Types of Heat Exchanges Used in Different Industries - Essay Example

Heat Exchangers al Affiliation Introduction Heat exchangers refer to gadgets made for smooth transfer of heat from one point of the fluid to the other. The transfer occurs over a solid surface. Either absorption or dissipation is the forms in which the transfer of heat can occur (Fiore& Severini, 2011).Heat exchangers are present in almost all equipment that we use in our daily lives. Among the equipment which contain heat exchangers are; air conditioners, refrigerators, boilers and furnaces. These heat exchangers serve different purposes in different manufacturing industries. There are those used in fruit and vegetable processing industry, those used in confectionary industries and others used in dairy industry. In each of the industry above, there are different heat exchangers used. Below is a discussion of these different types of heat exchangers used in different industries (United States, Hodgson, Hunziker, & Dahlberg, 1942). Fruit and Vegetable Processing Industry In fruit and vegetable processing industry, there are a number of heat exchangers used. The first is the juice pasteurizer. These are machines used for pasteurizing fruit juices and preserving fruits in the processing industry (Burch, Rickson, & Lawrence, 1996). In most cases, they are made of stainless steel, has a large heating capacity and suitable for large scale use. The advantages of these pasteurizers are; the equipment manufactured today are highly automated, they are supplied on a modular designed on the principle of plug and play, they are supplied with a control manual to ease the control process, they are designed with the latest microprocessors capable of controlling and holding the required temperatures, and are made of stainless steel which prevent it from wearing out. The second heat exchanger is the blending and mixing vessels. They are used in blending and mixing different types of fruit juices to give birth to new blends. They have different volumetric capacities depending of the financial ability and manufacturing capacity of the firm. They can be single or multiple walled and are purchased to suit the processing industry needs. Some have insulators and others do not. They are fitted with mixing turbines for the purpose of mixing. They also contain two speed scrappers moving in opposite directions to facilitate quality and fast mixing. Depending on the taste of a particular industry owner, they are either supplied with conical or flat bottom and top. In case no one of the vessels suits the client’s preferences, the manufacturing industry can design one for him/her from scratch (Fiore& Severini, 2011).This is the advantaged of these vessels. The other advantage is that they are designed in different sizes to suit different sizes of the industry. The other advantage is that they are automated to save on energy. The third type of heat exchanger in vegetable and fruits processing industries is the juice concentration plant. They are either continuous or batched. They are mounted with vacuum pans together with vapor condensers. Vacuum pumps are also present in them. They have different recirculation stages meant to concentrate the juice. The advantage is that they are made in different sizes suitable for different sizes of processing industries (Beyer, 1985). They are easily repaired because the most of the supplying firms take it upon themselves to repair these machineries for their clients. The fourth heat exchanger found in fruit processing industries is the ketchup and jam manufacturing equipment. The equipment is fitted with various storage tanks and boiling pans. Other fittings are slow speed agitators and mixers with high shear. The supply firms carry out a complete planning for the installation of this equipment. They lay down the equipment, electric cables, panels and pipes (New Zealand, 2010). Product trial and commissioning is also their duty. This is the advantage related to buying this equipment. The repairs and the necessary servicing of this equipment are carried out by the supplying firm. The fifth heat exchanger is the fruit and vegetable washer. This is equipment used in cleaning the fruits and vegetables during the processing. It is suitable for vegetable, fruits as well as leafy vegetables. It involves a continuous washing process. The currently manufactured washers have low water consumption for cost efficiency. The water flow in the washer causes the movement of the fruits and vegetables through the turbulence caused by air that is forced in. at the discharge conveyor, the final washing is done. There is a water collection tank which facilitates the recycling of water for initial stage washing (Keogh, Twomey, Teagasc & Dairy Products Research Centre, 2001). The advantage is that the washer is cost effective in that the water consumption is low and finally, the used water is recycled for re-use. The sixth equipment is the boiling pans and kettles. They are the most equipment in the food industries. They are of different types. They are provided with a jacket for hot liquids and are insulated. There is a provision of having them fitted with mixers, agitators and scrappers. These pans are fitted on tabular legs if their capacity is high. On the other hand, kettles are supplied in either conical, dished or flat end top or bottom (Critical reviews in food