System for internal backmixing of reactant mass in a rotating cylindrical reactor

Abstract

The present invention relates to a system for backmixing of reactant mass in a rotating cylindrical reactor. In this context, the present invention provides a system for internal backmixing of reactant mass in a rotating cylindrical reactor (2), comprising a first set of drag fins (27) configured to pull the reactant mass in a first direction and a second set of drag fins (28) configured to pull the reactant mass in a second direction opposite the first direction, the first set of drag fins (27) and the second set of drag fins (28) being arranged internally along the length of the cylindrical rotating reactor (2). The system allows mixing of a portion of the reactant mass at a more advanced stage of the reactor with another portion at an earlier stage of processing, homogenizing the temperature of the reactant mass and increasing reactor productivity.

Description

[Technical Field]

[0001]

[0001] The present invention relates to a system for backmixing of reactant masses, in particular to a system for backmixing of reactant masses in a rotating cylindrical reactor. [Background technology]

[0002] Among the most common applications of rotating cylindrical reactors are the drying of organic matter and food products, the torrefaction of biomass and food products, the pyrolysis of biomass, and the thermal treatment of coal. Generally, these processes seek to exploit the properties of the rotating cylindrical reactor that give the highest possible productivity associated with the quality of the solid product.

[0003]

[0003] The biomass pyrolysis process involves preliminary endothermic reactions of drying (up to 180 °C) followed by torrefaction (up to 340 °C), followed by highly exothermic chemical reactions around 350 °C characterized by significant mass loss of the reactant system and significant changes in the chemical structure of the solid biochar.

[0004]

[0004] In pyrolysis, the organic matter in biomass is thermochemically decomposed by heating in the absence of oxygen to produce products with high carbon content. The product characteristics, the relative proportions of gas, liquid, and solid phases, and the energy required for the process depend on several factors, including the nature of the precursor biomass and reactant atmosphere, pressure, reactant gas uptake rate, temperature, heating rate, and particle size.

[0005]

[0005] The pressure and draw rate of the reactant gases affect the process by which the reactant gases recombine with the solid matrix product, biochar, a process called chemical vapor deposition.

[0006]

[0006] Temperature, heating rate and particle size affect the overall heat transfer rate from the external medium to the interior of the biomass particle and therefore the productivity of the process.

[0007]

[0007] Considering the thermodynamic evolution of the biomass pyrolysis process, with an endothermic initial stage followed by an exothermic final stage, and the goal of realizing a higher throughput rotating reactor, a primary goal sought by designers of rotating cylindrical reactors is a way to mix a portion of the reactant mass in the final stage with the reactant mass introduced into the reactor in the initial processing stage.

[0008]

[0008] In rotating cylindrical reactors, one way of achieving this mixing has been through a screw conveyor external to the reactor. The solid product at the discharge of the rotating cylindrical reactor is divided and a portion is returned via a closed screw conveyor and re-injected into the feed throat of the rotating cylindrical reactor. However, this is a complicated system because the reaction mass is at a high temperature of about 400°C or more and the product does not come into contact with the atmosphere. Summary of the Invention [Problem to be solved by the invention]

[0009]

[0009] An object of the present invention is to solve the above problems practically and efficiently.

[0010]

[0010] The present invention has a first object of providing a system for internal backmixing of reactant mass in a rotating cylindrical reactor, which makes it possible to mix a portion of the reactant mass at a more advanced stage of the reactor with another portion at an earlier stage of processing, homogenize the temperature of the reactant mass, and increase the productivity of the reactor.

[0011]

[0011] The present invention has a second object of providing a system for internal backmixing of reactant mass in a rotating cylindrical reactor which eliminates the need for an external system for moving said mass and greatly simplifies reactor design. [Means for solving the problem]

[0012]

[0012] In order to achieve the above-mentioned objectives, the present invention provides a system for internal backmixing of a reactant mass in a rotating cylindrical reactor, comprising: (i) a first set of drag fins configured to pull the reactant mass in a first direction; and (ii) a second set of drag fins configured to pull the reactant mass in a second direction opposite to the first direction, wherein the first set of drag fins and the second set of drag fins are disposed internally along the length of the cylindrical rotating reactor.

