DOUBLE FLOW CAGE DRYER COMPACTOR AND PROCEDURE FOR COMPACTING AND DRYING WASTE.

Description

DESCRIPTION accompanying a patent application for an INVENTION entitled: Double-flow cage dryer compactor and process for compacting and drying waste named: Antonio LA GIOIA Inventor: Antonio LA GIOIA The present invention relates to a double-flow cage dryer compactor apparatus and a process for compacting and drying waste. The invention falls within the field of equipment for the treatment of waste materials from industrial processes, urban waste or similar materials. The disposal of municipal solid waste is becoming increasingly important in modern society. The most common solutions currently available are landfilling or, alternatively, incineration. Both of these solutions have environmental drawbacks. In fact, most landfills quickly reach saturation. IMG. GARZANO & ZANARDO ROMA SpA - 3 And it's increasingly difficult to identify new areas without incurring protests from neighboring residents, concerned about air pollution from waste fumes. Incinerators, on the other hand, even though the most advanced waste-to-energy plants can produce energy with efficiency approaching 20%, release large quantities of carbon dioxide into the air for every ton of waste burned. They also pose a risk due to the formation of toxic fumes, primarily due to the high level of moisture in the waste, which prevents complete combustion. Recently, modern systems are spreading which aim at simultaneously reducing Volumetric waste reduction and inertization of the putrescible fraction. The goal of this technology is to obtain a solid, dry, sterilized, and detoxified product that can be sent to landfill or, due to its excellent stability and drying properties, used as a material for environmental restoration projects or as an excellent fuel for waste-to-energy plants. The type of technical problems faced and only - 4 partially solved by the known systems according to the said technique, are mainly related to the optimization of the working potential and consequently to the high operating costs of the equipment. For example, Italian industrial invention patent No. 1 262 260 illustrates a two-stage system: a first compaction stage, in which the material to be treated is pressed, at room temperature, depriving it of the initial imbibition water; and a second drying stage, in which the / *· 1 f.. ·:pretreated waste material is left inside a furnace, on the side casing of which is applied a box through which a fluid passes; heat transfer fluid with the function of administering. heat to the material. During this second phase, the waste is deprived of residual water by evaporation and the steam produced escapes through openings made on the side surface of the oven. This type of system presents several drawbacks: in fact, it is not possible to obtain a regular hydraulic regime of the heat transfer fluid, which is detrimental to the optimization of the heat exchange, nor are the resistance capacities satisfactory. - 5 of the furnace body, even in the face of modest pressure stresses, due to the openings on the lateral surface of the heating chamber required for the escape of steam. Furthermore, the presence of these lateral openings reduces the contact surface between the waste material and the hot areas, to the detriment of drying efficiency. A more advanced solution is described in European patent EP 0 663 227 B1, relating to a cage-type compacting dryer apparatus for waste materials, comprising a cylindrical body to contain the waste materials to be treated and two robust pressing plates to compact them, said pressing plates being arranged opposite each other and acting as mobile bases of said cylindrical body. Compared to the previous technique, the European patent EP 1 066 490 Bl, in the name of the same applicant, presents innovative features that allow for better results. It describes a cage-type compacting dryer system, equipped with a cylindrical body made up of longitudinal tubes arranged along the generators. - 6 ci of said cylindrical body so as to be spaced from each other, said tubes being traversed by a heat transfer fluid, acting simultaneously as the load-bearing structure of the apparatus and as a heat exchange surface between said heat transfer fluid and the waste material to be treated contained in the cylindrical body. The compaction action of the waste materials is carried out by means of two pressing plates arranged opposite each other, acting as mobile bases of said cylindrical body. ' t / The heating pipes are tied together h by means of retaining rings, arranged with i. given interaxis to ensure the stability of the tubes that form the cylindrical body stressed by the radial thrusts exerted by the waste materials being pressed and by thermal gradients. The compactor dryer system also includes means for discharging the water vapor generated by the heating operation of said waste materials, consisting of the longitudinal slits formed between the heating pipes. The plant, similarly to those of the previous technique, requires a pre-treatment section, in which the waste material is pressed to - 7 room temperature to remove the surface liquid fraction consisting of the imbibition water. The compactor-dryer then receives a pre-drained batch, from which, through the further press-drying process, the remaining constituent water is also extracted by evaporation, simultaneously further reducing the volume of the treated mass. The plant