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2024 AGRICULTURAL AND BIOSYSTEMS ENGINEERING BOARD EXAM REVIEWER INTRODUCTION by Engr. Alexis T. Belonio, MS Agricultural and Biosystems Engineer ASEAN Engineer Volume 6 –AGRICULTURAL AND FO...
2024 AGRICULTURAL AND BIOSYSTEMS ENGINEERING BOARD EXAM REVIEWER INTRODUCTION by Engr. Alexis T. Belonio, MS Agricultural and Biosystems Engineer ASEAN Engineer Volume 6 –AGRICULTURAL AND FOOD PROCESS ENGINEERING Disclaimer Photos, illustrations and schematic diagrams of equipment or machine parts shown in the presentation are solely for educational purposes to facilitate comprehension of the topics by the students. Showing them does not endorse a product nor imply criticism of similar products not mentioned. AGRICULTURAL AND FOOD PROCESS Goals ☐ Removal of inedible parts from agricultural and fishery products (Agricultural Processing) by various primary operations to make it ready for human consumption and secondary operations. ☐ Processing the products from primary operation for various secondary process operations (Food processing) to make it palatable for human consumption. ☐ Subjecting the processed products to various preservations methods to lengthen the life span as much as possible without losing its quality and palatability. ☐ Processing the by- products to various operations to make use of them for animal feeds, agro- industrial uses such as fertilizer, or as feedstock to generate energy and to a final end as carbon for CO2 sequestration. Definition of Terms ☐ Processing as defined is an operation or set of action from a specific sequence to the specific final end. Example, cleaning of harvested cassava into a starch is one and may extend further to processing to bioethanol. ☐ Unit Operation – is the “action” that constitute a process, such as cleaning, heating, cooling, size reduction, particle separation, mixing and blending, and many others that produces a product. Agricultural Processing Plant Food Processing Plant Classifications 1. Batch Processing (a) Portion of the material is separated from the entire material; (b) Process condition such as temperature, pressure, etc usually vary during the process; (c) It has definite duration and repeated for other the same cycle; (d) Less capital intensive but may cause more due to handling between batches; (e) Easy to control and lend for intervention during the process; and (f) Suitable for small-scale operation. 2. Continuous Processing (a) The material passes through the system continuously without separation of a part of material from the bulk; (b) The condition at the start may vary but on the later part may remain constant; (c) Ideally runs at steady state for most of the duration of the process; (d) More difficult to control; (e) Requires higher capital investment but provide better utilization of production capacity at lower operational cost. (f) Suitable for producing products on large quantities for long duration of time. Example rice milling, feed milling, and many others. 3. Mixed Processing (a) Composed of sequence of continuous and batch processes; (b) Usually starts with continuous then followed by batch process at the middle and then followed by continuous process at the end; (c) This process requires buffer storage between batch and continuous process. (d) Example is in feed milling where raw materials are reduce in sizes followed by mixing of ingredients and then undergo on pelleting and others; (e) In food processing in first phase preparation of producing banana catsup followed by batch for formulation and mixing prior for quality assurance. Final continuous process is for heat treatment etc and packaging. Unit Operations in Agricultural and Food Processing Industry Process Operation Applications Cleaning Particle Separation Removal of foreign materials from grains and cereals; Dressing Removal of feathers from poultry Slaughtering Removal of fur from livestock (cattle and swine, etc) Washing Fruits and vegetables, poultry and livestock, marine products, etc Peeling Fruits and vegetables, root crops, etc Physical Filtration Sugar refining, water treatment, Separation Screen Grain milling, feed milling Sorting Coffee beans, tomato, fruits, onion, eggs, Centrifugation Milk separation, predrying of sliced fruits and vegetables Pressing, expression Oil seeds, fruits Molecular Adsorption Bleaching of edible oil Separation Distillation Alcohol production Extraction Vegetal oils Process Operation Applications Mechanical Size reduction Corn milling, starch