A MULTIFUNCTIONAL PORTABLE SOLAR DRYER

TECHNICAL FIELD

The invention relates to portable, direct solar energy, drying systems, and apparatus for drying food in general, and more specifically solar dryer with integrated preheating, heat storage, and dehumidification units.

BACKGROUND

Drying with solar energy is carried out with drying in the sun, drying in the shade, dryers with heat generators (indirect), greenhouse-type indoor drying (direct) dryers, and hybrid dryers. The product dried in sun and shade drying applications is damaged by dust, soil, rain, and various insects, therefore, dryers that perform drying in a closed area are preferred.

In particular, solar hot air dryers are widely used in food drying. Especially in indirect dryers for photosensitive agricultural products for overcoming the drawbacks of direct solar drying, in general, the air is heated in a central place (for example, by a solar collector) and the heated air is conveyed with a duct system to the drying cabinet, which usually has a tray or trays on which the product can be placed, and has inletoutlet parts. In order to prevent heat losses caused by the use of ducts/pipes between the solar collector and the cabinet, the collectors are installed adjacent to the drying cabinet, in which case energy losses can be limited and cost savings can be achieved. However, such solar dryers are relatively bulky, so they may require a large area and some effort may be required to transport them from one place to another. It is relatively difficult to use where spatial requirements are partially important. Also, such dryers are more complex to design and cost more than the other type.

In addition to the systems mentioned above, there are also direct-type dryers that dry the product in a way that exposes it to direct sunlight. These type of dryers consists of a clean room (drying cabinet) with slot-like or hole-like inlet-outlet vents in a closed chamber to direct the hot air to the product to be dried and to discharge the moist air. Such conventional drying cabinets; are designed to consist of a box-shaped enclosure or glass cover placed at certain angles, wooden or insulated metal cabinet walls, filtered air inlets, and outlets, and generally one or more trays. In box-shaped ones, the transparent cover is placed either on the front (south) side or the top, in this case, sunlight does not reach the vertical or nearly vertical product throughout the year. Therefore, either the trays or the box-shaped cabinet, or both are positioned at an angle. There is no need to make an adjustment for those with an angled transparent cover. However, although PV panels and fans are added to box-shaped and angled solar dryers, they generally do not have efficiency-enhancing add-ons, so they only undertake the task of trapping and transferring solar energy to the product, rather than generating energy.

In direct solar drying, products are exposed to direct sunlight, which causes discoloration of agricultural products. The increase in the total heat energy in the cabinet causes deterioration of product quality due to the inability of the heat to escape to the atmosphere air, the glass cover in the dryer, and the development of long wavelength radiations. The moisture content in the product condenses on the glass cover in the early stages of drying, the moisture condensation on the glass surface reduces the transmission of sunlight into the cabinet, which after a while causes a decrease in the overall temperature of the drying area. The steam removal rate is poor, which affects the drying rate of the product relatively compared to other drying methods, and the insufficient increase in product temperature affects the dehumidification. In the opposite case, very high temperatures can be reached, which causes the product to overheat and deteriorate its quality of the product. In drying, besides drying characteristics such as drying rate, humidity rate, effective diffusion coefficient, activation energy, and rehydration rate, product quality is also extremely significant.

Typical prior approaches using a containment still require considerably longer times to obtain a uniform and suitable dry product. Since the insufficient drying rate continues to be a problem, it stretches the fast drying rule of the product, which is essential in drying. Therefore, the general object of the present invention is to reveal a newly developed portable multifunctional solar dryer that helps to overcome the above- mentioned shortcomings over previous dryers of the same general type. Another object of the present invention is to obtain a new and improved solar food dryer that is relatively complex in terms of manufacture and use but meets the required performance criteria. BRIEF DESCRIPTION OF THE INVENTION

The invention is a portable direct solar hybrid drying unit comprising;

- a mesh for placing the item to be dried and a tray with metallic materials on the sides of said mesh for drying the product,

- support legs on which the tray will sit and which contain heat storage material,

- a heat collector, such as a solar collector, on the rear wall, both as a door and as a heat sink plate on it,

- a glass cover that is placed in the protected area under the dryer cabinet by removing it from its special clips when the dryer is not in use, allows the solar radiations to enter, ensures that the heat is trapped in the cabinet, is placed at an angle,

