Continuous thermochemical processing device

Abstract

Thermochemical treatment device (1) comprising: - a chamber (10); - a material inlet port (18) for material (80) and a material discharge port (19) for material (80); - a steam injection device (60) for steam (50); - a screw-type propeller (30) extending within the internal volume (15); wherein the steam injection device (60) for steam (50) includes a steam diffusion conduit (61) for steam (50). Figure for the abbreviation: Figure 1

Description

Title of the invention: Continuous thermochemical treatment device. Technical field.

[0001] The present invention relates to continuous chemical processing, and more particularly to a thermal hydrolysis device using steam injection. Thermal hydrolysis is a chemical process consisting of the controlled degradation of organic substances at high temperature and under the action of steam, enabling the efficient thermochemical conversion of complex organic materials (sludge, agricultural waste, biomass) into valuable compounds in various industrial sectors, such as fine chemicals, energy production, and the manufacture of specialty chemicals. PREVIOUS STATE OF THE ART

[0002] Thermal hydrolysis is a chemical decomposition technique that involves using high temperatures and steam to break the complex molecular bonds of organic matter. This process converts this matter into smaller chemical products, such as organic acids, alcohols, and aromatic compounds. Thermal hydrolysis offers potential advantages in waste valorization, renewable energy production, and the creation of sustainable chemicals.

[0003] Conventionally, a thermal hydrolysis device using steam injection consists of a hermetically sealed reaction chamber into which the organic materials to be treated are introduced. Steam is then injected into the chamber at specific temperatures and pressures, thus creating an environment conducive to thermal hydrolysis. The organic materials are exposed to these conditions for a controlled period, thereby enabling the breakdown of complex molecular bonds. The efficiency of the device is generally improved by the use of rotary mixers.

[0004] Known devices present three main problems: significant heat loss through the enclosure walls, long loading / unloading times, and obstruction of the enclosure and / or mixers by the organic matter to be treated. This results in longer material processing times (loading / unloading time, unclogging operations, maintenance) and significant energy costs, which limit the widespread adoption of this type of installation despite its numerous advantages. SUBJECT OF THE INVENTION

[0005] The invention aims to reduce the operating costs of a thermochemical treatment device. Description of the invention

[0006] To this end, a continuous thermochemical treatment device for the material to be treated is provided, comprising a chamber extending along a longitudinal axis and defining an internal volume of the chamber, a material inlet port and a material discharge port opening respectively into a radial feed plane and a radial discharge plane, the radial feed plane and the radial discharge plane being separated by a first longitudinal distance, a steam injection device for the internal volume, and a screw-type propeller extending within the internal volume and arranged to transfer the material from the inlet port to the discharge port. According to the invention, the steam injection device comprises a steam diffusion duct extending within the internal volume over a second distance considered along the longitudinal direction, which is at least equal to half the first distance.

[0007] According to other specific, non-exclusive and optional embodiments of the invention: - the diffusion duct extends in a direction substantially parallel to the longitudinal axis; - the diffusion duct extends along the longitudinal axis; - the injection device is arranged to perform a steam injection in an essentially radial direction; - the propeller includes a helical groove rigidly attached to the steam diffusion duct - the helix includes a helical groove separate from the vapor diffusion duct; - the helical groove is attached to a wall of the enclosure; the helix is ​​driven; - the enclosure includes a partition which separates the internal volume into a material processing volume and a steam supply volume, the diffusion duct including a steam supply portion extending into the steam supply volume; - the diffusion duct includes perforations; - the device includes a hollow shaft extending in the direction longitudinal and comprising the diffusion conduit, a helical groove being added to the shaft to define the helix, the shaft including radial perforations to connect an internal shaft conduit to the volume internal to the enclosure, the enclosure comprising a radial wall which separates the internal volume into a material processing volume and a steam supply volume, the diffusion duct comprising a supply portion extending into the steam supply volume, the shaft comprising an end integral with a drive actuator for rotating the shaft around a longitudinal axis of rotation.

[0008] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

[0009] Reference will be made to the attached figures, among which:

[0010] [Fig-1] [Fig.1] is a schematic cross-sectional representation of the device the invention.

[0011] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0012] As a preliminary matter, a longitudinal direction and a radial direction which is orthogonal to the longitudinal direction are defined.

[0013] With reference to [Fig. 1], the continuous hydrothermal carbonization device according to the invention, and generally designated 1, comprises a cylindrical enclosure 10 extending along a longitudinal axis Ox. The enclosure 10 includes a peripheral wall 11 which is closed at its lower end 11.1 and at its lower end 11.2 respectively by a lower closing wall 12 and an upper closing wall 13 extending transversely with respect to the axis Ox. The enclosure 10 also includes a partition 14 which separates the internal volume 15 of the enclosure 10 into a treatment volume 16 for the material 80 to be treated and a steam supply volume 17 for the steam 50.