therefore operates using a discontinuous operation. The waste materials are fed to the pre-treatment section, where they undergo initial draining and are then extracted to be sent to the compactor dryer, where they are inertized before being collected and sent to storage. The solution proposed in the patent EP 1 066 490 B1 is such as to avoid any problem of hydraulic regime of the heating heat transfer fluid and WG. BAR» & to impeccably resolve the problem of steam leakage. Furthermore, the totally original structure of the cage dryer compactor is solid and perfectly resistant to the thermal and mechanical stresses developed during operation. At the same time, the compactor dryer according to patent EP 1 066 490 B1 has some limitations that reduce its efficiency. First, the thermal regime that develops inside the waste material contained in the cylinder has a logarithmic trend; the slow increase in temperature, moving towards the center of the mass to be treated, compromises the achievement of the design temperatures and their uniform distribution throughout the product in a short time. Furthermore, the arrangement of the tubes along the generators of the cylindrical body inevitably means that the exchange surface that can actually be used, i.e. the one actually in contact with the material to be treated, is only that facing towards the inside of the cylindrical body, i.e. a small percentage of the entire heating surface of the tubes. These two limitations would impose opposing solutions, in fact if on the one hand, to increase the useful fraction of the exchange surface, it would be necessary to increase the diameter of the cylindrical body which constitutes the compactor dryer, on the other hand the logarithmic trend of the thermal regime would impose - 9 the construction of plants with a reduced diameter, which would also entail the need to build longer plants or plants made up of several compactor dryers operating in parallel, to maintain the same standard volumetric capacity. Finally, a further limitation is due to the difficulties in coordinating the synchronisms of the cyclical sequences of loading, compaction and expulsion from the plant, which inevitably lead to the division of the operational flow into multiple steps spaced out by long time intervals and consequently to a decrease in productivity. It would be much better to have a dryer compactor with a smaller volume but capable of treating larger quantities of waste, reducing the drying process times and allowing for continuous operation. In this context, the solution according to the present invention comes into play, according to which the previous aims are achieved by means of a cage dryer compactor system, structurally modified in order to increase the average traction useful as an exchange surface of the pipes. - 10 paths from the heat transfer fluid and at the same time allow continuous operation of the system. To achieve the above purposes, it is proposed, according to the present invention, to insert additional heat sources, consisting of pipes traversed by heat transfer fluid, within the cage compactor dryer system along its entire length, suitably sized. The additional pipes, in addition to being located in the middle of the waste mass, and therefore offering a much larger usable surface area for heat exchange than the pipes constituting the outer perimeter of the cage, can be arranged so as to divide the waste compactor dryer into multiple sections along its entire length, each section having an equivalent diameter smaller than the diameter of the cage and therefore being more efficient in terms of heat transmission to the waste mass. Consequently, the temperature of the treated mass reaches the design values ​​in a shorter time. The arrangement of the tubes made according to the present invention also allows for obtaining a better resistance of the device to mechanical and thermal stresses, with the consequence that - 11 it becomes possible to also entrust the cage dryer compactor with the pressing task which in known systems is carried out in the room temperature compaction section positioned upstream of the dryer compactor. The elimination of the pre-treatment section allows the waste materials to be directly fed to the compactor dryer via a hopper. Consequently, the system can be operated continuously. Continuous running has further advantages including: - a further reduction in total processing times chin, - the increase in specific productivity, - the reduction of the number of modules that make up 1st plant, - optimization of the push rod stroke, - the containment of investment costs, - the reduction of operating costs. The compacting dryer apparatus according to the present invention can be conveniently used for drying and pressing solid waste material of any nature, having a humidity level even higher than 40%, be it - 12 derived from civil or industrial activities, in quantities such as to be inserted into operational cycles of up to 600-1000 tons per work shift, with consequent containment of the total management cost per kilogram of waste treated. The specific object of the present invention is therefore a cage-type compacting dryer for waste materials, comprising a cylindrical body and at least one pair of pressing plates, said cylindrical body being made up of longitudinal heating tubes, through which a heat-transfer fluid flows, arranged along the generators of the cylinder and spaced apart from each other, so as to form longitudinal