[0013] In the following detailed description, reference will be made to the accompanying drawings and their respective reference numerals. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 shows a cross-sectional side view of a cylindrical reactor equipped with a backmixing system according to a preferred embodiment of the present invention. [Figure 2] FIG. 1 shows a plan view of the interior side of a rotating cylindrical reactor. DETAILED DESCRIPTION OF THE INVENTION

[0015]

[0016] It should be emphasized beforehand that the following description begins with preferred embodiments of the present invention, however, as will be apparent to those skilled in the art, the present invention is not limited to these specific embodiments.

[0016]

[0017] The present invention solves the above technical problem by providing a system for internal backmixing of the reactant mass in a rotating cylindrical reactor 2. For the purposes of this specification, a rotating cylindrical reactor 2 is defined as a cylindrical body of revolution having openings at its ends.

[0017]

[0018] According to a preferred embodiment shown in Figures 1 and 2, the system of the present invention comprises a first set of drag fins 27 configured to pull the reactant mass in a first direction and a second set of drag fins 28 configured to pull the reactant mass in a second direction opposite the first direction, the first set of drag fins 27 and the second set of drag fins 28 being disposed internally along the length of the rotating cylindrical reactor 2.

[0018]

[0019] As shown in the cross-sectional side view of FIG. 1, the first set of drag fins 27 and the second set of drag fins 28 are preferably sheet metal having a height that typically corresponds to about one-tenth the diameter of the rotating cylindrical reactor 2.

[0019]

[0020] Preferably, the first set of drag fins 27 and the second set of drag fins 28 are attached to the inside of the rotating cylindrical reactor 2 by welding. However, the fins may be attached to the inside of the rotating cylindrical reactor 2 by any attachment method known in the art.

[0020]

[0021] 2 shows a plan view of the inner surface of the side of the rotating cylindrical reactor 2. In the cylindrical shape, point A coincides with point A', and point B coincides with point B'. In this example, which actually consists of a manufacturing plan, the inner side of the rotating cylindrical reactor 2 was divided into 36 sections along its length and 8 sections along its width. It is worth pointing out that this division of sections is only representative and illustrative, and other configurations can be implemented by a person skilled in the art.

[0021]

[0022] In this example, the length and diameter of the rotating cylindrical reactor 2 are L and D, respectively, the number of imaginary lines along the length and width of the flat side are n and m, respectively, and the fins are plates attached at an angle to the longitudinal lines a, b, c, d, e, f, g, and h. .centre The inclination of the fin is as shown in Figure 2.

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[0022]

[0023] The plan view of FIG. 2 also shows different sets of drag fins 27, 28 arranged along longitudinal lines a, b, c, d, e, f, g, and h, where the drag fins 27, 28 of the sets are adjacent to each other and parallel to the longitudinal axis of the cylindrical rotary reactor 2. The first set of drag fins 27 is configured to pull the reactant mass from the feed inlet to the outlet (left to right). The second set of drag fins 28 is configured to pull the reactant mass from the outlet to the feed inlet (right to left). Obviously, the ultimate goal is for all reactant mass entering the feed inlet to be processed and exiting at the outlet, so the total area of ​​all fins of the first set of fins 27 that contact the reactant mass is greater than the total area of ​​the second set of fins 28. This can be achieved, for example, by having a greater number of fins in the first set of drag fins 27 compared to the second set of drag fins 28. Alternatively, the two sets of fins may have the same number, but the fins of the first set of drag fins 27 may have a greater length and / or width than the fins of the second set of drag fins 28.

