MX2007007216A - Method and apparatus for removing solute from a solid solute-bearing product. - Google Patents

Abstract

The process and apparatus are for removing a solute from a solute-bearing solid product by means of a solvent which remains in liquid state throughout the entire extraction vessel conducted in extraction chamber (24). The solvent and solute are collected as a miscella in vessel 42 and then separated from each other in a separation vessel (48). Temperatures and pressures are maintained so as to maintain the solvent in liquid state in both extraction chamber (24) and separation vessel (48).

Description

METHOD AND APPARATUS FOR REMOVING DISSOLVED SUBSTANCES OF A SOLID SUBSTANCE CARRIER PRODUCT DISSOLVED Field of the invention The present invention relates in general to a method and apparatus for removing dissolved substances from a solid product carrying dissolved substances, and more particularly to a method and apparatus for removing oil from a product. solid that has oil by means of a solvent that drains the oil from the oil-bearing product BACKGROUND OF THE INVENTION Processes for removing oil from oil-bearing products are known in the art. Such processes occur in an extraction chamber wherein the solvent is sprayed or otherwise injected into the oil-bearing product, to drain the oil. outside the solid product This results in a composition comprising a mixture of oil and solvent, which is transported to a solvent-oil separation chamber. Such processes make use of a liquid solvent that is required for certain values. of temperature and pressure of extraction determined, but which is normally gaseous at ambient temperature and pressure values After the oil has been drained out of the solid product with the solvent in the liquid state in the extraction chamber, the composition is separated into its different components of oil and solvent in the separation chamber that is heated to such a temperature that the solvent becomes gaseous while the oil remains liquid, which allows the oil and solvent to be easily collected. A problem associated with such prior art processes is that oil and solids are often denatured by applying heat to solids and / or oil, which is inconvenient. Denaturation is defined as a physical, chemical or molecular change in the dissolved substances or in the solid product. This is especially true in the processes of the prior art, during the separation phase of the composition, where relatively high oil denaturation temperatures are often reached.

Brief Description of the Invention The present invention relates to a process for separating the dissolved substances from a solid product carrying dissolved substances comprising the steps of: providing an extraction chamber with determined values of temperature and extraction pressure; control the extraction pressure to maintain it over an environmental pressure value; control the extraction temperature to maintain it at a temperature that does not denature the dissolved substances or the solid product; feed the solid product carrying dissolved substances in the extraction chamber; providing a solvent that is mainly in the liquid state at the pressure and extraction temperature values, the dissolved substances are soluble in the solvent at the pressure and extraction temperature values; injecting the solvent in the liquid state in the carrier product of dissolved substances in the end chamber to drain the dissolved substances from the solid product with the solvent; recovering distinctively the solid product from which at least a portion of the dissolved substances have been drained, and a composition comprising a mixture of solvent and the dissolved substances drained from the solid product; transport the composition to a separation unit with the values of temperature and separation pressure determined, with the solvent remaining mainly in the liquid state at the temperature and separation pressure values and with the temperature value in the separation unit that is controlled to maintain it at a temperature that does not denature the dissolved substances; separating the solvent from the dissolved substances in the separation unit through a process of separation of liquid to liquid; and recovering solvent solvent and dissolved solids separately in the separation unit, where the solvent remains mainly in the liquid state throughout the entire process. In one embodiment, the solvent is in the gaseous state at ambient temperature and pressure values but mainly in the liquid state at ambient pressure and temperature values.

In one mode, the extraction and separation temperatures are equal to the ambient temperature, with the solvent being maintained mainly in the liquid state throughout the process, by means of which the extraction and separation pressures are maintained on the temperature environmental. In one embodiment, the solvent recovered from the separation unit is reused within the extraction chamber to extract additional dissolved substances from the material carrying dissolved substances, whereby the solvent is used within a closed loop circuit and remains mainly in the liquid state through the closed-loop circuit. In one embodiment, the liquid-to-liquid separation process is one of the processes of molecular weight separation, specific gravity and viscosity differential. In one modality, the process is a batch process, with the step of feeding the solid product carrying dissolved substances in the extraction chamber, which is achieved by charging a batch of solid product carrying dissolved substances in the chamber of extraction. In an alternative mode, the process is a continuous process, with the step of feeding the solid product carrying dissolved substances in the extraction chamber, which is achieved by continuously circulating the product carrying dissolved substances through the chamber. extraction and continuously recovering the solid product of which, at least a portion of oil has been drained by an outlet of the extraction chamber.