slots for the escape of steam but not for the escape of material, constrained by means of retaining rings, arranged with a given centre distance, and said pressing plates being arranged opposite one another, operating as mobile bases of said cylindrical body and acting as pressing pistons, the water steam generated by the heating operation of said waste materials being discharged through the longitudinal slots formed between said heating tubes,which includes additional heat sources, arranged inside, - 13 of the cage dryer compactor apparatus, along its entire length, consisting of at least one tube crossed by heat transfer fluid, means for the entry of the material to be treated, in a position close to one of the two ends, and means for collecting the treated material, at the opposite end. In particular, according to the invention, said additional heat sources comprise several tubes crossed by heat transfer fluid and arranged, aligned with each other, spaced apart from each other, so as to divide the internal volume of the cylindrical body into sections connected to each other, preferably into four equivalent sections, for each section. a pair of opposing pressing plates being provided, shaped to the shape of each section. According to the present invention, said pressing plates are shaped so that the profile facing the external surface of the cage, and optionally also the profile facing the additional heat sources, can have a saddle profile, so that the cusps defined between one saddle and the other are inserted into the space that occurs between one tube and the other. - 14 In particular, according to the invention, said additional heat sources are constrained by means of a containment structure, consisting of several retaining plates, arranged with a given centre distance. Also according to the invention, the compacting dryer apparatus comprises inlet and outlet manifolds for said heat transfer fluid in the pipes, connected via flexible fittings, so as to allow a uniform distribution of the fluid in the / 1 pipes, preferably said manifolds being arranged so that the direction of flow inside each single pipe is opposite to that of the adjacent pipe. Still according to the present invention, said means for the entry of the material to be treated comprise a loading hopper, from which the waste falls into a loading chamber at the entry end of the cylindrical body. Furthermore, according to the invention, said compacting dryer apparatus further comprises a casing made of heat-insulating material which closely incorporates said cylindrical body, with the function of collecting the steam coming out of said longitudinal slots and placed in depression by a closed-cycle condensing unit so that - 15 said device has no impact on either the working or external environment. Again according to the invention, said retaining rings are mounted on a series of support and sliding means forming a hyperstatic labile structure, with the aim of minimising the effects of the tensions deriving from the high thermal gradients developed, as well as from the radial thrusts due to the compressive forces exerted by the opposing pressure plates. A second specific object of the present invention also includes a process for compacting and drying waste using a compacting-drying apparatus as previously described, which, in its standard operation, comprises the following phases, which are repeated cyclically: - withdraw the pressing plates on both sides of the appliance up to their respective lower dead points, - insert a design quantity of material to be treated into the compactor dryer at operating temperature, which already contains a certain quantity of waste introduced during the previous cycles, - operate the pressing plates on the side of - 16 material inlet, so that they press the material introduced with the new load against the material already present in the cylindrical body of the dryer compactor, pushing it so that a fraction of the material, at the end opposite to the material inlet, is made to exit the appliance, - retract the pressing plates on the material inlet side to the bottom dead center, - take the quantity of material that came out of the appliance, - operate the pressing plates on both sides of the appliance, so that they press the material contained within it, - repeat the cycle from the first phase. According to the invention, steady-state operating conditions are achieved by means of the following steps, starting with the appliance empty: - allow the heat transfer fluid to flow through the pipes to reach the operating temperatures, - withdraw the pressing plates on both sides of the appliance up to their respective lower dead points, - insert a load of material into the compactor dryer, which is at operating temperature, - 17 to be treated, - operate the pressing plates on both sides of the appliance, so that they press and move the material contained therein, these phases being repeated cyclically until the design filling level is reached. Further features and advantages of the present invention will become evident from the following description with reference to the attached drawings, in which the preferred embodiment is represented for illustrative and non-restrictive purposes. In the drawings: Figure 1 shows a schematic longitudinal sectional side vertical view of an appaft® «βΓ, « & & r? And. apparatus according to the present invention, Figure 2 shows a schematic front vertical cross-sectional view of the