[0023]

[0024] First setIn implementations where the drag fins 27 have a greater number of fins, the number of fins that carry the reactant mass forward (from the feed inlet to the outlet) will always be greater than the number of fins that carry the reactant mass backward. For example, for every eight fins in the rotating cylindrical reactor 2, six may belong to the first set of drag fins 27 and two may belong to the second set of drag fins 28. In this case, there are effectively six fins that perform the job of carrying material forward, and the remaining two serve to backmix the reactant mass, mixing some of the reactant mass at a more advanced (higher temperature) stage of the reaction with some of the reactant mass at an earlier (lower temperature) stage of the reaction.

[0024]

[0025]

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[0025]

[0026] Thus, as revealed above, the present invention provides a system for internal backmixing of reactant mass in a rotating cylindrical reactor, which makes it possible to mix a portion of the reactant mass at a more advanced stage of the reactor with another portion at an earlier stage of the process, homogenizing the temperature of the reactant mass and increasing the productivity of the reactor. The system thus eliminates the need for an external system for moving said mass, considerably simplifying the design of the reactor.

[0026]

[0027] Numerous variations are possible that affect the scope of protection of the claims, and it is therefore emphasized that the present invention is not limited to the specific configurations / embodiments described above. The inventions described in the claims of the present application as originally filed are set forth below. [C1] In a system of internal backmixing of the reactant mass in a rotating cylindrical reactor (2), a first set of drag fins (27) configured to pull the reactant mass in a first direction; a second set of drag fins (28) configured to pull the reactant mass in a second direction opposite the first direction; Equipped with 1. An internal backmixing system, wherein the first set of drag fins (27) and the second set of drag fins (28) are disposed internally along the length of a rotating cylindrical reactor (2). [C2] The internal backmixing system of claim C1, characterized in that the first set of drag fins (27) are configured to pull the reactant mass from the feed inlet to the outlet of the rotating cylindrical reactor (2). [C3] 3. The internal backmixing system of claim 1 or 2, wherein the second set of drag fins (28) are configured to pull the reactant mass from the outlet of the rotating cylindrical reactor (2) to the feed inlet. [C4] The internal backmixing system according to any one of claims C1 to C3, characterized in that the first set of drag fins (27) are adjacent to the second set of drag fins (28), both of which are parallel to the longitudinal axis of the rotating cylindrical reactor (2). [C5] The internal backmixing system according to any one of claims C1 to C4, characterized in that the first set of drag fins (27) and the second set of drag fins (28) are attached to the inside of the rotating cylindrical reactor (2) by welding. [C6] An internal backmixing system according to any one of claims C1 to C5, characterized in that the total area of ​​all fins of the first set of fins (27) in contact with the reactant mass is greater than the total area of ​​the second set of fins (28). [C7] The internal backmixing system of claim C6, characterized in including a greater number of fins in the first set of drag fins (27) compared to the second set of drag fins (28). [C8] The internal backmixing system of claim C6, characterized in that the fins of the first set of drag fins (27) have a greater length and / or width than the fins of the second set of drag fins (28).

Claims

1. In an internal backmixing system of the reactant mass contained in the rotating cylindrical reactor (2), a first set of a plurality of fins (27) configured to pull a reactant mass in a first direction from a feed inlet of the rotating cylindrical reactor to an outlet of the rotating cylindrical reactor; a second set of fins (28) configured to pull the reactant mass in a second direction opposite the first direction from the outlet to the feed inlet; Equipped with the first set of fins and the second set of fins are disposed internally along the length of the rotating cylindrical reactor and adjacent to one another; the first set of fins and the second set of fins are attached to the inside of the rotating cylindrical reactor by welding; An internal backmixing system, wherein a total area of ​​said first set of fins in contact with said reactant mass is greater than a total area of ​​said second set of fins.

2. 2. The internal backmixing system of claim 1, wherein the fins in the first set of fins have a greater length and / or width than the fins in the second set of fins.

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