- a heat storage reservoir placed inside the drying cabinet, the upper surface of which can be used as an absorber plate and containing heat storage material,

- Grilles that allow air to pass between the grid-shaped heat storage reservoir placed inside the drying cabinet and distribute the air evenly,

- the apparatus mounted on the upper wall, which acts both as a dehumidifier and as a fin to direct the heated air,

- reflectors that are located on both sides of the drying cabinet and transfer solar radiation into the dryer cabinet,

- an infrared (IR) lamp so that it can be used in areas close to the electricity source,

- a preheating apparatus with a reverse absorber plate added to the filtered air inlet,

- The condenser section embedded in the heat storage reservoir and multiple heat pipes comprising the evaporator section in the region that carries the solar radiation directed by the preheater to the reservoir,

- In case of an increase in energy need, can be converted to a mixed (direct and indirect) type dryer, by connecting a solar collector or a heat source,

- It can be easily transported by removing it from its special clips, can be moved thanks to its wheeled feet with brake, and can dry many products whose moisture is desired to be removed, except for liquid products. The drying process in solar dryers is highly dependent on changing weather conditions, which can lead to poor quality of the dried product. Therefore, the solar dryer, which is the subject of the invention, is integrated with a heat storage unit to store excess solar energy and eliminate fluctuations in air temperature by releasing heat when energy availability is insufficient in bad weather conditions and extend the daily usage time of the dryer beyond the hours of sunlight. The grid-shaped base heat storage reservoir in the aforementioned solar dryer and the heat storage unit, comprising shelf supports, are balancing factor that absorbs heat and prevents reaching extreme temperatures, on the one hand, it acts as a thermal support element that allows drying even when no energy is available from the sun. In addition, thermal support is taken when necessary from the support legs that extend holistically inside the cabinet where the tray will sit and contain heat storage material or that only serve as support at certain points.

The most effective features of this dryer are its portable structure that focuses on low cost and energy savings with new and effective apparatus and methods. On the other hand, thanks to the combination of a simple designed heat recovery unit and a secondary drying cabinet positioned above it and a PV panel placed on it, its capacity is increased and an additional unit in which special products can be dried is included in the dryer.

LIST OF FIGURES

Figure 1 . Perspective view of the solar dryer

Figure 2. Side section view of the solar dryer

Figure 3. Front section view of the solar dryer

Figure 4. External view of the primary (Main) cabinet

Figure 5. Perspective view of the primary (Main) cabinet

Figure 6. Top view of the placement of the heat storage reservoir and air distribution grids inside the cabinet

Figure 7. Exterior view of the door

Figure 8. Perspective view of the door

Figure 9. Top view of the door

Figure 10. Perspective view of the preheater reflector

Figure 11 . Front view of the preheater reflector

Figure 12. Side view of the preheater reflector Figure 13. Solar dryer trays

Equivalents of numbering used in figures:

100. Solar dryer

110. Bottom wall

111. Grid-shaped floor heat storage reservoir

1111. Heat storage material

1112. Heat storage reservoir absorber surface

1113. Heat storage reservoir absorber surface fins

1114. Perforated air distribution diffuser

112. Preheater

1121. Preheater reflector

1122. Preheater glass cover

1123. Preheater reverse absorber plate

1124. Preheater reverse absorber plate fins

1125. Heat pipe

1126. Air inlet

1127. Air intake duct filter

113. Infrared lamp group

114. Product tray

115. Clip-on glass cover housing compartment

116. Foot with wheels

120. Side wall

121 . Support bar

122. Side wall reflector that transfers solar radiation into the dryer cabinet

123. Side wall hinges

124. Side wall fixing pins

130. Front wall

131 . Front wall reflector that transfers solar radiation into the dryer cabinet

140. Back wall

141. Door

1411. Door handle

1412. Door absorber plate 1413. Door absorber plate fins

1414. Door hinges

142. Cleaning cover

143. Back wall hinges

144. Back wall fixing pins

145. Support legs (Rack) with heat storage material

150. Upper wall

151. Dehumidifier-directing curved wing

1511. Dehumidifying material

152. Clip-on glass cover

153. Fan(s)

154. Air outlet port

155. Heat recovery channel

156. Compass

160. A secondary drying cabinet with PV

161. PV panel

162. Product tray of drying chamber under the PV panel

163. Insulation plate that prevents heat escape to the PV panel

164. PV panel hinge

165. Fixed product tray

170. Control and monitoring unit

171. Wireless smart thermostat

172. Temperature meter

173. Humidity meter

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a dryer that can provide long-term preservation of moist (fresh) products that are whole, sliced, or ground, or remove moisture from the product in an economical way, in a waterproof and stainless structure, in which thermal solar energy is used as the main energy source and electrical power is used as an additional energy source, offering the great advantage of being used in different seasons, and a foldable via door hinges (1414), rear wall hinges (143), PV panel hinge (164) side wall fixing pins (124) and rear wall fixing pins (144). The invention comprises a solar dryer (100), which is the primary (Main) drying cabinet, the heat storage material (1111) and the dehumidifier apparatus, as well as the pre-heater (112), pre-heater reflector (1121 ), side wall reflector that transfers solar radiation into the dryer cabinet (122) and secondary drying cabinet with PV (160) located in the cabinet. There is a control panel that allows the values taken from the temperature meter (172) and the humidity meter (173) to be instantly monitored and adjusted to certain values. In addition, remote monitoring and control of the system can be done with the control and monitoring unit (170).

The inventive has the side walls (120) and rear wall (140) are foldable, or the side walls (120) and rear wall (140) of the dryer can be vertically fixed employing the side wall fixing pins (124) and the rear wall fixing pins (144). These are the most important features of the solar dryer (100). This dryer, which can be easily transported and installed, allows its use in places such as balconies or terraces if it is produced on a small scale, while it also provides the opportunity to be used in large areas or industrially if it is produced on a large scale.

The solar dryer (100) further comprises a trapezoidal geometry enclosure with a pair of mutually insulated side walls (120), a mutually insulated front wall (130), and a rear wall (140) connecting the respective end edges of the side walls (120) separately.

The prominent features of the product are briefly as follows; a) being portable, b) containing the condenser chambers embedded in the floor heat storage reservoir (111 ), the evaporator sections are the preheater reverse absorber plate (1123) which carries the solar rays directed by the parabolic preheater reflector (1121) to the grid-shaped floor heat storage reservoir (111 ) and multiple heat pipes (1125) combined with the preheater reverse absorber plate fins (1124), c) grid-shaped floor heat storage reservoir (111 ) and enlarged heat storage reservoir absorber surface fins (1113) to absorb heat on the reservoir, d) having a back wall (140) with an openable door (141) that allows the tray on which the product is placed to be placed and taken into the drying cabinet, and at the same time acts as an absorber plate with the door absorber plate fins (1413) on the surface facing the interior of the dryer, e) having a heat collector, such as a solar collector, on the back wall (140), due to the door (141), the heat sink door absorber plate (1412), and the door absorber plate fins (1413) on it, f) contains the side wall reflector that transfers solar radiation into the dryer cabinet (122) on both sides of the solar dryer (100) and the front wall reflector that transfers solar radiation into the dryer cabinet (131), g) comprises an upper wall-mounted dehumidifier-directing curved wing (151 ) that absorbs sunlight, controls humidity, and extends the airway, allowing to keep the heat inside for a longer time, h) having a secondary drying cabinet with a PV (160) with a heat recovery channel (155) for additional shade drying under the PV panel (161 ), i) having a temperature and humidity control, j) having an infrared lamp group (113) to be used when more heat and/or continuity is needed, k) comprises a detachable preheater reflector (1121 ). In case of an increase in energy demand and/or when a heat source is desired to be connected, by removing the preheater reflector (1121 ) mechanism, it can be converted into a mixed (direct and indirect) type dryer by connecting a solar collector or a heat source, l) there is a control and monitoring unit (170) that allows instantaneous monitoring of temperature, received temperature, and humidity values and sets them to certain values.

Compact structure, useful volume, combining different productivity-enhancing equipment, summer-winter modes, ability to be used after sunset, high drying rate, the structure that provides direct and indirect drying, heat and electrical energy generation feature, and increased absorbent surface areas, thanks to its multi-functional design, adaptation to the four-season climate, homogeneous and rapid drying of the products and providing the desired product quality, as well as the ease of assembly of the collector-like heat generator, the ease of transportation, its foldable feature, small footprint, and ease of transportation are superior features of the invention.

The subjects and equipment summarized above are detailed in the sections below.

