MULTI-SOURCE ALTERNATIVE SOLID FUEL IN-LINE INJECTOR FOR INTRODUCING SOLID FUEL FROM AN UNPRESSURIZED SOURCE TO A LEAN PHASE PNEUMATIC TRANSMISSION LINE AND ASSOCIATED SPARE PART.

Abstract

The invention relates to an alternative multi-solid combustible material inline injector for introducing material from an unpressurized source to a lean-phase pneumatic conveying line (1), the injector comprising a rotary pocket valve (2) and a differential pressure control system, and an associated part.

Description

Title of the invention: MULTI-SOURCE ALTERNATIVE SOLID FUEL IN-LINE INJECTOR FOR INTRODUCING SOLID FUEL FROM AN UNPRESSURIZED SOURCE TO A LEAN PHASE PNEUMATIC TRANSMISSION LINE AND ASSOCIATED SPARE PART. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a multi-source inline injector for alternative solid fuels (ASF) for industrial applications, including supplying burners in cement kilns, lime kilns, and other mineral industries. This innovation aims to meet the growing demand for pneumatic conveying of alternative solid fuels, with an emphasis on smooth fuel transfer. This is essential for minimizing system losses and damage, while reducing operating and maintenance costs.

[0002] Alternative solid fuels (ASFs) are unconventional solid materials used as substitutes for traditional fossil fuels (such as coal and petroleum coke) in industrial or energy applications. They are often derived from waste or biomass and aim to reduce environmental impact. Examples of ASFs include any type of recycled solid waste such as plastics, textiles, non-recyclable wood chips, biomass such as wood chips, pellets, and agricultural residues, as well as industrial waste such as used tires and dried sludge, these materials being pre-treated to make them suitable for injection into a pneumatic conveying line.

[0003] ASFs are commonly used in cement plants, thermal power plants and other industries to recover energy from materials while reducing CO emissions and the use of landfill sites.

[0004] The injection of alternative solid fuels (ASFs), particularly for burners, presents unique challenges due to the diversity of their two-dimensional and three-dimensional shapes, their variable moisture content, their abrasiveness, as well as their volumetric characteristics and the density required for efficient injection operation in a burner, since their apparent density is often much lower than that of conventional solid fuel, which often leads to discharge difficulties in the injectors. One of the most important requirements for Many inline pneumatic conveying systems provide a smooth and regular transfer of material, minimizing waste and damage to the system, thus reducing costs. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0005] Existing systems on the market, such as rotary valves, progressive pitch gravimetric screws and gravimetric valves, have several technical limitations.

[0006] Existing inline injection systems are equipped with rotary valves for distributing and injecting materials from a solid fuel storage and distribution unit to a pneumatic injection line in which a gas, generally air, flows at a given speed and pressure, with injection into a venturi-type section of the pneumatic injection line. The injection is based solely on the fluidic vacuum created by the airflow in the pneumatic injection line. The disadvantage of these systems is that they are only suitable for powders or materials with very small particle sizes and almost no surface moisture. Therefore, injection by these injectors in these systems is not compatible with ASF-type solid fuels, which have a much larger two-dimensional particle size and a high surface moisture content, generally between 0% and 15%.

[0007] Existing inline injection systems do not allow the use of ASF for burner operation. These systems do not guarantee adequate filling and ejection of the solid fuel from their rotary valves to the pneumatic injection line when using ASF as solid fuel. Therefore, burners require stable and continuous fuel injection, with a stable and continuous flow rate of injected fuel, to ensure optimal burner operation.

[0008] Since ASFs have a lower apparent density than conventional solid fuels, the use of ASF as a solid fuel for injection adapted to the required mass flow rate of a burner causes the formation of fuel agglomerates in the pockets of the rotary valves, partial ejection of the fuel, as well as the reduction of the filling factor of the pockets of the rotary valve, as well as accelerated wear of the stator of the rotary valves and of the feed tube.

[0009] In addition, these systems also have air leakage problems, which have a significant impact on the efficiency of pneumatic conveying.

[0010] Furthermore, existing injection systems do not have adequate suction for the use of ASF, which damages the distribution mechanism and causes dust deposition, or even the failure to inject at least part of the fuel to be injected, which can eventually cause the injection mechanism to stop. and increase maintenance constraints, abraded parts and accessibility for the user.

