Combination Of Steam Research Articles

An experimental research on the cooling performance of the turbine vane with an advanced duplex-medium combined cooling

Internal steam cooling used in the vane can not only reduce the consumption of high-pressure air but also improve the overall turbine cycle efficiency. The present paper presents a research on a turbine vane with complicated cooling structure. The vane was cooled by a combination of steam and air, which was achieved by (1) cooling the leading edge with four rows of cooling air film holes; (2) cooling the middle chord area with two internal cooling steam ribbed channels; (3) cooling the trailing edge with a row of cooling air jet holes. The temperature and the static pressure were measured by the thermocouples and pressure taps located on the vane middle section. The coolant temperature and the coolant flow were then adjusted to obtain the cooling effectiveness to assess the vane cooling performance in different cooling conditions. The results of this study confirm that (1) when the test vane is applied to the advanced duplex-medium combined cooling, surface temperature can be even, accompanied with a small thermal stress as well as a high cooling effectiveness (the average cooling effectiveness was over 0.68), which implies that a satisfactory cooling performance has been achieved; (2) film cooling used at the leading edge can shift the stagnation point downstream and produce some flow losses, which, however, does not significantly affect the entire flow field of the vane passages; (3) the best cooling effect on the vane surface is in the middle chord area with internal steam cooling and its worst is on the pressure side near the trailing edge; (4) in improving cooling performance, increasing the steam flow rate is the most effective, enhancing the coolant pressure the next, and lowering the coolant temperature the least; (5) in lowering the overall vane surface temperature, lowering the coolant temperature is the most effective, increasing the steam flow rate the next, and enhancing the coolant pressure the least.

Combined steam and ultrasound treatment of broilers at slaughter: A promising intervention to significantly reduce numbers of naturally occurring campylobacters on carcasses

Steam or hot water decontamination treatment of broiler carcasses is hampered by process limitations due to prolonged treatment times and adverse changes to the epidermis. In this study, a combination of steam with ultrasound (SonoSteam®) was investigated on naturally contaminated broilers that were processed at conventional slaughter speeds of 8,500 birds per hour in a Danish broiler plant. Industrial-scale SonoSteam equipment was installed in the evisceration room, before the inside/outside carcass washer. The SonoSteam treatment was evaluated in two separate trials performed on two different dates. Numbers of naturally occurring Campylobacter spp. and TVC were determined from paired samples of skin excised from opposite sides of the breast of the same carcass, before and after treatments. Sampling was performed at two different points on the line: i) before and after the SonoSteam treatment and ii) before the SonoSteam treatment and after 80min of air chilling. A total of 44 carcasses were examined in the two trials. Results from the first trial showed that the mean initial Campylobacter contamination level of 2.35 log10 CFU was significantly reduced (n=12, p<0.001) to 1.40 log10 CFU after treatment. A significant reduction (n=11, p<0.001) was also observed with samples analyzed before SonoSteam treatment (2.64 log10 CFU) and after air chilling (1.44 log10 CFU).In the second trial, significant reductions (n=10, p<0.05) were obtained for carcasses analyzed before (mean level of 2.23 log10 CFU) and after the treatment (mean level of 1.36 log10 CFU). Significant reductions (n=11, p<0.01) were also found for Campylobacter numbers analyzed before the SonoSteam treatment (2.02 log10 CFU) and after the air chilling treatment (1.37 log10 CFU). The effect of air chilling without SonoSteam treatment was determined using 12 carcasses pre- and postchill. Results showed insignificant reductions of 0.09 log10 from a mean initial level of 2.19 log10 CFU.Numbers of TVC before treatments ranged between 3.47 and 4.79 log10 CFU. In all cases, TVC was significantly (p<0.001, n=45 in each trial) reduced by approximately 0.7 log10 CFU.An authorized sensory panel at the Danish Veterinary and Food Administration concluded that broiler carcasses treated with SonoSteam were acceptable for purchase. These conclusions were based on organoleptic differences (smell, skin/meat consistency, texture and color) of treated vs. untreated carcasses.Results obtained from this study suggest that steam–ultrasound treatment of carcasses at broiler processing plants can significantly reduce numbers of Campylobacter on naturally contaminated broilers.