Solar dryer (100); for conservatively drying an object to be dried, comprises a frame defining a clean room surrounded by the bottom wall (110), the left and right side walls (120), the back wall (140), the upper wall (150), and the front wall (130), which is smaller than the other walls. The clip-on glass cover (152) is removed and placed in the clip-on glass cover housing compartment (115) prepared for the glass under the cabinet. Both side walls (120) and back wall (140) fold inward and the front wall (130) remains stable. Thus, both the clip-on glass cover (152) is protected, and the solar dryer (100) is reduced to a more portable size by folding the back wall (140), upper wall (150), and side walls (120).

The insulated bottom wall (110); is provided with a preheater (112) and a gridshaped floor heat storage reservoir (111 ) with a heat storage reservoir absorber surface (1112) on its upper surface, infrared lamp group (113), a clip-on glass cover housing compartment (115) at the bottom of which the clip-on glass cover (152) can be placed when not in use.

Preheater (112); comprises a preheater reverse absorber plate (1123) with a concentrated heat pipe (1125) extending within the solar dryer (100) that can both preheat outside air and store heat and a cylindrical preheater reflector (1121 ) attached to it with a preheater glass cover (1122) to minimize convective heat losses from the preheater reverse absorber plate fins (1124) attached to it. The preheater reflector (1121 ), which is positioned close to the front wall (130) of the solar dryer (100), is placed on the bottom wall (110) in a sliding structure that allows the sun's rays to be focused on the preheater reverse absorber plate (1123) and it to be removed and mounted. The ambient air entering the solar dryer (100) from the air inlet (1126) located in the front of the preheater reflector (1121 ), thanks to the preheater reflector (1121 ) that focuses the solar radiation, the concentrated heat is rapidly absorbed by the plurality of heat pipes (1125) configured to receive solar radiation and the enlarged surface preheater reverse absorber plate (1123) with a plurality of preheater reverse absorber plate fins (1124) on it. A plurality of heat pipes (1125) that receive the heat transfer the heat by conduction to the heat storage material (1111 ) inside the gridshaped floor heat storage reservoir (111 ) in contact and from there to the heat transfer components and then the temperature of the heat storage materials (1111 ) and the temperature of the air entering the cabin increase, hence the temperature in the solar dryer (100) rises. Thus, the dry air passed over the products absorbs more moisture and the drying rate of the product is increased. When more heat energy is required for the solar dryer (100), or when the dryer cannot reach a sufficient drying rate, the preheater reflector (1121 ) mechanism of the preheater (112) can be removed and a solar collector or a heat source can be connected, and thus it can be converted into a mixed (direct and indirect) type dryer.

Heat storage; In the drying cabinet to ensure that the solar dryer (100) operates continuously (for a while after sunset), there is a grid-shaped floor heat storage reservoir (111), which can preserve the heat for a longer time for both vertically and horizontally, is heat storage material (1111 ) inside and the upper surface, can be used as a heat storage reservoir absorber surface (1112) and with a plurality of heat storage reservoir absorber surface fins (1113) on the upper surface.

As the grid-shaped floor heat storage reservoir (111 ) is under the tray, although not exposed to direct sunlight, the heat storage reservoir with a plurality of matte black selective surfaces (preferably conical in order to expand the surface area and create even heat beams, including but not limited to) attached to the grid-shaped floor heat storage reservoir (111) comprising the heat storage reservoir absorber surface fins (1113). Compared to a conventional solar dryer of the same volume, thanks to its thermal interaction with the drying air, numerous heat storage reservoir absorber surface fins (1113) increase the surface area of the absorber plate, while increasing its heat holding and dissipation capacity, thus increasing its performance.

With an improved sensible heat storage material (given or taken to change the temperature of the product without changing its physical state) or a latent heat storage material (which changes the physical state of the product), this solar dryer (100), which can be built more economically than conventional drying units in terms of price/performance, has the feature of shortening the moisture absorption time of the product at night, especially for products with long drying times, by providing hot air to the products for a longer time (up to a few degrees higher than ambient temperature, even in the absence of sunlight), allowing them to dry. In order to carry out the intended heat storage, but not limited to; Environmentally friendly and/or waste products, such as cherry pits, cherry pit powder, or non-uniform copper/aluminum shavings from machining workshops, on the other hand, as latent heat storage material (1111), which can change its state when it receives heat, but is not limited to this, phase-changing materials such as paraffin wax are used with at least one of the sealing elements.