[0011] These limitations prevent providing a constant supply, precisely modulating the return pressures in the pneumatic conveying lines and meeting the high flow requirements for the dosing, injection, conveying and combustion of ASF.

[0012] Finally, some injectors have rotary valves that rely solely on a gravimetric injection mechanism. These injectors are not configured to regulate the back pressure created by the airflow through the pneumatic conveying line, resulting in significant air leakage through the rotary valve, inadequate ladle filling, and constraints that prevent smooth injection of the alternative solid fuel (ASF) into the pneumatic conveying line. This problem is particularly significant for higher ASF flow rates, whether during metering, injection, conveying, or combustion of this type of fuel.

[0013] The invention remedies these drawbacks and offers a solution that overcomes these technical challenges by optimizing the design and operation of ASF injectors, thus ensuring efficient transport of alternative fuels injected reliably and economically in demanding industrial environments. Summary of the invention

[0014] The invention relates to a multiple alternative solid fuel inline injector for introducing a solid fuel material from an unpressurized source to a lean-phase pneumatic conveying line, the injector comprising a rotary pocket valve, comprising a rotor composed of multiple pockets defined radially around a Y axis inside a cylindrical stator, each pocket is configured to have one end in contact with the cylindrical stator, and rotating in said cylindrical stator, the cylindrical stator having a top opening connected to a fuel material metering device and a bottom opening hermetically connected to the pneumatic conveying line via a connecting conduit.

[0015] According to a general definition of the invention, the injector includes a differential pressure regulation system, configured to create and adjust a selected pressure differential between a pressure at the top of the connecting conduit and a lower pressure at the connecting conduit in order to define a suction force between the material accumulated in at least one pocket and an injection point when said pocket is aligned with at least one part of the connecting conduit.

[0016] Advantageously, the differential pressure regulation system according to the invention allows the establishment of an increased local suction force at the point of injection of the fuel material, which makes the injector compatible with alternative solid fuels (ASF), which have a lower apparent density and a higher surface moisture than other solid fuels.

[0017] The multiple alternative solid fuel inline injector, hereinafter referred to as the "injector", is configured to introduce an alternative solid fuel type fuel material from an unpressurized source to a lean-phase pneumatic conveying line. The lean-phase pneumatic conveying line will be referred to as the "pneumatic line".

[0018] The combustible material of the alternative solid fuel type will be referred to as "material".

[0019] In practice, the differential pressure control system includes a lower pressure control module comprising at least two connecting tubes between the connecting conduit and an upstream point of the pneumatic line having a reduced local diameter, said reduced local diameter of the upstream point being able to locally increase the pressure of the circulating air, the lower pressure control module further comprising at least one flow control means, configured to define a chosen pressure differential AP=Pa-Pb, creating an internal pressure differential between the upper part of the connecting conduit and a lower part of the connecting conduit, allowing facilitated injection of material by increased local suction at said injection point.

[0020] Advantageously, the lower pressure regulation module according to the invention allows the generation of an increased local suction force at the point of injection of the material, while modulating the pressure differential in response to the variability of the operation of the injector, allowing the use of several types of ASF and multiple mixtures of ASF to be injected, and allowing to ensure a regular and constant flow of material injected into the pneumatic line.

[0021] According to one embodiment, the differential pressure control system comprises an intermediate pressure control module hermetically connected to a lateral face of the cylindrical stator, allowing a temporary connection of said cylindrical stator with each empty return bag after injection, each empty return bag having an internal pressure PI greater than a measured pressure PO at the material metering unit, and configured to reduce the measured pressure in the empty bag temporarily connected to the intermediate pressure control module to the pressure PO, allowing the ejection of some of the air in the empty bag and air from air leakage in the rotary valve in order to prevent a air return induced by a pressure difference once the bag is at least partially aligned with the upper opening of the material dispenser.

[0022] Advantageously, the intermediate pressure regulation module eliminates the risk of backflow induced by pressure differentials once the rotary valve pockets reach the material metering device, particularly with ASFs having a very low bulk density. Backflow in the material metering device can cause inconsistency in the material injection rate as well as structural obstruction of the injector; the intermediate pressure regulation module facilitates material feeding into the rotary valve. Furthermore, pressure equalization reduces the pocket pressure during the backflow phase from a pressure at the injection point defined by the differential pressure module, which is lower than the pressure in the material metering device.This pressure reduction also allows for the removal of dust from empty pockets during the return phase, improving the material filling capacity of each pocket while reducing damage that could affect the cylindrical stator during operation.