In one embodiment, the extraction chamber comprises a number of portions of the extraction chamber, through which the product carrying dissolved substances is circulated sequentially to extract the dissolved substances from the solid product carrying dissolved substances, each portion of the extraction chamber defines corresponding parameters of the extraction chamber and at least certain parameters of the extraction chamber differ from one extraction chamber to another. In one embodiment, the step of injecting the solvent into the extraction chamber is achieved by means of at least one spray nozzle extended in the extraction chamber, with the ability to form a spiral-shaped spray pattern. In one embodiment, the step of continuously circulating the product carrying dissolved substances through the extraction chamber is achieved by means of a plunger equipped with stirring blades, the process also comprising the step of stirring the particles of the carrier product of dissolved substances to promote the formation of free-floating solid product particles that will be carried, at least in part, within the spiral-shaped solvent spray pattern. In a mode, the step of controlling the extraction pressure to maintain it above the ambient pressure value is achieved by means of a gas nozzle that injects into the extraction chamber one of a steam from the solvent and a gas that does not react with the solvent, oil or solid product. The present invention also relates to an apparatus for separating the oil from a product carrying dissolved substances, which comprises: an extraction chamber; a solvent injector for injecting solvent into the extraction chamber for draining the oil of the solid product carrying dissolved substances to form a composition comprising a mixture of solvent and oil; a composition outlet in the extraction chamber to collect the composition; and a liquid-liquid separation unit linked to the composition outlet, to separate the composition in its respective oil and solvent components; wherein the solvent injected into the extraction chamber remains mainly in the liquid state in order to drain the oil from the oil-bearing product to form a composition therewith, and remains primarily in the liquid state in the separation unit. Iquid to the liquid. In one embodiment, the apparatus also comprises: an inlet valve located upstream of the extraction chamber and which allows the oil carrier product to enter the extraction chamber without allowing the passage of fluid between the extraction chamber and the atmosphere; an outlet valve located downstream of the extraction chamber and that allows the solid product from which the oil has drained to leave the extraction chamber without allowing the passage of fluid between the extraction chamber and the atmosphere; and an impeller for circulating the solid product from the inlet valve through the extraction chamber to the outlet valve; wherein the apparatus allows the continuous feeding of the solid product by the inlet valve, the continuous oil runoff of the solid product, the continuous output of the solid product from the outlet valve and the continuous collection of composition at the composition outlet. In one embodiment, the apparatus also comprises a safety solvent extraction unit downstream of the outlet valve, to remove residual solvent vapors with the application of heat to the solid product. The present invention also relates to a valve that defines an inlet and an outlet, to allow the solid product to pass from the inlet to the outlet, while preventing the fluids from being exchanged between the inlet and the outlet, and comprises: a channel internal that extends between the entrance and the exit; a fluid exhaust port in the internal channel, intermediate to the inlet and outlet, the fluid exhaust port is in communication with a vacuum pump and is equipped with a filter that allows the passage of fluids through the port fluid exhaust, but prevents the passage of solid product through the fluid exhaust port; a rotary valve member located in the internal channel and that can rotate therein, the rotary valve member comprises a main body coupled with the internal channel in an air-tight manner fluid and having an elongated transverse channel, the rotary valve member has the ability to rotate between a first position, wherein the transverse channel is co-extensive and communicates with the internal channel of the valve and where the main body obstructs the fluid exhaust port, and a second position where the transverse channel is in register and communicates with the fluid exhaust port and the main body obstructs the internal channel of the valve; and a piston that can move longitudinally within the elongated transverse channel between the two limit positions.