Recommended drying temperatures are 35-50 °C for herbs, 50 °C for vegetables, and 55 °C for fruits. Recommended drying temperature for medicinal plants is 40 °C, 50 °C can be considered ideal for fruits and vegetables. In general, the final moisture value should be below 10%, while for fruits such as apricots, figs, and grapes, 20% can be taken as a basis. Accordingly, in food drying, the desired drying air temperature is 50 °C and the final humidity value is below 10%, which are considered ideal values. Accordingly, the minimum melting temperature of the phase change material (PCM) should be 5-10 °C higher than the desired temperature of the heat transfer fluid, and considering this situation, paraffin wax, which has an average melting temperature of 58-60 °C, seems to be an ideal FDM product as an energy storage material. In case PCM is used as the heat storage material (1111 ), a capsule casing is added to the parts of the heat pipes within the grid-shaped floor heat storage reservoir (111 ) so that the copper material does not react with the PCM.

Perforated air distribution diffusers (1114) adapted on the bottom wall (110) of the drying cabinet, allow air to pass through the gaps of the grid-shaped floor heat storage reservoir (111 ), extend from the south (front) to the north (back) and place crosswise from small to large hole diameters for smooth airflow and temperature distribution. This offers a convenient design for drying products evenly. To avoid shading effect, support legs (Rack) with heat storage material (145) are mounted between the side walls (120), the front wall (130), the back wall (140), and the upper wall (150) are mounted in such a way that the sunlight is not blocked and at a height. IR (Infrared) lamp group (113); Rod type or short type infrared lamp group (113) is placed under the tray in the cabinet for IR lamp application, which shortens the drying process speed and is known to have inversely proportional drying kinetics with both distance and air velocity. Thus, the distance between the infrared lamp group (113) and the product is configured in such a way that it does not increase the cabinet size and does not burn the product. In this way, the air is heated inside of the solar dryer (100). In other words, hot air is produced in the solar dryer (100) and also directed to the product to be dried by means of infrared radiation diverters. The infrared lamp group (113) is placed at an equal distance from each other. The infrared lamp group (113) is placed under the product tray (114) in accordance with the principle that the heated air rises, to be used in cases where the solar radiation is absent or insufficient and when the temperature inside the cabin is desired to be kept constant or when drying is desired to continue at night. Instead of the infrared lamp group (113), ultraviolet (UV) lamps can be used in low doses and for a short period for product and cabinet sterilization, as a result of both reducing the microbial load and providing optimum application conditions where the quality is least affected, considering their effects on food quality. The solar dryer (100) comprises a clip-on glass cover housing compartment 115, at the bottom of the insulated bottom wall (110), where the clip-on glass cover (152) can be placed when not in use, thus, the clip-on glass cover (152) is taken under protection for transportation and protection.

Insulated back wall (140); It is equipped with door absorber plate (1412) with door absorber plate fins (1413), back wall hinges (143) and upper wall (150) moving connected to it, upper wall mounted fan (153), dehumidifier-directing curved wing (151 ), a secondary drying cabinet with PV (160) and a PV panel (161 ).

On the inside of the back wall (140) (also front wall (130)) are support legs (Rack) with heat storage material (145) to hold the product tray (114). The support legs (Rack) with heat storage material (145) are combined with the grid-shaped floor heat storage reservoir (111 ) on the bottom wall (110), and the supports are filled with heat storage materials (1111 ) and have a structure that can be filled and emptied. The foot heights of the support legs (Rack) with heat storage material (145) containing heat storage material are configured at a height that will not allow the products on the tray to be shaded.

The insulated back wall (140) has an openable door (141 ) that allows the tray to be placed and taken into the drying cabinet, and also acts as an absorber plate with the door absorber plate fins (1413) on the surface facing the interior of the dryer.

A door (141 ) fitted with a door handle (1411 ) and swing-out door hinges (1414) on the outward-facing side, sized to cover the opening, since it is made of an insulating material and is exposed to direct sunlight, a plurality of door absorber plate fins (1413) with a matte black selective surface are added to the door (141 ). In this way, it acts as a solar collector and undertakes the task of retaining and spreading heat. There is an open-close cleaning cover (142) in the lower region of the back wall (140) of the solar dryer (100), so that the accumulated dust, dirt, and dried product parts can be easily cleaned.

