Air Washers Research Articles

INFLUENCING CONSUMER PREFERENCE AND SATISFACTION TOWARDS BUYING BEHAVIOUR OF KITCHEN APPLIANCE PRODUCTS IN KRISHNAKIRI DISTRICT

Every business in India, particularly in the country's largest cities, is attempting to survive on its platform as best it can under the current circumstances in order to reach the target number of prospective clients. The world economy will inevitably shift, and liberalisation is essential to our nation. With its extensive and excellent product line, the premier multinational company has joined the Indian market and is already playing a significant role. We understand that our "Customer is the King" and that the Indian market is expanding with a superior product line in electronic home appliances as compared to the global market. Customers are sufficiently aware and sound to make the best choices when it comes to purchasing the chosen brand of home appliances in order to meet the necessary objective. Without home appliances, a contemporary house is incomplete, particularly in large cities and metropolitan regions. In large metropolises, electronic home appliances are seen as a boon as they significantly reduce the amount of time needed for the majority of domestic household chores. Thus, the researchers took into consideration their study on the purchasing habits of consumers in Krishnagar District, Tamil Nadu, with regard to electronics and household appliances. Products related to home appliances such as air coolers, refrigerators, washers, microwaves, and televisions are included in this study. 253 respondents in Krishnagar were chosen for this study using an expedient sampling technique. This study employed a demographic research design, using a questionnaire as a means of gathering data from participants. Additionally, data segmentation will be used in the study. The conclusion reached was that while price, quality, offer, and appliance features empowered the consumer to purchase the appliance, demographic characteristics also influenced the consumer's decision to purchase.

An Approach to Analyzing and Comparing the Cooling Performance of Two Indirect Evaporative Cooler Designs

Abstract Energy-efficient air cooling systems are always in demand. Direct evaporative coolers are energy-saving and have low cost, but in hot and humid areas, they produce an almost uncomfortable environment. Alternatively, modified indirect evaporative coolers with different technical configurations can produce better thermal output. This paper presents a simple thermodynamic approach developed to analyze, for comparison, the behavior of conventional and regenerative indirect evaporative coolers that comprise different process structures. The analysis is based on the energy balance of the coolers to consider which is more applicable for further modification. Similar performance cross-flow heat exchangers with separate air washers are adopted for both units. The two coolers are subjected to the same general summer operating conditions. The results showed that the conventional indirect evaporative cooler provided better cooling performance in terms of all thermal comparison parameters. The supply temperature trend in regenerative indirect evaporative cooler (RIEC) is higher by 23.4–34.1%, while its effectiveness is lower by 26–56% compared to that of the conventional indirect evaporative cooler (CIEC). The cooling capacity of CIEC is always higher at any air ratio value. At an equal secondary air flowrate where the primary air flowrate of RIEC is 25% more than that of CIEC, CIEC still generates lower air supply temperature and its effectiveness is higher. Thus, CIEC deserves priority attention for further development and additional improvement of performance.

Effect of diffusion processes on the movement and cooling of droplets in the air washers of heat power systems

The work explores the processes of movement, evaporation, change of temperature and weight of water droplets in the air washers of heat power systems. The motion of the evaporating drop is described by the variable-mass body mechanics equation without regard to reactive force. Two laws of movement resistance of water droplets in the air washer are considered. The diffusion and evaporation of droplets are calculated using traditional equations, taking into account the conditions of the air washer. Changes of droplet temperature were found from the heat balance equation. Numerical calculations of the change of the weight and temperature of the droplet are given depending on the distance droplet travelled in the air washer. Conclusions have been drawn on the effect of evaporation and changes in droplet temperature on mechanical movement and associated processes. A rational range of droplet sizes is defined for efficient operation of air washers.