apparatus of Figure 1, Figure 3 shows a perspective view of the cylindrical body cage detail of the apparatus of Figure 1. Referring now to the Figures, it can be seen that the main body of the compacting dryer apparatus of the invention consists of a cylindrical body 1 made from an assembly of pipes 2 traversed by - 18 a heat transfer fluid, arranged along the generators of the cylinder. A cylindrical space is therefore defined within the tubes 2, which is in turn divided into four equivalent sections by further tubes, also traversed by the heat transfer fluid, arranged in a cross shape. The waste material to be compacted and dried is loaded into the device from above, into a loading chamber 12 near one of the two bases of the cylindrical body, by means of a hopper 3. By virtue of the heat exchanged by the tubes, the device heats the loaded waste material, acting as a true oven. Furthermore, given the good ability of the pipes to work as beams, they are sized and constrained so that the cylindrical lateral body also acts as a load-bearing structure for the material to be treated, capable of reacting to the pressure and thermal stresses developed during operation. The tubes 2 which form the cylindrical body and which further divide it into four sections are traversed by a heat transfer fluid having temperatures of 170 - 190°C; they are bound together respectively by means of retaining rings 4 the tubes - 19 which constitute the lateral cylindrical body and, by means of cross-shaped retaining plates 5, the tubes that divide the cylindrical body into four sections. Said retaining rings 4 and said retaining plates 5 are arranged with a given centre distance to ensure the stability of the tubes subjected to the radial thrust exerted by the pressed material and by thermal gradients. These retaining structures have a seat designed on the profile of the tubes themselves. The longitudinal axial thrust for the compaction of the waste material contained in the cylindrical body 1 is exerted by pressing on both opposite sides of the mass of material by means of four pairs of pressing plates 6, suitably shaped to fit into the internal space of each section of the cylindrical body and in particular providing, in correspondence with the side wall, cusps inserted into the space that appears between one tube and the other. The pipes 2 communicate with the inlet 7 and outlet 8 collectors of the diathermic fluid connected by means of flexible pipes to the external part of the cylindrical body of the cage dryer compactor so as not to hinder the movements of the plates. - 20 pressing 6, which operate as pistons inside the different sections of the cylindrical body 1. In particular, the inlet and outlet manifolds are alternated so that the inlet side of each tube corresponds to the outlet side of the adjacent tube. The cylindrical cage body 1 is mounted on ground constraints consisting of sliding pads 9 suitably arranged so as to create a hyperstatic labile structure capable of minimising the effects of the tensions deriving from the high thermal gradients developed, as well as from the longitudinal thrusts due to the compressive forces exerted by the pressing plates 6. A fundamental element of the present invention is the particular geometric arrangement of the tubes 2 which act, as already mentioned, as heat sources and containment structure. They are arranged according to two different functions, the majority along the generatrices of the cylindrical body, appropriately spaced from each other so as to leave a series of longitudinal slits between one tube and the other, necessary for the escape of the steam; the remaining part along two directions orthogonal to each other, to form a cross that divides said cylindrical body into - 21 four equivalent sections, also spaced apart. The longitudinal slots along the side wall of the cylindrical body 1 are extremely effective not only as escape routes for steam, but also as an aid in the heat exchange between the pipes 2 and the material to be treated, by virtue of their cusp-shaped section, decreasing towards the outside, so as to offer the material pushed by the pressure a gradual and naturally increasingly higher resistance, which will end when the compressive forces have stabilized as designed, ensuring that the material does not escape during treatment. The tubes, arranged in a cross within the cylindrical body, are located in the middle of the waste mass: they will be in contact with the material to be treated over a fraction of their surface area much larger than the tubes that make up the cylindrical body, with each tube facing two different sections of the device. Consequently, these tubes increase the surface area available for thermal exchange of the heat released by the heat transfer fluid to the material to be treated. Furthermore, the division into sections configux'a more of body material - 22 cages with equivalent diameters smaller than the diameter of the main cylindrical body: the smaller cross-sectional area of ​​each section allows for greater heat transmission efficiency to the waste mass. Consequently, the temperature of the treated mass reaches design values ​​more quickly. Finally, the cylindrical body 1 complex is enclosed by a casing 10 made of heat-insulating material, which functions as a collector for the steam that is released through the said escape routes, which is placed under vacuum, through a duct 11, by a closed-cycle condensing unit, so that the system has