Brief Description of the Drawings In the accompanying drawings: Fig. 1 is a schematic view of an apparatus for carrying out the present invention in accordance with a continuous process for removing oil from an oil carrier product. Figure 2 is a schematic, enlarged cross-sectional view of the inlet valve of the apparatus of Figure 1. Figures 3 to 5 are cross-sectional, schematic views of a rotary valve member only of the valve of Figure 2, on a smaller scale, sequentially showing the rotary valve member in three positions thereof and suggesting the rotation of the valve member and the linear displacement of the piston with the arrows. Figure 6 is a schematic cross-sectional view of an alternative embodiment of a valve assembly in accordance with the present invention, which includes two valves similar to the valve of the Figure 2 Figure 7 is a longitudinal cross-sectional view of an extraction chamber in accordance with the present invention Figure 8 is a schematic cross-sectional view taken along the line VI II-VI II of Figure 7 , and Figure 9 is a schematic view of an alternative apparatus for carrying out the present invention, in accordance with a batch process for removing oil from an oil carrier product.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates in general to a method and apparatus for removing dissolved substances from a solid product carrying dissolved substances by means of a solvent that remains in a liquid state throughout the process of oil extraction In one embodiment, the solvent is normally in the gaseous state at the environmental pressure and temperature values, but it is used in the liquid state within the method and apparatus of the present invention, by maintaining such pressure and temperature values within the apparatus, so that the solvent remains in its liquid state. In another embodiment, the solvent is already in the state The liquid at ambient pressure and temperature values, and is maintained in the liquid state within the apparatus of the invention. In accordance with one embodiment of the invention, the product carrying dissolved substances is a solid product containing a certain amount of oil. or fats The solid product may be, for example, an animal tissue, household oily waste or commercial, oily hazards, oily industrial by-products, oil bearing sands, strata, minerals, rock formations, fried or saturated edible and non-edible substances, pulses and their shells and shells, seeds and their shells, shells, nuts and their husks, and / or shells, leaves, branches and roots of trees, leaves and stems of plants, leaves, branches and basic roots, marine life, whether organic, mammalic or aquatic, crops and vegetables of all kinds, for separation of solids of natural fats and oils, contained, maintained or suspended intrinsically, in organic form in them or by them. The solvent can be any suitable solvent in which the dissolved substances will dissolve at the determined temperature and extraction pressure values. In one embodiment, as indicated above, the solvent will be in the gaseous state at ambient temperature and pressure values, but will remain in a liquid state at the temperature and extraction pressure values. The solvent may be, for example, mixtures of propane or butane or a coolant. It should be understood that the method and apparatus of the present invention may use different solvents, the exact nature of the solvent will largely depend on the oil carrier product and the oil contained in the oil carrier product. More particularly, the process of the present invention for separating dissolved substances from a solid product carrying dissolved substances comprises the steps of: providing an extraction chamber with temperature and temperature values; Extraction pressure determined; control the extraction pressure to maintain it above the environmental pressure value; control the extraction temperature to maintain it at a temperature that does not denature the dissolved substances or the solid product; feeding the solid product carrying dissolved substances in the extraction chamber; to provide a solvent that is mainly in the liquid state at ambient temperature and pressure values, the dissolved substances are soluble in the solvent at the temperature and extraction pressure values; injecting the solvent into the carrier product of dissolved substances in the extraction chamber to drain the dissolved substances from the solid product with the solvent; recover distinctively the solid product from which at least a portion of the dissolved substances have been drained, and a composition comprising a mixture of solvent and the dissolved substances drained from the solid product; transfer the com position to a unit of separation with the values of temperature and pressure of separation determined, with the solvent remaining mainly in the liquid state at the values of temperature and pressure of separation and with the value of temperature in the unit of separation that is controlled to maintain it at a temperature that does not denature the dissolved substances; separating the solvent from the dissolved substances in the separation unit through one of the separation processes by molecular weight, specific gravity and viscosity differential; and distinctly recovering the solvent and the dissolved substances separated in the separation unit, where the solvent remains mainly in the liquid state throughout the entire process. The process of the invention can be carried out as a continuous process or as a batch process. Figure 1 is a schematic view of one embodiment of an apparatus 20 used to carry out the process of the present invention as a continuous process. The apparatus 20 comprises a raw material inlet valve 22 connected to a number of consecutively contiguous extraction chambers 24a, 24b, 24c, 24c, 24c, 24e, 24e, generally referred to as extraction chambers 24, which are actually portions of the extraction chamber, and part of a single extraction chamber, as described in detail later, since they are in fluid communication with each other. However, in alternative embodiments, which are not illustrated, the extraction chamber 24 may be insulated in fluid form by appropriate valves. Downstream of the extraction chambers 24 is a solid product outlet valve 26 connected with an optional safety solvent extraction unit 28. The oil carrier product or the raw material, which is to be treated by the apparatus 20 to distinctively recover the oil the solid product thereof, is fed through the raw material inlet valve 22 and circulates in the sequentially through the contiguous extraction chambers 24, wherein a certain proportion of oil will be extracted from the oil-bearing solid product, as detailed below. The solid product from which the oil has been extracted is then transported through the solid product outlet valve 26, to the outlet of the apparatus 20 downstream of the solvent extraction safety unit 28. The inlet and outlet valves 22, 26 are valves that allow a continuous or essentially continuous flow of solid product, while avoiding the flow of other fluids. In this way, the solid product can flow freely through the valves 22, 26, while there is no exchange of fluids between the extraction chambers 24 and the atmosphere. In one embodiment, to facilitate the treatment of the oil-bearing solid product, the solid product is fed through the inlet valve 22 into a pill or pellet form, with the maximum particle size of the empirically selected solid product and / or calculated for optimized oil production. The determined temperature and extraction pressure values are adjusted and maintained within the extraction chambers 24. More particularly, the extraction pressure is controlled to maintain it above the ambient pressure value, and the extraction temperature is controlled to maintain it at a temperature that will not denature the oil or the oil-bearing solid product. These values of extraction pressure and temperature are adjusted to allow the solvent to remain in a liquid state within the extraction chambers 24, while in one embodiment, this same solvent will be in the gaseous state at ambient temperature and pressure values. For example, the extraction temperature may be essentially equal to the ambient temperature, for example, between 1 ° C and 40 ° C, and the extraction pressure may be maintained well above the ambient pressure value, for example, approximately 1 0. bars. However, these exemplary values of extraction pressure and temperature are not considered restrictive, as they may vary depending on the nature of the oil, the oil carrier product and the solvent to be used. Also, maintaining the ambient temperature value within the extraction chambers 24 has the advantage of helping to prevent most oils and solid products from being denaturated, since they can be found naturally at room temperature. One way to maintain the extraction pressure on the ambient pressure is to have a gas injection pump 29a connected to a gas injector 29, which injects gas into the extraction chambers 24. re 1 shows a single gas injector 29 for all extraction chambers 24, but it should be understood that multiple gas injectors can be provided. The nature of the gas to be injected will be described later. A closed-loop liquid solvent circuit is provided within the apparatus 20, wherein the liquid-state solvent circulates for use in extracting the oil from the oil-bearing product fed into the extraction chambers 24. More particularly, it is provided a primary tank 30 of solvent in the apparatus 20, within which the solvent is stored at such temperature and pressure values that it remains essentially in the liquid state. A solvent pump 32 transports the solvent from the main solvent tank 30 to a solvent pipe 34, the latter connected to