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 treatment, and more particularly to a thermal hydrolysis device by steam injection. Thermal hydrolysis is a chemical process consisting of the controlled degradation of organic substances at high temperature and under the action of water vapor, allowing efficient thermochemical conversion of complex organic materials (sludge, agricultural waste, biomass) into compounds that can be used in various industrial sectors, such as fine chemicals, energy production and the manufacture of specialty chemicals. STATE OF THE PRIOR ART

[0002] Thermal hydrolysis is a chemical decomposition technique that involves the use of high temperatures and water vapor to break the complex molecular bonds of organic materials. This process converts these materials into smaller chemicals, such as organic acids, alcohols, and aromatic compounds. Thermal hydrolysis offers potential benefits in waste recovery, renewable energy production, and the creation of sustainable chemicals.

[0003] Conventionally, a steam injection thermal hydrolysis device consists of a sealed reaction chamber into which the organic materials to be treated are introduced. Water vapor 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 of time, thus allowing the decomposition of complex molecular bonds. The efficiency of the device is generally improved by the use of rotating mixers.

[0004] Known devices have three main problems: significant heat loss through the walls of the enclosure, significant loading / unloading times and obstruction of the enclosure and / or mixers by the organic materials to be treated. This results in extended material processing times (loading / unloading times, unblocking operations, maintenance) and significant energy costs, which limit the spread of this type of installation despite their many advantages. SUBJECT OF THE INVENTION

[0005] The aim of the invention is to reduce the operating costs of a thermochemical treatment device. Statement of the invention

[0006] For this purpose, a device for continuous thermochemical treatment of material to be treated is provided, comprising an enclosure extending along a longitudinal axis and which defines an internal volume of the enclosure, a material inlet port and a material discharge port which open respectively into a radial feed plane and into a radial discharge plane, the radial feed plane and the radial discharge plane being separated by a first longitudinal distance, a device for injecting steam into the internal volume, a worm-type propeller extending into the internal volume and which is 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 conduit which extends into the internal volume over a second distance considered in the longitudinal direction which is at least equal to half of the first distance.

[0007] According to other particular, 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 carry out a steam injection in an essentially radial direction; - the propeller comprises a helical groove rigidly attached to the steam diffusion duct - the propeller comprises a helical groove separate from the steam diffusion duct; - the helical groove is secured to a wall of the enclosure; the propeller is actuated; - the enclosure comprises a partition which separates the internal volume into a material treatment volume and a steam supply volume, the diffusion conduit comprising a steam supply portion extending into the steam supply volume; - the diffusion duct includes perforations; - the device comprises a hollow shaft extending in the longitudinal direction tudinal and which comprises the diffusion duct, a helical groove being attached to the shaft to define the propeller, the shaft comprising radial perforations to connect an internal duct of the shaft to the internal volume of the enclosure, the enclosure comprising a radial wall which separates the internal volume into a material treatment volume and a steam supply volume, the diffusion duct comprising a supply portion extending into the steam supply volume, the shaft comprising an end secured to an actuator for driving the shaft in rotation around a longitudinal axis of rotation.

[0008] Other characteristics and advantages of the invention will appear on reading 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.l] is a schematic sectional representation of the device of the invention.

[0011] DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

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

[0013] With reference to [Fig.l], 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 comprises 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 comprises a partition 14 which separates the internal volume 15 of the enclosure 10 into a treatment volume 16 of material 80 to be treated and a supply volume 17 of steam 50.

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

[0015] The evacuation planes PrE and supply planes PrA are separated by a first longitudinal distance DHA. The inlet 18 and evacuation 19 ports are, here, produced in the form of radial conduits added by welding 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 comprises a steam supply port 20 50 here produced in the form of a radial conduit added by welding to the wall 11 and which opens into the supply volume 17.

[0016] The treatment device 1 also comprises a worm-type propeller 30 extending into the treatment volume 16.

[0017] As seen in [Fig.l], the propeller 30 comprises a tubular shaft 31 extending in the longitudinal direction Ox and on which a helical groove 32 is added by welding. 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 using two bearings 35.1 and 35.2 respectively secured to the walls 12 and 13.

[0019] The shaft 31 comprises a lower end 36 secured to a geared motor 37 for driving the shaft 31 in rotation around the axis Ox. The shaft 31 therefore comprises a supply portion 38 which extends into the supply volume 17 and a diffusion portion 39 which extends into the treatment volume 16.

[0020] The shaft 31 comprises radial perforations 40 which connect the internal conduit 33 to the internal volume 15. The perforations 40 are made both on the supply portion 38 and on 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 from 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 supply 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 comprises 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 in the longitudinal direction of the axis Ox, which separates the proximal assembly 41.6 and the distal assembly 41.13. The second distance D6[ is, here, substantially equal to the first distance DEA.