[0023] The position and function of the intermediate pressure control module also establish a venting circuit, allowing air from leaks originating from the material metering unit to be vented outside the injector, while simultaneously eliminating the additional pressure induced by air leaks at the injection point in the connecting line. This feature makes the differential pressure modulation defined by the lower pressure control module more precise, since the only pressures to monitor for accurate differential pressure modulation are the back pressure of the pneumatic line and the pressure of the air injected by the lower pressure control module.

[0024] According to another embodiment, the differential pressure control system comprises: - pressure measurement means configured to measure the pressure at several points of the lower pressure control module and the intermediate pressure control module; - means for data processing to calculate the pressure difference between the pressure Pa in the upper part of the connecting conduit and the pressure Pb in the lower part of the connecting conduit, and to compare the measured pressures Pa, Pb, generate and send commands to the pressure control means to adjust the pressure Pa and the pressure Pb to the chosen pressure differential AP; - pressure regulation means to actuate the controls and adjust the pressure in the lower pressure regulation module and the intermediate pressure regulation module.

[0025] Advantageously, it allows the differential pressure control system to modulate in real time all pressure control means in order to maintain a precise and targeted set of operating conditions for ASF injection, allowing the injector to inject ASF at a constant and stable flow rate to the burners for combustion.

[0026] According to an embodiment according to the invention, the lower pressure regulation module comprises at least two air injection circuits, each connected on one hand to an upstream point of the pneumatic conveying line, a first air injection circuit is connected to the lower part of the connecting conduit, and a second air injection circuit connected to the upper part of the connecting conduit at the base of the cylindrical stator.

[0027] The lower pressure regulation module is configured to maintain a pressure difference AP between the upper part of the connecting conduit and the lower part of the connecting conduit between 30 mbar and 200 mbar.

[0028] This pressure difference in the connecting conduit allows for easier injection of the material, and in particular of ASF with a low apparent density, i.e. an apparent density less than or equal to 0.35 t / m2, and with a surface moisture content between 0% and 15%.

[0029] According to a particular embodiment, the intermediate pressure regulation module includes at least one air leak dust removal device designed to reduce the pressure measured in the pocket to a pressure equal to the PO pressure, and a damper to modulate the ventilation speed of the air injected into said intermediate pressure regulation module.

[0030] It allows the dust to be eliminated from each pocket and extends the operational life of the rotary valve.

[0031] According to another embodiment, the connecting conduit comprises an upper part configured to be connected to the cylindrical stator, an upstream inlet and downstream outlet each connected to the pneumatic conveying line, and a lower part comprising a removable horizontal half-pipe, each part being hermetically sealed to allow a closed volume for injection.

[0032] Advantageously, since ASFs are generally very abrasive and damage the lower part of the connecting duct, the combustible material falls by gravity, at least partially, and comes into contact with this lower part of the connecting duct before being conveyed in the pneumatic line. The integration of the removable half-pipe allows for easy replacement and maintenance of the system without having to dismantle the entire injector and keeping said injection non-operational for a short period during the part change.

[0033] According to one example of an implementation of the invention, the upper part of the connecting conduit includes a hermetically sealed transparent window.

[0034] Advantageously, this window allows the user to visually check whether the injection of material into the pneumatic line is carried out within the operating parameters.

[0035] In practice, the injector is capable of injecting materials such as alternative solid fuels with a feed cross-section of 0 ~ 35 mm and an apparent density between 0.15 t / m2 and 0.35 t / m2.

[0036] Advantageously, the injector is compatible with a wide range of alternative solid fuels and can operate under various operating conditions and be adaptable to one type of ASF or a mixture of several types of ASF while allowing stable and consistent injection parameters to the burners.

[0037] The upstream inlet of the connecting conduit includes an annular diameter reduction structure configured to locally increase atmospheric pressure in the pneumatic line upstream of the upstream inlet.

[0038] Advantageously, it makes it possible not to depend on an external air pressurization device to produce the pressure differential in the connecting conduit, and to use the air flow of the pneumatic line already in place, which makes the injector less expensive and more energy-efficient.

[0039] The invention also relates to a removable horizontal half-pipe for a connecting conduit of a multi-source alternative solid fuel (ASF) inline injector.