[0014] An inlet port 18 for material 80 and an outlet port 19 for material 80 open respectively into a radial supply plane PrA and into a radial outlet plane PrE, here located in the respective vicinity of the partition 14 and the wall 13.

[0015] The discharge planes PrE and PrA supply planes are separated by a first longitudinal distance DHA. The inlet ports 18 and discharge ports 19 are, here, implemented as radial conduits welded to the wall 11 to open into the treatment volume 16 respectively through openings 18.1 and 19.1 made in the wall 11. The enclosure 10 also includes a steam supply port 20 50, here implemented as a radial conduit welded to the wall 11 and opening into the supply volume 17.

[0016] The processing device 1 also includes a worm-type helix 30 extending into the processing volume 16.

[0017] As shown in [Fig. 1], the helix 30 comprises a tubular shaft 31 extending along the longitudinal direction Ox and onto which a helical spline 32 is welded. The shaft 31 defines an internal conduit 33 which is closed by a lower plug 34.1 and a lower plug 34.2

[0018] The shaft 31 extends through the partition 14 and is mounted to rotate relative to the enclosure 10 by means of two bearings 35.1 and 35.2 respectively attached to the walls 12 and 13.

[0019] The shaft 31 includes a lower end 36 attached to a geared motor 37 for rotating the shaft 31 around the Ox axis. The shaft 31 therefore includes a supply portion 38 extending into the supply volume 17 and a diffusion portion 39 extending into the treatment volume 16.

[0020] The shaft 31 includes radial perforations 40 that connect the internal conduit 33 to the internal volume 15. The perforations 40 are made on both the supply portion 38 and the diffusion portion 39. More precisely, the perforations 40 are made in the form of a plurality of sets 41 of eight perforations 40.1 made on the same radial plane at forty-five degrees to each other. Here, thirteen sets 41.1 to 41.13 of perforations 40 are shown. Sets 41.1 to 41.5 are made on the feed portion 38 of the shaft 31 and sets 41.6 to 41.13 are made on the diffusion portion 39 of the shaft 31. Relative to the inlet port 18, set 41.6 is a proximal set and set 41.13 is a distal set.

[0021] The shaft 31 constitutes a steam injection device 60 which includes a steam diffusion conduit 61 in the treatment volume 16, in the form of the diffusion portion 39, as well as a steam supply portion 38. The diffusion conduit 61 extends in the volume 16 over a second distance D6[, considered along the longitudinal direction of the Ox axis, which separates the proximal assembly 41.6 and the distal assembly 41.13. The second distance D6i is, here, substantially equal to the first distance DEA.

[0022] During operation, steam 50 is supplied to the feed volume 17 through port 20. The steam 50 enters the internal conduit 33 through perforations 40 in assemblies 41.1 to 41.5 and travels through the internal conduit 33 to the diffusion portion 39. The rotation of the propeller 30 is also controlled by electrically supplying the geared motor 37. The material 80 to be treated is introduced into the treatment volume 16 through the feed port 18. Due to the rotation of the propeller 30, the material 80 is transferred from port 18 to the discharge port 19. During its passage through the treatment volume 16 between ports 18 and 19, the material 80 is subjected to an injection of steam 50 through perforations 40 in assemblies 41.6 to 41.13. The injection of steam 50 is carried out according to this method of realization, along an essentially radial direction. The management of the thermochemical conversion of materials 80 can be done by acting in particular on the steam flow rate 50 and on the rotation speed of the propeller 30.

[0023] A reliable thermochemical conversion device is obtained. Indeed, the heat diffusion from inside the internal volume 15 of the enclosure 10 improves the energy efficiency of the treatment device 1 compared to known devices. In fact, heat losses occur mainly at the wall 11. By the time the heat supplied by the steam 50 injected from inside the enclosure 10 reaches the wall 11, it has already largely transferred its energy to the material 80. The propeller 30 is a robust and reliable mixing means that is capable of self-cleaning by friction with the wall 11, reducing the risk of clogging of the treatment device 1.

