Rotary Dryer Roaster in Continuous Drying and Roasting

Rotary dryer Roaster is a continuous multi-zone convection system that has best drying/roasting in a mild and sanitary manner. First-in, first-out production and even heating with a sensible, step-spiral, and flighted drum design achieves uniform drying and roasting.

Energy-efficient, product-focused heating maximizes heat transfer and reduces heat loss with heated air that’s focused solely into the product bed and nowhere else. Positive temperature control offers unmatched product uniformity because the dryer/roaster automatically regulates its own internal temperature. A variety of product characteristics is feasible by utilizing multiple processing zones.

Ideal Applications:

  • Nuts and dough-coated nuts
  • Seeds
  • Jerky
  • Meat chips and protein-based snacks
  • Pet treats
  • Pellet snacks
  • Pork rinds

Satisfy a diverse and demanding consumer palette with a range of product characteristics created possible by a customizable array of distinctive processing zones that severally control temperature and air flow. Maximize heat transfer and reduce heat loss with heated air that is focused into the product bed and nowhere else.

The Rotary Dryer Roaster (RDR) from Heat and Control is designed to provide snack food operators with a complete end-to-end solution for the dry roasting of nut and seed products.

The RDR multizone convection dryer/roaster system uses the latest technological advances in dry roasting so food processors can continuously process high volumes of snack foods, such as nuts, seeds and protein/meat-based snacks.

The unit provides operators with complete control to dry or roast in a continuous, gentle and sanitary manner with optimal quality and uniform results.

Along with nut products, the RDR is also suitable for applications such as the drying of meats and poultry to create jerky and meat chips, as well as drying pet products to create food and treats.

Kerone provides a whole vary of snack line capabilities for seasoned and coated nut snacks, as well as frying, dryer/roasting, seasoning, coating, conveying, weighing, packaging, case packing, examination and controls.

The Rotary Dryer Roaster is meant to supply high volume processing of various product whereas ensuring uniform results.

Target Applications

  • Dry roasting of nuts and seeds, including dough coated styles
  • Drying of meat and poultry to create products such as jerky and meat chips
  • Drying of pet products to create food and treats

With thousands of food processing applications worldwide and testing centers to support your needs, Kerone will bring information, experience, and technology to your next project.

We at KERONE have a team of experts to help you with your need for Rotary Dryer Roaster for Continuous Drying in various products range from our wide experience.

The Drying of Foods and Its Effect on the Physical-Chemical

Drying of foods is an ancient practice that has been adopted to preserve foods beyond their natural period of time. The method started with the exposure of foods to the sun, to extract from them an excellent proportion of the water, so contributing for their conservation. the standard solar dying with direct exposure to the sun had several disadvantages and presently more modern ways are used, like hot air drying, spray drying, lyophilization, infrared, microwave or radiofrequency drying, osmotic dehydration or several combined processes. Many foods may be preserved through drying; however their organoleptic and nutritional properties are greatly altered as compared to the fresh counterparts.

Among the many ways used for food conservation, drying is definitely the most ancient however still much used today. It’s a method by that water is removed from the food, by vaporization or sublimation, so reducing the water available for degradation reactions of chemical, enzymatic or microbial nature. The drying rate is influenced by transfer mechanisms, like the vapor pressures of the food and of the drying air, temperature and air velocity, moisture diffusion within the product, thickness and surface exposed for drying.

The main objectives of drying include to preserve foods and increase their period of time by reducing the water content and water activity; avoid the requirement for use of refrigeration systems for transport and storage (expensive); reduce space necessities for storage and transport; diversify the provision of foods with totally different flavors and textures, so providing the consumers a good selection when buying foods.

There are several advances in drying technology in latest years, as well as pretreatments, techniques, equipment and quality of the final product. The pretreatments, for instance, are used with the aim to accelerate the drying method, enhance quality and improve the safety of foodstuffs. Besides they also help decreasing energy needs.

 There are hundreds of types of dryers, based on different principles of operation.

  • Solar Drying

 In solar drying the energy source is the sun. Therefore it is a very cheap drying method, but on the other hand it has many drawbacks because the food is exposed to contamination sources (insects, birds and other animals) and is also strongly susceptible to weather conditions.

  • Hot Air Convective

Drying the convective drying of porous media, including foods, has a pivotal role in several industrial applications. Owing to its high availability and moisture saturation capacity, the air is undoubtedly the most used drying fluid.

  • Spray Drying

Spray drying is a widely used technique to convert a liquid state into a powder form. It is used for solutions or slurries that go through an atomizer or spray in order to divide the material into droplets (10-200 mm). The quality of spray-dried microcapsules is quite dependent on processing parameters of the spray dryer and properties or composition of the feed solution.

  • Lyophilization

In lyophilization, also called freeze-drying or freeze dehydration, the water is first frozen and then sublimated, under special conditions of pressure and temperature. Lyophilization is slower and with higher costs, because it involves freezing, the production of vacuum and the equipment is itself expensive.