[0040] According to another definition of the invention, the removable horizontal half-pipe includes a protective lining covering its internal surface, said protective lining being distributed radially and comprising several regularly spaced longitudinal protruding parts, parallel to the Y axis on said internal surface of the removable horizontal half-pipe, and creating a continuous layer of protective coating with a longitudinal structure alternating between a first radial thickness and a second radial thickness lower than the first radial thickness.

[0041] Advantageously, since ASFs are highly abrasive and damage the lower part of the connecting conduit during use because the material falls by gravity and comes into contact, at least partially, with this lower part before being conveyed in the pneumatic line, the removable half-pipe allows for easier maintenance of the injector without having to disassemble it completely, thus reducing the time during which the injection is inoperative, while also extending the service life of the removable half-pipe. Furthermore, the lining portion with a greater thickness is exposed to wear first, while air can still circulate in the recesses created by the thickness sequence of the coating, thus allowing minimal airflow if temporary aggregates form on the half-pipe. BRIEF DESCRIPTION OF THE FIGURES

[0042] Other advantages and features of the invention will become apparent from an examination of the description and drawings in which:

[0043] [Fig.l] schematically represents an overall view of the injector according to the invention.

[0044] [Fig.2] schematically represents a top view of the injector according to the invention.

[0045] [Fig.3] schematically represents a side view of the injector according to the invention.

[0046] [Fig.4] schematically represents a rear view of the injector according to the invention.

[0047] [Fig.5] schematically represents an exploded view of the injector according to the invention.

[0048] [Fig.6] schematically represents a cross-sectional view of the injector according to the invention;

[0049] [Fig.7] schematically represents the pressure distribution in the injector according to the invention;

[0050] [Fig.8] schematically represents the removable half-pipe of the conduit connection according to the invention;

[0051] [Fig.9] schematically represents the cross-section of the removable half-pipe of the connecting conduit according to the invention; and

[0052] [Fig. 10] schematically an enlarged view of the cross-section of the half-pipe removable from the connecting conduit according to the invention. DETAILED DESCRIPTION

[0053] According to figures 1 to 10, the injector according to the invention comprises a rotary valve 2 having several radially defined pockets 22, rotating inside a stator 21, said rotary valve 2 being hermetically connected to a connecting conduit 5, said connecting conduit 5 being connected to the pneumatic transport line 1, the injector also comprising a differential pressure regulation system.

[0054] The rotary valve 2 comprises a rotor with several pockets 22 defined radially around an axis Y, capable of rotating radially around an axis Y inside a cylindrical stator 21, also called stator 21.

[0055] Each pocket 22 is defined as two consecutive blades configured to each have one end substantially in contact with the stator 21, said stator 21 having an upper end opening 23 connected to a material metering device 6 and a lower end opening 24 hermetically connected to the pneumatic conveying line 1 via the connecting conduit 5.

[0056] The rotary valve 2 is configured to receive the material through an opening 23 at the upper end from the material metering device 6, and releases said material downwards through the lower end opening 24 at an injection point 13 located at the junction of the lower end opening 24 of said rotary valve 2 with the connecting conduit 5.

[0057] According to a particular embodiment of the invention, the rotary valve 2 is composed of at least one precision-machined heavy rotor, with blades comprising adjustable polyurethane tips with an adjustable extended portion, ensuring a tolerance of 00 ~ 0.18 mm with the stator 21, and further comprises several radially defined pockets 22 with cyclic air purging at 1.5 bar ~ 2.0 bar of compressed air for cleaning each pocket 22.

[0058] According to another embodiment, the pockets 22 of the rotary valve 2 are configured to rotate at a speed of between 16 and 18 revolutions per minute.

[0059] According to a particular embodiment, the stator 21 comprises an anti-abrasive coating layer covering the entire internal surface of said stator 21.

[0060] The connecting conduit 5 comprises an upper part configured to be connected to the stator 21 and a lower part, the upper and lower parts of the connecting conduit are assembled to form a venturi device 15, with an upstream inlet 11 and a downstream outlet 12 each connected to the pneumatic line 1.

[0061] The connecting conduit 5 is configured to be integrated into the pneumatic line 5 with gas / air circulating from an upstream part of the pneumatic line 1, injected into the connecting conduit 5 through the upstream inlet 11, said gas / air circulating exiting the connecting conduit 5 through the downstream outlet 12 towards a downstream part of the pneumatic line 1 connected for example to a burner.