Proof of concept for eradication of vancomycin resistant Enterococcus faecium from broiler farms

BackgroundVancomycin resistant enterococci (VRE) in Swedish broiler production has been shown to persist at farms between batches. The aim of this study was therefore to determine the possibility to eliminate VRE by disinfection of compartments in broiler houses as a proof of concept.FindingsVRE could not be detected in environmental samples from the disinfected test compartments in the broiler houses but was detected in environmental samples from the control compartments. The proportion of broilers colonized with VRE decreased in both the test and the control compartments.ConclusionsThe results are promising and show that the occurrence of VRE in broiler houses can be reduced by adequate cleaning and disinfection with a combination of steam and formaldehyde.

Optimization of pretreatments for the hydrolysis of oil palm empty fruit bunch fiber (EFBF) using enzyme mixtures

A study was conducted to optimize sugar production from oil palm empty fruit bunch fiber (EFBF). Three different pretreatments were applied to EFBF, namely steam, steam with 5% sodium hydroxide (steam + 5% NaOH) and steam with 5% acetic acid (steam + 5% acetic acid). The hydrolyzability of the pretreated EFBF was determined using cellulolytic enzyme mixture comprising of Celluclast 1.5L (C), Viscozyme L (V) and Novozyme 188 (N). The different pretreatments showed varying degree of severities to the morphology of the fiber. Steam + 5% acetic acid pretreatment was found to cause the most severe changes to the EFBF surface. The optimum combinations of the enzymes for EFBF degradation, using a fixed parameters, were determined using Simplex Lattice mixture design. For untreated, steam pretreated, steam + 5% NaOH, steam + 5% acetic acid EFBFs, the optimum combinations enzyme were 0.49C: 0.45V: 0.06N, 0.88C: 0.12N, 0.78C: 0.03V: 0.2N and 0.90C: 0.03V: 0.07N respectively. Surface morphology of EFBF appears to be the major contributing factor that affects efficiency of enzymatic hydrolysis. Among these four samples, steam + 5% acetic acid pretreated EFBF gave the highest yield of sugars (44.36% xylose; 52.03% glucose). Applying the best enzymatic combinations, saccharification of pretreated samples was optimized using RSM. saccharification of the steam + 5% acetic acid pretreated EFBF was able to yield 99.90 ± 10.92 mg g−1 xylose and 281.77 ± 28.00 mg g−1 glucose at 2.51% enzyme loading (with total protein loading 22.1 mg per gram EFBF) in 4.55% EFBF for 35.08 h of reaction. Overall, through the combination of steam + 5% acetic acid pretreatment, enzyme mixture optimization and optimization of enzymatic saccharification, EFBF has the potential to produce substantial amount of sugars (62.36% xylose; 81.84% glucose).

Synergistic effect of steam and lactic acid against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes biofilms on polyvinyl chloride and stainless steel

This study was designed to investigate the individual and combined effects of steam and lactic acid (LA) on the inactivation of biofilms formed by Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on polyvinyl chloride (PVC) and stainless steel. Six day old biofilms were developed on PVC and stainless steel coupons by using a mixture of three strains each of three foodborne pathogens at 25°C. After biofilm development, PVC and stainless steel coupons were treated with LA alone (immersed in 0.5% or 2% for 5s, 15s, and 30s), steam alone (on both sides for 5, 10, and 20s), and the combination of steam and LA. The numbers of biofilm cells of the three foodborne pathogens were significantly (p<0.05) reduced as the amount of LA and duration of steam exposure increased. There was a synergistic effect of steam and LA on the viability of biofilm cells of the three pathogens. For all biofilm cells of the three foodborne pathogens, reduction levels of individual treatments ranged from 0.11 to 2.12logCFU/coupon. The combination treatment of steam and LA achieved an additional 0.2 to 2.11 log reduction compared to the sum of individual treatments. After a combined treatment of immersion in 2% LA for 15s or 30s followed by exposure to steam for 20s, biofilm cells of the three pathogens were reduced to below the detection limit (1.48 log). From the results of this study, bacterial populations of biofilms on PVC coupons did not receive the same thermal effect as on stainless steel coupons. Effectiveness of steam and LA may be attributed to the difference between Gram-negative and Gram-positive characteristics of the bacteria studied. The results of this study suggest that the combination of steam and LA has potential as a biofilm control intervention for food processing facilities.

