Passage Of Steam Research Articles

The application of nano-hydrogels and hydrogels in wound dressings.

Wounds and the healing process are one of the main concerns of medical science today. A wound is any loss of integrity, or rupture of the layers of skin (epidermis, dermis, and hypodermis) or subcutaneous tissue caused by physical factors (surgical incision, trauma, pressure, and gunshot wounds) or chemical factors (acid burns). It is observed that soft tissue, muscle, or bone is involved in occurrences of wounds. Lesions and fractures of the skin surface necessitate medical attention, wherein dressings expedite the healing process by establishing a physical barrier between the wound and the external environment, thereby preventing further injury or infection. Hydrogel dressings create a moist environment that facilitates common healing steps, such as granulation hyperplasia, epidermal repair, and removal of excess dead tissue. The limited adhesion of the hydrogel and the hydrated wound bed allows for easy removal of the dressing without secondary damage, thereby significantly reducing the discomfort and risk of infection during dressing changes. These modern, wet dressings foster a moist healing environment by absorbing excess inflammatory secretions and allowing proper passage of steam and air, which expedites the healing process. In this analysis, the utilization of hydrogels as wound dressings is briefly presented.

Development of a Laboratory-Scale Steam Boiler for Polyurethane (Foam) Waste Recycling Machine

In this paper, a laboratory-scale (small) Steam Boiler was designed and developed for a small-scale polyurethane recycling machine. A small-sized polyurethane machine was developed for the recycling of polyurethane foams to reduce wastes in the polyurethane production industries and also to reuse old discarded foams after their useful lives. It has been observed from studies carried out in many foam manufacturing industries that the polyurethane foam wastes generated from various plant operations are enormous. Also, polyurethane (foam) products are everywhere in our homes, industries and automobiles and are always discarded after their useful lives. These wastes need to be recycled always in other for them not to get back into our ecosystems thereby polluting our environment because polyurethane foams are non-biodegradables and can remain in the environment for a very long time. However, only a few companies with strong financial capabilities are able to embark on this venture because of the high costs of machinery and large quantities of chemicals involved. The high costs of machinery and chemicals also deter cottage industries from participating in the recycling of old and discarded polyurethane foams. Therefore, there is a need to develop small-scale polyurethane foam waste recycling machines to reduce the costs of machinery and chemicals involved in the recycling thereby allowing more participation in the recycling process. The boiler is used to generate high-temperature steam for curing and better bonding of the shredded foams. The heating chamber of the machine consists of the steam boiler, and pressure hose to enable passage of steam from the steam boiler into the molding box. The total volume of the boiler is 2.5 Litres. The outlet steam temperature is 135 0C and 25 psi pressure. The heat rate is 1.52 kJ/s. The recycled foams were able to cure and bonded better with the addition of steam compared to without the steam. The percentage difference in I.F.D, Resilience, Tensile Stress and percent elongation are +0.56, -2.00, +85.45, and +68.39 respectively. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

Optimization of the thermal circuit by introduction of the steam screw-rotor machine

The aim of the work is to increase the efficiency of the CHP by introducing a steam screw-rotor machine (SSRM) into the thermal circuit. It is proposed to exclude the passage of steam from the selection of the turbine through the pressure reduction and desuperheating station (PRDS) of own needs. Superheated steam is diverted to be sent to a steam screw-rotor machine installed parallel to the PRDS. This technical solution will allow to obtain steam used in low pressure deaerators, as well as electricity for own needs of the CHP. The article presents the operating parameters, as well as the calculation results of the backpressure turbine. A feasibility study was carried out for the introduction of SSRM into the plant’s thermal circuit: the equivalent fuel and electricity savings for own needs were calculated, as well as the payback period of the project for introducing a steam screw-rotor machine. In the course of the calculations, the following results were obtained: a decrease in the specific consumption of equivalent fuel for the production of 1 kWh of electricity – by 1,9 g; saving of equivalent fuel during the implementation of the SSRM will be 13 tons per year, which also entails a reduction in emissions into the environment; Electricity production for own needs is 8100 kWh, the payback period for the project to introduce a steam screw machine in the thermal circuit of a thermal power plant is 5 years.