  • Infrared Drying

 In infrared drying, the solid food is exposed to a source of infrared heating increasing the temperature of its surface. Because most of the solids have a low thermal conductivity, the rate of heat conduction to the interior is very slow. Hence, the application of infrared radiation primarily intends the surface treatment of foods.

  • Microwave Drying

 This method provides a high heating rate and does not originate alterations on the surface of the food and hence no crust is formed. The industrial microwave treatment is limited due to its high cost and to the need to synchronize the generator for different foods. Thus, it is used industrially for low moisture foods, or as a final stage of the dehydration process.

  • Radiofrequency

Drying the use of radiofrequency energy for dielectric heating of food materials is an important application area, which has been studied as a possible method for drying agricultural products. The radiofrequency heating addresses directly the product, so that its interior is heated faster than its surface. The water is released without overheating or dehydration of the surface. Therefore, it can be used as a complement to other drying processes, and allows reaching very low humidity levels, of the order of 1 to 2%, with minimal impact on quality. This novel drying method provides shorter time, higher energy efficiency and better product quality as compared to conventional hot air heating.

  • Osmotic Dehydration

 Osmotic dehydration is based on the principle that when cellular materials are immersed in a hypertonic aqueous solution, a driving force for water removal sets up because of the higher osmotic pressure of the hypertonic solution. It is generally used for partial removal of water from fruits or vegetables which are immersed in a sugar or salt solution. The food loses water to the solution but in many cases its final moisture content is not stable.

  • Combined Processes

 There are many conventional drying methods used in post-harvest technology including solar drying, osmotic dehydration, vacuum drying, hot-air drying, fluidized bed drying, and freeze drying. However, most of these drying techniques involve longer drying time and high amount of energy, resulting in poor quality of the dried products. It has been suggested a new way of improving the existing conventional drying processes based on self-heat recuperation technology. However this method, which focuses mainly on increasing the energy efficiency of the drying process, is complex and expensive to adapt.

  • Fruits

Many fruits have been for long dried in the sun, including grapes, figs, dates, pears, peaches and apricots. Nevertheless, the hot air for drying is also amply applied to fruits such as apple slices, apricot halves, pineapple slices or pears in halves or quarters. Other drying methods like vacuum drying or combined methods can be used to dry fruit, such as kiwi, mango and banana. The osmotic dehydration is applied to orange, pineapple, kiwi, apple, cherry, papaya, coconut, and strawberry, among many others.

In general fruits are not blanched but are sulphited by exposure to vapors resulting from the burning of sulphur, to control minimize browning reactions. Fruit purees can be drum dried to obtain powders or flakes, like in the case of banana, apricot, mango and peach. Some of these products are hygroscopic and sticky, so it is beneficial to add glucose syrup to facilitate removal of the product from the drum and its subsequent handling. For the drying of fruit juices can be used atomization or spray drying.


The drying operation may be a very ancient practice for food preservation, however rather than being abandoned presently it continues very important process of treatment for wide-ranging food products. A lot of innovation and technological advancements have led to higher drying processes, more efficient in energetic terms and allowing a much better preservation of the organoleptic and nutritional qualities. The applicability of the method to a wide range of foods, with numerous characteristics renders this operation a prominent position within the process of food industries.

We at KERONE have a team of experts to help you with your need for Drying in various products range from our wide experience.

Injection Moulding Process and Advantages

Injection molding is a manufacturing process for producing components by injecting melted material into a mould, or mold. Injection molding will be performed with a bunch of materials mainly including metals, glasses, elastomers, confections, and most typically thermoplastic and thermosetting polymers. Material for the half is fed into a heated barrel, mixed, and injected into a mould cavity, where it cools and hardens to the configuration of the cavity. When a product is designed, typically by an industrial designer or an engineer, moulds are created by a mould-maker from metal, typically either steel or aluminium, and precision-machined to create the features of the specified part. Injection molding is widely used for manufacturing a range of elements, from the tiniest elements to entire body panels of cars. Advances in 3D printing technology, utilizing photopolymers that don’t soften throughout the injection molding of some lower-temperature thermoplastics, will be used for a few easy injection moulds.

Injection molding uses a special-purpose machine that has 3 parts: the injection unit, the mould and therefore the clamp. parts to be injection-molded should be very carefully designed to facilitate the molding process; the material used for the half, the specified form and options of the half, the material of the mould, and therefore the properties of the molding machine should all be taken into consideration. The versatility of injection molding is facilitated by this breadth of design considerations and possibilities.


A mold is a hollow metal block into which molten plastic is injected to from a certain fixed shape. Although they are not illustrated in the figure shown below, actually there are many holes drilled in the block for temperature control by means of hot water, oil or heaters.

Molten plastic flows into a mold through a sprue and fills cavities by way of runners and gates. Then, the mold is opened after cooling process and the ejector rod of the injection molding machine pushes the ejector plate of the mold to further eject moldings.