The Production of Synthesis Gas by a Combination of Steam and Dry Reforming Using GHR

Synthesis gas is one of the most important intermediates in the chemical and petrochemical industries. There are various processes for synthesis gas production, and each has advantages and disadvantages. In this article, a process is introduced for producing synthesis gas based on a gas-heated reformer (GHR). By burning part of the input natural gas in a pressurized furnace and conducting the produced hot gases to the GHR shell, the heat of reactions taking place in the GHR tubes can be supplied. The other part of natural gas is converted to synthesis gas in the GHR tubes. Exit carbon dioxide from the furnace can be separated and left to react in the reformer as a feed. Compactness, low environmental pollution, flexibility in H2/CO ratio of product gases, and no need for O2 are some features of this process. A GHR reformer has been modeled and discussions and conclusions have been made by computer simulation of the reformer and process.

Acetic Acid, Ethanol and Steam Effects on the Growth ofBotrytis cinerea in vitroand Combination of Steam and Modified Atmosphere Packaging to Control Decay in Kiwifruit

The effects of acetic acid fumigation, ethanol fumigation, and steam heat treatment on growth of Botrytis cinerea in vitro were investigated. The effect of steam heat treatments in combination with modified atmosphere packaging (MAP) on Botrytis decay development on ‘Hayward’ kiwifruit was also studied. The fungus was grown in Petri dishes on potato dextrose agar. Ethanol fumigation with 100 μl/l for 3 or 6 min, or 200 μl/l for 6 min enhanced the growth of B. cinerea. The effect of acetic acid on growth of B. cinerea was time and dosage-dependent. Fumigation with 1 μl/l for 6 min, 2 μl/l for 3 min, and 4 μl/l for 3 min promoted radial growth of the fungus when compared to the growth of the untreated control. Fumigation with 2 μl/l for 6 min delayed the growth of the fungus for the first 6 days, while fumigation with 6 μl/l for 3 min delayed the growth of the fungus after the sixth day. Fumigation with 4 or 6 μl/l acetic acid for 6 min, and 8 μl/l acetic acid for 3 or 6 min resulted in complete inhibition of fungal growth. Steam heat treatment at 45°C for 6 min, and at 48, 51, and 54°C for 3 or 6 min completely inhibited fungal growth in vitro. Furthermore, steam treatments at 47, 50, and 53°C for 3 or 6 min completely inhibited decay at the stem end of kiwifruit kept at 10°C in MAP for 12 days. However, none of the steam treatments inhibited decay in wounds on the surface of the fruit kept in MAP.

Water Adsorption in Feed Ingredients for Animal Pellets at Different Temperatures, Particle Size, and Ingredient Combinations

Production of animal feed pellets with uniform, predictable, and good technical pellet quality is challenging. The objective of this work was to investigate water adsorption in dry ingredients and in mixture of dry ingredients commonly used in animal feed. Rehydration at 20 and 80°C and water adsorption in moist air at 80°C were studied. Ingredients studied were soybean meal, wheat, barley, dehulled oats, rapeseed cake, sugar beet pulp, maize, and wheat bran. The ingredients were milled fine (< 0.5 mm) or coarse (> 0.5 mm). Results show that the chemical composition of ingredients and the physical state of water affect water adsorption. A combination of steam and water should be used to optimize production of pelletized feed. The combination of a fine degree of milling, high temperature, and a long residence time favor the water adsorption process for most of the dry ingredients. For mixtures of dry ingredients, the individual chemical composition of each ingredient could be as important as physical factors such as particle size, temperature, and residence time in water.

Development and testing of a heat–cool methodology to automate oyster shucking

A heat/cool methodology was developed to facilitate oyster shucking. Eastern oysters Crassostrea virginica from several locations were used. Two methods were designed to shuck oysters, which incorporated various heat–cool regimes. The first was a combination of low-pressure steam and cryogenic CO 2, the second a combination of steam and cooling, either from cryogenic N 2 or ice water. The oysters were instrumented with T-type thermocouples connected to a datalogger to monitor and record process temperatures. Methods also were developed to quantify meat detachment, shelf-life and textural changes. The methods developed allowed for the measurement and optimization of the shucking process. Advantages of the steam–ice water combination include availability of facilities and low cost. Additionally, under selected regimes, meat quality was similar to that of raw oysters, while some reduction in microbial activity was recorded. Results indicated quantifiable methods, which yielded oyster meat detachments in excess of 85%.