The Application of the Baumann Stage in the Low-Pressure Cylinders of Condensing Turbines

Among the characteristics of the power-generating steam turbines, the specific metal intensity ranks very high. Low-pressure cylinders (LPCs) that use a two-tier Baumann stage have the lowest value of this parameter. The Baumann stage allows a 50% increase in the limit steam passage rate to the condenser without increasing the last-stage blade length and the weight of the turbine. In Russia, such a solution was implemented in the most widely used K-200-12.8 (K-200-130) turbine manufactured by LMZ. However, the experience from operating the turbine and results of investigations into the economic efficiency of the K-200-12.8 turbine have shown that these turbines equipped with the Baumann stage have lower efficiency than similar turbines without the Baumann stage. In the course of subsequent modernization of the K-200-12.8 turbine, the Baumann stage was replaced by a new last stage with longer rotor blades. The design solutions employed by different turbine manufacturers to modernize the K-200-12.8 turbine have been analyzed. It is pointed out that the LPC of this turbine was modernized without analyzing the causes of the low economic efficiency of the basic LPC. An investigation into the real causes of the reduced efficiency of the K-200-12.8 turbine has shown that the LPCs modernized by different companies preserved the drawbacks intrinsic to the basic design. In view of this, a simple variant for modernization of the LPC preserving the Baumann stage is proposed. Its efficiency should not be inferior to the efficiency of modern LPCs whose last stage is equipped with longer blades; a conclusion that is supported by the results of mathematical modeling of the flows in the penultimate- and last-stage nozzle diaphragms of the new LPC.

Efficiency of introducing a steam screw-rotor machine to the heating power plant circuit

The aim of the work is to increase the efficiency of the Nizhnekamsk CHPP-1 (combined heat and power plant) by introducing a steam screw-rotor machine (SSRM) into the thermal circuit. It is proposed to exclude the passage of steam from the exit of the turbine through the pressure reduction and desuperheating station (PRDS) for own needs. Superheated steam is diverted to be sent to a steam screw-rotor machine installed parallel to the PRDS. This technical solution will allow to obtain steam used in low pressure deaerators, as well as electricity for own needs of the CHPP. The article presents the operating parameters, as well as the calculation results of the backpressure turbine. A feasibility study was carried out for the introduction of SSRM into the plant’s thermal circuit: the equivalent fuel and electricity savings for own needs were calculated, as well as the payback period of the project for introducing a steam screw-rotor machine. In the course of the calculations, the following results were obtained: a decrease in the specific consumption of equivalent fuel for the production of 1 kWh of electricity by 1.9 g; saving of equivalent fuel during the implementation of the SSRM will be 13 tons per year, which also entails a reduction in emissions into the environment; Electricity production for own needs is 8100 kWh, the payback period for the project to introduce a steam screw machine in the thermal circuit of a thermal power plant is 5 years.

Investigating the Dehumidification Characteristics of Turbine Stator Cascades with Parallel Channels

Steam turbines play a vital role in the power industry. The efficiency of the steam turbine can be improved by reforming the flow structure. For the White cascade, a parallel channel which is an additional steam passage was designed to connect adjacent steam flow channels. In view of the steepening and sensitive characteristics of the steam condensation parameters in the White cascade, the two-fluid model was applied to study the condensation and aerodynamic characteristics of the prototype cascade and the modified cascade. Wetness losses were regarded as the evaluation standard, and the optimum design of the parallel channel was obtained. The influence of channel width was also studied. The location of the suction surface (D point) has great influence on the dehumidification performance of the cascade. On the contrary, the location of the pressure surface (C point) has no significant effect on dehumidification performance. Moreover, it is necessary to select the width of the parallel channel in combination with the cascade performance. It is suggested that the parallel channel width should be between 3 and 5 mm. The research results can provide a reference for the optimal design of a turbine stator cascade.