[0024] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0025] In particular, - although here the propeller includes a helical groove attached to the steam diffusion duct, the invention also applies to other configurations of the propeller such as for example a propeller including a helical groove separate from the steam diffusion duct, the helical groove being able to be attached to the wall of the enclosure; - although here the diffusion duct is a straight duct extending along the longitudinal axis, the invention also applies to other configurations of the diffusion duct such as for example a helical duct attached to an inner or outer edge of the helix; - although here the device includes a tubular shaft fitted with plugs, the invention also applies to other types of hollow shafts such as a shaft drilled and plugged at one end or a conduit made by additive manufacturing; - although here the device is a hydrothermal carbonization device, the invention also applies to other types of continuous thermochemical treatment such as hydrolysis or hot rehydration; - although here the treatment device includes a steam supply volume, the invention also applies to other types of steam supply for the steam injection device such as, for example, a conduit connected at one end of the shaft; - although here the power, inlet and outlet ports open into the internal volume of the enclosure through holes made in the wall for To achieve steam injection, material supply and discharge in a radial direction, the invention also applies to other types of ports such as ports opening into the partition or wall in longitudinal or any other direction. The radial plane considered is then the plane of the partition or wall; Although here the groove is attached by welding to the diffusion duct, the invention also applies to other means of rigidly attaching the groove to the diffusion duct such as screwing, gluing, or solid machining; Although here the radial perforations are made in the form of sets of eight made at forty-five degrees, the invention also applies to other means of carrying out steam injection such as perforations in sets of two to eight or more than eight, or even a central porous conduit; Although here the second distance is substantially equal to the first distance, the invention also applies to other configurations of the diffusion duct, such as a diffusion duct which extends over a second distance considered along the longitudinal direction equal to or greater than half of the first distance; Although here the screw includes a geared motor to ensure its rotation, the invention also applies to a fixed screw for guiding the material to be treated, the material to be treated being injected under pressure; Although here the steam injection is carried out in an essentially radial direction, the invention also applies to other types of steam injection orientation such as, for example, injection in a direction comprising an essentially longitudinal component; Although here the device is described in application to a hydrothermal carbonization process, the invention also applies to other types of thermochemical treatment, such as a hydrolysis process.

Claims

Demands

1. A continuous thermochemical treatment device (1) for material (80) to be treated, comprising: - a chamber (10) extending along a longitudinal axis (Ox) and defining an internal volume (15) of the chamber (10); - a material (80) inlet port (18) and a material (80) outlet port (19) opening respectively into a radial feed plane (PRA) and a radial discharge plane (PRE), the radial feed plane (PRA) and the radial discharge plane (PRE) being separated by a first longitudinal distance (DEA); - a device for injecting steam (50) into the internal volume (15); - a screw-type propeller (30) extending into the internal volume (15) and arranged to transfer the material (80) from the inlet port (18) to the discharge port (19);in which the steam injection device (60) includes a steam diffusion conduit (61) extending into the internal volume (15) over a second distance (D6i) considered along the longitudinal direction (Ox) which is at least equal to half of the first distance (DEA), in which the enclosure (10) includes a partition (14) which separates the internal volume (15) into a material processing volume (16) and a steam supply volume (17), the diffusion conduit (61) including a steam supply portion (38) extending into the steam supply volume (17).

2. Processing device (1) according to claim 1, wherein the diffusion conduit (61) extends in a direction substantially parallel to the longitudinal axis (Ox).

3. Processing device (1) according to claim 2, wherein the diffusion conduit (61) extends along the longitudinal axis (Ox).

4. Processing device (1) according to any one of the preceding claims, wherein the injection device (60) is arranged to carry out a vapor injection (50) in an essentially radial direction.

5. Processing device (1) according to any one of the preceding claims, wherein the propeller (30) comprises a helical groove (32) rigidly attached to the vapor diffusion conduit (61) (50).

6. Processing device (1) according to any one of the preceding claims, wherein the helix (30) comprises a helical groove (32) distinct from the vapor diffusion conduit (50).

7. Processing device (1) according to claim 6, wherein the helical groove (32) is integral with a wall (11) of the enclosure (10).

8. Processing device (1) according to any one of the preceding claims, wherein the propeller (30) is actuated.

9. Processing device (1) according to any one of the preceding claims, wherein the diffusion conduit (61) includes perforations (40).

10. Processing device (1) according to claim 1, comprising a hollow shaft (31) extending along the longitudinal direction (Ox) and having the diffusion conduit (61), a helical groove (32) being provided on the shaft (31) to define the helix (30), the shaft (31) comprising radial perforations (40) for connecting an internal conduit (33) of the shaft (31) to the internal volume (15) of the enclosure (10), the enclosure (10) comprising a radial partition (14) which separates the internal volume (15) into a material processing volume (16) for the material (80) and a steam supply volume (17) for the steam (50), the diffusion conduit (61) comprising a supply portion (38) extending into the steam supply volume (17) for the steam (50), the shaft (31) comprising a fixed end (36) of an actuator (37) for driving the shaft (31) in rotation around a longitudinal axis of rotation (Ox).

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