science and nutrition, 1980). In case the available designs do not match the preferences of specific clients, the manufacturing company makes a design in accordance with the client’s instructions. This is the advantage of purchasing such boiling pans and kettles from a renowned manufacturer. The seventh equipment is the plate heat exchanger. These plate heat exchangers are manufactured using plates of different brands. They are fixed with single clad frames with terminal connections. They have terminal controllers which pressure and temperature flow. There are those which generate hot water using steam to heat. Plate heat exchangers for vegetable oil industries have MS painted frames which facilitate heating or cooling of the oil. The advantage of using them is that they are efficient in the amount of electric energy they consume because they are automated. They are also insulated to prevent the loss of heat. This reduces the consumption of electric power. The eighth heat exchanger is the yeast extruder and yeast manufacture equipment. These are equipment found under the category of industries which deal with fruit and vegetable processing. The equipment is fitted with cum cutters, CIP tanks, phosphoric acid tanks, service tanks and flow plates. The tanks are usually insulated and are fitted with slow speed agitators (Derossi, Fiore & Severini, 2011). The yeasted extruders are together with on-line cutters. There is a PLC panel which is used to control the length of the yeast extruded to obtain the desired weight of the yeast blocks. Their advantage is that they are automated to preserve power consumption and hence are cost effective for specific industries. Dairy Industry In dairy industry, there are a number of heat exchangers used. The first type of heat exchanger is the milk pasteurizer. They are used in manufacturing both the cream and the milk. They are usually based on the parameters of the dairy industry involved (Schwarzweller & Davidson, 2000). These parameters are but not limited to; necessary conditions for homogenizer and milk separator which suit the milk pasteurizer, feed temperature for either milk or cream, availability of cooling media, availability of heating media, automated temperature control, and automated diversion of under heated milk. Then advantage is that most of the operations of the equipment are automated hence reduces the wastage of resources such as time, and heat generated by electric power. The second heat exchanger is the batch pasteurizer. The vessels have SS inner shell coated with dimple jacketed layer which help in smooth circulation of air. An option of having this equipment fitted with scrappers, mixers or agitators is provided. The tanks are manufactured with tubular legs for support. The advantage of these heat exchangers is that they are economically friendly and they make work easier hence facilitating the production process. They are also designed to suit the preference of the customer (Beyer, 1985). The third type of heat exchanger is the ghee boiler. These are heat exchangers present in ghee processing industries. They are used in manufacturing of ghee. They are fitted with motorized scrappers and are hemispherical in shape. They contain a tubular continuous melting system which has a pump and a mixing system of hot water steam. Their advantage is that they are provided with a jacket which acts as an insulator hence preventing the loss of heat. The fourth type of exchanger is the C.I.P system. The abbreviation stands for cleaning in place. Different manufacturer manufacture different C.I.P systems. These types include; PLC controlled system which is skid mounted, single or double CIP circuit PHE for heating and fitted with a PLC panel, single or double CIP circuit that is semi-automated with an electric timer, a single pump with small rectangular tank which is double partitioned fitted with a manual CIP system suitable for small plants among other types (Schwarzweller & Davidson, 2000). They are easy to control and are effective in power consumption because they are automated. They are also manufactured in different sizes to suit different consumers. The fifth type is the milk/cream chillier. They are offered by different companies and are used to chill the milk or the cream. They are provided with SS clad frame and the end connections which terminate with SMS Unions. The advantage is that they can be provided specifically suiting the preferences of customers and are made to meet the requirements of the standard union. This assures the health of the consumers and also a prolonged service to the industry. They are automated to save on the power consumption. They are essential in ensuring a prolonged storage and use of milk and cream. Otherwise, without these milk/cream chillers, the milk/cream would get spoilt and disposed thereafter. The cream/milk is mixed with some preservatives apart from being stored in the chillers. They prolongs the period of stay more. More of the milk and the cream can now be produced and stored in large quantities and even if the demand is low, it is stored to meet the times of high demand. The sixth type of heat exchanger in dairy industry is the dual duty milk pasteurizer cum milk heating system. The equipment has several special features. These features are; independent milk heating for up to between 35C to 90C, milk pasteurizer providing milk