production, chocolate refining Transformation Mixing Feed processing, beverage, dough Emulsification Mayonnaise Homogenizing Milk, cream Forming Cookies, pasta Agglomeration Milk powder Coating, encapsulation Chemical Cooking Rice, meat, fish Transformation Baking Bread, cakes, pastries, biscuits Frying Potato fries, yogurt Fermentation Cheese, wine, Aging, curing Rice, fish, vegetables Extrusion Breakfast cereals, pop corn Cooking Process Operation Applications Preservation Thermal Dressing poultry and scalding livestock, blanching processing fruits and vegetables, pasteurized milk, canned (Blanching, vegetables, bottling of foods, vacuum frying of fruits pasteurization, and vegetables, etc sterilization) Chilling Fresh meat, fish, eggs Freezing Frozen foods, ice cream, sherbet, frozen vegetables Concentration Tomato paste, citrus juice concentrate, sugar Addition of solutes Salting of fish, fish souce. Lams. preserves Chemical Pickles, slated fish, smoke fish preservation Dehydration Dried fruits, dehydrated vegetables, milk powder, mashed potato flakes, drying mushroom Freeze drying Freeze dried fruits and vegetable, instant coffee. Packaging Filling Bottled beverage Sealing Canned foods, plastic packaging, Wrapping Fresh salads, Process Flow Diagram ☐ Flow Diagram – also called flow chart that shows the graphical representation of various processes. It show the major operation of a process in their sequence, the raw materials, the product and by products. ☐ Block Diagram – This is a more detailed description of the process that provides the information on the main pieces of equipment selected to perform the operation. Standard symbols are used for frequently utilized equipment such as pumps, blowers, conveyors, vessels, etc. ☐ Equipment Flow Diagram – shows the pictorial of the equipment to be used in the process. In here, secondary equipment and instrument are reflected in the diagram. Usually this is the starting point in listing, calculations and selection f all the physical element in the processing plant fpr development of what we called plant layout. COMPARATIVE TERMS ☐ Agricultural Processing – deals with the principles and practices of processing agricultural products suitable for food/feed. It covers the activities after harvesting and process the food/feed for safe storage for the next harvest. It is a primary processing activity which does not alter the shape and form of the product. ☐ Food Processing – deals with the secondary processing of a product after it undergoes primary processing. The original shape and form of the product is altered making it more attractive for human consumption. Storage period of the product is quite longer and transporting it is not a problem. One of the distinct features considered in the design of food process equipment as compared with agricultural process equipment is the consideration of hygienic design in the design of machinery. ☐ Durable Crops – crops that are produced and harvested with normally low moisture content of about 20 to 30% and are not easy to deteriorate or spoil. Cereal grains and legumes are the examples of these crops. ☐ Perishable Crops – crops that have high moisture content (30% and above) such as fruits and vegetables, including dairy, meat, and fish and that easily deteriorate and spoil. CATEGORY OF PROCESSING OPERATION ☐ Primary Processing – processing operations which do not heavily change the physical characteristics of the product. Drying and dehydration of grains and fruits are examples of primary operation. ☐ Secondary Processing – processing operations that change the physical properties of the product. On-plant processing such as converting banana to catsup or mango to puree are examples of secondary operation. BASIC ENGINEERING ASPECTS ☐ Hydrostatic Fluid at rest A study that deals with the fluid at rest, such as those fluid stored in tanks, etc. ☐ Hydrodynamics Fluid in motion A study that deals with the various factors affecting the relationship between the rate of flow and the various pressures tending to cause or inhibit the flow. CLASSIFICATIONS OF FLUIDS ☐ Gases They are compressible in nature and, when compressed, some gases change their state of matter. Examples of these are air, flue gases, biogas, etc. ☐ Liquids They are highly not compressible. They can be compressed into a very small degree only. Examples of these are oil, milk, water, etc. ANALYTICAL BASIS OF FLUID SYSTEM ☐ Conservation of Mass Mass in an isolated system is neither created nor destroyed by chemical