the solvent injectors in the form of several spray nozzles 36a, 36b, 36c, 36d, 36e, controlled in a controlled manner. independent, generally called as spray nozzles 36, which will inject solvent into the corresponding extraction chambers 24. Since the dissolved substances are soluble in the solvent at the temperature and extraction pressure valuesAs the solvent is sprayed into the extraction chambers 24, the oil drains from the oil-bearing solid product, with the solvent and the oil forming a composition which is recovered, for example, through a filter ( shown in Figure 1), which will prevent solid product particles from flowing through it, while allowing the composition to flow therethrough. The composition is collected through the corresponding composition output channels 38a, 38b, 38c, 38d, 38e -recommended generally as composition output channels 38. The composition pumps 40a, 40b, 40c, 40d, 40e - generally referred to as composition pumps 40, are connected to the composition channels 38 to ensure an outflow of composition from the extraction chambers 24. The composition thus recovered is transported to a composition collection tank 42. Although only one composition tank is shown, it must be understood that they can be use composition tanks corresponding to each extraction chamber. A pump 44 transports the composition from the supply tank 42 through the particulate filter 46 and into the separation unit 48, where the oil is separated from the solvent in the tank. liquid state through a liquid separation process to the known liquid, for example, one of the processes of separation of molecular weight, specific gravity and viscosity differential Also, the values of pressure and temperature of separation determined remain within the separation unit 48, with the solvent in essentially liquid state at the temperature and separation pressure values, wherein the temperature value of the separation unit is controlled to maintain it at a temperature that will not denature the oil In one embodiment, the pressure and separation temperature values are identical to the temperature and pressure values of ext For example, the solvent separated from the oil in the separation unit 48 is then transported by means of a pump 50 back into the main solvent tank 30, while the oil separated. The solvent is collected at the oil outlet, after having passed through an optional segregation unit 52, which will remove any remaining residual solvent vapor, if any. Through the closed-loop solvent circuit, the solvent essentially remains in the liquid state at all times In the specification and claims present, although it is indicated that the solvent remains in the liquid state, it must be understood that certain solvent in liquid state, in fact, will evaporate unless the corresponding surrounding area within the apparatus 20 is saturated with solvent vapor, thus, in any case, the solvent vapor will be present. The solvent will not be completely in liquid state at all times in the apparatus 20. Consequently, when it is established that the solvent remains in the liquid state, it refers to the active solvent that will be injected through the injectors 36, draining the solvent. The oil of the solid product will form a composition with the oil, it will be taken to separate in the liquid state in the separation unit 48, and then it will be re-used to be injected through the injectors 36. In this way, apart from a proportion of the solvent that will naturally evaporate in the unsaturated areas of the apparatus 20, it can be said that the solvent will remain "mainly" in the liquid state. Maintaining the closed-loop solvent circuit in the liquid state can be achieved, for example, by keeping the temperature constant at about an ambient temperature value and maintaining the ambient pressure value within the closed-loop solvent circuit. This is particularly advantageous, since it will help to prevent the oil and the solid product circulating inside the apparatus 20 from being denatured, since they are not subjected to a considerable heat ratio, which is frequent in the devices of the prior art. In the normal mode of operation of the apparatus 20, most of the solvent in the liquid state will be recovered through the composition within the extraction chambers 24. However, there may be some cases where the solvent is not completely removed from the product solid, when leaving from the extraction chamber 24, especially, certain solvent vapors which are residents of the extraction chamber 24 and which are trapped in the solid product. Thus, the optional solvent extraction safety unit 28 which is located downstream of the outlet valve 26 is used to remove the residual solvent in the solid product by the application of heat to prevent the solvent from accidentally leaving the product. of the device 20. This heat level is relatively low, since the temperature in the optional safety unit, of solvent extraction will be below a temperature that can denature the solid product processed therein. When the solvent is removed from the solid product in the solvent extraction safety unit 28, it can be recovered, liquefied or transported to the main solvent tank by means of appropriate pipes (not shown). The same happens with the solvent vapors recovered in the segregation unit 52. In cases where there is a net loss of at least part of the solvent during the oil extraction process of the present invention, then a solvent auxiliary tank 55 equipped with its pump 55a can be included in the apparatus 20 to provide the additional solvent required to be distributed through the pipe 34. Alternatively, the solvent vapor recovered in the unit 28 safety solvent extraction can be transported to the injector 29 of gas to be re-used to maintain it above the ambient pressure within the extraction chambers 24. Certainly, it is possible to have 24 extraction chambers filled with solvent vapor, which allows to maintain the desired pressure in them. This does not change the fact that the solvent injected in the liquid state in the extraction chambers 24 drains the oil out of the solid product, while still in a liquid state through the process of the present invention. Certainly, the solvent vapor is used to maintain the required pressure and although there will be a natural exchange between the solvent in the gaseous state and the solvent in the liquid state, the solvent in the liquid state remains essentially in the liquid state. Alternatively, when the solvent vapor is not used to adjust and maintain the pressure on the environment in the extraction chambers 24, then another gas can be used in the gas injector 29 which will not react with the oil, the solvent or the solid product, for example, an inert gas or other non-reactive gas such as nitrogen. An optional heating device 53 is provided between the extraction chambers 24 and the outlet valve 26. The heating device 53 is equipped with a heating means, for example, in the form of a heating element 53a, for a light heating of the solid product before it is subjected to a sensor device 51 which detects the oil content in the solid product emided. This detection of the oil content can help the operator to properly adjust the parameters of the extraction chamber to obtain the desired oil content in the solid product at the outlet of the apparatus 20. The sensors known as the sensor 51 work well at a constant temperature and the purpose is, therefore, to maintain the solid product at this constant temperature. In one embodiment, shown in Figure 1, the inlet and outlet valves 22 and 26 are each connected to a vacuum pump 54 and to a compressor 56 that provides the appropriate pressure differentials required to (A) prevent the gases and fluids of the outer atmosphere of the apparatus 20 (for example, the air) are introduced into the extraction chambers 24, and (B) prevent the gases and fluids from the interior of the apparatus 20 (e.g. solvent vapors) leave the apparatus 20 through the valves 22, 26. The valves 22, 26, in particular, include an intermediate chamber where a vacuum will be created to remove all fluids in the same, such as air , before allowing solid products to be transported downstream. Since there is a positive pressure inside the extraction chambers 24, the compressors 56 will also function to pump the gas back into the valves 22, 26. Certain particular embodiments of the valves 22, 26 will now be described, although it should be understood that the present invention is not limited thereto. Figure 2 shows a first embodiment of an inlet valve 22. Although the valve 26 will not be described in detail, it should be understood that the valve 26 is similar to the valve 22. In the embodiment of Figure 2, the inlet valve 22 comprises a hollow housing 200 comprising an internal channel 202 that defines a raw material inlet opening 204 open to the environment, a raw material outlet opening 206 leading to the extraction chambers 24 and an extended air flow shaft between the inlet and the inlet openings 204, 206; departure. A plunger 208 is provided in the inlet opening 204. The entry opening may be located at the lower end of a full funnel, at least partially with the primary material. The housing 200 also comprises an enlarged intermediate portion 210 that defines a portion 21 of the indi- rect digital channel 21 in which a complementary cylindrical rotary valve member 214 can rotate about an axis of rotation., which is perpendicular to the flow axis of primary matter. The rotary valve member 21 4 defines a main body 21 which engages the internal channel 202 of the valve in a fluid-tight manner. The rotary valve member 214 comprises a transverse channel 21 6 in which a piston 21 8 can move longitudinally between a first and a second limit position, corresponding to