Countercurrent exchange

About: Countercurrent exchange is a research topic. Over the lifetime, 2255 publications have been published within this topic receiving 28687 citations. The topic is also known as: Countercurrent exchange.

Method and device for utilizing smoke afterheat of roasting furnace

Abstract: The invention discloses a method and device for utilizing smoke afterheat of a roasting furnace. The method comprises the following steps that (1) smoke of the roasting furnace is fed into a smoke heat exchanger; and the smoke is in direct contact with self-circulating water sprayed from the top of the smoke heat exchanger to heat the self-circulating water; (2) the heated self-circulating water is fed into a water collecting area at the bottom of the smoke heat exchanger; (3) circulating water is filtered; the filtered circulating water and the heated self-circulating water exchange heat; and the circulating water is heated; (4) the self-circulating water is cooled and then return to the top of the smoke heat exchanger for spraying; the dropping self-circulating water and the smoke in the smoke heat exchanger perform the countercurrent flow heat exchange; the self-circulating water is circulated like this for heat exchange; and (5) the heated circulating water is fed to users. The method is suitable for industrial production or civil heating.

Effects of heat conduction and countercurrent heat exchange in selective brain cooling in humans

Abstract: The purpose of this work was to study the countercurrent effects of cooling blood in the carotid artery during the selective brain cooling. To determine the contribution of countercurrent exchange we compared results between the heat flow models with heat generation and without heat generation. The potential for cooling of blood in the carotid artery on its way to brain by heat exchange with the jugular vein and by radial heat conduction loss to the cool neck surface was evaluated. Our model demonstrated that the average temperature of the arterial blood reaching the brain drops by 1.18°C while traveling through the neck. The overall temperature drop of blood between the inlet to the carotid artery and the outlet was found to decrease with increasing blood flow rates and surface temperatures. The temperature drop was evaluated at a blood flow rate of 240ml/min with vein inlet blood temperature at 25°C and neck temperature at 19°C. The factors that had the most influence on penetration depth were the specific heat of the blood and varying the thermal conductivity of the tissue. Results of the present study will help provide a better understanding of the thermoregulation during hyperthermia.

Countercurrent column with dynamically controlled fluid distributor

Abstract: FIELD: technological processes.SUBSTANCE: countercurrent column comprises of a dynamically controlled fluid distributor including a fluid supply pipe and a plurality of distribution bodies that are arranged in the column above the packing, with the possibility of forming several partial flows in the upward flowing gas at the height of the distribution bodies. There are backflow zones between the packing and distribution bodies. The distribution bodies are storage volumes of fluid 3 disposed on a base plate, each of which includes a plurality of holes in the bottom for flowing fluid, which are coaxial with the plurality of holes in the base plate, a level gage 11, a fluid supply pipe 9, comprising of a pump 16, a flow meter, consisting of the flow meter primary transducer 12 and the flow meter calculator 13, an inlet valve 4. The storage volumes of the fluid are separated by ports in the base plate for the upward flowing gas.EFFECT: uniform distribution of fluid over the entire volume of the packing, even with a strong gas flow and significant deviations in the geometric dimensions of the textured packing surface from the specified parameters.3 dwg

Countercurrent multiphase flow heavy oil hydrocracking process

Abstract: The invention relates to a countercurrent multiphase flow heavy oil hydrocracking process. The process includes: mixing the raw material, the catalyst and part of hydrogen, and dispersing and sprayingthe mixture downwards into the reactor through the upper part of the reactor, and forming countercurrent with upward hydrogen at the bottom of the reactor; directly feeding a gas-phase product at thetop of the reactor into a fixed bed hydrogenation device to obtain a clean fuel oil product, feeding a liquid-phase product at the bottom of the reactor into a gas-liquid separating device, and feeding a gas-phase-removed liquid product into an atmospheric and vacuum distillation device; then directly discharging an oil residue part at the bottom of the atmospheric and vacuum distillation deviceout of the device, circulating a part of the oil residue part circularly to the countercurrent multiphase flow heavy oil hydrocracking reactor, and uniformly dispersing a second vacuum distillation line oil part and the catalyst on the mixing device and then enter the countercurrent multiphase flow heavy oil hydrocracking reactor. According to the invention, raw materials enter from the upper partof the reactor, are discharged from the lower part of the reactor, and gas is fed from the lower part and discharged from the upper part of the reactor, so that the mass transfer and heat transfer capabilities of a reaction system are enhanced, and a good hydrogen supply effect is achieved; meanwhile, deposition of solids such as coke and ash generated in the reaction process is avoided.

A Study of the Separation Efficiency in the Concentric-Tube Countercurrent Separation Process under Generalized Linear Applied Fields and with Recycles at Both Ends

Abstract: The mathematical model for the separation of binary mixtures has been extended to a concentric-tube continuous-contact countercurrent column under generalized linear external fields and with recycles at both ends. An analytical solution is obtained by use of the orthogonal expansion method. Numerical results for separation in a thermal diffusion column are also illustrated.