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Boilers and Fired Systems
Published in Stephen A. Roosa, Steve Doty, Wayne C. Turner, Energy Management Handbook, 2020
A mass balance is used to determine where all mass enters and leaves a system. There are several methods in which a mass balance can be performed that can be useful in the analysis of a boiler or other fired system. In the case of a steam boiler, a mass balance can be used in the form of a water balance (steam, condensate return, make-up water, blowdown, and feedwater). A mass balance can also be used for water quality or chemical balance (total dissolved solids, or other impurity). The mass balance can also be used in the form of a combustion analysis (fire-side mass balance consisting of air and fuel in and combustion gasses and excess air out). This type of analysis is the foundation for determining combustion efficiency and determining the optimum air-to-fuel ratio.
Processing Solid Wastes and Recyclable Materials
Published in Charles R. Rhyner, Leander J. Schwartz, Robert B. Wenger, Mary G. Kohrell, Waste Management and Resource Recovery, 2017
Charles R. Rhyner, Leander J. Schwartz, Robert B. Wenger, Mary G. Kohrell
One cannot fully understand or effectively design a processing system unless a detailed mass balance can be established to trace the flow of materials through the sequence of unit processes. A mass balance is simply the application of the law of conservation of mass to the system. The mass balance traces the movement of materials through the system; that is, the total mass of the feedstock entering the system must equal the sum of the masses of the output streams. The results of such an analysis may be used for specifying the proper capacities for individual processing units.
Material Balance
Published in C. Anandharamakrishnan, S. Padma Ishwarya, Essentials and Applications of Food Engineering, 2019
C. Anandharamakrishnan, S. Padma Ishwarya
Including a material balance check exercise on at least one key ingredient or packaging material of a product is essential to test the efficacy of a traceability system in a food industry. Here, the purpose of mass balance exercise is to check whether the manufacturer can account for any input material that is involved in the production of a lot or batch of the product. The input material can be a food ingredient, semi-processed product, or packaging material. Mass balance and traceability are extremely crucial in the reported event of a critical food safety (contamination) or regulatory (mislabeling) issue, which demands a complete recall of a particular lot of the product from the market. The application of mass balance in a traceability exercise is explained by the following example. Following are the steps involved in conducting the traceability exercise. To conduct the reconciliation exercise and obtain details on the quantity of the product that has been sold, retained in the inventory, and disposed of for reasons if any.The collection of abovementioned details gives the total quantity of unaccounted material.Determine the percentage effectiveness of the traceability procedure using the following formula: %Effectiveness oftraceability procedure=B+C+DA×100
Contrasting long-term trends of chloride levels in remote and human-disturbed lakes in south-central Ontario, Canada
Published in Lake and Reservoir Management, 2020
Huaxia Yao, Andrew M. Paterson, April L. James, Christopher McConnell, Timothy Field, Ron Ingram, Dejian Zhang, Shelley E. Arnott, Scott N. Higgins
A mass balance approach, through determination of inputs, outputs, and changes in storage, can be used to quantify the relative sources of nutrients or pollutants to inland waters. In watersheds in south-central Ontario, mass balances have recently been updated to elucidate long-term changes in inputs and concentrations of many elements (e.g., Yao et al. 2011 for calcium, Yao et al. 2016 for base cations). Chloride mass balances have been conducted in other regions, such as for Onondaga Lake in New York (Ecologic et al. 2000), that revealed the possibility of loading sources that had been missed previously (e.g., from a shoreline area that had intensive pollution). In Seneca Lake (New York; Halfman et al. 2006), a mass balance was used to explain the differences in Cl concentrations between the lake and inflowing streams. Cl budgets for Australian (Somaratne and Smettem 2014) and Florida lakes (Sacks et al. 1998) improved estimation of groundwater basin recharge and groundwater exchange. Analysis for the Great Lakes (Chapra et al. 2009) found varied Cl trends over a 150 yr period as a result of changes in input loads. Despite these previous studies, little is known regarding sources of Cl to recreational inland lakes within the Canadian Shield.