[0062] According to one embodiment, the upstream inlet 11 of the connecting conduit 5 includes an annular diameter reduction structure 162 configured to locally increase the air pressure in the pneumatic line 1 before the upstream inlet 11.

[0063] Advantageously, it allows a continuous and regular air injection flow in the differential pressure regulation system.

[0064] According to one embodiment, the lower part of the connecting conduit 5 comprises a removable horizontal half-pipe 14, hermetically mounted on the connecting conduit 5 and removable.

[0065] Advantageously, the removable horizontal half-pipe 14 allows for easier maintenance and replacement of part of the connecting conduit 5, preventing obstruction of material which could derail the gas / air flow inside the connecting conduit 5 and cause inconsistent injection of the material flow into the pneumatic line 1.

[0066] According to one embodiment, the removable horizontal half-tube 14 includes a protective lining 141 covering its internal surface, said protective lining being distributed radially.

[0067] By way of example, the protective lining 141 comprises several longitudinal protruding parts spaced uniformly parallel to the Y axis on said internal surface and creating a continuous layer of protective coating with a longitudinal structure alternating between a first radial thickness T1 and a second radial thickness T2 lower than the first radial thickness T1, the area with a second radial thickness T2 forming grooves.

[0068] According to one implementation, the protective lining 141 is made of abrasion-resistant steel.

[0069] According to one example, the protective lining 141 is made of abrasion-resistant steel with an abrasion hardness between 550HB and 640HB.

[0070] Advantageously, the protective lining 141 according to the invention allows the protruding parts to be fatigued first by repeated contact with the flow of abrasive material ASF, while retaining its protective function in operation, and extending the durability of the removable half-pipe 14 in use.

[0071] According to another embodiment, the upper part of the connecting conduit 5 includes a hermetically sealed glass viewing window 51 located on the downstream side of the connecting conduit 5.

[0072] Advantageously, the glass viewing window 51 allows the user to visually monitor the material injection flow in order to assess the operating status of the material injection and potentially identify problems such as clogging, and an irregular flow of material exiting the connecting conduit 5.

[0073] The injector according to the invention further comprises the differential pressure regulation system, capable of creating and adjusting the pressure distribution in the injector.

[0074] The differential pressure control system is configured to create and adjust a chosen pressure difference AP between a pressure Pa of the upper part and the pressure Pb of the lower part in the connecting conduit 5 to define a suction force between the material accumulated in at least one pocket 22 and an injection point 13 when said pocket 22 is aligned with at least a part of the connecting conduit 5, this controlled suction force is optimized to facilitate the ejection of the ASF material from the pocket 22, into the airflow of the pneumatic conveying line 1.

[0075] The differential pressure control system is also configured to adjust and modulate the pressure of the emptied air pockets 22 returning to the upper end opening 23 of the rotary valve 2.

[0076] The differential pressure control system includes at least one lower pressure control module 3 and one intermediate pressure control module 4.

[0077] The lower pressure regulation module 3 includes at least two air injection circuits 31, 32 each connected to an upstream point 33 of the pneumatic line 1 with a reduced diameter at one end, and the connecting conduit 5 at a second end.

[0078] According to one embodiment, the lower pressure regulation module 3 comprises a first air injection circuit 31 connected at one end to the upstream point 33 of the pneumatic line 1 and connected at the other end to at least one connection point 311 located at the upper end 24 of the connecting conduit 5, substantially below the injection point 13, and configured to inject clean air at a chosen pressure Pa.

[0079] According to one example of an implementation of the invention, the first air injection circuit 31 has several connection points 311.

[0080] According to another embodiment of the invention, the first air injection circuit 31 is configured to inject clean air reasonably perpendicular to the Y axis and perpendicular to the general direction of the airflow F.

[0081] According to one embodiment, the lower pressure regulation module 3 further comprises a second air injection circuit 32 connected at one end to the upstream point 33 of the pneumatic line 1 and connected at the other end to at least one connection point 321 located on the lower part of the connecting conduit 5 and configured to inject clean air at a chosen pressure Pb.

[0082] According to one example of an implementation of the invention, the second air injection circuit 32 comprises several connection points 321.

[0083] According to another embodiment of the invention, the second air injection circuit 32 is configured to inject clean air reasonably perpendicular to the Y axis and perpendicular to the general direction of the airflow F.

