RU2799995C1 - Static dryer - Google Patents

Abstract

FIELD: gas dryer.

SUBSTANCE: invention relates to a dryer for drying compressed gas. The dryer (1) contains a drying medium (2) with a predetermined number of drying sections (3a, 3b, ... 3f) that extend next to each other and are connected to at least one hole (8) at each of the first connecting end (4) and the second connecting end (5), moreover, the specified number is greater than six, and each connecting end contains the first and second concentric elements that are able to rotate relative to each other about the axis (9), wherein holes are formed in the first concentric elements along a ring rotating around the axis, while each of the second concentric elements limits at least two channels (10A, 10B) that open in the position of said rotating ring, so that the respective channels of the first and second connecting ends are connected to each other through the holes and the drying sections to provide the first air flow and the second air flow through the dryer.

EFFECT: technical result consists in optimal distribution of drying air flows and regeneration air flows.

15 cl, 14 dwg

Description

The invention relates to a dryer for drying compressed gas.

BE2016/5804 describes a dryer for drying compressed gas. This document describes how the heat of the compressed gas coming from the compressor element can be used efficiently. This connection method allows the compressed gas to pass through the dryer both as a regeneration air stream and as a drying air stream. The dryer is a continuous dryer which has the feature that dry air passes through a portion of the drying medium while regeneration air passes through another portion of the drying medium. The position in which the regeneration air and the drying air pass through the medium changes almost continuously. BE2016/5804 describes a cylindrical drying medium that rotates through essentially statically arranged air streams. In this way, the portions of the drying medium which rotate around the axis will sequentially penetrate the regeneration air stream and the drying air stream. In practice, this is called a rotary dryer.

EP 1 140 325 describes a drying apparatus in which a substantially cylindrical drying medium is stationary. Means for separating gas streams are rotatably arranged above and below the drying medium. Thus, a drying apparatus is obtained in which the same relative rotational movement is carried out between the drying medium and the air currents as in the rotary dryer described above. The difference is that this document describes that the drying medium is stationary while the air streams are rotating, since the air stream separation means are rotating.

US 7,077,187 describes an alternative device in which the drying medium has three cavities. These cavities are mutually separated by a wall. The three cavities are connected at their first and second ends by three air chambers. The air distribution element is located in the center between the three air chambers. The air distribution element can be rotated so that the cavities are alternately supplied with a regeneration air flow and a drying air flow.

The aim of the invention is to provide a drying device by means of which an optimum distribution between the drying air flow and the regeneration air flow can be obtained, and wherein the drying device can be manufactured in a cheaper and less maintenance-intensive manner.

The invention describes, for this purpose, a drying device comprising a drying medium with a predetermined number of drying sections that extend side by side and are connected to at least one opening at each of the first connecting end and the second connecting end, the predetermined number being greater than six, and each connecting end comprising first and second additional concentric elements that rotate relative to each other about an axis, the openings being formed in the first concentric elements along a rotating ring about the axis, with each second concentric element delimiting, at least two channels that open at the position of said rotating ring, so that the respective channels of the first and second connecting ends are connected to each other through holes and drying sections to provide a first air flow and a second air flow through the dryer.

The invention is based on the understanding that when the number of drying stations is greater than six, the ratio between the regeneration air flow and the drying air flow can be optimized. More specifically, a portion of a larger volume of the common drying medium may be used to allow passage of drying air. Then, a portion of the smaller volume of drying medium can be used to pass through the regeneration air flow. Thus, the drying medium is used more optimally and the efficiency of the drying device is also improved.

The invention is further based on the understanding that connecting the tumble dryer to the air element in the conventional manner, allowing relative movement between the tumble dryer and the air element, results in a complex structure and a more expensive dryer that is more difficult to maintain. By connecting the drying sections to the holes that are formed on the additional concentric elements, the air can be distributed through the channels defined by the second concentric elements to the holes in the first concentric elements. This is a much simpler design that can be implemented cheaper and is less prone to wear. This design is also easier to maintain. The dryer according to the invention is thus more efficient, cheaper and easier to maintain than known dryers.