the two ends of the transverse channel 21 6 of the rotary valve member. An air exhaust port 220, equipped with a filter 222 of solid material which allows the fluids to pass while preventing the solids from passing, is provided on one side with the intermediate portion 21 0 of the housing, separated in an angular manner from the internal valve channel 202 at a 90 ° angle to the right side of Figure 2. An air exhaust port 220 is connected with a selectively activated vacuum pump (number 54 in Figure 1) through a vacuum channel 224, and an air channel 226 in turn, is connected to a gas source (number 56 in Figure 1) is also in communication with the exhaust port 220 of air. The gas circulating through the gas channel 226 may be solvent vapor, or any other suitable gas, for example, such as nitrogen, which will not react chemically with the solvent, the oil or the solid product. A solvent outlet port 228 equipped with a filter 230 of solid material that allows the fluids to pass while preventing the solids from passing, is provided on one side of the filter. the intermediate portion 21 0 of the housing, opposite the air exhaust port, relative to the internal valve channel 202 - namely the left side in Figure 2 The solvent exhaust port 228 is thus angularly separated from the channel 202 I nternal valve at an angle of 90 °, and from the exhaust port of ai re to an angle of 1 80 ° The port 228 of solvent exhaust connects with a vacuum pump activated selectively (number 54 in Figure 1) through a vacuum channel 232, and with an air channel 234 that connects with the outside atmosphere. During use, the valve 22 is initially in a position as shown in Figure 2, with the valve member 214 rotary positioned so that the transverse channel 21 6 is coextensive with the internal valve channel 202 and with the piston 21 8 located in a first position imitate at or near the end of the transverse channel 21 6 which is the closest to the raw material inlet opening 204 In this position, the rotating valve 214, the piston 21 8 is continuously driven towards its first limit position due to the pressure on the environment inside the extraction chambers 24 The raw material, for example, in the form of a solid material carrying granulated oil can be forced by the plunger 208 and by the force of gravity, down to the material inlet opening 204 valve cousin 22. As the raw material is fed into it, the piston 21 8 will gradually be forced into its second limit position, against the pressure impulse within the extraction chambers 24. Eventually, the piston 21 8 will reach its second limit position as shown in Figure 3. At this point, the rotary valve member 214 rotates 90 ° to the right as shown in Figure 4, to the open end of the channel 216 transverse, that is, the end of the transverse channel 216 is not obstructed by the piston 21 8, and enters register with the air exhaust port 220. A vacuum is then created in the exhaust port 220 and consequently, in the transverse channel 21 6, for purging the fluids of the transverse chamber 21 6 by sucking all the fluids out of the transverse channel 21 through the vacuum channel 224. . The solids are retained in the transverse channel 21 through the filter 222. Accordingly, all the air is removed from within the cross channel 216 filled with raw material to prevent the introduction of air into the extraction chambers 24 being allowed. Once the vacuum is obtained, the vacuum pump is stopped and the gas, such as the solvent vapor is injected into the transverse chamber through the gas channel 226, until the pressure within the transverse channel 216 becomes essentially equal to that of inside the extraction chambers 24. Once the above is reached, the rotary valve member 214 will go a second time in the same direction to the right at 90 °, as shown in Figure 5, until the open end of the transverse channel 21 6 is in register with the exit aperture 206 of raw material of the valve 22. Under the force of gravity, and with the piston 21 8 pushed downward as new raw material is fed through the raw material entry aperture 204 by the plunger 208, the raw material present in the transverse channel 21 6 will be forced out and through the raw material exit opening 206. It should be noted that when the rotary valve member 214 is moved to a position in which its open end is in register with the air exhaust port, as shown in Figure 4, its closed end, that is, the end that is obstructed by the piston 21 8, simultaneously remains in register with the solvent exhaust port 228. Then, a vacuum is created through the vacuum channel 232 to purge all the solvent present in the small area at the end of the transverse channel, since the piston 21 9 can not be located exactly in its second limit position and as such Small area may exist accordingly. The gas exhaust port 228 thus helps to prevent the accidental fl ow of gas out of the valve 22. It should be noted that for this purpose, although the piston 21 1 8 has been shown with the opposite upper and lower surfaces flat, they can be made with opposite convex upper and lower surfaces, which have the same radius of curvature as that of the outer surface of the rotary valve member 214. Once the vacuum pump stops purging fluids through the vacuum channel 232, the air at atmospheric pressure is injected through the air channel 234 to fill the void left by the previously purged fluids. In this way, as the rotary valve member rotates another 90 °, all the solvent that may be present between the piston 21 8 and the inner wall of the housing, will have been previously purged to prevent the solvent from accidentally escaping into the atmosphere. Figure 6 shows another embodiment of the valve assembly 300 in accordance with the present invention, which comprises a pair of valves 22a, 22b similar to the valve 22 described above. A buffer 302 is installed over the valves 22a, 22b and a pair of apertures 304, 306 of tapered lower part in the funnel 302 provide access to the respective raw material inlet openings 204, 204 of the valves 22a, 22b. A removable cover 308 allows access to the internal chamber of the funnel 302. A pair of motors 31 0, 31 2 control the plungers 208, 208 of the valves 22a, 22b. The respective raw material outlet openings 206, 206 of the valves 22a, 22b open inside the funnel 314 having an outlet opening 6 of the funnel leading to the extraction chambers 24 (not shown in Figure 6). During use, the valves 22a, 22b operate in a manner similar to the valve 22 described above. The raw material located in the funnel 302 is gradually fed simultaneously to both valves 22a, 22b through their respective raw material inlet openings 204, 204. The raw material is discharged into the respective outlet openings 306, 306 of the valves 22a, 22b, as described above for the valve 22 and the funnel 314 directs the incoming raw material towards the inlet of the extraction chambers 24 (not shown in Figure 6). In one embodiment, valves 22a, 22b will have regular cycles which are displaced one relative to the other More particularly, their respective rotary valve members 214, 214 will be controlled to be angularly displaced at 90 ° at all times, which allows an alternate discharge of primary material from a valve 22a, and then from the other 22b In the embodiment of the invention illustrated in Figure 1, two extraction chambers 24a, 24b, 24c, 24d, 24e, 24e, sequentially connected are shown. The raw material that is transported to the chambers 24 after being fed through the inlet valve 24, it is intended to be continuously transported sequentially through all the extraction chambers 24, namely first through the extraction chamber 24a, then through the extraction chamber 24b and so on, until it reaches the extraction chamber 24e, after which it is transported out of the extra chamber unit. to the heating chamber 53 The transport means for transporting the solid product sequentially along the extraction chambers 24 is provided, for example, in the form of a single impeller which extends through the chamber unit. complete extraction Within the extraction chamber 24, the solvent is dispensed in accordance with the solvent injection parameters for the determined extraction chamber. More generally, the extraction chambers 24 have certain extraction chamber parameters that will influence the extraction. Oil extraction process in the same These parameters of the extraction chamber are adjusted in accordance with each solid product bearing oil to be treated, in accordance with the oil to be collected from the solid product, and in accordance with the solvent to be used. These parameters can also be modified from one extraction chamber 24 to another, when different extraction chamber parameters are desired in different extraction chambers 24. The parameters that can be modified include, but not imitated the type of impeller used, including its geometry, the speed of rotation of the impeller, when it is a rotary impeller such as a piston, the size of the extraction chamber, the speed of flow of solvent to be dispensed in extraction chamber 24, the flow velocity of the composition flowing outside the extraction chamber 24, the manner of dispensing the solvent, such as by providing particular solvent spray patterns, etc. The purpose of controlling these parameters is to calibrate the draining process of the oil within each extraction chamber 24, and consequently, the complete process of oil draining through the assembly of the extraction chamber. Certainly, it is often desirable to achieve certain specific and relatively precise parameters of recovery of the oil in the final product at the outlet of the apparatus, for example, in order to maximize the recovery of the oil or achieve certain oil proportions within the solid product produced.