Insulated upper wall (150); equipped with fan(s) (153), dehumidifier-directing curved wing (151 ), a secondary drying cabinet with PV (160), and PV panel (161 ).

Dehumidification process; in the dryer, dehumidification is also carried out by using the dehumidifier-directing curved wing (151 ). The dehumidifier-directing curvilinear wing (151 ) has a multi-functional structure that creates a turbulent effect in the rising air by heating, absorbing sunlight, controlling humidity, extending the airway, and keeping the heat in the cabin for a longer time. The dehumidifier-directing curved wing (151 ) has the ability to reduce the humidity in the air and is filled with at least one dehumidifying material (1511) made of silica gel or calcium chloride (CaCI2) as a colorindicating desiccant. The dehumidifier-directing curved wing (151 ) comprises a cover with holes or slots on it and a cover for filling and emptying, which is also used as an absorber plate in a solar collector, whereby the regeneration process can be carried out. The dehumidifying product changes color by absorbing the moisture in the products, especially during the night. Thus, on the one hand, it positively affects the drying time, on the other hand, it reduces aflatoxin pollution, which is produced by fungi, poisons the liver, has carcinogenic effects, is a harmful toxin for human and animal health, and increases with slow drying. The solar dryer (100) heats up in the morning. As the temperature in the cabinet increases, the moisture in the products and also in the desiccant pack moves away from the cabinet, the desiccant pack is renewed and its color changes again. Based on, but not limited to, using a desiccant pack with natural or specially developed desiccant materials (absorbent products) such as silica gel, activated charcoal, activated alumina, zeolite, or calcium chloride, which have porous structures that increase specific surface areas and the ability to adsorb liquid or gas phase fluids at high capacity, and especially using it in the area close to the glass and the upper part of the cabinet prevents water vapor from condensing on the glass surface, so that the sun's rays are not prevented from entering the cabinet.

Secondary drying cabinet with PV (160): In standard solar dryers, the air coming out of the drying cabinet is vented directly to the outside. The reason for this is that although the expelled air has high-temperature values, it also has high humidity values. However, in the invention, the insulated upper wall (150) has a rectangular air outlet port (154) extending along the wall, one mouth facing the inside of the solar dryer (100) and the other mouth facing the atmosphere with a mesh-like filter that does not block the airflow but has a protective mesh-like filter against the passage of insects and heat recovery channel (155) and a secondary drying cabinet with PV (160) are included above it. Fan(s) (153) are added to the mouth of the heat recovery channel (155) facing the interior of the solar dryer (100). Since the fan(s) (153) is on the cabinet upper wall (150), the airflow and temperature distribution are more uniform and the moisture removal rate from the product is increased. While the heat recovery channel (155) is insulated from the bottom and the sides of the channel, the upper part of the channel is uninsulated and has an enlarged surface that increases heat transfer. The aim here is to recover only the heat energy of the humid air with high heat values, which is about to be exhausted before it is discharged. Some products should not be exposed to direct sunlight as it causes a loss of color and quality. For this reason, this recovered heat is dried in the secondary drying cabinet with PV (160) for products that are desired to be dried in the shade or at low temperatures. A PV panel (161 ) is placed on the cabinet to be used at almost horizontal inclination angles in summer and steeper inclination angles in other seasons to provide electrical energy to the solar dryer (100) so that the electrical energy needed for the fan(s) (153) is met. An adjustable PV panel hinge (164) is attached to the PV panel (161 ) for use horizontally or at an angle, depending on latitude and the position of the sun, as well as for transportation and storage. Fan(s) (153) that controls the airflow through the solar dryer (100) and accelerates evaporation and exhausts the air in relation to the relative humidity and temperature of the air, is operated by a PV panel (161) placed on the solar dryer (100). The fan(s) (153) are controlled by the temperature-controlled fan speed regulator in two different modes as automatic or manual control. In automatic control mode, the fan speed is automatically changed by the control and monitoring unit (170) according to thermal conditions and configuration. The minimum and maximum temperature parameters are used to determine the configuration of this mode. In manual mode, the air velocity is constant. In manual control mode, the user can adjust the fan speed in steps from 1 to 3.