Preferably, at least a first channel is formed in each of the second concentric elements, which opens at the position of said rotating ring into the first selection of holes to provide the first air flow through the first channel and the corresponding areas. By forming a first channel in each of the second concentric elements, this first channel can be connected in a simple way to move the external air flow through the first channel. By rotating the second concentric elements, the respective portions, i. the portions connected to the first selection holes into which the channel opens may vary. Thus, the first air stream and the second air stream can pass alternately through one section.

Each of the second concentric elements is preferably further formed to leave a second selection of holes, different from the first selection, open to define a second conduit around the second concentric elements to allow a second air flow through the second conduit and corresponding portions. By leaving the second selection holes open, the first channel can be separated from the second channel in a simple manner. More specifically, the first channel extends inwardly through the second concentric elements, while the second channel is located around, around the second concentric elements. The second channel may be connected by providing a housing around the second concentric elements with airflow, while the first channel is connected by connecting the second concentric elements.

Each said at least one hole preferably contains a first hole formed along a rotating ring and a second hole formed along an additional rotating ring, wherein the second concentric elements are formed to close the second holes, where the first channel opens into the first holes, and leave the second holes open, where the first holes are closed. The formation of the first hole and the second hole in each section allows the connection of the first air flow through the first holes and the connection of the second air flow through the second holes. This greatly increases the freedom to design concentric elements. Airflow resistance is also reduced.

The holes are preferably of a substantially constant size, and the holes are preferably located at a substantially constant intermediate distance from each other along the rotating ring. Due to the practically constant size and the practically constant intermediate distance, the air can flow through the channels to the openings in an optimal way. The rotation of the channels relative to the holes will also have a predictable effect that is independent of the angular position of the concentric elements relative to each other.

The drying sections and the first concentric elements are preferably located statically in the dryer, and the second concentric elements are preferably rotatable in the dryer. By means of the static arrangement of the drying sections, the drying medium is also statically arranged. Therefore, by means of the static arrangement of the drying sections and the first concentric elements, most and the largest working elements of the dryer are fixed. The fixed design of the dryer is much simpler than when a significant number of elements, or when large elements must be rotated. Thus, the dryer can be manufactured more cheaply and more reliably.

The target number is preferably less than 50, more preferably less than 40, most preferably less than 30, and the target quantity is preferably greater than 10, more preferably greater than 15, and most preferably greater than 20. Tests have shown that the optimal number of drying stations is about 25. By increasing the number of drying stations, the ratio of the drying air flow to the regeneration air flow can be determined more accurately. With so many drying stations it also becomes possible to have a third air stream, such as a cooling air stream, to pass through the drying medium.

Additional concentric elements have a surface area in cross section perpendicular to the axis, which may be significantly less than the surface area of the medium for drying in cross section perpendicular to the axis. In other words, it is possible to form the dryer in such a way that the concentric elements which are intended to distribute the air are significantly smaller than the drying medium in which the air itself is distributed. This significantly reduces the relative movement of the elements relative to each other for air distribution.

Preferably, an air chamber is formed between the holes and the drying medium, so that the air passing through the holes can be evenly distributed in the drying medium. In other words, the air chamber connects the small surface area of the concentric elements and the large surface area of the drying medium. This allows air to pass radially between the holes on one side and the drying medium on the other.

The second concentric elements are preferably operatively connected for synchronous rotation relative to the first concentric elements. The working connection is preferably formed by a shaft that physically connects the second concentric elements to each other. Due to the physical connection, the concentric elements will always move in synchrony, whereby the channels on each side of the drying medium are arranged respectively to allow two air streams to pass through the sections of the drying medium. Due to the synchronous rotation, the successive sections that are connected to at least one opening can be alternately used at both the first and the second connecting end for the first air flow and the second air flow. As an alternative to a mechanical connection, it is also possible to provide an electrical, electronic or hydraulic working connection so that the second concentric elements can be actuated synchronously.