Transmission and Suppression of Avian Influenza Virus

The growth of AIV is possible with supply of minerals from aeolian desert dust, as cofactors of enzymes, and thus the blockage of the aeolian desert dusts to the poultry farmhouse is important to suppress the enzymatic activity of AIV. South Georgia of Subantarctic Islands may be the source of Continental AIV, so that Continental AIV can become endemic within the local bird population when surrounding environments are close to Subantarctica of South Georgia. There are food webs in sequence of aquatic virus, bacteria, phytoplankton, zooplankton, krill, fish and squid while penguins feed on the fish or squid infected by mutant virus to generate LPAI after an incubation period. When migratory birds move to the Continents, HPAI can spread in the Continents due to low UV-B radiation, enough feed of rice, wheat, corn, wetland, and mineral-enriched desert dust. The clean room is equipped with air washers to remove aeolian dusts and migratory birds feces from working personnel and equipments, heaters to keep the pasteurisation of ultra-high temperature at 135°C for 1 - 2 seconds to inactivate AIV, humidifier to keep wet state above 65% relative humidity for weak virus activity, and the UV-C lamps (254 nm) to finally inactivate AIV. Since AIV doesn’t like the high salinity and high relative humidity, seawater is blanketed as sprayer to maintain high salinity (>20 ppt) and high relative humidity (>65%) from the top to the bottom of the poultry farmhouses for suppression of AIV transmission from infected aeolian dust coming from outside.

A rapid tool for emission outlet concentration simulation of scrubber and make-up air unit at different inlet concentrations

Currently in the cleanroom-related industries, both the air quality of indoors intake and outdoors emission should be controlled at a certain level. Wet scrubbers and air washers are the main facilities to clean up air for the process required. However, previous studies have found that these devices typically have lower removal efficiency for low inlet concentration contaminations; little information is available to explain the efficiency deterioration and only on the empirical basis. A theoretical model is proposed, which applies Fick’s second law to derive a rapid efficiency simulating formula. This model is different from the empirical equations of former studies, and is able to describe the relationship between the inlet concentration and removal efficiency of the air washing facilities. Moreover, the calculation time of the nonlinear recurrence equation is effectively lessened by the Euler equation and proven to be practical and concise for the rapid efficiency determination. Confirmation of the simulation formula was conducted by using the experimental data from the previous studies of the wet scrubber and in situ historical record of a make-up air unit. In this article, we describe how an outlet concentration and removal efficiency can be predicted using a generic simulating formula, leading to better design with less effort. The proposed model and equation minimize the design complexity and help to optimize the sizing and operational control of the air washing facilities. This not only decreases the construction and operating costs, but also lead to better energy usage. Practical application: Engineers can use the output of this paper to optimize air washer facility designs instead of intuitively extending the rinsing duration or enlarging the scale of the equipment. The model can be applied to both residential and industrial air washers to predict the efficiency and evaluate the performance. It also allows the quantitative analysis and risk assessment of an abrupt air washer breakdown in the clean manufacturing industries.

Energy and exergy analysis applied to the evaporative cooling process in air washers

This paper presents a study on the performance of the evaporative cooling process in air washers with the use of mass balances, energy and exergy equations. Usually, the performance of these devices is described in terms of their saturation effectiveness based on energy analysis. This method, however, is inappropriate to identify the main sources of irreversibility within the process. It is also unsuitable to give the optimum conditions for operating the system with a proper use of energy resources. Thus, an exergy analysis was developed to complement the energy analysis of the process. A mathematical model based on mass and energy balances was used to determine the water and air properties in the washer. The influence of the humidity and temperature of the air and water at the inlet, the washer length in the saturation effectiveness, and the second law efficiency was investigated. The results showed that the best condition of the intake air for obtaining thermal comfort does not coincide with the best condition for the thermodynamic performance of the system. The energy and exergy analyses were carried out simultaneously to generate the conditions required for optimum performance with minimal exergy depletion.