A molding consists of a sprue to introduce molten resin, a runner to lead it to cavities, and products. Since obtaining only one product by one shot is very inefficient, a mold is usually designed to have multiple cavities connected with a runner so that many products can be made by one shot.

If the length of the runner to each cavity is different in this case, the cavities may not be filled simultaneously, so that dimensions, appearances or properties of the moldings are often different cavity by cavity. Therefore the runner is usually designed so as to have the same length from the sprue to each cavity.

Injection molding is used to create many things such as wire spools, packaging, bottle caps, automotive parts and components, toys, pocket combs, some musical instruments, one-piece chairs and small tables, storage containers, mechanical parts, and most other plastic products available today. Injection molding is the most common modern method of manufacturing plastic parts; it is ideal for producing high volumes of the same object.

Usually, the plastic materials are formed in the shape of pellets or granules and sent from the raw material manufacturers in paper bags. With injection molding, pre-dried granular plastic is fed by a forced ram from a hopper into a heated barrel. As the granules are slowly moved forward by a screw-type plunger, the plastic is forced into a heated chamber, where it is melted. As the plunger advances, the melted plastic is forced through a nozzle that rests against the mould, allowing it to enter the mould cavity through a gate and runner system. The mould remains cold so the plastic solidifies almost as soon as the mould is filled.

Different types of injection molding processes

Although most injection molding processes are covered by the conventional process description above, there are several important molding variations including, but not limited to:

  • Die casting
  • Metal injection molding
  • Thin-wall injection molding
  • Injection molding of liquid silicone rubber[23]:17–18
  • Reaction injection molding
  • Micro injection molding
  • Gas-assisted injection molding
  • Cube mold technology

Robotic molding

Automation means that the smaller size of parts permits a mobile inspection system to examine multiple parts more quickly. In addition to mounting inspection systems on automatic devices, multiple-axis robots can remove parts from the mould and position them for further processes.

Specific instances include removing of parts from the mould immediately after the parts are created, as well as applying machine vision systems. A robot grips the part after the ejector pins have been extended to free the part from the mould. It then moves them into either a holding location or directly onto an inspection system. The choice depends upon the type of product, as well as the general layout of the manufacturing equipment. Vision systems mounted on robots have greatly enhanced quality control for insert molded parts. A mobile robot can more precisely determine the placement accuracy of the metal component, and inspect faster than a human can.

Finally, you must seek for an injection molding business which will handle huge projects. once you got to scale up production, you don’t wish to have to seem for a brand new supplier just because the company turned out to be incapable of doing larger runs.

We at KERONE have a team of experts to help you with your need for Injection Molding Process in various products range from our wide experience.

Infrared heating in food industry

Energy conservation is one of the key factors determining profitability and success of any unit operation. Heat transfer occurs through one of three ways, conduction, convection, and radiation. Foods and biological materials are heated primarily to increase their shelf life or to boost taste. In conventional heating that is achieved by combustion of fuels or by an electrical resistive heater heat is generated outside of the item to be heated and is sent to the material by convection of hot air or by thermal conduction. By exposing an object to infrared (IR) radiation, the heat energy generated will be absorbed by food materials. Together with microwave, radiofrequency (RF), and induction, IR radiation transfers thermal energy within the form of electromagnetic (EM) waves and encompasses that portion of the EM spectrum that borders on visible radiation and microwaves. Bound characteristics of IR heating like efficiency, wavelength, and reflectivity set it except for and build it more effective for some applications than others. IR heating is additionally gaining popularity because of its higher thermal efficiency and quick heating rate/response time as compared to conventional heating. Recently, IR radiation has been widely applied to numerous thermal processing operations within the food industry like dehydration, frying, and sterilization.

The amount of the IR radiation that is incident on any surface has a spectral dependence because energy coming out of an emitter is composed of different wavelengths and the fraction of the radiation in each band, dependent upon the temperature and emissivity of the emitter. The wavelength at which the maximum radiation occurs is determined by the temperature of the IR heating elements. This relationship is described by the basic laws for blackbody radiation such as Planck’s law, Wien’s displacement law, and Stefan–Boltzman’s law.

The effect of IR radiation on optical and physical properties of food materials is crucial for the design of an infrared heating system and optimization of a thermal process of food components. The infrared spectra of such mixtures originate with the mechanical vibrations of molecules or particular molecular aggregates within a very complex phenomenon in overlapping.

The application of infrared radiation to food processing has gained momentum due to its inherent advantages over the conventional heating systems. Infrared heating has been applied in drying, baking, roasting, blanching, pasteurization, and sterilization of food products.

Drying and dehydration Infrared heating provides an imperative place in drying technology and extensive research work has been conducted in this area. Most dried vegetable products are prepared conventionally using a hot‐air dryer. However, this method is inappropriate when dried vegetables are used as ingredients of instant foods because of low rehydration rate of the vegetables. Freeze‐drying technique is a competitive alternative; however, it is comparatively expensive.