reaction or physical transformation. The mass of the product in a chemical reaction must equal that of the reactant. ☐ Conservation of Energy The total energy of an isolated system remain constant – it is said to be constant over time. Energy can neither be created nor destroyed. It only transforms from one form to another. ☐ Newton’s Law of Motion Everybody continues in a state of rest or of uniform motion in a straight line unless compelled by force to change that state. The rate of change of momentum is proportional to the force applied and takes place in the direction of the force application. To every action, there is always an equal and opposite reaction. RATE OF FLOW ☐ The rate of flow of fluid is constant at any point in a system and there is no accumulation or depletion of fluid within the system. ☐ Formula Q = A 1 V1 d = A 2 V2 d where: Q – mass flow rate, kg/s A – cross-sectional area of pipe, m2 V – linear velocity of fluid, m/s d – specific weight of fluid, kg/m3 What is the rate of flow of coconut oil in a 2in. pipe if the velocity of the fluid is measured at 0.025 m/s? The specific weight of oil is 1500 kg/m3. Given: Inside diameter of pipe - 2 in. Fluid velocity - 0.02 m/s Specific weight of fluid - 1500 kg/m3 Required: Mass flow rate Solution: Q = AVd = 3.14 (2 in.)2/4 x 0.025 m/in. x 0.02 m/s x 1500 kg/m3 = 2.35 kg/sec MECHANICAL ENERGY BALANCE ☐ Energy available because of elevation above a reference plane (Potential Energy). ☐ Energy available because of the internal pressure (Pressure Energy). ☐ Energy available from the moving fluid (Kinetic Energy). POTENTIAL ENERGY ☐ When fluid is released and is permitted to fall or move from an initial position or a given reference plane, the fluid will have an ability to do certain amount of work equal to the product of weight of fluid and its distance from the reference plane. ☐ Formula Eh = w h where: Eh - potential energy, lb-ft w - weight of fluid, lb h - distance above a reference plane, ft PRESSURE ENERGY ☐ Fluid, in addition to the potential energy, is subjected into an internal static pressure expressed in lbs per in2, kg per m2. ☐ Formula Ep = 144 w p / d where: Ep - pressure energy, lb-ft w - weight of fluid, lb p - pressure of fluid, psi d - specific weight of fluid flowing, lb/ft3 KINETIC ENERGY ☐ A body in motion possesses an amount of kinetic energy. ☐ Formula Ek = w ( V2 / 2g ) where: Ek - kinetic energy, lb-ft w - weight of the material, lb V - velocity of fluid, ft/sec g - gravitational acceleration, ft/sec2 TOTAL HYDRAULIC ENERGY ☐ Total hydraulic energy is the sum of the three types of energy plus the work supplied by a machine (pump) less friction of fluid in the system (conduit and fittings, etc.). ☐ Formula wh1 + 144wp1/d + wV1 2 /2g + wW – w f = wh2 + 144 wp2 / d + w V2 2 / 2g where: w - weight of fluid, lbs p - pressure of fluid, psi V - fluid velocity, ft per sec W - work, ft-lb f - friction g - gravitational acceleration, lb/ft3 BERNOULLI’S EQUATION h1 + 144p1/d + V1 2 /2g + W – F =h2 + 144 p2 / d + V2 2 / 2g CHARACTERISTICS OF FLUID FLOW ☐ Factors affecting the flow of fluid: Characteristics of the fluid Size of pipe Shape of pipe Condition of the inside surface of the pipe Fluid velocity CLASSIFICATIONS OF FLOW ☐ Streamlined Flow – Fluid flows in parallel elements. – Direction of motion of each element is parallel with the other element. ☐ Turbulent Flow – Fluid moves in elemental swirls or eddies. – Both velocity and direction of each element changes with time. VELOCITY DISTRIBUTION IN PIPES ☐ Fluid flowing in a pipe has the highest velocity at the center and decreases towards the surface of the container. ☐ The velocity gradient for streamlined flow in a long circular conduit is parabolic in shape. ☐ The average velocity is one-half the maximum which is at the center of the conduit. ☐ The velocity gradient for turbulent flow flattens and the relationship between the maximum and the average velocity changes. REYNOLDS NUMBER ☐ Reynolds is an English investigator who first demonstrated the finite existence of the streamlined and turbulent flow. ☐ Equation Re = D V d / u where: Re - Reynolds number, dmls D - inside diameter of pipe, ft V - average velocity of fluid, ft/sec d - specific weight of fluid, lb/ft3 u - fluid viscosity, lb/ft-sec VISCOSITY ☐ Viscosity is the internal resistance of fluid to shear. ☐ The coefficient may be considered as the coefficient of friction of fluid to fluid. FLUID CLASSIFICATION ☐ Newtonian Fluid Characterized by the rate of fluid shear that is linearly