homogenizer, super pasteurizer of milk to a maximum holding time of 12 minutes among other features. Its design provides a change up from milk pasteurizer to milk heater by shifting the U bend connections. The U bend is at the Flow Plate provided at the milk feed pump end. The advantage of this heat exchanger is that it is a multipurpose machine. This is because it can be used as a milk pasteurizer as well as a milk heater (Derossi, Fiore & Severini, 2011). Therefore, it is a two in one machine which is pocket friendly and saves the agony of purchasing two machines. The seventh type of heat exchanger is the S.S centrifugal pump. It is a very high efficiency machine with low power consumption, has a hygienic mechanical shaft seal which is leak proof, access to all vital parts is made easy by its compact design, and can be used for manufacture of corrosive liquids such as sour milk. Its advantages are that the pump can be easily dismantled into several parts in case a change is required, the cost of maintenance is low, its power consumption low and the space require for its fixing is small. Confectionary Industry In a confectionery industry, there are different types of heat exchangers used. The first type is the universal cooker. It is specifically used in production of hard candy, caramel and toffee. It is made up of two parts. The upper part is made up of stainless steel pan used for cooking and it contains a steam jacket (Keogh& Dairy Products Research Centre, 2001).The lower part is made up of a tilting pan responsible for removing the moisture. Due to this reason, it is made up of copper on its lower part. The raw materials are put in through the opening on the top and are cooked by pressure. After the raw materials are cooked, they are discharged from the lower part of the cooker. The discharge is then directed to a cooling plate through a rotating mechanism of the lower part. The second type of heat exchanger is the batch stiller. It is used for on kind mixing of the inputs in large amounts. It is also made up of two parts. The first part is the frame stand that holds the stiller in place and the other part SS stiller (Keogh& Dairy Products Research Centre, 2001). The stiller is mounted on the frame and its motion is an up and down one. The raw materials are first put in this machine for a uniform mixing. They are then put into the cooker. The advantage of the machine is to ensure uniform mixing of the products. It also saves time which would be used to mix the components manually. This ensures that quality products are provided to the consumers. They are of different capacities and speed. The third type of heat exchanger is the batch roller. It is a heat exchanger used to roll the cooked mass of raw materials into different sizes. The machine rotates in the same direction to roll the mass into thin ropes (Keogh& Dairy Products Research Centre, 2001).An electric heater is connected to this machine to keep the mass hot. These machines are of different makes and sizes. Some are two-in-one because they are combined with a rope seizer. This is advantageous by saving the customer’s agony of purchasing two machines. It is also advantageous in saving space. The fourth type of heat exchanger in confectionery industry is the tablet forming machine. It is made up of a tablet forming die and sizing wheels. The rope obtained from the rope forming machine is directed to the tablet forming machine for tablet forming and die application (Keogh& Dairy Products Research Centre, 2001). Different candies are given different colors to suit different preferences of different consumers. This is an advantage in itself because it ensures provision of variety of the product. It is capable of forming sweets with different thickness and length. They are of different capacity, dimensions; motor rating and weight. The advantage is that they ensure fast provision of different sizes, shapes and colors of candies. This is an upper hand of providing quality to customers with different financial capabilities and tastes in terms of sizes, colors and shapes. The fifth type is the die. It is a recent air exchanger used in confectionery industry to produce perfect shapes and sizes of candies with a perfect die precision. To ensure precision, CNC machine is used. The candies produced are usually warm and hence are directed to the cooling conveyor. They are then feed to the wrapping machine. The cooling belts are usually 3 which have a galvanized wire mesh. Blowers which are of 4 to 12 inches are fitted over the belts. These dies are advantageous in realizing different colors of candies which suit different preferences of consumers (OECD Workshop on Agro-Food Policies in Estonia, Latvia and Lithuania, 2002). If this was to be done manually, it would never meet the required precision and quality. It could also take a lot of time. The sixth type is the 3 stage cooling conveyor. Warm candies are cooled in cooling conveyor after they are released from the tablet forming machine. The wire mesh is galvanized and fitted over the conveyor cooler (Keogh& Dairy Products Research Centre, 2001). The machine may hold a capacity of 2500 kilograms in an 8 hours shift. The motor rating may be of 2.2 kilo watts weighing approximately 375 kilograms. The machine is advantageous in that it makes the cooling of the candies before wrapping quick hence facilitating the quantity which can