Analytical solution for the simultaneous heat and mass transfer problem in air washers

An analytical solution approach for the simultaneous heat and mass transfer problem in air washers operating as evaporative coolers is presented. A one-dimensional model using the coupled mass and energy balance equations in the air washer is presented. Then, starting from a linear approach for the experimental curve of the air saturation, an analytical solution for the model was derived. The solution showed an excellent agreement with the available results found in the literature. The influence of several important parameters for the cooling process such as temperature and ambient air humidity, air flow rate and feeding water temperature, in the air cooling rate was investigated. The efficacy of the process can be greatly increased by reducing the cooling water temperature and the applied air flow rate. The analytical solution can be easily included into the models used for simulating desiccant air-conditioning systems operating in conjunction with air washers.

The desiccant air-conditioning system

SYNOPSIS This research work is concerned with the investigation of a novel liquid desiccant system for air-conditioning of buildings. A flexible fibre “mop” fan was employed as a device that fulfils the functions of contaminant-removal, de-dusting, humidifying or dehumidifying and circulation of the air stream simultaneously. This fan, similar to a chimney sweep brush, was mounted on a shaft within a centrifugal fan casing. The flexible fibre needle impeller (mop fan) is used to increase the heat and mass transfer in the evaporator and absorber units. The mop fan has similar performance characteristics to those of centrifugal fans. Experimental investigations were carried out using the mop fan to humidify and cool air. The results showed that the cooling achieved across the mop impeller was an adiabatic process. The efficiency of the mop in saturating a passing air stream was as good as commercial air washers. Further tests on the mop to dehumidify air were undertaken. The mop fan showed potential by using liquid absorbent sprays to absorb moisture from passing air streams. The absorbents used were lithium bromide and, less corrosive, potassium formate (HCOOK). A system combining the cooling and absorbing effect of the mops was designed and constructed for testing. The desiccant system has the potential to be driven by natural gas, solar energy or hybrid sources (e.g., solar/gas). It employs an “environmentally-friendly” refrigerant such as water.

A novel evaporative air cooler

SYNOPSIS The paper describes a novel evaporator cooler using a flexible fibre “mop” fan. The mop fan is similar to a conventional centrifugal fan but it utilises a brush disk instead of the blade disk of the latter. Experimental work was carried out to determine the effectiveness of the mop fan to humidify and cool air. This was achieved by spraying the rotating mop fan with water. The results showed that the cooling across the mop impeller was an adiabatic process. The efficiency of the mop fan in saturating a passing air stream was similar to that of commercial air washers and approached 98%.

A general mathematical model of evaporative cooling devices

In this paper a general nondimensional mathematical model for the description of all types of evaporative cooling devices in today's use (water cooling towers, evaporative condensers and evaporative fluid coolers, air washers, dehumidifying coils etc.) is presented. The system of differential equations describing nonadiabatic evaporation processes is transformed to a pure nondimensional form by the introduction of nondimensional coordinates and parameters and by the substitution of a straight air saturation line instead of the real one. In such a way, not only the description of the entire process becomes very simple, but also the overall performance of any such device can be expressed in terms of only few parameters and presented in one or few diagrams. This nondimensional model forms a basis for simple and rather accurate methods for rating various types of evaporative cooling devices. For every type of device, a unique rating procedure can be established, irrespective of the relative flow direction of the fluids involved, which is very convenient when cross-flow devices are considered. Since every particular type of evaporative device deserves considerable attention, the application of this general model to various evaporative devices, together with the resulting rating procedure and accuracy test will be presented in detail in the follow-on papers, each devoted to one particular type.

Proposed energy-efficient air-conditioning system using liquid desiccant

Abstract Energy consumption due to conventional air-conditioning is very high, especially in hot, humid areas. The total air-conditioning cooling load can be divided into sensible and latent parts. Liquid desiccant solutions have the property of holding water vapor, therefore they can be used to overcome the latent part of the air-conditioning cooling load. In this work, an energy-efficient system is proposed to reduce energy consumption in air-conditioning ( A C ) systems using CaCl2 solution as a liquid desiccant. The proposed system consists mainly of two packed beds, a heat pump, air washers and a cooling coil. Mathematical modeling of various components and fluid properties of the proposed system was undertaken. A computer program was prepared to study the system performance under different conditions. Over most of the conditions at which the program was tested, the proposed system was found to be more energy-efficient than a conventional A C system.