no impact on either the external or working environment. The structure of the compacting dryer apparatus according to the present invention also allows for improved resistance of the device to mechanical and thermal stress, as the pipes behave like very resistant beams, even if of small thickness. As a first consequence, the compacting dryer can be made with materials of low and medium mechanical resistance, with the safety, unlike materials of high mechanical resistance. - 23 nica, to be able to solve the problems related to general corrosion, which, ultimately, can be controlled with adequate oversizing of the structures. From this perspective, it is understood that surface treatments suitable for imparting abrasion resistance to pipes are made possible thanks to the possibility of using low-alloy steels. Furthermore, it becomes possible to entrust the cage dryer compactor with the pressing task which in known systems is carried out in the compacting section at room temperature positioned upstream of the oven. The elimination of the pre-treatment section g allows, through the means of loading the waste material and appropriate measures to regulate the recovery of the treated material, the plant to operate continuously. The loading of the appliance, during start-up, involves heating the oven by making the heat transfer fluid flow to the design temperature inside the pipes, therefore it contemplates a cyclical trend composed of three phases, the first of which consists in withdrawing the pressing plates 6 up to their respective dead points, so that it does not conflict - 24 no with the insertion of the material to be treated. The second phase involves the insertion of the waste material which is dropped, in quantities reduced compared to the loading capacity of the device itself, from the hopper 3 into the loading chamber 12. The mouth of the hopper is then closed and the pressing plates 6 push the material into the cylindrical body 1 and subsequently from both sides, compressing it and pushing it into the dryer compactor in the direction of the side opposite the "input" side. This operation is repeated a certain number of times until the filling level compatible with the design data is reached, which are set based on engineering calculations that take into account the internal and external friction coefficient of the material (and therefore its nature and size) and the residence time in the device required for inertization (a function of the degree of humidity of the material to be treated and the degree of residual humidity required). During this filling phase, the heat transfer fluid is always kept at steady-state temperatures. This avoids fluctuations in thermal performance, resulting in energy savings. - 25 energy and reduction of corrosion processes. Once this first phase has passed, which already involves a certain progress in the compacting and drying operation of the material, the machine begins to operate at full capacity. It should be noted that, along its entire length, the compactor dryer object of the invention constitutes an environment in which each portion has the same temperature as the upstream portion and the Hr·*· portion. downstream. This means that heat can be released in the same way whether the material to be treated is... be positioned on fixed coordinates of the device, gg «K whether the same moves with respect to the device, translating from the loading mouth to the outlet mouth. Each new load of material introduced into the device will undergo the following treatment, consisting of an insertion phase, a treatment phase that is repeated for a total number of cycles that depends on the design parameters and a removal phase of the treated material. During the insertion phase, the material to be treated is dropped from the hopper 3 into the loading chamber 12, while the pressing plates 6 are located at their respective lower dead points. So the charge, which is described here as ref - 26 pressing, is pressed by the pressing plates 6, on the inlet side, into the cylindrical body 1 of the apparatus, against the previously introduced part of the material, which in turn is pressed by the respective pressing plates on the outlet side. Then, the plates on the exit side retract and all the material is fed towards the exit, with some of the material reaching the exit mouth and being removed. After that, the plates on the inlet side also retract and a new charge is dropped into the loading chamber, pushed into the cylindrical body and compressed against the reference charge, introduced in the immediately preceding cycle, and with it against all the material previously introduced, helping first to compress it further and then to move it towards the exit. After a certain number of cycles, during which it continues to dry out due to the heat transfer carried out by the heat transfer fluid through the exchange surface offered by the tubes, the reference charge reaches the outlet and is removed. IMG. BMMO 6 ® R00 MS - 27 In this way, by varying the number of cycles the waste remains in the appliance, or by varying the length or quantity of charge introduced each time, it is possible to continuously treat the material until the desired degree of drying and pressing is obtained. The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that variations and / or modifications may be made by those skilled in the art without departing from the relevant scope of protection, as defined by the claims attached.