Figures 7 and 8 show an embodiment of an extraction chamber 24, which ends 400 and 402 upstream and downstream, opposite, respectively, and comprising a hollow housing 404 that defines an internal extraction channel 406 extended between extremes 400, 402 upstream and downstream of the extraction chamber. The downstream end 402 of each extraction chamber 24 is in fluid communication with the end 400 upstream of the adjacent extraction chamber 24 sequentially, up to the last extraction chamber 24e, which communicates with the heating chamber 53. In this way, the same pressure and extraction temperature values can be maintained through the extraction chambers 24. An energy-activated impeller in the form of a plunger 408 extends through the internal channel 406, with the plunger 408 extending through the complete assembly of the extraction chamber, from the inlet valve 22 to the valve 26 of output, including through the heating chamber 53. The ram 408 also comprises a number of stirring blades 41 0 coupled in an integrated manner thereto in designated areas of the extraction chamber 24. The spray nozzles 36, connected to the pipe 34, extend into the internal channel 406. In the embodiment shown in Figures 7 and 8, the particles of the solid product are transported and agitated by the plunger 408 and also agitated with the stirring blades 41 0 in a first portion of each extraction chamber 24, so as to induce the particles of the flotation fluid product to flow in the pattern configuration, for example, according to the pattern shown in dotted lines in the reference number 41 2 in Figure 8. Simultaneously, the nozzles 36 dew and inject the solvent in such a way that they induce the injected solvent into a spiral pattern configuration, for example, according to the spray pattern shown schematically in dotted lines on the Reference number 414 in Figure 8. The spiral pattern of the solvent will raise some particles of solid product from free floating in the spiral, which improves the effect of the solvent on the particles of the solid product, which improves the oil runoff. Other alternative solvent injection means can be contemplated, with which the solvent is injected into the extraction chambers to drain the oil from the solid products circulating therein. The solvent thus injected into the extraction chamber 24 will drain a certain proportion of oil from the oil-bearing product, to form a composition defined as a mixture of solvent and oil. Downstream of the spray nozzles 36 in the extraction chamber 24, a composition collection trough 41 6 is provided below the filter 41. The composition, carried by the impeller 408, will flow and be collected in the tundish 416, with solid product particles retained by fi lter 41 8 within channel 406. It should be understood that an appropriate filter should be selected in accordance with the type of solvent to be used, the type of oil to be collected, and the type of solvent to be used. of solid product to be processed. The composition collected in the tundish 41 6 will be carried away through an outlet channel 38 of corresponding composition (Figure 1) communicating with the tundish 41 6. The extraction chamber 24, accordingly, defines two operative portions. different, namely a first portion of solvent injection, wherein the solvent is injected into the particles of solid stirred material and a second portion of compound collection, in where the composition is collected. The stirring blades 41 and the spray nozzles 36 are present only in the injection portion of the solvent, and the filter 41 8 and the tundish 41 6 are present only in the composition collection portion. In accordance with the invention, it can be seen that a continuous process for extracting oil from a solid oil-bearing product is provided, whereby the solid product is continually fed through the inlet valve 22, continuously flowing through the chambers 24 of extraction and it is continuously collected in the outlet valve 26. Simultaneously, in each extraction chamber 24, a certain proportion of oil is continuously extracted from the oil carrier product, whereby, the final proportion of oil is extracted at the outlet of the complete assembly of the extraction chamber. It is contemplated, in accordance with one embodiment, to provide appropriate sensors of a known construction (not shown), similar to the sensor 51, to detect the proportion of the remaining oil in the solid product at the outlet of each extraction chamber 24 and use a control mechanism (not shown) for dynamically controlling the parameters of the extraction chamber in each extraction chamber 24, in order to obtain the proportion of residual oil desired in the solid products in the outlet of the apparatus 20. For example , when it is predetermined that 50%, 90% or even 1 00% of the solid product oil must be recovered, then the control mcm dynamically will control in each extraction chamber 24 the flow velocity of the solvent, the setting of the solvent dew pattern, the rotation speed of the plunger driver, and any other parameters of the extraction chamber, in order to modify the parameters of the oil extraction to obtain the desired result in accordance with the proportion of oil detected at the outlet of each extraction chamber 24. According to the present invention, the series of extraction chambers 24 through which the solid product is transported sequentially, will make it possible to extract an important proportion (when it is convenient), if not all, the oil of the product. solid. Indeed, each pass of the solid product through an extraction chamber 24 allows the oil to be drained out of the solid product, and consequently provides a series of extraction chambers 24 that allow the proportion of oil in the solid product to be exponentially inverse, which tends towards zero, and eventually reaches zero. This oil extraction can also be calibrated by means of dynamic control over oil extraction within the extraction chambers, as described above. Certainly, contrary to the prior art known to the applicant, the present invention makes use of a process to extract the oil in which the parameters of the extraction chamber can be modified, during the operation of the apparatus 20 in accordance with the results that they are detected by the sensors, either at the output of the apparatus and / or at the outlet of each individual extraction chamber 24. By dynamically controlling and eventually modifying the parameters of the extraction chamber, such as the spray patterns of the solvent and the flow rate and the speed of the impeller, for example, the proportion of oil extraction can be controlled in a controlled manner. selective In addition to relying on the sequence of extraction chambers, the selective rate of oil extraction is also based on the manner in which the oil is extracted into each extraction chamber. Certainly, not only the parameters of the extraction chamber can be modified dynamically, but also the particular agitation of the solid product particles within each extraction chamber 24, together with the solvent spirals created by the spray nozzles 36 in FIG. each extraction chamber 24, which provides the possibility of a high extraction rate in each extraction chamber 24. It should be understood that a high extraction rate is referred to herein as an option or possibility for the operator of the apparatus 20. Certainly, in some cases maximum extraction may be desirable as in the case of land decontamination, in other cases, as in The preparation of food may be desirable a certain proportion of oil content in the solid product produced. Having the extraction pressure on the ambient pressure, for example, at approximately 10 bars, is advantageous not only because it allows the use of a solvent in the liquid state, which would normally be in the gaseous state at ambient pressure, at a value of determined temperature, if not because it also increases the efficiency of the process. Certainly, the filters with the wrong one can be used through which the composition will be transferred, when the extraction pressure is important, to promote the passage of the composition to through the filters 41 8. It should be noted that the respective separation pressure and extraction pressure within the separation unit 48 and the extraction chambers 24 may differ. An alternative embodiment of the invention is shown in Figure 9, where an apparatus 500 of the batch process is shown. The apparatus 500 comprises an extraction chamber 502 which includes a raw material inlet 504, which can be closed by a door (not shown) once the raw material is fed into the extraction chamber 502. The extraction chamber 502 includes a first thick filter 506 and a flowing outlet 508 leading to a second fine filter 51 0. During use, a batch of raw material comprising the solid carrier product is fed through the raw material inlet 504, then the door of the extraction chamber 502 is closed and the process can be started in oil extraction batch. To achieve oil extraction, the solvent in the main oil tank 2 is injected into the extraction chamber 502 by means of a solvent injection pump 514. The solvent thus injected drains a certain proportion of oil from the oil carrier product to form the composition comprising a mixture of oil and solvent. The composition is collected through the 506 g filter while the coarse particles of the solid product are retained in the extraction chamber 502 and then through the fine filter 51, while the fine particles of the solid product are retained by the filter. fi lter 51 0 fine. The composition thus collected is transported to a unit 51 6 of liquid to liquid separation, wherein the oil is separated from the solvent through an appropriate liquid-to-liquid separation process, as one of the processes of molecular weight, specific gravity or viscosity differential. The solvent separated from the oil is transported back to the main tank of the solvent, while the oil separated from the solvent is collected at the exit 51 8 of the oil. Also, a solvent vapor circuit 520 is provided which involves a solvent vapor pump 522 which will transport the residual solvent vapor from the extraction chamber 502 to bring the solvent back into the solvent tank 2 2, where it will be requested in an empty state, once the batch of solid material has been treated. This prevents the solvent vapor from escaping into the atmosphere once the door of the extraction chamber 502 is opened to remove the solid product therefrom. In the embodiment of Figure 9, the pressure and temperature values are also controlled in the extraction chamber 502 and in the main solvent tank 2 to keep the solvent mainly in the liquid state through the loop circuit. closed of the solvent. Any solvent vapor transported by pump 522 back into tank 51 2 is subjected to temperature and pressure conditions that will cause the solvent vapor to precipitate. As with the first mode, which shows a continuous process, the remaining solvent mainly in liquid state through its closed loop circuit prevents the heat from having to be used to separate the oil from the solvent upon evaporation of the solvent. This absence of heat helps to avoid the denaturing of the oil. Any other modification for the present invention, which does not deviate from the scope of the appended claims, will be apparent to those skilled in the art, and is also considered to be included within them.

