Mykhailyk V. JUSTIFICATION OF THE PARAMETERS OF THE WORKING PROCESSES OF A HYDRAULIC-DRIVEN SINGLE-PISTON MORTAR PUMP WITH A COMBINED PRESSURE PULSE COMPENSATOR

The relevance of creating a modern universal mortar pump is also due to the constant expansion of the range and structure of building mixtures. In modern construction, cement, cement-adhesive, cement-lime, gypsum, polymer-modified, heat-insulating, fire-retardant and decorative mortars are widely used, which have different physical, mechanical and rheological properties. Modern pump designs do not fully ensure the effective transportation of such mixtures without violating their structure, delamination or loss of technological characteristics. This requires the design and creation of universal pumping systems that will be able to stably transport a wide range of modern building mixtures. A modern volumetric mortar pump is the main technological means of mechanization of finishing works and a component of a plastering unit, on the technical perfection of which labor productivity, quality of finishing works, economy of construction production and reliability of the technological process depend. That is why the development of new designs of mortar pumps aimed at increasing productivity, durability, energy efficiency, automation and versatility of application is one of the most important directions of development of modern construction engineering and mechanization of finishing processes. The purpose of the scientific work is to create and study a highly efficient single-piston mortar pump through the use of a hydraulic drive and a new combined compensator to reduce the degree of pulsations of the mortar supply pressure through the pipeline, which will ensure an increase in its productivity and volumetric efficiency under rational modes of technological processes. The object of the study is the working processes of transporting building mortars through the pipeline when they are supplied by a hydraulically driven single-piston mortar pump with a combined pressure pulsation compensator. The subject of the study is a hydraulically driven single-piston mortar pump with a combined pressure pulsation compensator. The scientific novelty of the results obtained. 1. For the first time, the influence of the law of motion of the working body from the hydraulic drive and the design of the combined pressure pulsation compensator under study on the formation of the supply pressure dependence, the level of the degree of solution pressure pulsations, and a comparative analysis was conducted with a single-piston mortar pump with a combined compensator of increased volume. 2. The work of accumulating the solution from the compensator during the process of its complete discharge and reducing the gas pressure in the suction stroke of the mortar pump was theoretically investigated to determine the constructive full capacity, the volume reduced to atmospheric conditions. 3. The processes of diffusion permeability of the material of the closed chamber of the compensating device, the surface of the seals in contact with the gas and liquid phases depending on the temperature and stress were theoretically investigated. 4. Dependencies were established to determine the main parameters of the hydraulically driven mortar pump under study and quantitative indicators were determined: the degree of pulsations of the supply pressure, productivity, volumetric efficiency, energy consumption, which were confirmed by a multifactor experiment and a comparative analysis of the working processes of a mortar pump with an electromechanical drive was conducted. 5. The stiffness of the closed chamber (pneumatic cylinder) of the compensator was determined due to vertical compression during its operation and its rate of vibration damping (vibration absorption). 6. The relative air saturation of the free chamber of the compensator was determined. Practical significance of the results obtained. Based on the results of theoretical and experimental studies, a methodology was created for determining the main parameters of the hydraulically driven single-piston mortar pump with a combined pressure pulsation compensator, which allowed the development of documentation for a prototype of the machine. The experimental and production sample of the unit was used during the reconstruction of the warehouse of LLC "KONTUR BUD LTD" at 4 Burovykiv St., in Poltava, LLC "POLTAVABUDTEKHNIKA" during the replacement of the interior decoration of the warehouse wall at 2a Dovzhenko St., in Poltava Field of application. Mortar pumps are necessary for pumping solutions of various compositions and purposes through rubber-fabric or metal pipelines and for their mechanized application to the treated surfaces of building structures using an air nozzle or a compressor-free nozzle. The media pumped by mortar pumps include building solutions, namely: lime-sand plaster, cement-sand, chalk-based solutions of various mobility, which are used for plastering, screeds of self-leveling floors, painting, etc.