Claims

1. A cage-type compacting and drying apparatus for waste materials, comprising a cylindrical body and at least one pair of pressing plates, said cylindrical body being made up of longitudinal heating tubes, through which a heat-transfer fluid flows, arranged along the generators of the cylinder and spaced apart from each other, so as to form longitudinal slots for the escape of steam but not for the escape of material, constrained by means of retaining rings, arranged with a given distance between centers, and said pressing plates being arranged opposite each other, operating as mobile bases of said cylindrical body and acting as pressing pistons, the water vapor generated by the heating operation of said waste materials being discharged through the longitudinal slots formed between said heating tubes, characterized in that it includes further heat sources,arranged inside the cage dryer compactor apparatus, along its entire length, consisting of at least one tube crossed by heat transfer fluid, means for the entry of the material to be treated, in a position close to one of the two - 29 ends, and means for collecting the treated material, at the opposite end., 2. Compacting dryer apparatus according to claim 1, characterised in that said additional heat sources comprise several pipes crossed by heat-transfer fluid and arranged, aligned with each other, spaced apart from each other, so as to divide the internal volume of the cylindrical body into interconnected sections, for each section being provided a pair of opposite pressing plates, shaped to the shape of each section.

3. Compacting dryer apparatus according to any of claims 1 and 2, characterised in that said additional heat sources are arranged, aligned with each other, spaced from each other to allow the passage of the material to be treated, so as to divide the internal volume of the cylindrical body into four equivalent sections, each equipped with a pair of opposite pressing plates, shaped to the shape of each section.

4. Compacting dryer apparatus according to any of the preceding claims, characterised in that said pressing plates are shaped so that the profile facing the external surface of the cage has a saddle profile, so that the cusps defined between one saddle and the other are inserted into the space that occurs between one tube and the other.

5. Compacting dryer apparatus according to any of the preceding claims, characterised in that said pressing plates are shaped so that the profile facing the further heat sources has a saddle profile, so that the cusps defined between one saddle and the other are inserted into the space that occurs between one tube and the other.

6. Compactor-dryer apparatus according to any of the preceding claims, characterised in that said additional heat sources are constrained by means of a containment structure, consisting of several retaining plates, arranged with a given centre distance.

7. Compactor-dryer apparatus according to any of the preceding claims, characterized in that it comprises inlet and outlet manifolds for said heat transfer fluid in the pipes, connected through flexible fittings, so as to allow a uniform distribution of the fluid in the pipes.

8. Compactor-dryer apparatus according to claim 7, characterised in that said inlet and outlet manifolds of said heat transfer fluid in the pipes are arranged so that the direction of flow inside each individual pipe is opposite to that of the adjacent pipe.

9. A compacting dryer apparatus according to any of the preceding claims, characterised in that said means for the entry of the material to be treated comprise a loading hopper, from which the waste falls into a loading chamber at the entry end of the cylindrical body.

10. Compactor dryer apparatus according to any of the preceding claims, characterized in that it further comprises a casing made of heat-insulating material which closely incorporates said cylindrical body, with the function of collecting the steam coming out of said longitudinal slots and placed under vacuum by a closed-cycle condensing unit so that said apparatus has no impact on either the working or external environment.

11. Compacting dryer apparatus according to any of the preceding claims, characterised in that said retaining rings are mounted on a series of support and sliding means forming a hyperstatic labile structure, in order to minimise the effects of the tensions deriving from the high thermal gradients developed, as well as from the radial thrusts due to the compression forces exerted by the opposing pressure plates.

12. Process for compacting and drying waste using a compactor-dryer apparatus as defined in any of claims 1-11, characterised in that, in its standard operation, it comprises the following phases, which are repeated cyclically: - withdrawing the pressing plates on both sides of the apparatus to their respective lower dead centres, - inserting a design quantity of material to be treated into the compactor-dryer at operating temperature, which already contains a certain quantity of waste introduced during the previous cycles, - operating the pressing plates on the material inlet side, so that they press the material introduced with the new load against the material already present in the cylindrical body of the compactor-dryer, pushing it so that a fraction of the material, at the end opposite to the material inlet end, is made to exit from the apparatus,- retract the pressing plates on the material inlet side to the bottom dead centre, remove the quantity of material that has exited the machine, - operate the pressing plates on both sides of the machine so that they press the material contained therein, - repeat the cycle from the first phase.

13. Process for compacting and drying waste according to claim 12, characterized in that steady-state operating conditions are achieved through the following steps, starting with the appliance empty: - allowing the heat-transfer fluid to flow through the pipes to reach operating temperatures, - withdrawing the pressing plates on both sides of the appliance to their respective lower dead points, - inserting a load of material to be treated into the compactor dryer, which is at operating temperature, - operating the pressing plates on both sides of the appliance so that they press and move the material contained therein, said steps being repeated cyclically until the design filling level is reached.