Improvement of an Engineering Procedure for Calculating the Non­isothermal Transportation of a Gas­liquid Mixture

The study that we conducted into the process of transportation of a gas-condensate mixture from a well bottom to the separation production plant has revealed the features of isothermal and non-isothermal flow. It was proved that during non-isothermal flow, hydraulic losses in the product pipeline are significantly affected by throttle effect and energy accommodation effect. The influence of velocity and volumetric flow rate of the gas-liquid mixtures on hydraulic resistance and pressure drop on a section of product pipeline, taking into consideration non-isothermal flow was analyzed. It was found that the assessment of hydraulic resistance and pressure drop in the proposed dependences converges with standardized ones by 95 %. The result was obtained based on the developed system of equations of the mathematical model for non-isothermal non-stationary one-dimensional motion of the gas-liquid mixture of hydrocarbons in the pipeline. The proposed system beneficially differs from the known ones by the fact that it takes into consideration the inner convective heat exchange, estimated by the combined effect of Joule-Thomson.A distinctive feature of the improved procedure for calculation was the introduction of temperature correction and accommodation coefficient in the calculation of hydraulic resistance of a pipeline as a system with distributed parameters. Due to this, it became possible to improve the procedure for the calculation of non-isothermal transportation of a homogeneous gas-condensate mixture. Based on the analysis of calculation curves by the known procedures (formulas of Thomas Colebrooke, Leibenson and VNIIgas) for isothermal and non-isothermal processes and the proposed procedure, rational areas of their applications were shown. All calculations were performed at the velocity of a gas-liquid flow within the range 0–50 m/s, pipe roughness of 0.01–0.05 mm and their diameter of 100–300 mm, the data from actual production pipelines of Novotroitsk oil-gas condensate field were used. Comparison of the theoretical and industrial experiments showed sufficient for engineering practice accuracy of calculation of pressure drop on the stretches of oil and gas lead lines and allowed recommending the developed analytical dependences for the introduction in industrial engineering

Investigation of the Process of Crushing Solid Materials in the Centrifugal Disintegrators

The paper represents the results of investigation of magnetite quartzite centrifugal disintegrators crushing. It is demonstrated that when crushing quartzites of ingoing size 100 mm, it is possible to obtain crushed product size – 10 mm, in so doing product classes – 10 mm depends on the disintegrator rotor rotation frequency. It is shown that in crushed products of the centrifugal disintegrator of CD-50 type there are more classes minus 10, 5, 1 and 0.074 mm by 30, 42, 32, 13,5 % respectively, than in crushed products of KMD-2200 cone-type crusher. Herewith, it was established that iron content in CD-50 crushed products is 3.3 % higher, that in KMD-2200 ones.The obtained empirical dependencies of material destruction process via stroke in the field of centrifugal forces can be applied in performance prediction of material centrifugal disintegrators crushing.The final formula for calculating the material escape speed out of the accelerated disintegrator rotor, which provides required destruction of material, was obtained by means of classical hypothesis method application. Namely, the required speed of material escape out of the operating cylinder of centrifugal disintegrator is linear to specified material reduction degree and value of admissible (critical) stress of the given material destruction, and inversely proportional to Sin of meeting angle of material with bumper plates and value of material acoustic stiffness.Carried out empirical and theoretical investigations showed the advantages of magnetite quartzite crushing in centrifugal disintegrator before comminution in cone crushers, which makes the use of disintegrators in schemes of preparation of ore for further concentration well-grounded