Study on structure optimization of a bubble cap against erosion wear of an S Zorb desulfurization reactor distribution plate

Bubble cap structures are researched for the particle erosion wear of the distribution plate (tray for short) in an S Zorb desulfurization reactor. The semi-empirical model of erosion wear prediction of gas–solid two-phase flow is revised by means of erosion wear experiments at high temperature and high speed. According to the revised erosion wear, the influence of the h0 (the distance from the bottom of the bubble cap to the tray), h1 (distance from the outlet of the lifting pipe to the top of the bubble cap interface), N (the number of cavities), d0 (the inner diameter of bubble cap) on erosion wear of trays are studied. The results show that a smaller h0 will make the erosion degree of the tray more serious; it is recommended to keep h0 = 17 mm. A larger h1 will alleviate the erosion wear degree of adsorbent particles on the tray, but considering the efficiency of the reaction, h1 = 36 mm is more appropriate. The increase of N reduces the erosion wear less but enhances the fluid disturbance and makes the erosion wear area unstable; so, N should be kept at 10. The increase of d0 reduces the velocity and density of fluid impacting the tray, thus reducing the erosion wear degree, which is an effective means.

Commissioning Analysis and Improvement measures for Biomass Circulating Fluidized Bed Gasifier

This paper presents the debugging test of biomass circulating fluidized bed gasifier in a rice mill factory of Jiangsu Province. The main debugging process of the gasifier system is reported. The typical problems of the gasifier system during the debugging period are analyzed, including the blockage of the primary cyclone separator, blockage of loop seal, bed inventory leakage of blast cap on air distribution plate, feeding tube coking, and large fluctuation of bed pressure. Reasonable improvement countermeasures and implementation plan is provided. The operation characteristics of the gasifier are preliminaries mastered through debugging, which provides reference for the operation and adjustment of the biomass circulating fluidized bed gasifier. These results provide certain guiding significance for the scale application of biomass circulating fluidized bed gasifier.

Experimental Investigation of Oxygen Carrier Aided Combustion (OCAC) with Methane and PSA Off-Gas

Oxygen carrier aided combustion (OCAC) is utilized to promote the combustion of relatively stable fuels already in the dense bed of bubbling fluidized beds by adding a new mechanism of fuel conversion, i.e., direct gas–solid reaction between the metal oxide and the fuel. Methane and a fuel gas mixture (PSA off-gas) consisting of H2, CH4 and CO were used as fuel. Two oxygen carrier bed materials—ilmenite and synthetic particles of calcium manganate—were investigated and compared to silica sand, an in this context inert bed material. The results with methane show that the fuel conversion is significantly higher inside the bed when using oxygen carrier particles, where the calcium manganate material displayed the highest conversion. In total, 99.3–99.7% of the methane was converted at 900 °C with ilmenite and calcium manganate as a bed material at the measurement point 9 cm above the distribution plate, whereas the bed with sand resulted in a gas conversion of 86.7%. Operation with PSA off-gas as fuel showed an overall high gas conversion at moderate temperatures (600–750 °C) and only minor differences were observed for the different bed materials. NO emissions were generally low, apart from the cases where a significant part of the fuel conversion took place above the bed, essentially causing flame combustion. The NO concentration was low in the bed with both fuels and especially low with PSA off-gas as fuel. No more than 11 ppm was detected at any height in the reactor, with any of the bed materials, in the bed temperature range of 700–750 °C.

Numerical simulation and study of thermal characteristics of a lightweight floor heating system

The use of underfloor heating systems is an effective way to achieve thermal comfort for users in energy-efficient buildings. There are two kinds of such systems: traditional and dry-assembled. The first type is researched more deeply than the second one. The paper presents theoretical studies of the thermotechnical parameters of a water underfloor dry-assembled heating system. The design of the underfloor dry-assembled heating system, considered in the work, consists of a heat insulation (expanded polystyrene), on which the pipes of the heating system are located, in contact with an aluminum heat distribution plate. The system is covered with floor finishing. The calculation for a stationary operating mode of the floor heating system was carried out on the basis of a system of equations for momentum and energy. The model was validated using the results of experimental studies. The calculation results cause some overestimation of the experimental data, possibly, beecause of deviations in thermotechnical characteristics of materials. But the simulation model correctly estimates the behaviour of the system at change of its parameters. The paper concludes that this configuration of the underfloor heating system can be used in heating systems for residential and non-residential premises. The aluminum heat distribution plate significantly affects the heat transfer processes in the system. Due to the plate, the heat flux is made uniform in the plane of the floor surface, which has a positive effect on heat distribution and reduces thermal tension in the finish coating. The use of ceramic tiles increases the overall heat exchange efficiency of the system with the room air. An increase in the thickness of the expanded polystyrene board increases the value of the heat flux from the surface of the heated floor. An increase in the flow rate and temperature of the heat carrier also cause an increase in the density of heat flux from the floor surface.