[0084] The lower pressure regulation module 3 is configured to inject air at pressure Pa through the first air injection circuit 31, and at pressure Pb through the second air injection circuit 32 to define a chosen pressure differential AP = Pa-Pb, creating an internal pressure differential between the upper part of the connecting conduit 5 and the lower part of the connecting conduit 5, allowing facilitated injection at the injection point 13 by increased local suction at said injection point 13.

[0085] The lower pressure regulation module 3 also includes at least one flow control means for each air injection circuit 31,32, configured to modulate the injection of clean air into the connecting duct 5 and to stabilize the AP pressure difference to dampen any local pressure variation in the connecting duct 5.

[0086] According to one embodiment, the lower pressure regulation module 3 is configured to maintain a pressure difference AP between 30 mbar and 200 mbar.

[0087] The differential pressure control system further includes the intermediate pressure control module 4, hermetically connected to the cylindrical stator 21, allowing a temporary connection with each return vacuum pocket 22, each return vacuum pocket 22 having an internal pressure PI greater than a measured pressure PO at the level of the fuel material metering device 6 and configured to reduce the internal pressure PI in the vacuum pocket 22 to the pressure PO, and create an ejection of part of the air in the vacuum pocket 22 through the intermediate pressure control module 4 to prevent the return induced by the pressure difference once the pocket 22 is at least partially aligned with the upper end opening 23 of the rotary valve 2.

[0088] The intermediate pressure regulation module 4 includes tubes, hermetically connected to a side face 25 of the stator 21, which allow a temporary connection with each empty return pocket 22 and configured to compensate for air leaks in the rotary valve 2.

[0089] Advantageously, the air leak generally flows from the combustible material metering device 6 to the connecting conduit 5 due to the back pressure induced by the air flow from the pneumatic line 1.

[0090] The total pressure PI in the connecting conduit is therefore calculated on the basis of the following formula:

[0091] Pl=Pneumatic line pressure + Pa + Pb + Air leak pressure.

[0092] Advantageously, the intermediate pressure regulation module 4 allows to divert the air leak in said intermediate pressure regulating module 4 by reducing / eliminating the air leak reaching the connecting conduit 5.

[0093] The total pressure PI in the connecting conduit 5 with the intermediate pressure regulating module 4 in operation is therefore calculated on the basis of the following formula: Pl = Pneumatic line pressure + Pa + Pb which allows to reduce the variations of total pressure PI and local pressure at various points of the connecting conduit 5, and thus simplify the regulation of the injection pressure.

[0094] In practice, the differential pressure control system includes means for measuring local pressure at several points of the lower pressure control module 3 and the intermediate pressure control module 4.

[0095] According to one embodiment, the differential pressure control system includes data processing means to calculate the pressure differential between pressure Pa and pressure Pb in the connecting conduit 5 and measure the pressure in the return pockets of the vacuum return pocket 22, generate and send commands to the pressure control means to adjust the pressure to the selected pressure differential AP and the selected pocket pressure range PO.

[0096] According to one embodiment, the differential pressure control system includes pressure control means for actuating the controls and adjusting the pressure in the lower pressure control module 3 and the intermediate pressure control module 4.

[0097] The injector according to the invention is designed to allow a regular and consistent injection of alternative solid fuel (ASF).

[0098] According to one embodiment, the injector uses an alternative solid fuel whose apparent density is between 0.15 t / m2 and 0.35 t / m2.

[0099] ASFs have a lower apparent density than standard solid fuel and, consequently, are too light to fall by gravity to the injection point and must therefore be drawn into the pneumatic line 1 in a controlled and efficient manner to allow a constant flow of injected fuel.

[0100] According to a particular embodiment of the invention, the injector is capable of using an alternative solid fuel ASF which belongs to at least one mixture of agricultural waste, carbon black, plastic waste chips, PET fluff and chips, rejected derived fuel, solid waste, wood chips, sawdust, other waste, dried sludge.