Decontamination of pork carcasses by steam and lactic acid

The efficiency of a new apparatus for surface decontamination of pork carcasses was evaluated under industrial conditions. The combination of steaming by a special nozzle, followed by treatment with lactic acid (spraying with 2% solution), was applied on the surface of carcasses at the end of the slaughter process (30 min p.m.). Total counts of psychrophilic and mesophilic microorganisms were evaluated immediately after treatment and during cold storage up to five days. The treatment was effective in reducing the surface microflora by one to three decimal orders of CFU during the time of cold storage.

Analysis of terpenoic composition of conifer needle oils by steam distillation/extraction, gas chromatography and gas chromatography-mass spectrometry

The essential oils of Estonian spruce and pine needles have been analysed by a combination of steam distillation/extraction, GC and GC-MS. According to their monoterpene composition Estonian pines belong to a high carene chemotype with monoterpenes representing up to 85% of total oil. Estonian spruce needle oil contains up to 70% of oxygenated terpenes and more limonene and 1,8-cineole than the same spruce species [Picea abies (L.) Karst.] from other localities.

Ind

Study for improving the recovery and quality of activated charcoal through the combination of chemical and gasification treatments is presented in this paper. The material used in this experiments was charcoal derived from coconut shell. The material was immersed respectively in NaOH, Na 2 CO 3 , H 3 PO 4 and ZnCl 2 for 24 hours. Charcoal activation was conduted by using steam or combination of steam and mixed C0 2 and N 2 . The activated charcoal was produced in a stainless steel retort with electric heater at temperature of 900 - 1000°C. The result shows that the low dossage chemical treatment using NaOH at a concentration of 0,75%, or Na 2 C0 3 at a concentration of 0,75%, or ZnCl 2 at a concentration of 5%, followed by activation by steam or the combination of steam and mixed C0 2 and N 2 .could produce good.quality activated charcoal which fullfils the commercial standard according to JIS. The produced charcoal attained the iodine adsorptive capacity of more than 1050 mg/g. By increasing the concentration of ZnCI 2 to 10% or H 3 P0 4 to 20 %. followed by steam activation at 900°C - 1000°C, the iodine adsorptive capacity increased to more than 1200 mg/g.

Enhanced Recovery of Bitumen by Steam with Chemical Additives

ABSTRACT Enhanced recovery of bitumen by a combination of steam and caustic chemicals with and without alcohol has been investigated using both static and dynamic techniques. Static experiments were conducted on the basis of information derived from a previous investigation to define the alcoholic caustic formulations potentially effective for bitumen mobilization. The aliphatic alcohol that gave increased bitumen emulsification with a further indication of a more favorable condition for bitumen microemulsion displacement was then selected for the dynamic tests, in which a caustic concentration level up to 0.4 wt% was propagated by a saturated steam at 400 kPa through oil-bearing sand packs. Data obtained from these tests revealed a better bitumen displacement and greater sweep efficiency in steamfloods with caustic and 50% octanolic-caustic additives than in steam drive. In addition, bitumen production began earliest in the alcohol system and was accompanied by increased production rate, leading to more ...

Application Of Numerical Modelling To The Simulation Of The Electric-Preheat Steam-Drive (Epsd) Process In Athabasca Oil Sands