A Throttle Control Valve for Steam Turbines Operating with Large Volumetric Flowrates of Working Fluids

A new design of a throttle control valve for steam turbines with throttle steam admission and large volumetric steam flowrates is considered. The difficulty associated with using these valves is that increasing the seat dimensions of spools entails a drastic decrease in the relative valve chest free volume for steam passage. This, in turn, results not only in higher hydraulic losses in the steam admission system but also in a higher nonuniformity of steam flow in the flow paths of such valves. Both these factors facilitate generation of very high pulsations of pressure in the valve’s entire flow path, which gives rise to high levels of acoustic emission and dynamic loads acting on all components of the valve, thus degrading its vibration reliability. Along with the proposed valve design, the article considers the design version of standard balanced control valves installed in large-capacity Russian steam turbines. It is shown that the passage of large volumetric steam flowrates through standard valves entails a significant reduction in the free valve chest volume for passing steam. This results in a growth of local steam velocities inside the chest and in a more pronounced negative influence of the chest shape on the valve flowrate and vibration performance. This situation can be improved by using one of the following two ways: to make the chamber with a significantly larger structural volume (which entails a larger cost of making the chamber) or to radically change the valve design. The article considers the second approach to solving the problem. In the proposed design version, the entire valve balancing system is shifted to the valve chest upper part, and the guide bonnet is made with large lateral ports ensuring free passage of steam to the diffuser seat. To achieve a more uniform circumferential field of velocities in the valve flow path, its cup is made with two perforation belts, the holes of which are connected to a common damping chamber, and the chamber itself is connected via a hollow cylinder with the axial force relief system.

Анализ причин низкой экономичности цилиндра низкого давления паровой турбины К-200-130

Designing a low-pressure cylinder (LPC) with a one-and-a-half steam exhaust from it is the only way in which a larger steam flowrate can be passed to a condensing steam turbine’s condenser without increasing the length of the turbine last-stage blades. For implementing this idea, K. Baumann has developed a special next-to-last two-tier stage, which diverts part of the steam passing through the stage’s upper tier directly into the condenser in bypass of the last-stage bucket. In the former Soviet Union, this solution was implemented in a number of medium- and high-pressure turbines, as well as in the K-200-130 turbine produced by the Leningrad Metal Works (LMZ). However, field experience gained from operation of this turbine, as well as special investigations, showed that the LPC fitted with the Baumann stage had poor efficiency, and during the subsequent modernizations the Baumann stage was removed from the K-200-130 turbine’s LPC flow path. Factors that have caused dramatic degradation of the cylinder efficiency are analyzed. It is shown that the factors relating directly to the Bauman stage that were considered in the scientific literature could not play the key role in degrading the stage efficiency and, accordingly, in affecting the cylinder efficiency. It has been shown from the performed analysis that poor efficiency of the LPC equipped with the Baumann stage is not due to the stage itself, but due to the conditions of steam admission to it and to the K-200-130 LMZ turbine last stage. As a result, two out of four (in total) stages contained in this cylinder operate with dramatically degraded efficiency. These design drawbacks removed, the Baumann stage can well be used to increase the maximum possible steam passage through the LPC.

Conditions for cessation of complete steam condensation during passage of a steam-air mixture through the water layer in a condenser-bubbler

This is a report of an experimental study of conditions for the cessation of complete steam condensation during movement of a steam-air mixture through the water layer in a condenser-bubbler. An analysis and generalization of the experimental data yields a dimensionless dependence of the underheating of the water at which it begins to allow the passage of steam, without condensing it completely, on the velocity of the steam-air mixture, the air content, and height of the water layer for a wide range of parameters.