PROCEDURE FOR DETERMINING HYDRAULIC JET BARBOTTER RESISTANCE FOR COLLECTING FINE DUST

В СКГМИ (ГТУ) разработана конструкция струйного барботера, в основу которого положена запатентованная конструкция основного узла аппарата -распределительной тарелки, позволяющей реализовать в барботере пенный режим. Данный пылеуловитель позволяет улавливать мелкие частицы пыли ( < 1 мкм), включая наночастицы, не улавливаемые в рукавных фильтрах. В статье приведена методика расчета гидравлического сопротивления барботера, необходимая для использования при выборе вентилятора для процесса пылеулавливания в барботере. Гидравлическое сопротивление барботера определяется как сумма составляющих: статического давления слоя жидкости, капиллярного перепада в зоне образования пузырьков и сопротивлений деталей распределительной тарелки. Разработанная методика была использована при проектировании технологической линии очистки газов от пылевидных возгонов вельц-печей цинкового производства, содержащих наночастицы. North Caucasian Institute of Mining and Metallurgy (State Technological University) has developed a design of a jet bubbler which is based on the patented design of the device main unit - a distribution plate, which allows to implement a foam mode in the bubbler. This dust collector allows you to capture small dust particles (< 1 microns), including nanoparticles, that are not captured in bag filters. The article presents a method for calculating the hydraulic resistance of the bubbler, which is required for use, when selecting a fan for the process of dust collection in the bubbler. The hydraulic resistance of the bubbler is defined as the sum of the components: the static pressure of the liquid layer, the capillary drop in the zone of bubbles formation and the resistances of distribution plate parts. The developed method was used in the design of a process line for cleaning gases from pulverized ascents of waelz kiln of zinc production containing nanoparticles.

Mathematical Model of Uniform Cereal Crops Seeding Using a Double-Disk Coulter

The paper provided presents a new design of two-disk wide-row coulter that ensures uniform distribution of seeds to an even bed at the furrow bottom, as well as preserving of optimal distances between the seeds. Seeds fall from the seed tube of coil sowing apparatus onto a metal distribution plate with staggeringly arranged metal pins, which distribute the seeds to furrow bottom surface in a form of separate strips. To substantiate the kinematic and constructive parameters of proposed coulter design, a mathematical model for transport of seeds along the surface of a distribution plate was developed and the Cauchy problem for a system of the second-order quasi-linear differential equations was solved by the finite difference methods using embedded software procedures in mathematical software packages (Mathcad, Maple, etc.). The finite-difference method implementation was carried out using computer software allowing the determination of coordinates of seeds and, if necessary, changing of direction of their movement by adjusting the coulter operation to improve the distribution of seeds to soil in order to reduce the injury to them, which ultimately can contribute to an increased yield. Coverage of the plate surface and distribution pins with a rubber material can also contribute to a significant reduction in seed injury during sowing.

Capaian standar pelayanan minimal gizi di Rumah Sakit Umum Daerah (RSUD) Manokwari Papua Barat

Achievement of the nutrition minimum service standard at Manokwari District Hospital in West PapuaBackground: There are three indicators of nutrition services that are regulated in the hospital Minimum Service Standards (MSS), namely the timeliness of food distribution, patient's plate waste, and the accuracy of the patient’s diet. The achievement of minimum service standards as the indicator of quality for nutrition services at Manokwari District Hospital has not yet been known.Objective: To find out the implementation of minimum service standards for nutrition services,i.e. the promptness of food distribution, the proportion of plate waste, and accuracy of the patient’s diet at Manokwari District Hospital. Methods: This was a mixed-method study conducted at Manokwari District Hospital, West Papua, from January until March of 2018. A quantitative approach with patient samples was carried out to quantify the achievement of MSS for nutrition service. Punctuality of food distribution and accuracy of the diet was measured using observational sheets while the patient’s plate waste was determined using food weighing. A qualitative approach through in-depth interviews with patients, nutritionists, cooks, food service workers, and nurses was performed to explore the influencing factors. Results: The percentage of timeliness of patient food distribution was only 37.1%, the waste of patients’ food reached 34.5% and the accuracy of the patient's diet was only 83.87%. These were affected by poor human resource management, inadequate hospital facilities, and foods brought from outside of the hospital. Conclusions: Promptness of patient’s food distribution, plate waste and diet accuracy in Manokwari District Hospital has not reached the minimum service standard for nutrition service.

Environmental technology: Fluidised-bed steam dryers — latest developments and practical experience

Fluidised-bed steam dryers have been in use for industrial-scale drying of pressed beet pulp for more than 20 years. This highly energy-efficient process can be considered to be state of the art in the industry. Scientific laboratory and pilot-plant testing have provided the basis for a detailed description of the principles of fluidisation and drying in superheated water vapour. Advances in production data acquisition, in particular regarding the options for the real-time presentation and evaluation of high-resolution operating data (Industry 4.0), have opened up new potentials for optimisation of the drying process in fluidised-bed steam dryers. By analysing and interpreting sequences of events, or simultaneous events, it is now possible to analyse process behaviour in great depth. This allows malfunctions to be avoided by improved design or, assisted by suitable measuring and control systems, to be detected at an early stage. Failures can then be prevented altogether by initiating automated countermeasures. On the basis of more recent insights gained from the analysis of faults and disruptions using modern operating data acquisition, BMA’s fluidised-bed steam dryer (WVT) has been subjected to fundamental technological and technical improvements, so it now meets today’s demands for efficiency and reliability. Modifications include the product inlet, the distribution plate and several other parts, in addition to the known and patented PPS (Plug Protection System; EP 2457649 B1), and the patented rotary weir (EP 2146167 B1).

Numerical Simulation of Air Distribution Plate at the Inlet of Wet Electrostatic Precipitator

The air distribution uniformity of electrostatic precipitator is one of the key factors to affect the efficiency of dust collector. A layer of air distribution plate was set in precipitator and its opening rate of distribution plate was adjusted to explore the optimal allocation of air distribution in the precipitator. With the design requirements, we used the Fluent to simulate the airflow distribution in the precipitator. The results show that it can obtain more uniform air distribution to adjust the hole shape and the opening rate of air distribution plate, and the efficiency is ideal when the opening rate is 30%.