Application of FIR drying in the food industry is expected to represent a new process for the production of high‐quality dried foods at low cost. The use of IR radiation technology for dehydrating foods has numerous advantages including reduction in drying time, alternate energy source, increased energy efficiency, uniform temperature in the product while drying, better‐quality finished products, a reduced necessity for air flow across the product, high degree of process control parameters, and space saving along with clean working environment.

Two conventional types of infrared radiators used for process heating are electric and gas‐fired heaters. These 2 types of IR heaters generally fit into 3 temperature ranges 343 to 1100 °C for gas and electric IR, and 1100 to 2200 °C for electric IR only. IR temperatures are typically used in the range of 650 to 1200 °C to prevent charring of products. The capital cost of gas heaters is higher, while the operating cost is cheaper than that of electric infrared systems. Electrical infrared heaters are popular because of installation controllability, ability to produce prompt heating rate, and cleaner form of heat. Electric infrared emitters also provide flexibility in producing the desired wavelength for a particular application.

IR heating is a unique process; however, presently, the application and understanding of IR heating in food processing is still in its infancy, unlike the electronics and allied sector where IR heating is a mature industrial technology. It is further evident from this review that IR heating offers many advantages over convection heating, including greater energy efficiency, heat transfer rate, and heat flux that results in time‐saving as well as increased production line speed. IR heating is attractive primarily for surface heating applications. In order to achieve energy optimum and efficient practical applicability of IR heating in the food processing industry, combination of IR heating with microwave and other common conductive and convective modes of heating holds great potential. It is quite likely that the utilization of IR heating in the food processing sector will augment in the near future, especially in the area of drying and minimal processing.

We at KERONE have a team of experts to help you with your need for Infrared Heating in food industry in various products range from our wide experience.

PET Flakes Crystallizer and Dryer

PET is highly hygroscopic and absorbs moisture from the atmosphere. Tiny amounts of moisture can hydrolyse PET within the melt part, reducing molecular weight. PET should be dry just prior to processing, and amorphous PET needs crystallization prior to drying so that the particles don’t stick together as they’re going through glass transition.

Hydrolysis can occur due to moisture and this often can be seen as a reduction in the IV (Intrinsic Viscosity) of the product. PET is “semi-crystalline”. When the IV is reduced, the bottles are more brittle and tend to fail at the “gate” (injection point) during blowing and filling. It is very possible that due to the initial moisture level in the resin, and the amount removed during vacuum that a significant amount of moisture still remains as it is reaching its melt phase in the extruder.

In its “crystalline” state it has both crystalline and amorphous portions in its molecular structure. The crystalline portion develops where the molecules can align themselves in a very compact linear structure. In the non-crystalline regions the molecules are in a more random arrangement. By insuring that your crystallinity is high, prior to processing, the result will be a more uniform and higher quality product.

Another thing to consider is the number of times the PET has been processed. Each time the PET is processed there is a reduction in IV. Therefore, PET that has been used to make a bottle, recycled and used again, does not have the IV of the original bottle. Each time the bottle is recycled, the IV is further reduced. This is why a percentage of virgin resin is often added to increase the products properties.

Flake size is determined by the grinder. I have seen customers who think that ¼ inch is perfect and those who think ¾ is best. The smaller the flake the more fines will be produced and the better the material will flow in the drying hopper and vacuum chambers. Extremely fine grinds tend to lead to higher pressure drop in the hopper and can cause reduced air flow and uneven distribution. Large grinds can sometimes cause uneven hopper material flow.

60% regrind or more is common in extrusion. Most bottle applications are less than 10% for food and beverage and less than 30% otherwise. It depends on the source of the regrind and the end product. Blow molding is more difficult when you use material with different heat history and IV. Fines can also cause processing problems.

The disadvantage of using regrind versus virgin resin is that regrinds have a heat history and have a significantly lower IV (Intrinsic Viscosity). Lower IV in the finished part causes it to be more brittle/less flexible. The second disadvantage is that there tends to be more “yellowing” in regrind materials that can cause a color or haziness issue.

It is more important to remove the moisture than to heat it. However, it is very difficult to measure moisture on-line in a process so time and temperature is generally used to set the moisture level achieved. For instance, with PET processing, it is generally assumed that if there is 4-6 hours in the drying hopper at 325-350° F, the moisture will be reduced to less than 50 ppm.

After the PET has been formed into a sheet, there isn’t typically any additional pre-conditioning required before thermoforming. The sheet will undergo heat in the thermoforming and as long as it doesn’t approach the melt temperature the process just changes the shape of the already formed sheet and the stresses imparted to the sheet tend to give it strength.

In general, crystallizing master batch can have a lot of drying/crystallizing issues. Unless the quantity is so large that you can afford to purchase a crystallizer, buying crystallized master batch is probably preferred.

We at KERONE have a team of experts to help you with your need for PET flakes crystallizer and dryer in various products range from our wide experience.

