rotor imbalances. The thesis has developed methods for the furnishing of batches of rotors, representing an assembly unit of modular type. For the first time three variants of optimization model with a target function and corresponding limiting conditions are offered. Two algorithms for solving the problem are developed: the first algorithm is based on a random search (Monte Carlo method), the second one is based on pair exchanges of elements. This reduces vibration and noise in the workplaces. The method of calculating the composite sound absorbing cover of the room, designed to reduce noise in the way of distribution in the production environment, has been developed. The method of placement and orientation of sources of constant noise (technological equipment) inside the production premises has been developed