Claims

Demands

1. Multiple reciprocating solid fuel in-line injector for introducing solid fuel material from an unpressurized source to a lean-phase pneumatic conveying line (1), the injector comprising: -a rotary valve (2) comprising a rotor composed of multiple radially defined pockets (22) about an axis Y inside a cylindrical stator (21), each pocket (22) is configured to have an end substantially in contact with the cylindrical stator (21) and rotating in said cylindrical stator (21), the cylindrical stator (21) having an upper end opening (23) connected to a fuel material metering device (6) and a lower end opening (24) hermetically connected to the pneumatic conveying line (1) by a connecting conduit (5);-a differential pressure control system, configured to create and adjust a chosen pressure differential AP between a pressure Pa of an upper part and a pressure Pb of a lower part of the connecting conduit (5) to define a suction force between the material accumulated in at least one pocket (22) and an injection point (13) when said pocket (22) is aligned with at least a part of the injection point (13).;

2. Injector according to claim 1, wherein the differential pressure control system comprises: -a lower pressure control module (3) comprising at least two air injection circuits (31,32) between the connecting conduit (5) and an upstream point (33) with a reduced local diameter (161) of the pneumatic line (1), capable of locally increasing the pressure of the circulating air, and at least one flow control means, configured to set a selected pressure difference AP=Pa-Pb, creating an internal local pressure differential between the upper part of the connecting conduit (5) and a lower part of the connecting conduit (5), allowing increased local suction injection at the injection point (13).

3. Injector according to claim 1 or 2, wherein the differential pressure control system comprises an intermediate pressure control module (4) hermetically connected to a lateral face (25) of the cylindrical stator (21), allowing a temporary connection with each empty pocket (22), each empty pocket (22) having an internal pressure PI greater than a measured pressure PO at the level of the fuel material metering device (6), and configured to reduce the measured pressure in the empty pocket (22) to the pressure PO, creating an ejection of some of the air in the empty pocket (22) and an air leak from the rotary valve (2) to prevent a backflow of air induced by the pressure difference once the empty pocket (22) is at least partially aligned with the upper end opening (23) at the level of the fuel material metering device (6).

4. Injector according to claim 1 to 3, wherein the differential pressure control system comprises: - pressure measuring means configured to measure the pressure at several points of the lower pressure control module (3) and the intermediate pressure control module (4); - data processing means to calculate the pressure difference between the pressure Pa in the upper part of the connecting conduit (5) and the pressure Pb in the lower part of the connecting conduit (5), and compare the measured pressures Pa, Pb, generate and send commands to the pressure control means to adjust the pressure Pa and the pressure Pb to the desired selected pressure differential AP; - pressure control means to actuate the commands and adjust the pressure in the lower pressure control module (3) and the intermediate pressure control module (4).

5. Injector according to claim 2 to 4, wherein the lower pressure regulating module (3) comprises at least two air injection circuits (31,32), each connected at one end to the upstream point (33) of the pneumatic line (1), the first air injection circuit (31) is connected to an upper part of the connecting conduit (5) at the base of the cylindrical stator (21), and the second air injection circuit (32) is connected to the lower part of the connecting conduit (5).

6. Injector according to claim 2 to 5, wherein the lower pressure regulation module (3) is configured to maintain a differential pressure AP between 30 mbar and 200 mbar.

7. Injector according to claim 3 to 6, wherein the intermediate pressure regulation module (4) includes at least one air leak dust removal device configured to reduce the measured pressure PI of the empty pocket (22) to a pressure substantially equal to the pressure PO and a damper to modulate the ventilation speed of the air stream.

8. Injector according to claim 1 to 7, wherein the connecting conduit (5) comprises an upper part configured to be connected to the cylindrical stator (21), an upstream inlet (16) and a downstream outlet each connected to the pneumatic line (1) and a lower part comprises a removable horizontal half-pipe (14), each part being hermetically assembled to permit a closed volume for injection.

9. Injector according to claim 8, wherein the upper part of the connecting conduit (5) comprises a hermetically sealed glass viewing window (51).

10. Injector according to claim 1 to 9, wherein the injector is capable of injecting a material such as alternative solid fuels with a 2D feed cross-section less than or equal to 35 mm and an apparent density between 0.15 t / m2 and 0.35 t / m2.

11. Injector according to claim 8, wherein the upstream inlet (11) of the connecting conduit (5) comprises an annular diameter reduction structure configured to locally increase the pressure locally in the pneumatic line (1) upstream of the upstream inlet (11).

12. Removable horizontal half-pipe (14) for a connecting conduit (5) of an inline injector of combustible material according to claim 8 to 11, wherein the removable horizontal half-pipe (14) comprises a protective lining (141) covering its inner surface, said protective lining (141) being distributed radially and comprising several longitudinal protruding parts spaced uniformly apart, parallel to the Y axis on said inner surface and creating a continuous layer of protective coating with a longitudinal structure alternating between a first radial thickness (T1) and a second radial thickness (T2) less than the first radial thickness (T1).

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