There is a fixed product tray (165) inside the secondary drying cabinet with PV (160). Also, as is known, as the temperature of the PV panel (161 ) increases, its efficiency decreases. For this reason, an insulation plate that prevents heat escape to the PV panel (163) is added to the ceiling of the PV secondary drying cabinet (160). The products placed in the secondary drying cabinet with PV (160), which has a very low capacity and lower drying ability compared to the other, are dried by indirectly heating with the exhaust heat from the primary drying cabinet.

The insulated side wall(s) (120); is a structure that can be folded inwards and can be placed on a clip-on glass cover (152) when positioned vertically. On the fixed outer part of the insulated side wall (120), there is a wall-mounted, collapsible side wall reflector that transfers solar radiation into the dryer cabinet (122). These increase the temperature and drying rate in the cabin by reflecting the solar radiation into the cabin and also contribute to increasing the regeneration efficiency of the dehumidifier with increased cabin temperature. Therefore, the invention can be used in two different modes, summer and winter mode. The winter mode can also be used in summer to prevent aflatoxin and to dry in a much shorter time. The maximum length of the side wall reflector that transfers solar radiation into the dryer cabinet (122), which is collapsible and angle adjustable, and transfers the solar radiation into the dryer cabinet, is the distance of the clip-on glass cover (152) from the front wall (130) to the back wall (140), and their maximum width is in height of the short front wall (130).

When it is desired to convert the dryer into an indirect solar dryer by adding heat-providing equipment such as a solar collector, or when it is not desired to expose the products directly to the sun, the side wall reflector that transfers solar radiation into the dryer cabinet (122) and the movable part of the side wall can be used to cover the clip-on glass cover (152) thanks to the side wall hinges (123).

The insulated front wall (130); has a front wall reflector that transfers solar radiation into the dryer cabinet (131 ) on which one side of the clip glass cover (152) sits at an angle and reflects the solar radiation into the cabinet, therefore, that can be folded outwards and can be adjusted at an angle, which increases the drying rate, and transfers the solar radiation into the dryer cabinet. The maximum length of the front wall reflector that transfers solar radiation into the dryer cabinet (131 ) is as long as the front wall (130) and its maximum width is at the height of the front wall (130).

The drying efficiency of the dryer; may vary depending on outdoor conditions, usage type, loading type, material to be dried, and amount of product to be dried. The dryer can dry the products from several hours to several days, after which the products can be stored for a long time in suitable room conditions and containers.

Monitoring and control system; The indoor temperature and relative humidity of the said solar dryer (100) can be monitored via a screen. The process of limiting the air temperature and relative humidity in the solar dryer (100); air inlet (1126), air outlet port (154), door (141 ), and fan(s) (153) are provided by airflow. Otherwise, excessive heat formation may be caused, which causes the products to cook and even burn instead of just drying them. Conversely, if the total clearance area is excessive, it can result in an insufficient temperature level to achieve the desired drying. Thanks to a wireless smart thermostat (171) that regularly detects the temperature in the cabin and can be adjusted via it, in case of overheating, the fan(s) (153) will be activated when the set temperature is reached, otherwise the fan(s) (153) will be disabled. Similarly, when the humidity reaches the value set on the humidity meter (173), the fan(s) (153) are activated by a simple electronic circuit, otherwise, the fan(s) (153) is turned off. There is a screen that allows the values taken from the temperature meter (172) and the humidity meter (173) to be instantly monitored and adjusted to certain values. A plaque indicating which product will be dried at which temperature and the initial and final humidity values are located in a visible area of the cabinet. The solar dryer (100) has a control panel where certain products can be selected from the display. In this way, the user can select the product to be dried on the screen. When the user selects the product he placed in the dryer from the control panel; the system operates in a way that does not exceed the relative humidity value of the selected maximum indoor air and the permissible indoor temperature value for the selected product, that is, with temperature and humidity control. In addition, thanks to the webbased remote monitoring and control system, in-cabin air temperature and humidity values, and drying time can be monitored, also, the wireless smart thermostat (171 ) set the temperature, that is, the air temperature inside the cabin, can be changed. The control panel in the dryer is in one-to-one communication with the dryer and transmits the operating data to the server via the internet via a modem. The user, who connects to the system via the web interface, accesses the data, measurements, and reports of the defined product through the server. The user can access the web interface at any time and place via a device with internet access.

In addition, a compass (156) is placed on the solar dryer (100). Thus, the dryer can be placed in the optimum position in the south direction, a location that will expose the products to the sun, making the most of the sun before starting the drying process.