HVAC Systems As Emission Sources Affecting Indoor Air Quality: A Critical Review

This study evaluates literature on heating, ventilating and air conditioning (HVAC) systems as contaminant emission sources that affect indoor air quality (IAQ). The various literature sources and methods for characterizing HVAC emission sources are reviewed. Characterization methods include in situ tests, longitudinal and cross-sectional studies, and laboratory studies. A critique of the literature reveals that few studies are well-controlled, comprehensive and quantitative. Significant gaps in the data are highlighted and procedures are suggested to improve the characterization of bioaerosol and VOC (volatile organic compound) emission sources. Several HVAC components are cited frequently as emission sources, and there is broad agreement regarding their significance. These sources include biological growth and bioaerosol generation in the presence of moisture provided by air washers and other recirculating water systems, or by poor control of humidity, badly designed humidifying systems, and inadequatel...

Comparative study of different air-conditioning systems incorporating air washers

Cooling towers and air washers are members of the heat exchanger family. The function of both systems is to bring the air and water into direct contact. Heat is rejected by evaporation from a drained water film into air flowing through a cooling tower and the heat is transferred from the air into flowing through the air washer. The air washer could be integrated into a thermally powered summer air-conditioning system (cooling system). In this paper, a mathematical model for an air washer is developed and used as the basis for a comparison of seven proposed air-conditioning systems. Each of these systems consists of an air washer and either a chemical dehumidifier or a water chiller. Commercial units are chosen and their technical data are used in the system performance evaluations. The performance of each system is studied and the system outlet air temperature is determined for a specified value of outlet air humidity ratio and variable ambient air humidity ratio. For the purposes of comparison, the power consumption per unit air temperature drop is determined and compared for all the systems.

Microorganism Contamination of HVAC Humidification Systems: Case Study

Abstract Water samples were collected from 33 of the 54 heating, ventilation, and air conditioning (HVAC) humidification system water reservoir pans in a large office building. Two different forms of humidification are used in this building: air washers and steam injection. Thirty-eight samples were cultured for human-source and heterotrophic bacteria, thermophilic organisms, and fungi. While one microbe, an unidentified bacterium, was found on more plates than any other organism, Streptococcus and Pseudomonas were found to be the most predominant microorganisms. In a comparison of the air wash and steam injection humidification systems, only small quantities of bacteria were found in the steam systems, while water collected from the air wash systems was highly contaminated. Data were also available to test the effectiveness of the cleaning system. A sample collected one day before cleaning had 58,100 colony forming units per milliliter (CFU/ml). Samples collected 1 and 2 days after cleaning had 250,200 and 528,160 CFU/ml, respectively. This demonstrates not only that the cleaning process is ineffective, biologically, it may increase the risk of bioaerosol contamination. Sample concentrations, in colony forming units per milliliter, were found to be quite different depending upon the side of the baffle plates from which the sample was collected. In some units the spray side of the water reservoir was visually clear with no observable microbial contamination. However, water on the backside (intake air side) of the reservoir would have a green, slimy and frothy contaminant floating on top of the water. This study demonstrates that gross contamination of microorganisms can exist in the water reservoirs of HVAC humidification systems. Burkhart, J.E.; Stanevich, R.; Kovak, B.: Microorganism Contamination of HVAC Humidification Systems: Case Study. Appl Occup. Environ. Hyg. 8(12):1010–1014; 1993.