The two channels are preferably formed to allow the first airflow to pass through the X sections and to allow the second airflow to pass through the Y sections, where X is greater than Y. X is preferably greater than 1.5 times Y, X is more preferably greater than 2 times Y. X is preferably less than 5 times Y. Tests have shown that this ratio between the drying air flow and the regeneration air flow is optimal for the dryer and ensures efficient operation.

The dryer is preferably configured to provide the first airflow and the second airflow in opposite directions. This provides an efficient dryer design.

The device is preferably configured to provide a third airflow that extends between the end of the first airflow on one side and the end of the second airflow on the other. The first airflow forms the drying airflow and the second airflow forms the regeneration airflow. The dried air, as a rule, is also cooled. This cooled and dried air can be partly used as cooling air. Channels for this purpose can be formed in such a way that not all of the dried air is exhausted, but a small part of the dried air is fed back into at least one area as cooling air. This cooling air then typically runs parallel to and adjacent to the regeneration air and may be collected on the other side of the dryer along with the regeneration air flow. The main function of cooling air is to provide cooling. Secondly, cooling air can also have other results. The two channels are preferably formed to allow a third airflow to pass through the sections Z, where Z is less than Y. Z is preferably a maximum of 10% of the total number of sections, more preferably a maximum of 5%.

The invention further relates to a compressor for compressing a gas, the compressor comprising at least one compressor element with a compressed gas outlet, said compressed gas outlet being connected to a dryer according to the invention as described above. The compressor produces dried compressed gas with the advantages of a dryer described above.

The invention will now be further described based on the exemplary embodiments shown in the drawings.

On the drawings

Fig. 1A is a schematic view of a compressor with a prior art dryer that is connected to a compressor element;

1B is an alternative schematic view of a compressor with a prior art dryer that is connected to a compressor element;

Fig. 2 is an exploded perspective view of a dryer according to a preferred embodiment;

Fig. 3 is a sectional view of a dryer according to another embodiment;

Fig. 4 is a perspective view of additional concentric elements;

figure 5 - connecting end of the dryer;

Fig. 6 is a schematic view of the operation of the drying medium;

Fig. 7 is a schematic view of part of the air distribution channels;

Fig. 8 is a sectional view of a first connecting end according to an embodiment;

Fig.9 is a top view of the first connecting end;

Fig. 10 is a schematic view of another alternative embodiment of a dryer according to the invention; And

Fig.11 is a schematic view of an alternative implementation of additional concentric elements.

The same or similar elements are designated in the drawings by the same reference numerals.

FIG. 1A shows a first embodiment of a compressor unit 11 according to the invention, which in this case comprises two compressor elements 12a and 12b. The invention, however, is not limited to this, and the compressor unit 11 according to the invention may also comprise one or more than two compressor elements 12a and 12b.

Compressor elements 12a and 12b are connected to drive means not shown in the drawing, such as one or more electric motors, turbines, sprockets or the like.

The compressor elements 12a and 12b in this case form a first low pressure stage 12a and a downstream second high pressure stage 12b. The intercooler 13 is preferably located in a connecting pipe between the respective compressor elements 12a and 12b.

The high pressure compressor 12b includes a compressed gas outlet 14 to which the first outer end of the pressure line 15 is connected.

The compressor plant 11 according to the invention further comprises a compressed gas dryer 1, the dryer 1 comprising a housing in which the drying medium 2 is located. The drying air flow and the regeneration air flow pass through this drying medium. In the drawing, the drying air flow passes through the drying medium 2 from the first inlet 16 to the first outlet 17. The first outlet 17 is usually located at the opposite end relative to the first inlet 16. Said pressure line 15 is connected at its second outer end to said first inlet 16 for compressed gas for drying.

Said pressure line 15 may comprise a heat exchanger 18 for heating the regeneration air, wherein the heat exchanger 18 also partially cools the compressed gas passing from the high pressure compressor element 12b into the first inlet 16 of the dryer 1. The design of said heat exchanger 18 is thus such that cooling occurs before the compressed gas coming from the high pressure compressor element 12b passes into the dryer 1.