related to shear force. Examples: oil, water, etc. ☐ Non-Newtonian Fluid The characteristics of fluid is not linear with the shear force. Examples: slurries, food purees, paints, butter, mayonnaise, etc. FRICTION LOSSES ☐ Darcy’s formula F = f ( L/D ) ( V2 / 2 g ) where: F - friction loss, ft f - coefficient, dmls L - length of pipe, ft D - pipe diameter, ft V - linear velocity, fps g - gravitational acceleration, 32.2 ft/sec2 ☐ Friction losses in agricultural and food processing operations are usually found in pipe lines and fittings, air duct and branching, heat exchanger, perforated floors, materials being processed, and others. Once product or material to cause it to move will encounter friction which decreases the energy that utilized in it. As much as possible design it that energy loss in the system is minimal. This would be vital if there is sufficient understanding in fluid mechanics. FLOW OF GRANULAR MATERIALS ☐ Rate of Flow - The flow rate varies with the cube of the orifice diameter. The exponent ranges from 2.50 to 2.96. ☐ Angle of Repose – It is the side of pile in relation to the horizontal. It varies with the moisture content and with the amount of foreign matters present. ☐ Coefficient of Friction – This determines the minimum pitch of conduit intended to move the materials by gravity. Applications of Fluid Properties in Agricultural Processing Operation PRESSURE AND VELOCITY MEASUREMENTS ☐ Pressure head is expressed in column of fluid under consideration, in feet, inches, meters, etc. ☐ Pressure is usually indicated in psi, in. mercury, in. of water. ☐ At higher pressure, psi is usually used. ☐ At lower pressure, inches of water is used. ☐ At pressure lower than the atmospheric, inches mercury is used. PRESSURE CONVERSION 1 bar = 14.5 psi psi x 27.648 = inches of water psi x 2.036 = inches mercury in. of water x 0.0361 = psi in. of water x 0.0736 = in. mercury in. mercury x 0.491 = psi in. mercury x 13.6 = in. water Megapascal =145.04 psi = 101.99 m STATIC AND DYNAMIC PRESSURES ☐ Static Pressure It is a pressure resulting from elevation and indicates forces perpendicular to the walls of a container. Pressure taken perpendicular from the direction of fluid. ☐ Dynamic Pressure It is a pressure that results from force due to change in velocity of the fluid. Pressure taken from the direction of fluid. PRESSURE GAUGES ☐ Manometer – the simplest and most reliable pressure gauge in which pressures are determined by the difference in height of the fluid inside a tube. ☐ Bourdon Tube – widely used for operation control wherein accuracy of approximately 2% is acceptable. ☐ Diaphragm – consists of spring- loaded diaphragm or bellow which actuates a series of levers attached to the indicating hand. VELOCITY MEASUREMENT ☐ Pitot tube - It is an open tube pointing into the stream of fluid. - The impact of moving fluid creates pressure head nearly equal to the velocity (V2/2g). - The fluid static pressure or head is added to the pressure head so that a pressure gage attached to the tube indicates the sum of the velocity pressure and of the elevation head. ☐ Venturi meter - Preferable to the pitot tube when average cross-sectional velocity is desired. - Velocity indicated is a true average. - Pressure difference can be magnified by increasing the diameter ratios. - More accurate readings can be obtained. - An excellent measuring device for permanent installation. ☐ Hot-wire anemometer - Based on the variation in resistance of an electrical conductor with conduit temperature. - Variation of the conductor temperature with the velocity of gas passing through the wire. - Increase in velocity permits an increase in the current flowing. - Cooled wire offers less resistance to electrical flow. FLOW MEASUREMENT ☐ Operating conditions ☐ Meter characteristics (a) characteristics of materials (a) operating range to be metered (b) accuracy through operating (b) operating range range and consistency of (c) line pressure calibration with time (d) characteristics of flow, (c) resistance to corrosion steady or surging (d) ability to be disassembled (e) required accuracy for cleaning, if used for foods GAS AND LIQUID METERS ☐ Bellow meter - Consists of two bellows - Inner connected by valves used for measuring gas flow - As bellows being filled from the supply line, the other is being emptied into a service line - Valve shifts the direction of flow at the end of the stroke - Empty bellow filled from the supply line. - Oscillation of the mechanism activates a volumetric indicator. ☐ Propeller meter - Operates from the motion of the fluid rather than the volume that is flowing. - Activated by the fluid motion - Examples are vane, propeller, or cup rotors. ☐ Pressure-Gauge Flow Meter Flow of gases is measured by the pressure it created in the meter. The higher the airflow, the more it causes a ball indicator to indicate the amount of flow rate in the gas pipe. REFERENCES ☐ Berk, Z. 2009. Food process engineering and Technology. Food Science and Technology Series. First Edition. Elsevier. 