be produced in a given span of time. If wrapping is done before the cooling is done, the taste of the candies will be distorted. This will have a negative effect on the overall consumption of the producing company products. The seventh type of heat exchanger in confectionery industry is the robust cooling conveyor. It is similar to the ordinary cooling conveyor apart from some distinctive extra features. The speed of one of the 3 belts which is narrower is high. The speed of the remaining two belts is slow. The first belt is designed to move candies from the high forming machine as they cool down. The candies from this belt are then spread over the other belt uniformly. This is to ensure the original shape of the candies is maintained and are not deformed. To do so, sprinkler is used. With the help of the guiding plate, the candies are pushed to the third belt. On this belt, there are two supplies of air from the blower (Keogh& Dairy Products Research Centre, 2001).The nozzles on top of the belt number one circulate air to the third belt hence facilitating cool. Side nozzles are also provided to facilitate further cooling. The first belt has a width of 11cm the second 65cm and the third 105cm.the driver power consumption is 1 HP, the blower power consumption is 5 HP, the weight is approximately 1560 kilo grams. The eighth type is the double side twist wrapping machine. It is for packing hard candies. The machine is capable of using all packaging materials which are used for commercial purposes. It is feed with both inner and outer wrappers. The candies are charged from their place of release into S.S Hopper. This is automatically done by a vibrator. The candies are chopped into appropriate sizes and wrapped thereafter. The rubber gripper holds them in place and some mechanical twisting fingers are responsible for the twisting operation. They are of different technical specifications but the most common specifications are; 300-325 wraps per every minute, 1.1 kilo watts motor rating, 1200 kilo grams in wait, and 250 mm packing dimensions (Dictionary of food science and nutrition, 2006). The ninth type of heat exchanger in confectionery industry is the blade grinding machine. It is presented to us as being easy to operate. This is an advantage by itself. It is used to grind candy and toffee wrapping papers (United States, Hodgson, Hunziker, & Dahlberg, 1942). Its most significant advantage is that it does not occupy more space. The specifications of the machine can be easily changed on request. The most common has a motor rating of 0.5 HP, a weight of 100 kilo grams, and friendly dimensions of approximately 650 by 650 by 750 mm (L x W x H). Its advantage is the ease to operate, less space occupation, and the fact that it comes in different size is also an advantage attached to it. Conclusion In conclusion, we have a variety of heat exchangers which are mostly used in fruit and vegetable processing industries, dairy industries and confectionery industries. The overall advantages pertaining to these exchangers are; the simplicity in operation, the ease to interchange, flexibility, and prolonged usage. The services of obtaining these exchangers are available on-line. Prior to any purchase, it is advisable to put into consideration the different factors in play. First, one should verify the credibility of the supplier. Secondly, the purpose of the machine i.e. whether it is to be used for large scale or small scale production, thirdly, the buyer should consider the specific features the he/she is looking for. Fourthly, it is good to consider the ease in the usage of the exchanger. The fifth consideration should be the price. It is logic to go for what you can afford. Different sizes and qualities will have different costs. References Beyer, M. (1985). The dairy industry. Canberra: Dept. of the Parliamentary Library. Burch, D., Rickson, R. E., & Lawrence, G. (1996). Globalization and agri-food restructuring: Perspectives from the Australasia region. Aldershot, Hants, UK: Avebury. Critical reviews in food science and nutrition. (1980). Boca Raton, Fla: CRC Press. Derossi, A., Fiore, A. G., De, P. T., & Severini, C. (January 01, 2011). A Review on Acidifying Treatments for Vegetable Canned Food. Critical Reviews in Food Science and Nutrition, 51, 10, 955-964. Derossi, A., Fiore, A. G., De, P. T., & Severini, C. (January 01, 2011). A Review on Acidifying Treatments for Vegetable Canned Food. Critical Reviews in Food Science and Nutrition, 51, 10, 955-964. Dictionary of food science and nutrition. (2006). London: A. & C. Black. Keogh, M. K., Twomey, M., Teagasc (Organization), & Dairy Products Research Centre. (2001). Dairy ingredients for chocolate and confectionery. Dublin: Teagasc. New Zealand. (2010). Dairy Industry Restructuring (Raw Milk Pricing Methods) Bill: Departmental report. Wellington, N.Z.: Ministry of Agriculture and Forestry. OECD Workshop on Agro-Food Policies in Estonia, Latvia and Lithuania. (2002). Global trends in the dairy industry: Outlook for the Baltics. Paris: Organization for Economic Co-operation and Development. Schwarzweller, H. K., & Davidson, A. P. (2000). Dairy industry restructuring. New York: Jai. United States., Hodgson, R. E., Hunziker, O. F., & Dahlberg, A. C. (1942). The dairy industry. Washington: U.S. Dept. of Agriculture, Agricultural Research Administration, Bureau of Dairy Industry. Read More