On the Difficult Birth of SAGD

Introduction This contribution attempts to address some questions suggested by the series(1,2,3) to date. The answers are not all technical in nature: "Problems aren't solved by technology alone; we also need a thorough understanding of social dynamics."(4) After some select technical observations, this contribution is indeed an essay on social dynamics, as they relate to R&D in general, and SAGD development in particular. Is There any Evidence SAGD is Better Than Conventional Methods? The best evidence of this is that the more successful SAGD projects have demonstrated comparable oil/steam ratios (OSRs) to those of vertical/thermal implementations, even though the SAGD projects were conducted in reservoirs of significantly lower quality. This is illustrated in Figure 1, which compares the realized or projected OSRs of four actual projects plus a projected "prime Athabasca" case. Reservoir quality is characterized by permeability times thickness. It can be seen that approximately twice the kh is needed to achieve the same OSR using vertical technology, as can be obtained with twin-well SAGD. Pikes Peak and Cold Lake were each conducted in essentially the best reservoirs ever found in their respective formations; whereas the pay zone at Senlac, at only about 40 feet thick, would have failed most screening criteria that have been proposed for vertical CSS or steam flood. The low value of kh assigned to the UTF B Pattern is actually on the generous side. A low-energy estuary resulted in good quality sand units (5 Darcys) but with frequent silty laminations (25 – 250 mD), which prevented easy passage of steam around them. The reservoir was too heterogenous to estimate an effective bulk permeability, but geostatistical simulations and the observed project performance suggest an overall effective SAGD permeability of about 1.0 ± 0.3 Darcy. The projected Prime McMurray case is based on 40 m of 5 D sand, representing perhaps a top-decile Athabasca reservoir. Such reservoir quality is not ubiquitous over the deposit, but is known in commercial quantity at a number of widely-separated places.(5) Finally, OSR is by far the most important economic indicator for steam recovery, but the high productivity of SAGD pairs also promises lower unit costs for drilling, workovers, wellbore heat losses, and field operating labour. Why Do All SAGD Wells Seem to Produce at 100 m3/d? The UTF B pattern performance has widely come to be viewed as representative of the better Athabasca reservoirs. Nothing could be further from the truth; at least 1/3 of the total Athabasca resource is better than the B pattern, and the top 10% is enormously better. The author hypothesises that this situation has resulted in a syndrome of significant under-design in many projects, exploiting much better reservoirs. In order to reconcile predictions for such reservoirs with UTF results (while assuming sand quality is comparable), unrealistically low values for kh, kroi' and/or kv/ kh must be employed. Acceptable OSRs are nevertheless predicted, and the project proceeds. The resulting field design may be too conservative by a factor of two or three, in terms of unit-length well performance.

Heat pipes and their use in technology

Heat pipes may be employed as temperature regulators, heat diodes, transformers, storage batteries, or utilized for transforming thermal energy into mechanical, electric, or other forms of energy. General concepts were established for the analysis of the transfer process in heat pipes. A system of equations was developed to describe the thermodynamics of steam passage through a cross section of a heat pipe.

Production of superheated steam from vapor-dominated geothermal reservoirs

Vapor-dominated geothermal systems such as Larderello, Italy, The Geysers, California, and Matsukawa, Japan yield dry or superheated steam when exploited. Models for these systems are examined along with production data and the thermodynamic properties of water, steam and rock. It is concluded that these systems initially consist of a water and steam filled reservoir, a water-saturated cap rock, and a water or brine-saturated deep reservoir below a water table. Most liquid water in all parts of the system is relatively immobilized in small pores and crevices; steam dominates the large fractures and voids of the reservoir and is the continuous, pressure-controlling phase. With production, the pressure is lowered and the liquid water boils, causing massive transfer of heat from the rock and its eventual drying. Passage of steam through already dried rock produces superheating. After an initial vaporization of liquid water in the reservoir, the decrease in pressure produces increased boiling below the deep water table. With heavy exploitation, boiling extends deeper into hotter rock and the temperature of the steam increases. This model explains most features of the published production behavior of these systems and can be used to guide exploitation policies.

Sesamolの合成について

A solution of the diazonium compound obtained from 3, 4-methylenedioxyaniline was decomposed by adding it dropwise into the hot aqueous solution of urea, copper sulfate, and sulfuric acid, the mixture was distilled by the passage of steam, and the distillate was extracted with ether from which sesamol (3, 4-methylenedioxyphenol) was obtained in 12% yield.

Performance of Two 101,000-Sq-Ft Surface Condensers

Abstract The results of tests of two 101,000-sq-ft single-pass condensers in the Hudson Avenue Station of the Brooklyn Edison Company are summarized, and the design features are briefly described. The steam-flow path of the Worthington condenser is through an effectively shallow tube bank of the folded-layer type, having deep inlet lanes to facilitate the passage of steam with minimum pressure drop. The entire tube bank is contained in a practically cylindrical shell. In the Ingersoll-Rand unit the generally heart-shaped shell maintains with a decreasing volume of steam an active flow over all tubes. Bypass lanes around the top sections of tubes allow part of the steam to reach the lower tube banks without passing through the top section. The Worthington air cooler is placed internal to the shell as being the most convenient location and involving the least costly construction. The Ingersoll-Rand design uses an external air cooler to provide a more efficient design of flow areas. Reheating is provided for in the condensate circuits of both units, the Worthington using a contact-type reheating hotwell integral with the condenser and the Ingersoll-Rand having a 1600-sq-ft-surface closed reheater after the condensate pump, supplied with steam from one of the top bypass belts. Steam-flow control, air removal, and circulating systems are compared.