Abstract An implicit three-dimensional electrothermal simulator has been developed to numerically model multi-phase electric-preheat steam-drive (EPSD) processes in the Athabasca deposit. Two versions of the model are discussed. In the first version (Model 1), the electric preheat phase of process is modelled assuming that fluid expansion and flow can be neglected. The second model (Model 2) accounts for the flow of oil, water, and steam, as well as heat transfer due to conduction and convection during both the electric preheat and steam-drive phases of the recovery process. Data from two simple two-dimensional reservoir simulations using both models are presented and compared. The results suggest that in most circumstances the expansion and flow of fluids during the electric preheat may have negligible effect on the temperature distributions established in the reservoir, and hence, that the computationally less complex Model 1 is generally adequate for simulating EPSD processes in the Athabasca deposit. Finally, an EPSD process in a representative reservoir is simulated using a 1 ha repeated 5-spot pattern with an electric preheat of 365 days. The preheat is followed by a combination of steam and hot waterflooding extending for a period of approximately eight years. Cumulative recovery is shown to be about 60% original-oil-in-place (OOIP) at an OSR of 0.42. Introduction Large portions of the Athabasca oil sand deposits of Alberta have porosities, oil saturations and pay thicknesses that should make them excellent candidates for economical steamflooding. However, to inject steam and produce bitumen continuously at practical rates it is necessary to have some initial fluid communication between injector and producer wells. Under in situ conditions the reservoir fluids in these formations are virtually immobile. In an electric-preheat steam-drive (EPSD) process the reservoir is first selectively heated electrically so as to lower the viscosity of the oil along predetermined paths between wells. Fluid mobilities along these heated interwell channels are generally several hundred times greater than in the original reservoir, and steam can be injected at satisfactory rates, at pressures well below fracture pressure. Electrode wells (which may also be required to serve as injectors or producers), excited at power frequency), are located with due consideration given to reservoir lithology and electrical properties so as to cause current to pass through the regions that are desired to be heated. Electric current flows primarily through the interconnected water paths in the oil sand and the electrical power dissipated along these filamentary paths is rapidly transferred to the surrounding bitumen and to the sand matrix. Detailed considerations for the selection and placement of electrode wells for various reservoir lithologies have been previously reported(1–3). As well, a considerable literature relating to the numerical and physical modelling of electric-preheat processes has developed(1–16). Recently the economics of such processes have been examined by the Alberta Oil Sands Technology and Research Authority(17) and by Petrotec Systems Inc. of Denver(18). Few of the referenced articles consider the problem of fluid flow during electrical preheating(4, 6, 7, 12, 15, 16, 17). Only three of these(12, 15, 17) specifically address modelling of the electric-preheat steam-drive process.

Zone 1 Steam Project, Coalinga Field

Summary This paper discusses thermal development, both steam soak and steam drive, of the Temblor Zone 1 reservoir in Coalinga field, Fresno County, CA. Zone 1 is a thick, multilayered; steeply dipping reservoir. It contains a 12 degrees API (973 kg/m3) oil and its viscosity averages 3,000 cp (3 Pa.S) at reservoir conditions. Zone 1 has been producing on primary since the early 1930's, but cumulative production has been very small as a result of low reservoir pressure and high crude viscosity. Attempts at thermal production were made in the 1960's and early 1970's, but they were unsuccessful. Results of recent activity indicate that both steam soak and steam drive are applicable to the Zone 1 reservoir at Coalinga; however, it appears that a combination of steam drive and steam soak is the most desirable process. The reservoir now is being developed as a full-scale steam drive project. Introduction The Coalinga field is midway between Los Angeles and San Francisco. It has been producing since the 1890's and to date almost 700 MMbbl (111 × 10 to the 6th m3) of comparatively light [20 degrees API (934-kg/m3)] oil have been recovered from its Zone 2 reservoir. Large volumes of heavy oil in the Zone 1 and Etchegoin reservoirs have been produced only recently. This paper refers to the Zone 1 formation underlying a productive area of approximately 300 acres (121 ha) in Sections 29, 30, and 32 as shown in Fig. 1. Zone 1 is a shallow marine deposit. It is productive at various locations in the Coalinga field. It is about 300 ft (91 m) thick; however, the lowermost third of the section is tightly cemented and considered nonproductive. The reservoir rock averages about 200 ft (61 m) in thickness with net pay up to 150 ft (46 m). The reservoir is a layered system containing up to five distinct members separated by silts or diatomites. Fig. 2 shows a composite type log from a typical well in Section 29. The productive reservoir ranges in depth from 800 to 1,700 ft (244 to 518 m) and dips at 21 degrees (0.37 rad) to the southeast. It is limited by a depleted zone updip and an oil/water contact downdip. The accumulation is separated from the overlying and underlying formations by shales. It outcrops to the northeast, but is thought to be sealed completely by crushing, folding, and inspissation. Zone 1 subcrops to the northwest and appears to be continuous into Section 31. It is estimated that there are 50 MMbbl (8 × 10 to the 6th m3) of oil currently in place on Sections 29, 30, and 32. Fig. 3 shows a net pay isopach of Zone 1 and the wells completed in it. Table 1 lists some of the pertinent reservoir rock and fluid properties. Previous Recovery Attempts Primary development began during the 1930's but with very poor results caused by the highly viscous nature of the crude. Cumulative primary production has amounted to 1.7 MMbbl (0.27 × 10 to the 6th m3) from 52 wells. Attempts at both steam soaking and steam driving Zone 1 were made during the 1960's and early 1970's. During early 1961, a 1 1/2-acre (0.61 -ha) inverted five spot steam drive pilot consisting of one injector, three producers, and four observers was begun. The pilot responded in the dip direction with both increased temperature and increased oil production. No production or temperature increases were seen in the strike direction. Cumulative production as of Jan. 1, 1980, amounted to 65 Mbbl (10 × 10 to the 3rd m3) at an oil/steam ratio of 0.34. On the basis of pilot results. it was decided to try a full scale pilot, but with a line drive pattern. Unfortunately, this second pilot was placed in a then unknown depleted zone and was a complete failure, producing no additional oil. It was run during 1963 and 1964. During the early 1970's, four steam soak wells were completed in Zone 1. They were completed in the lowermost 50 ft (15 m) of the productive Zone 1 interval and given 10,000-bbl (1600-m3) soaks. JPT P. 511^

