MX2007006061A - System and method for dehydrating food. - Google Patents

Abstract

The present invention discloses a closed-circuit system and method for dehydrating food, such as fruit, shrimp, meat and further products which are arranged parallel to the main hot stream. The system handles times for performing the dehydrating process under those currently available, the method of the present invention providing quality and innocuousness for complying with any standard for exporting food products. The system includes a centrifugal turbine (2) for flowing air that is heated by a resistance arrangement (4), the air being uniformly supplied to the inner portion of a container by air deflectors (15), said container (8) having inlet gates (5) and outlet gates (6) for controlling the amount of air entering into the container (8) and controlling the moisture-charged air exiting therefrom. The inner portion of the container (8) includes weight (16), humidity (10), pressure (13), temperature (9) and air rate (14) sensors. The whole elements forming the system are controlled by a programmable electronic system, which is useful for gathering information and processing the same for generating an acceptable final product.

Description

SYSTEM AND METHOD FOR DEHYDRATION ALJMENTS TECHNICAL FIELD This invention is related to activities carried out in the industry of dehydration with agricultural products, livestock and aquaculture for processing, giving them an added value through this action, in addition to obtaining a high degree of safety in the final product for its marketing.

BACKGROUND OF THE INVENTION Currently there are designs of machines to dehydrate products and materials where various solutions have been proposed to heat and boost the drying medium, generally air. Ways to eliminate the detached moisture resulting from the process have also been designed. The configurations of the dehydration machines range from the implementation of simple stoves to the application of adiabatic methods in simple tunnels of open or closed circuit that consist of placing a burner of some fossil fuel, a fan and some structure that supports the product to dry in front of the hot air stream generated.

Some more sophisticated equipment includes methods with recirculation d® air in a closed circuit, which helps to save the energy consumption needed to heat it. Others propose methods to extract the moisture present in the air using in-line drying mechanisms such as desiccants or cold plates to condense and expel it from the main stream, resulting in non-practical or high-cost designs.

In order to eliminate the complex design of the methods of expulsion of moisture contained in the air this technology of practical design and realizable to manufacture machines to dehydrate products and materials with the advantages of being of low energy consumption for being of closed circuit, and to discard the humidity by means of adjustable gates, thus giving a considerable decrease in the time required for drying, in addition of using washed air for a high degree of hygiene in the process.

DESCRIBING OF THE INVENTION The main details are shown in the following description and in the accompanying drawings. Figure 1 is a diagram showing how to extract air from the circuit. Figure 2 details the disposition of the parties.

With references in these figures, the following is described: the system and method consists of a closed-loop container in which a centrifugal fan that drives an air current at speeds ranging from 1 to 5 meters per second has been arranged in a section. , its entrance and exit coincides with the path followed by the main air stream, within this circuit is available the heating elements that can be electric or heat exchangers obtained by the direct or indirect combustion of fossil or artificial fuels.

Within this circuit is the section where the materials are placed without obstructing the main air flow, placed in trays of rigid material frame with a weft mesh tensioned to support the product, with vertical separation between them of 0.5 to 3 inches , in horizontal arrangements on mobile structures (carts) to transport the product to and from the machine or on fixed rails on the walls of the tunnel directly. Next to the entrance of the centrifugal fan there is a gate to admit fresh air it may or may not have been filtered and dried by step with static or dynamic desiccant methods to avoid contamination of the product to be dried.

Following the trajectory of the air leaving the centrifugal fan, there is a humid air outlet in the part where the highest density of air is obtained, since at this point the highest concentration of moisture contained in the main stream is observed. Because of that simple fact, the main air component loses humidity. The repeated passage of air through the heater allows to increase its temperature gradually and this can collect more moisture in each cycle.

Since the section of the centrifugal fan inlet is smaller than the area of the section of the main tunnel of the circuit, a positive pressure is obtained that allows to obtain a continuous flow throughout the section of the air path, so as not to lose this characteristic that allows to apply Fresh air and to expel the present humidity should be checked that the volume of fresh air admitted is not less than the volume of air expelled and thus always have a positive pressure inside the main tunnel.

The replaced volume of air should be such that it allows to maintain a relative humidity at low levels to allow the drying process to take place, hence the proportionality of the volume of air admitted and the volume of air expelled, when over time a decrease in the moisture collected from the material in process can be observed, the volume replaced by air can be decreased and thus increase the economy of the process. The control can be manual or electronically automated.

The temperature of the indoor air is controlled by electronic equipment with a simple algorithm switched on by a simple thermostat or by means of a PID algorithm.

The walls of the machine are double-walled with heat-insulating material to prevent heat loss through conduction, or if the material used in a fixed installation allows it to function as a natural heat insulator. The moist air outlet and dry air inlet are strategically placed to allow more efficient extraction of moisture, the outlet is placed at the edge of the centrifugal fan throat where the highest air density is observed.

PREFERRED REALIZATION OF THE INVENC80 The view of figure 2 shows that the turbine (2) moves the air (11) inside the dehydration circuit, this air (11) is introduced by the gate (5) and at its entrance is washed and disinfected by the filters (7) that are installed in the inlet of the dehydrator.

The air (11) is heated by the resistor bank element (4) and this same air inside the dehydration container reaches a positive pressure that is registered with pressure sensors (13) and at this moment the gate (5) closes completely.