360 Park Avenue South, New York, NY 10010-1710, USA. 603pp. ☐ Henderson, S. M, and R. L. Perry. 1976. Agricultural Process Engineering. Third Edition. The AVI Publishing Company, Inc. Wesport Connecticut. 442pp. QUESTIONS AND PROBLEMS 1. Study that deals with the a. Agricultural processing principles and practices of b. Food processing processing agricultural products c. Feed processing suitable for food and feeds. d. All of the above a. Agricultural processing b. Food processing 4. Crops that are produced and c. Feed processing harvested with normally low d. All of the above moisture content of about 20 to 30% and do not easily deteriorate 2. Study that deals with the or spoil. application and practices in a. Perishable crops converting agricultural products into b. Durable crops different kinds and forms of food c. Flexible crops suitable for animal consumption. d. None of the above a. Agricultural processing b. Food processing 5. Which country does not belong c. Feed processing to the ASEAN Free Trade d. All of the above Agreement? a. China 3. Study that deals with the b. Japan application and practices in c. Korea converting agricultural products into d. All of the above different kinds and forms of food. e. None of the above 6. Processing operation which 8. Crops that have high moisture changes the physical properties of content of 30% and more, such as the product, such as processing fruits and vegetables including banana into catsup. dairy, meat, poultry, and fish and a. Primary processing easily deteriorate or spoil. b. Secondary processing a. Perishable crops c. Tertiary processing b. Durable crops d. None of the above c. Flexible crops d. None of the above 7. Processing operation which does not significantly change the 9. A study of fluid at rest. physical characteristics of the a. Hydrostatic product, such as drying and b. Hydrodynamic dehydration of fruits and c. Hydrology vegetables. d. None of the above a. Primary processing b. Secondary processing 10. Which of the following is not a c. Tertiary processing fluid? d. None of the above a. Solid b. Liquid c. Gas d. All of the above 11. An operation that started 13. Processing operation which is from a specific sequence and usually smaller in size and only operate end to a specific final end. in definite duration. a. Work a. Batch processing b. Process b. Continuous processing c. Product c. Mixed Processing d. None of the above d. None of the above 12. Which of the following is not 14. Processing operation where the the goal of processing condition at the start may vary but on agricultural and food products? the later part may remain constant. a. Removal of inedible parts a. Batch processing from agricultural and fishery b. Continuous processing products c. Mixed Processing b. Processing the products from d. None of the above primary operation for various secondary process operations 15. Processing operation where more c Subjecting the processed difficult to control. products to various a. Batch processing preservations methods to b. Continuous processing lengthen the life span c. Mixed Processing d. None of the above d. None of the above 16. A flow chart that shows the 18. A diagram which shows the graphical representation of various pictorial of the equipment including processes and their sequence secondary equipment such as from raw materials to the final pump, valves, etc are reflected in product and by products. the diagram. a. Flow Diagram a. Equipment Flow Diagram b. Block Diagram b. Block Diagram c. Pictorial Diagram c. Pictorial Diagram d. All of the above d. All of the above 17. A more detailed description of 19. Processing operation that the process that provides the combines continuous and batch information on the main pieces of processes. equipment selected to perform the a. Semi-continuous processing operation which frequently use b. Semi-batch processing standard symbols. c. Mixed Processing a. Flow Diagram d. All of the above b. Block Diagram c. Pictorial Diagram d. All of the above