The article considers the study of Polyvinylchloride film properties and their change on exposure to microwave radiation with relatively low doses of energy. The work relevance is caused by wide application of products on PVC basis and their good interaction with electromagnetic radiation. The experiments have shown the improvement of operational properties at energy doses from 10 to 30 kJ / kg. The proposed method is more environmentally friendly, energy efficient compared with traditional methods of improving the polyvinylchloride film properties.

No abstract

No abstract

The article reviews the information on cooling the circulating water in tower coolers. It is shown that is the use of local re-cooling systems is the most relevant (small-sized devices) as they do not demand any expensive operation of extended pipeline networks, minimize emissions in the atmosphere. The designs of small-sized coolers and contact devices are also presented in this article. Currently, the used counterflow coolers have some drawbacks. The article proposes a cooling tower with a mixed current. A part of the air goes along the screw, and a part goes up helping to increase heat and mass transfer. Experiments were conducted and a comparative graph of the ratio of relative change in temperature of return water of the air flow rate was made to design the minicooler with a screw air flow in comparison with counterflow coolers. For the studied small-sized coolers in the range of ascending air flow rates up to 0.7 m/s, the relative temperature drop of the water is kept approximately in the same ratio. In the range of air flow velocities from 0.8 to 2.4 m/s, the increase in the value of the relative temperature drop of the water is more intense in the minicooler with a screw airflow. For example, at an air velocity of 1.4 m/s, the temperature difference for a minicooler with a screw air flow is 0.27. At the same time, in the specified value of the air flow velocity, the relative temperature of the water in the countercurrent minicooler is 0.24.

There is given an explanation of heat and mass transfer efficiency at developed mini-cooling tower with twisted air flow and also a comparison with counterflow mini cooling tower in this thesis. It is determined, that a moisture content and temperature of cooling air flow in volume on height of a cooling tower vary in height in accordance with a power law. Also calculated indexes of degree for moisture content and temperature, need for further determination of heat and mass transfer coefficients.~h 0,83~h 1,25 There is formed a formula for determination of heat and mass exchange coefficients. Also heat and mass exchange efficiency indexes are determined and carried out a comparison of researches on laboratory equipment of the mini cooling tower with a twisted air-flow and counterflow mini cooling towers, in result of which we can see, that heat and mass exchange coefficients of the mini cooling tower with a twisted air flow are more on 20% than heat and mass exchange coefficients of counterflow mini cooling towers.