When the air (11) is heated to the programmed temperature the product that is in the trays (6) begins to dehydrate by the speed of the internal air generated by the turbine (2) and the heat generated, this generates that it begins to release the moisture that is inside the product to dehydrate. In view of this figure 1, it can be observed that the humidity collector (3) which is in the lower part of the snail (1) is the outlet of the humidity because it is the place where the most concentrated point is, this humidity once collected it passes outside the container (8) through the gate (6).

This gate (6) is controlled by the main program and only opens when the control system detects high concentrations of humidity inside its dehydration container, the air intake gate (5) (11) is in function of the need dry and clean air that is generated by the filters (7) that are in the air inlet of the container (8) of the dehydrator. This air that is introduced to the dehydrated container (8) is calibrated to generate a positive pressure inside it, which is necessary to make a total air supply (11) inside the dehydrated container (8).

The opening of the gate (5) is also a function of the air (12) with moisture detached from the product inside the dehydrator accommodated in trays (6) in a direction parallel to the air flow generated by the turbine (2), humidity and temperature readings that occur within the circuit are collected by humidity sensors (10) and temperature sensors (9) installed at strategic points within the drying container.

The energy required to heat the internal air is given by the element, bank of resistances (4) that will be activated as many times as hot air is required at the programmed temperature of the dehydrator.

Well, the invention focuses on the system and method of being able to remove moisture from the dehydration circuit without losing the heat energy generated by the resistance bank, thus giving a system and method of dehydration.

Claims (6)

REINVIND8CACI0NES Having sufficiently described our invention, I consider it a novelty and therefore claim as our exclusive property what is contained in the following clauses:

1. System for dehydrating foods containing a turbine (2) to drive the air (11) inside the food container to a stream parallel to the product with trays (6) made of aluminum or stainless steel material with mosquito netting that are inserted in stainless steel carts or in the walls of the container that make up the dehydrating machine, where the product to be dehydrated rests. The container has an automatic gate (5) to introduce the air to the dehydrated area and gate (6) of exit to expel the concentration of moisture that is extracted to the product, the bank of resistances (4) to heat the air. The container inside has air speed sensors (14), temperature (9), humidity (10), weight (16) and has a programmable electronic system to collect control variables for the entire system. To balance the air inside it has air deflectors (15) made of aluminum or stainless steel material. It also has air cleaning filters (7) that are located at the entrance of the gate (5) of the dehydrated container. The system is characterized because it comprises of; a collector (3) of humidity in the lower part of the snail (1) where most of the air is concentrated with humidity, this being what makes it dehydrated in shorter times and that nothing is currently found in the market is equal in its form and operation. Also of a resistance bank (4) of heat transfer of 100 percent efficiency, this element being the source of heat for the dehydration system.

2. System for dehydrating food according to claim 11 which is further characterized because the food container can handle positive pressures of 1 to 3 atmospheres.

3. System to dehydrate foods according to Daivivi) which is also characterized because the programmable electronic system can manage programming times to detect the fine point of percent moisture that is required for the final state of the product.

4. System to dehydrate food according to Da reivindoeaidóifi) 3, which is also characterized because the programmable electronic system of moisture percent has a circuit of weight sensors where they are responsible for showing the weight of the product during the dehydration and their time through these is deduced in the end of the process.

5. System to dehydrate food according to Da reivinifcartesT) 4 which is also characterized because the weight sensors are located inside the dehydrated container showing accurate readings in real time of the detachment of the weight by dehydration.

6. Method to dehydrate foods that is characterized because it comprises the following steps: The product is put in the tray (6) and the trays (6) are introduced to the cart (17) and these are introduced to the dehydrated container, with the full container of the product to be dehydrated the following step is understood: The programmable electronic system is switched on and the weight is recorded separately from each of the trolleys (17) that contain the container (8) of dehydrated, this initial weight of each car (17) is stored in a database of the programmable electronic system and calculated, and programs the final weight of each car (17) depending on the humidity at which the product is wanted final, then the next step is understood: The temperature at which the dehydration process is to be developed is programmed, the positive pressure is programmed to which the container (8) of dehydration must be kept for the whole process of the same and the air speed that is desired is programmed use inside the dehydrated container, the humidity values of the gate opening (6) are programmed to eject it and the% humidity is programmed to which the gate (6) of the outlet must be closed. Collect more moisture after having expelled the required required moisture, it is understood the following step: With the control variables already programmed, the turbine (2) is turned on, and this in turn activates the gate (5) that allows air to enter the interior of the dehydrated container (8), the air entering the container (8) through the gate (5) is washed and disinfected by the filtering panels (7), this air generates a positive pressure inside the container (8), and when this pressure reaches the values that were programmed to the programmable electronic system, generates a signal to close the gate (5), and this in turn activates the resistance bank (4) that will be switching every time the temperature drops or rises by 1 degree of its initially programmed range in the programmable electronic system, after of this the following step is understood: The product begins to lose weight by means of the applied heat and the current of air inside the container (8) to dehydrate it and the positive pressure that they have. When the humidity% that was programmed to expel moisture is detected, the gate (6) of the outlet is opened, at the same time, the air inlet gate (5) is opened, always maintaining between the two gates an equilibrium that is reflected in the positive pressure that is censored inside the container (8) in such a way that it lets out the humidity until the humidity drops to the equivalent% that is programmed so that the gate (6) of exit closes, this is repeated as many times as necessary until the weight of the product reaches the programmed final weight. This method of dehydration is based on positive air pressures and a calibration of gates openings based on their openings with reference to the moisture that is coming off inside the dehydrator container, also clean the air in the process of introducing air to the interior of the container (8) of the dehydrator.