Claims (9)

1 . A process for separating dissolved substances from a solid product carrying dissolved substances, characterized in that it comprises the steps of: providing an extraction chamber with predetermined extraction temperature and pressure values; control the extraction pressure to keep it above the value of the environmental pressure; control the extraction temperature to maintain it at a temperature that does not denature the dissolved substances or the solid product; feeding the solid product carrying dissolved substances in the extraction chamber; to provide a solvent that is primarily in liquid state at the temperature and extraction pressure values, the dissolved substances are solids in the solvent at the temperature and extraction pressure values; i injecting the solvent in the liquid state in the carrier product of dissolved substances in the extraction chamber to drain the dissolved substances from the solid product with the solvent; recovering dissimilarly, the solid product from which at least a portion of unsoldered substances has been drained, and a composition comprising a mixture of solvent and dissolved substances drained from the solid product; transporting the composition to a separation unit with determined temperature and separation pressure values, with the solvent remaining mainly in the liquid state at the temperature and separation pressure values, and with the temperature of separation temperature controlled to keep it at a temperature that does not denature the dissolved substances; separating the solvent from the dissolved substances in the separation unit through a liquid-to-liquid separation process; and distinctly recovering the solvent and separate dissolved substances in the separation unit, wherein the solvent remains mainly in the liquid state through the process.