Performance of ceramic materials in high temperature steam and hydrogen

Materials considered for use in fusion blankets for synthetic fuel production were exposed to flowing steam and a combination of steam and hydrogen at temperatures up to 1668 K and flow velocities of 10 meters per second, which are characteristic of blanket design conditions. The penetration rate of 2mm per year on silicon carbide in steam at 1400 K increased to 6mm per year at 1600 K, while alumina, zirconia, and magnesia were below 0.1mm per year.Steam containing 32 to 44 volume percent hydrogen caused a large increase in the erosion rate of alumina, zirconia, and magnesia at elevated temperatures. The temperature above which the erosion rate greatly increased was 1400 K for magnesia, 1550 K for alumina, and 1600 K for zirconia. The penetration rates below these temperatures were less than 0.1 mm per year; however, 100 K above these temperatures, the penetration rate increased four to six times and continued to increase with temperature. The erosion rate on silicon carbide was unaffected by the presence of hydrogen in the steam.Carbon dioxide was substituted for steam and hydrogen in several runs up to 1670 K, and no significant weight losses occurred. The silicon carbide acquired a porous-glassy coating at the highest temperature.

Fracture Mechanics Analysis in In-Situ Oil Sands Recovery

ABSTRACT The success of in-situ recovery of oil from the Alberta Oil Sands depends inlarge measure on the success of formation fracturing to create the initial flowpaths. This paper reviews some of the factors which possibly contribute to theinitiation, development and orientation of fractures and pursues the idea ofapplying the theory of fracturing in elastic materials to un- consolidatedsands. Experimental data are compared with results from a numerical model whichemploys a nonisothermal, single-phase fluid. Background Any in-situ recovery process designed to recover oil from the Alberta Oil Sands must overcome the following major inherent constraints: low or nopermeability in oil-saturated sands; low or no oil mobility; and low reservoirtemperatures and pressures. Accordingly, there are several basic steps to mosttypes of heavy oil in-situ recovery methods(l), but for the purpose of thisdiscussion we need only consider the following:communication;mobilization; anddisplacement. Figure 1 summarizes some of the methods available to accomplish these steps.The selection of one or more categories under each step (and consequently therecovery method) depends largely on the reservoir characteristics. For example, at Cold Lake, Esso Resources, Norcen and Gulf Canada have used steam to part orfracture the formation and thereby improve reservoir injectivity. On the otherhand, because the reservoir has reasonable injectivity, BP Canada (also at Cold Lake) have used the connate water as the transport medium in one of their steampilots. Alternatively, one could use a permeable bottom water sand as thechannel of communication (e.g., Shell Canada at Peace River). Figure 2 shows that certain companies (e.g., Texaco and Amoco) have usedsteam or air (combustion) in dual capacity to:preheat and mobilize the oilin the reservoir; anddisplace oil to production wells. Other companiessuch as BP Canada, plan to use a combination of steam and air in theirviscosity reduction/fluid displacement process.

Notes on the cloud combination of steam and air

Notes on the cloud combination of steam and air