Air washing for the removal of formaldehyde from indoor air

One potentially suitable control technique for indoor formaldehyde is air washing: the absorption of formaldehyde by a liquid. In this report we present a mathematical model of an air washer, describe tests of two air washers, and compare the energy required for controlling formaldehyde concentrations by ventilation and by air washing. The two experimental air washers tested employed water as the washing liquid and incorporated a refrigeration system to control the humidity of the outlet airstream. Air flow rates through the air washers were 100–160 L/s and inlet formaldehyde concentrations were 80–480 ng/L. The steady-state formaldehyde removal efficiencies of the two designs were 0.36–0.47 and 0.30–0.63 with water consumption rates of 1.7–7.9 and 0.5–2.3 L/h, respectively. The power consumption of an air washer with a 140 L/s air flow rate is estimated to be 1500–1800 W. Results show that an air washer with an acceptable water requirement can effectively remove formaldehyde from indoor air. The net energy required for air washing can be less than for mechanical ventilation with heat recovery when most of the energy consumed by the air washer provides useable space heat.

Odour control with biological air washers

Odour nuisance caused by livestock and poultry farms is becoming a real problem in Holland. By installing biological air-scrubbers in the ventilation of the exhaust system, the air can be made dust-free, and the odour components can be reduced. In this way the complaints of neighbours can be eliminated. In the air-scrubbers the ventilation air is brought into contact with a large surface over water by using an inert material. The water is recirculated over the filter material. It is important that the surface of the water changes often. Activated sludge from a sewage plant is added to the circulating water. The reduction of smell is from 60 to 85% according to organoleptic and chemical analysis and depends on such different parameters as the initial amount of smell, the filter medium in the scrubber and the overflow of the circulation water. A description is given of the biological air washer, types of packing material used, circulation pumps and water distribution. Some of the theoretical aspects such as water consumption and mechanism of the air washer are discussed, together with a cost study. The wash-water contains nitrite and nitrate as a result of biological activity. Future research is indicated.

INVESTIGATION OF WATER‐AIR RADIATORS FOR COOLING GENERATORS AND MOTORS*

The satisfactory solution to the problem of ventilating large capacity electrical units in land stations, by means of ducts, air washers, etc., is not as readily applicable to the cooling of electrical apparatus where extreme compactness is essential—as for instance in the propelling machinery of a ship. The use of the customarily large ventilation air ducts would tend to offset one of the great advantages of electric marine drive; viz., the enlargement of the cargo carrying space. The following article reviews an investigation made to overcome the difficulty by applying a closed system of air ventilation with water‐air radiators for removing the heat from the circulating system.–Editor.

A High-Speed Air and Gas Washer

Abstract Nearly all of the recent improvements in air washers have been modifications of the standard form of spray-chamber washer. The author describes a new type of washer embodying a new combination of old principles. This has resulted in a very small washer with unusually high washing efficiency. Three of these washers have been built and the paper gives a brief description of the first and smallest of these.

Experience and recent developments in central station protective features

The protective features described in this paper are some of those now in use on the system of the Public Service Electric Co. which serves a population of about 2,200,000. The most interesting protective devices and schemes discussed in this paper are as follows: Aluminum cell arresters; arcing ground suppressor; faulty cable localizer; cable testing; high potential and high frequency testing; generator bus connection scheme; exciter connection scheme; reactors; relays; multi-recorder; insulation resistance recorder; air washers; resistance bulbs and thermo-couples; dampers on air blast transformers; coherer alarm devices; potential indicating devices.

Experience and Recent Developments in Central Station Protective Features

The protective features described in this paper are some of those now in use on the system of the Public Service Electric Co. which serves a population of about 2,200,000. The most interesting protective devices and schemes discussed in this paper are as follows: Aluminum cell arresters; arcing ground suppressor; faulty cable localizer; cable testing; high-potential and high-frequency testing; generator bus connection scheme; exciter connection scheme; reactors; relays; multi-recorder; insulation resistance recorder; air washers; resistance bulbs and thermo-couples; dampers on airblast transformers; coherer alarm devices; potential indicating devices.