2. The process according to claim 1, characterized in that the solvent is in the gaseous state at ambient temperature and pressure values, but mainly in the liquid state at the temperature and extraction pressure values.

3. The process according to claim 2, characterized in that the extraction and separation temperatures are equal to the ambient temperature, with the solvent being maintained mainly in the liquid state through the process by means of the extraction pressures and separation that remain on the environmental pressure.

4. The process according to claim 1, characterized in that the solvent recovered from the separation unit is reused inside the extraction chamber to extract additional dissolved substances from the material carrying dissolved substances. additional, whereby the solvent is used within a closed-loop circuit and remains mainly in the liquid state through the closed-loop circuit.

5. The process according to claim 1, characterized in that the liquid separation process to the liquid is one of the processes of molecular weight, specific gravity, viscosity differential.

6. The process according to claim 1, characterized in that the process is a batch process, with the step of feeding the solid product carrying dissolved substances in the extraction chamber that is achieved when loading a batch of product. solid carrier of dissolved substances in the extraction chamber.

7. The process according to claim 1, characterized in that the process is a continuous process, with the step of feeding the solid product carrying dissolved substances in the extraction chamber, which is achieved when the product is continuously circulated. carrier of loose substances through the extraction chamber and continuously recover the solid product from which at least a portion of oil has been drained at an outlet of the extraction chamber.

8. The process according to claim 7, characterized in that the extraction chamber comprises a number of extraction chamber portions through which the product carrying dissolved substances for sequentially circulating the substances passes through in a sequential manner. isueltas of the solid product containing dissolved substances, with each portion of extraction chamber that defines parameters of corresponding extraction chamber and with at least some parameters of the extraction chamber that differ from one extraction chamber to another.

9. The process according to claim 7, characterized in that the step of injecting the solvent into the extraction chamber is achieved by means of at least one spray nozzle extended in the extraction chamber with the ability to form a spray pattern. solvent spray with spiral shape. The process according to claim 9, characterized in that the step of continuously circulating the product carrying dissolved substances through the extraction chamber is achieved by means of a plunger equipped with stirring blades, the process also comprises the step of stirring the particles of the product carrying dissolved substances to promote the formation of free floating solid product particles that will be carried, at least partially, within the spray pattern of spiral solvent. eleven . The process according to claim 1, characterized in that the step of controlling the extraction pressure to maintain it above the ambient pressure value is achieved by means of a gas nozzle which injects into the extraction chamber one of a steam of the solvent and a gas that is not reactive with the solvent, oil and the solid product. 12. An apparatus for separating oil from an oil-bearing solid product, characterized in that it comprises: an extraction chamber; a solvent injector for injecting solvent into the extraction chamber for draining the oil from the oil-bearing solid product to form a composition comprising a mixture of solvent and oil; a composition outlet in the extraction chamber to collect the composition; and a liquid-to-liquid separation unit bonded to the outlet of the composition, for separating the composition into its respective oil and solvent components; wherein the solvent injected into the extraction chamber is mainly in the liquid state to drain the oil from the oil-bearing product to form a composition therewith, and remains mainly in the liquid state in the liquid-liquid separation unit. The apparatus according to claim 12, characterized in that it further comprises: an inlet valve located upstream of the extraction chamber and which allows the solid oil carrier product to enter the extraction chamber without allowing the passage of the fluid between the extraction chamber and the atmosphere; an outlet valve located downstream of the extraction chamber and allowing the solid product to exit from which the oil has drained from the extraction chamber without allowing the passage of fluid between the extraction chamber and the atmosphere; and an impeller to circulate the solid product from the valve entry through the extraction chamber to the outlet valve; where the apparatus allows the continuous feeding of the solid product in the inlet valve, the continuous flow of oil from the solid product, the continuous exit of the solid product from the outlet valve and the continuous collection of composition in the salt ida of composition. 4. The apparatus according to claim 12, characterized in that the liquid separation unit is a separation unit that makes use of one of the processes of molecular weight, specific gravity and viscosity differential. The apparatus according to claim 1, characterized in that it also comprises a main solvent tank connected to the solvent injector to provide solvent thereto, the separation unit is connected to the main tank of solvent for transporting the solvent in a liquid state separated from the oil in the separation unit, back to the main solvent tank, where the solvent circulates within a closed loop circuit in the apparatus and remains mainly in the liquid state inside the apparatus. 1 6. The apparatus in accordance with claim 1 3, characterized in that the extraction chamber comprises a number of successively contiguous extraction chamber portions, the impeller sequentially circulates the solid product through the portions of the extraction chamber, the solvent injector injects the solvent in each of them. the portions of the extraction chamber and a composition outlet collect the composition in each portion of the extraction chamber. 17. The apparatus according to claim 13, characterized in that the solvent injector includes at least one spray nozzle extended in the extraction chamber and with the ability to form a spiral spray pattern of solvent. 18. The apparatus according to claim 17, characterized in that the impeller comprises a plunger equipped with stirring blades that will promote the formation of free floating solid product particles to be carried, at least partially, within the pattern of solvent spray with spiral shape. 19. The apparatus according to claim 13, characterized in that it further comprises a solvent extraction safety unit downstream of the outlet valve to remove solvent vapor by the application of heat in the solid product. 20. A valve that defines an inlet and an outlet, to allow the solid product to pass from the inlet to the outlet while preventing the fluids from being exchanged between the inlet and the outlet, characterized in that it comprises: an internal channel extended between the inlet and the exit; a fluid exhaust port in the internal intermediate channel at the inlet and outlet, the fluid exhaust port is in communication with a vacuum pump and is equipped with a filter that allows the passage of fluids through the exhaust port of fluid but prevents the passage of solid product through the fluid exhaust port; a rotary valve member located in the internal channel and that rotated therein, the rotary valve member comprises a main body that engages the inner channel in a fluid-tight manner and having an elongated transverse channel, the rotary valve member has the ability to rotate between a first position where the transverse channel is coextensive and communicates with the internal valve channel and where the primary body obstructs the fluid exhaust port, and a second position where the transverse channel is in register and communicates with the port of fluid leakage and the primary body obstructs the internal valve channel; a piston that can move longitudinally within the elongated transverse channel between two limit positions. SUMMARY The process and the apparatus are used to remove a dissolved substance from a solid product carrying dissolved substances by means of a solvent that remains in a liquid state through a complete extraction recirculation conducted in the extraction chamber (24). The solvent and the dissolved substances are collected as a composition in the container 42 and then separated from one another in a separation vessel (48). The temperatures and pressures are maintained in order to maintain the solvent in liquid state both in the extraction chamber (24) and the separation vessel (48).