How to compost food waste and use as organic fertilize

Composting is the natural process of decomposition and recycling of organic material into a humus-rich soil amendment known as compost. Food waste is composed of organic matter which can be used for composting to make fertilizer. It is an effective and eco-friendly way of disposing of food waste in your kitchen.

By using leftovers and other food waste, you can convert these smelly items from the kitchen waste into a highly organic product rich in nutrients that you can use to grow vegetables or flowers with it. Things like paper, twigs, and leaves are rich in carbon while grass, coffee, and tea grounds, fruit, and vegetables are rich in nitrogen. The proper mixture is key to good compost.

Why use food waste as fertilizer?

Food waste is a major challenge in the present world, tons of food is thrown away in the garbage. We could use all the food waste and prepare compost out of them which can be used as organic fertilizer. This way we save the earth from the pollution caused by food waste and also do something productive.

Food waste is unique as a composting agent; it is the main source of organic matters. Fruits, vegetables, grains, coffee filters, eggshells can be composted.

How to prepare the compost:

  • Collect and separate your edible kitchen waste (vegetable peels, fruit peels, and small amounts of wasted cooked food) in a container.
  • Now collect some dry organic matter like dried leaves, sawdust, and wood ash in a small container
  • Take a big container or earthen pot or a bucket and drill 4 5 holes around the container at different levels to let air inside.
  • Now fill the bottom of the container with a layer of soil.
  • Now start adding food waste in layers alternating wet waste (food scraps, vegetable, and fruit peels) with dry waste (straw, sawdust, dried leaves).
  • Cover this container with a plastic sheet or a plank of wood to help retain moisture and heat.
  • Check the container every few days and if you think the pile is too dry, sprinkle some water so that it is moist.

You can also add wood ash and sawdust to the compost to help speed up the composting process. Vegetables and fruit peelings are the number one food remnants you should use. To come up with a nutrient-rich fertilizer, you need to add some natural waste to your compost like the grass clippings and leaves from your lawn.

The next is drying and cooling process, organic fertilizer drying and cooling usually can be combined together. After granulating, the organic granules are often with high moisture and heat, for making better quality organic fertilizer, the content of them should be reduced to a certain percentage.

Rotary drum fertilizer dryer is used to dry organic fertilizer granules and after drying, the moisture content can be decreased to 10%. And about organic fertilizer granules cooling, fertilizer rotary drum cooler will help remove the heat for granules. Granules enter from the inlet and cooling air enter from outlet join adversely. The fertilizers of low temperature will be discharged through outlet after transferring the heat to the cooling air. It can greatly improve cooling rate.

We at KERONE have a team of experts to help you with your need for organic fertilizer in various products range from our wide experience.

Heat and Mass Transfer Modeling for Fruit Drying

Drying is an efficient technique for fruit storage/preservation. Drying may retain quality end product that is difficult, because all fruits are variable in structure, so, heat and mass transfer modeling (operating parameters) is a helpful technique to deal with it. This could only be done by selecting the proper sort of drying equipment and understanding the science behind the drying method as well as thermal properties of fruit. Drying method have several effects on different heat sensitive fruits elements and equipment (sensors etc.) also that result into increase in maintenance price, diffusion rate goes to critical limits etc. Because, choice of an acceptable drying technique and equipment is most significant regarding product quality and its amount. Modeling of a drying method considering different drying parameters and their effects on final quality of product and economic importance are mentioned here. we must always have information regarding the drying mechanics. So, that knowledge of heat and mass transfer method for fruit drying helps to identify best operating conditions and saves the most quantity of energy.

Food is the necessity for mankind as it provides energy, growth, and repair to the body. Fruit is an agricultural commodity and most of the agricultural commodities are seasonal. Fruits are present in bulk amount during their season, but during the offseason, this seasonal fruit is unavailable because it gets wasted due to improper storage techniques. About 40% of the fruits production in Pakistan was wasted due to improper handling and preservation techniques. Fruit production in Pakistan in 2016–17 is 5,685,000tons and 440,000tons were exported and 2,274,000tons get wasted. To make food secure one should reduce post–harvest losses. Fruits get wasted due to improper harvesting, transportation, processing, and preservation methods. Agricultural products are sometimes categorized on the basis of water contents present in them; perishable, semi–perishable and non–perishable products. For few days fruit can be save according to its shelf life (perish ability value), but after these days sensory parameters like taste, flavor, texture, color degrades and finally, fruit becomes unable to eat. In order to prolong its shelf life for months, dry it by proper means and in a hygienic environment.

Drying is a unit operation that is carried out to preserve fruit, instead of a unit process, which is a chemical process. Drying is the removal of moisture from fruit products up to a certain level and dehydration is the bone–dry condition of that product. Drying is a physical process performs to stabilize fruit as biological changes in fruit lead to deterioration. Cost of transportation decreases and handling becomes easy as its weight and volume reduces, consumption is followed with calculated rehydration.