[0022] In operation, the supply volume 17 is supplied with steam 50 via the port 20. The steam 50 enters the internal conduit 33 via the perforations 40 of the assemblies 41.1 to 41.5 to travel in the internal conduit 33 towards the diffusion portion 39. A rotation of the propeller 30 is also controlled by electrically powering the geared motor 37. The material 80 to be treated is introduced into the treatment volume 16 via the supply port 18. Under the effect of the rotation of the propeller 30, the material 80 is transferred from the port 18 to the discharge port 19. During its travel in the treatment volume 16 between the ports 18 and 19, the material 80 is subjected to an injection of steam 50 through the perforations 40 of the assemblies 41.6 to 41.13. The injection of steam 50 is carried out, according to this embodiment, in an essentially radial direction. The management of the thermo conversion chemical transformation 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 diffusion of heat from inside the internal volume 15 of the enclosure 10 improves the energy efficiency of the treatment device 1 compared to known devices. Indeed, the heat losses mainly take place at the wall 11. When the heat provided 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, reliable mixing means which is capable of self-cleaning by friction with the wall 11, reducing the risks of obstruction 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 comprises a helical groove integral with the steam diffusion duct, the invention also applies to other configurations of the propeller such as for example a propeller comprising a helical groove separate from the steam diffusion duct, the helical groove being able to be integral with the wall of the enclosure; - although here the diffusion duct is a rectilinear duct which extends along the longitudinal axis, the invention also applies to other configurations of the diffusion duct such as for example a helical duct secured to an inner or outer edge of the helix; - although here the device comprises a tubular shaft provided with plugs, the invention also applies to other types of hollow shafts such as a drilled shaft plugged at one end or a conduit produced 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 for example hydrolysis or hot rehydration; - although here the treatment device comprises a steam supply volume, the invention also applies to other types of steam supply of the steam injection device such as for example a conduit connected at one end of the shaft; - although here the supply, inlet and outlet ports open into the internal volume of the enclosure through holes made in the wall to achieve steam injection, supply and outlet material in a radial direction, the invention also applies to other types of ports such as, for example, ports opening into the partition or the closing or opening wall in longitudinal or any direction. The radial plane considered then being the plane of the partition or the wall; although here the groove is attached by welding to the diffusion duct, the invention also applies to other means of rigidly securing the groove to the diffusion duct such as screwing, gluing, or full-body machining; although here the radial perforations are made in the form of a set of eight made at forty-five degrees, the invention also applies to other means of carrying out the injection of steam such as for example 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 for example a diffusion duct which extends over a second distance considered in the longitudinal direction equal to or greater than half of the first distance; although here the screw comprises 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 an 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 for example a hydrolysis process.

Claims

Claims

1. Device (1) for continuous thermochemical treatment of material (80) to be treated comprising: - an enclosure (10) extending along a longitudinal axis (Ox) and which defines an internal volume (15) of the enclosure (10); - an inlet port (18) for material (80) and an evacuation port (19) for material (80) which open respectively into a radial supply plane (PRA) and into a radial evacuation plane (PRE), the radial supply plane (PRA) and the radial evacuation plane (PRE) being separated by a first longitudinal distance (DEA); - a device (60) for injecting steam (50) into the internal volume (15); - a worm-type propeller (30) extending into the internal volume (15) and which is arranged to transfer the material (80) from the inlet port (18) to the discharge port (19);in which the steam (50) injection device (60) comprises a steam (50) diffusion conduit (61) which extends in the internal volume (15) over a second distance (D6i) considered in the longitudinal direction (Ox) which is at least equal to half of the first distance (DEA).;

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

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

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

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

6. Treatment device (1) according to any one of the preceding claims, in which the helix (30) comprises a helical groove (32) separate from the vapor diffusion conduit (50).

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

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11. A treatment device (1) according to any preceding claim, wherein the propeller (30) is actuated. Treatment device (1) according to any one of the preceding claims, wherein the enclosure (10) comprises a partition (14) which separates the internal volume (15) into a treatment volume (16) for the material (80) and a supply volume (17) for steam (50), the diffusion conduit (61) comprising a supply portion (38) for steam (50) extending into the supply volume (17) for steam (50). Treatment device (1) according to any one of the preceding claims, wherein the diffusion conduit (61) comprises perforations (40). Treatment device (1) according to claim 1, comprising a hollow shaft (31) extending in the longitudinal direction (Ox) and which comprises the diffusion duct (61), a helical groove (32) being attached to the shaft (31) to define the helix (30), the shaft (31) comprising radial perforations (40) to connect an internal duct (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 treatment volume (16) of the material (80) and a supply volume (17) for steam (50), the diffusion duct (61) comprising a supply portion (38) extending into the supply volume (17) for steam (50), the shaft (31) comprising an end (36) secured to an actuator (37) for driving the shaft (31) in rotation around a longitudinal axis of rotation (Ox).

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