Objectives of drying:

Drying slows down the microbial and enzymatic activity by lowering water activity. Apple has a water activity of 0.85–0.95 and drying reduces water activity to about 0.5.2 Fruits are dried due to many reasons; to consume seasonal fruits and to export these products in non–production areas of such fruits. Dried fruits enhance the taste of food products when used as food formulations in many food products such as ice creams, frozen desserts, sweets, bakery products, baby foods, jellies, crackers, horseradish, miscellaneous, and sauces etc.

Heat transfer:

Temperature difference is the driving force for heat transfer. So, heat transfer exchanges thermal energy from high concentration to low concentration between physical systems. There are three modes of heat transfer namely, conduction, convection, and radiation.

Specific heat:

Quantity of heat required to change a unit temperature of unit mass of product, without changing in its original state.

Thermal conductivity:

Quantity of heat is conducted through per unit thickness, per unit time of the product, if two materials having a unit temperature difference.

Thermal diffusivity:

Ratio of thermal conductivity to specific heat and density.

Mass transfer:

Mass transfer is the movement of chemical species from high concentration region to low concentration region and the presence of these two regions are necessary, but fluid flow moves from one location to another and occurs on a macroscopic level

Drying process:

Drying is a coupled heat and mass transfer mechanism. There are different types of drying units/machinery used in this modern era. Food Engineers are working very hard to develop more efficient methods for drying of perishable agricultural products that least alter its quality.

Fruit in its biological structure is variable and complex so every fruit needs a different model to dry it by retaining quality, which is challenging. So, modeling and simulation is a useful technique to deal with it. Mathematical model based on heat and mass transfer is used to study the behaviour of drying operation.

Fruits due to high water content and heat sensitive compounds in it are tough to dry, by maintaining quality. Understanding heat and mass transfer process and its parameters are mandatory for the drying processes, which minimally have an effect on the sensory and different quality parameters of edible fruit. Calculations for heat and mass transfer greatly help to optimize the efficiency of drying unit, drying rate and as well as reduces energy consumption, it additionally helps to identify the most appropriate operating conditions.

We at KERONE have a team of experts to help you with your need for Heat Transfer in various products range from our wide experience.

Evaluation of food drying with air dehumidification system

The main challenge in global food demand is how to obtain high quality dry food products in efficient processing. The dry food or its extract can be a good option due to the long life storage and consumer convenience. To realize this preference, drying process offers the major role corresponding to the moisture removal from wet product. In general, the agriculture and food products with high moisture content (vegetables, herbs, starch products) are dried at low to moderate temperatures to conserve the valuable ingredients (protein, vitamins, enzymes, oil) as well as physical appearance such as color, and texture.

Meanwhile, the modern drying technology has been widely developed with attractive results in the product quality aspects. However, the efficient dryer development has been scared. For example, the energy efficiency in freeze and low temperature dryers is lower than that of a conventional convective dryer. This is due to the low value of driving force for moisture transfer and higher latent heat of moisture evaporation. Recently, the energy usage has become an important issue with respect to the limitation of fossil fuel supply. On the other hand, the availability of biomass as side product of agriculture crops has not been intensively used as renewable energy resource in drying process.

Conventional dryer with sunlight is very advantageous due to its low energy cost, and environmentally benign. The dryer has been widely used for a long time in various sectors, such as agriculture, fishery, forestry, and herbal medicine products. Unfortunately, the uses of this dryer is also restricted by main drawbacks of this dryer such as sustainability and product quality, which are rooted from its climate dependent.

Thus, the application of dryer with pre-dehumidified air for various food or agriculture crops drying can be an attractive option.

Materials and Methods

Based on the model and simple experimental test, the adsorption dryer with zeolite has shown attractive performances. In this study, the dryer was tested in wider range application for agriculture crops drying. This work consisted of two main steps. Firstly, the two types of dryer (fluidized bed and tray dryers) were constructed in laboratory scale equipped with an air dehumidification section with zeolite. The dryers were used for different application (fluidized bed dryer for paddy drying, and tray dryer for onion drying). Secondly, the dryers performances were evaluated based on product quality, drying time, and or/ heat efficiency. The heat efficiency was estimated referring to the total heat used for evaporated water divided by the total heat introduced in the system. The product quality was analyzed based on physical properties as well as important substance content.

Paddy Drying

The paddy drying system was designed as a fluidized bed dryer. The dryer was equipped with a blower to deliver air for the fluidization process. Initially, ambient air at a relative humidity (RH) of 70 – 80% and temperature about 30°C was flown to the heater at a velocity of 4.0 m.s-1. The air was heated up to dryer temperature (designed as 40°C). The air was then used for paddy drying with initial moisture content of about 25% (w/w).

Onion Drying

Generally, onion was harvested from a farm with 88 – 92% moisture content. After drying, the average moisture content in the onion was desired to be 80 – 85%. The onion drying was conducted in tray dryer completed with zeolite, as presented. The fresh air was heated up to 50°C by an electric heater. The air was used for onion drying with addition of a zeolite pack.

Heat Efficiency Estimation

The paddy and onion drying were continued with rice husk combustion as a heat source. The rice husk with combustion heat value up to 15 was obtained as a side product of rice mill industries. Theoretically, with latent heat of moisture evaporation about 2.5 , one kilogram of rice husk can evaporate 6 kg of free moisture.


The air dehumidification has been applied for tray and fluidized bed dryers. The dryers were used for paddy and onion drying. The zeolite as moisture adsorbent performed well. Therefore, the air may be significantly dehumidified. Based on product quality retention, drying time estimation, and heat utilization, the air dehumidification affected the drying performance positively. The fluidized bed and tray dryers were then operated with rice husk as a heat supply. Results showed that the heat efficiency can achieve around seventy fifth. This performance may be promising for sustainable food drying development.

We at KERONE have a team of experts to help you with your need for air dehumidification in various products range from our wide experience.

Validation of Dry Heat Sterilization Processes

Dry Heat Sterilization is a sterilization process that can be used to terminally sterilize health care products, medical devices, equipment, components or bulk active pharmaceutical ingredients by exposing the items to a temperature of ≥ 160°C for a defined time.

For heat stable items, such as glassware or stainless steel equipment, a dry heat sterilization cycle can be run at 250°C to remove bacterial endotoxins from the items. This process is also referred to as Depyrogenation. Bacterial endotoxins are fever inducing compounds, or pyrogens, that are released when the cell walls of gram negative bacteria such as Escherichia coli are destroyed.

Validation of dry heat sterilization cycle(s) is required by ANSI, AAMI, ISO, USP and the FDA to ensure that all items that are required to be sterile or pyrogen free are able to consistently and reliably be sterilized to reduce the chance of introducing or spreading an infectious microorganism or pyrogen.

Installation Qualification (IQ)

Validation of a dry heat sterilization cycle begins with the execution of the Installation Qualification (IQ) protocol on the equipment (oven, tunnel, or cabinet) which will be used to perform the dry heat sterilization. The IQ protocol verifies and documents that the equipment is installed correctly and meets all of the manufacturer and user requirements. During the execution of the IQ protocol, the equipment drawings, calibration status of critical instruments, instrument and valve information, utility information, and standard operating procedures for the equipment are all confirmed.

Operational Qualification (OQ)

The next step in the validation of a dry heat sterilization cycle is the execution of the Operational Qualification (OQ) protocol of the equipment. The OQ protocol verifies and documents that the equipment is programmed and operating correctly, and is able to meet all of the manufacturer and user requirements. Execution of the OQ protocol involves verifying the parameters/settings (e.g. general system options, cycle length, airflow, sterilization temperature) of the dry heat sterilization cycle(s). It also ensures that the system alarms are operating correctly, that the equipment is functioning properly (e.g. verification that the control system functions as specified by the equipment manufacturer or system interlocks), and that the equipment is able to achieve and maintain the required sterilization conditions during the dry heat sterilization cycle(s).

Performance Qualification (PQ)

The execution of the IQ and OQ protocols covers the validation of the equipment. In order to validate a dry heat sterilization cycle, a Performance Qualification (PQ) protocol must be executed. The PQ demonstrates that the dry heat sterilization cycle(s) can repeatedly achieve the required Sterility Assurance Level (SAL) 1. In order to confirm that the necessary SAL can be reached, the dry heat sterilization cycle must be temperature mapped.

Temperature Mapping

To perform a temperature mapping, data loggers are placed throughout the equipment chamber (distribution data loggers) and the load being sterilized (penetration data loggers). In order to temperature map a depyrogenation cycle it is sometimes necessary to use thermal barriers to protect the data loggers from the extreme heat. All of the data loggers used should have at least a 3 point NIST-traceable calibration performed prior to use.

Kerone have the knowledge and experience needed to help you complete the IQ/OQ/PQ for your dry heat sterilization and depyrogenation equipment and processes. Our experts have your back, so you can rest assured that your dry heat sterilization or depyrogenation cycles are being completed – optimally, reproducibly, and consistently.

We at KERONE have a team of experts to help you with your need for Sterilization in various products range from our wide experience.

Effect of Drying Characteristics of Garlic

Natural sun drying is one of the most common ways to preserve agricultural product. the most purpose in drying farm manufacture is to reduce its water activity from the harvest level to the safe storage level in order to increase its shelf life. Once the product has been dried, its rate of deterioration because of respiration, insects, and microbial activity and biochemical reactions should diminish resulting in maintenance of quality of the stored product. It does improve bargaining position of the farmer to keep up comparatively constant value of his product. Drying reduces post-harvest losses and transportation prices since most of the water are taken out from the product throughout the drying method. In India, sun drying is the most typically used technique to dry the agricultural material like grains, fruits and vegetables. In sun drying, the garlic is spread in a very skinny layer on the bottom and exposed on to solar radiation, ambient temperature, wind velocity, relative humidity, initial moisture content, absorptive, exposure time and mass of product per unit exposed area.

Garlic is a bulbous perennial vegetable spice. The bulb is composed of pungent bolblets, commonly known as cloves. Garlic is a semi-perishable product. Due to lack of suitable storage and transportation facilities, about 30% of fresh crop is wasted by respiration and microbial spoilage. At times of shortages, India imports garlic of Chinese origin from Taiwan or via Nepal. Fresh garlic, dehydrated garlic flakes, dehydrated garlic powder and garlic oil is exported from India. India was once a leader in this field but is losing out to China in the overseas market. China has an edge over India in terms of both quality and quantity.

Food drying is one of the oldest methods of preserving food for later use. Food drying is a very simple, ancient skill. It is one of the most accessible and hence the most widespread processing technology. Sun drying of fruits and vegetables is still practiced largely unchanged from ancient times. Traditional sun drying takes place by storing the product under direct sunlight. Sun drying is only possible in areas where, in an average year, the weather allows foods to be dried immediately after harvest. The main advantages of sun drying are low capital and operating costs and the fact that little expertise is required. The main disadvantages of this method are as follows: contamination, theft or damage by birds, rats or insects; slow or intermittent drying and no protection from rain or dew that wets the product, encourages mould growth and may result in a relatively high final moisture content; low and variable quality of products due to over-or under drying; large areas of land needed for the shallow layers of food; laborious since the crop must be turned, moved if it rains; direct exposure to sunlight reduces the quality (colour and vitamin content) of some fruits and vegetables. Moreover, since sun drying depends on uncontrolled factors, production of uniform and standard products is not expected. The quality of sun dried foods can be improved by reducing the size of pieces to achieve faster drying and by drying on raised platforms, covered with cloth or netting to protect against insects and animals. In open sun drying, there is a considerable loss due to various reasons such as rodents, birds, insects and microorganisms. The unexpected rain or storm further worsens the situation. Further, over drying, insufficient drying, contamination by foreign material like dust dirt, insects, and micro-organism as well discolouring by UV radiation are characteristic for open sun drying. In general, open sun drying does not fulfil the quality standards and therefore it cannot be sold in the international market.

The major quality issues faced throughout garlic drying loss of flavour, discoloration and poor rehydration characteristics of the dried garlics. Garlic flavour and colour are usually perceived as important quality attributes. In drying, diffusivity is employed to indicate the flow of moisture from the material. in the filling rate amount of drying moisture removed is controlled mainly by molecular diffusion. Diffusivity is influenced by shrinkage, case hardening throughout drying, moisture content and temperature of the material.

Methods of Drying:

 Hot air drying

Hot-air drying of garlic slices in a common fixed bed method is unfortunately not suitable due to a significant decrease in the quality of dried product related to the fresh one. Applying high temperature (about 60°C) in a fixed bed drying causes an increase in drying period, energy consumption, color degradation and mass transfer.

Solar and Open sun drying

Recent efforts to enhance on sun drying have led to solar drying. Solar drying additionally uses the sun because the heat source. A foil surface within the dehydrator helps to extend the temperature. Ventilation speeds up the drying time. Shorter drying times reduce the risks of food spoilage or mold growth. it’s a complex operation involving heat and mass transfer which can cause changes in product quality. Physical changes which will occur include shrinkage, puffing and crystallization.

Infra-Red drying

Microwave and infrared (IR) drying are studied for achieving quick drying and reducing quality loss of fruits and vegetables. a mixture of hot air and microwave drying of osmotic dehydrated blueberries had similar or higher product quality compared with freeze-dried product with a lot of reduced drying time.

Fluidized bed drying

Thin layer drying properties of high moisture garlic sheets under semi fluidized and fluidized bed conditions with high initial moisture content (about 154.26% d.b.) were studied. Air temperatures of 50, 60, 70 and 80°C were applied to garlic samples. Among the applied models, Page model was the best to predict the thin layer drying behavior of garlic sheets.

Dried garlic Products

Garlic Powder: In Asian country thanks to lack of appropriate storage, transport and process facilities, significant losses are incurred both in terms of quality and quantity thanks to respiration, transpiration and microbiological spoilage. Through garlic is made abundantly and consumed as such, little efforts have so far been made to supply dehydrated garlic and garlic powder.


To obtain the dehydrated product of prime quality, the drying method should be specified it allows effective retention of colour appearance, flavour, taste and nutritive value, comparable to recent vegetables. The technique of drying is perhaps the oldest technique of food preservation practiced by human race for the extension of food period. The utilization of artificial drying to preserve agricultural commodities is increasing, making a requirement for a lot of fast drying techniques and ways that reduce the big quantity of energy needed in drying processes. Just in case of garlic is an antioxidant product used for many medicative purposes. New and innovation techniques that increase drying rates and enhance dried garlic quality are receiving substantial attention.

We at KERONE have a team of experts to help you with your need for Drying  in various products range from our wide experience.