Also located in the pressure line 15 in this case is an aftercooler 19, which is preferably located downstream of said heat exchanger 18, i.e. in the direction of the compressed gas flow, between this heat exchanger 18 and said first inlet 16 of the dryer.

The dryer and its operation are described in more detail below with reference to the following drawings. The drying device contains a drying medium 2 with a regenerated drying agent or so-called desiccant, such as, for example, silica gel beads, activated alumina or zeolite, or a combination thereof. The drying agent can, of course, also be made in other ways.

In the drawing, said regeneration air flow passes from the second inlet 20 for supplying regeneration gas and from the second outlet 21 located opposite, for exhausting used regeneration gas. Used regeneration gas is understood to mean a gas which, after having passed through the drying medium 2, is contaminated by the moisture extracted therefrom.

The outlet pipe 28 is connected to said first outlet 17 of the dryer 1 to remove the dried compressed gas to a consumer (not shown), for example, in the form of a compressed air system, a pressure vessel or a machine or tool that uses compressed gas.

According to the invention, the first outlet pipe 26, which is connected to the cooling inlet 27 of said heat exchanger 18, is connected to said outlet pipe 28, while said heat exchanger 18 further comprises a cooling outlet 29, which is connected through a second regeneration pipe 30 to said second inlet 20 of the dryer 1.

The respective cooling inlet 27 and the cooling outlet 29 in this case form part of the secondary section of the heat exchanger 18, the primary section of which is designed to pass compressed gas for drying.

The second outlet 21 of the dryer 1 is connected via a return line 22 to said pressure line 15 at a point downstream of said heat exchanger 18, and in this case on the side of a pressure line 15 which connects the aftercooler 19 to the first inlet 16 of the drying zone 8.

Also located in the return line 22 in this embodiment is an additional cooler 23 and a condensate separator, which may or may not be placed in the same housing as the cooling section of the cooler 23 and is not shown in FIG. 1A.

In the embodiment of FIG. 1A, the connection between the return line 22 and the pressure line 15 is made by means of a Venturi tube 24 located in the pressure line 15 and containing a suction port 25 to which the aforementioned return line 22 is connected.

The operation of the compressor unit 11 according to FIG. 1A is very simple and is as follows. The low pressure stage 12a draws in a gas or mixture of gases, such as air, for example, for compression. Part of the resulting compression heat is then removed by the intercooler 13.

After exiting the intercooler 13, the compressed gas passes to the high pressure stage 12b where it is further compressed and then to the primary section of the heat exchanger 18. In the respective heat exchanger 18, which at least partially functions as a gas-gas heat exchanger, the heat of compression is transferred to the gas, which passes into the heat exchanger 18 through the inlet 27 for cooling and exits the heat exchanger again through the outlet 29 for cooling.

It should be understood that the heat exchanger 18 is designed in such a way that the gas passing through the pressure line 15 does not mix with the gas that is directed as cooling gas through the secondary side of the heat exchanger 18. In this case, the heat exchanger 18 is designed in such a way that the two gas streams passing through it pass in mutual countercurrent, although this is not a strict requirement in accordance with the invention.

The pre-cooled compressed gas that leaves the heat exchanger 18 and passes through the pressure pipe 15 then enters the aftercooler, where this gas stream is further cooled.

Thereafter, the cold pressurized gas passes through the venturi 24 and the first inlet 16 through the dryer 1, where the moisture present in the gas is absorbed by the drying agent present in the drying medium 2.

Then, the cold, dry compressed gas exits the dryer 1 through the first outlet 17 and passes through the outlet pipe 28 to the compressed gas consumer.

In accordance with the invention, a portion of the cold, dry compressed gas is withdrawn from the outlet pipe 28 and then travels through the first outlet pipe 18 to the secondary section of the heat exchanger 18, and more particularly to the aforementioned cooling inlet 27, to serve as a drying medium there.

When the gas exits the cooling outlet 29, its temperature is raised by absorbing the compression heat generated in the high pressure compressor element 12b. In this way, the relative humidity of the gas discharged through the outlet pipe 26 will be further reduced in a very energy efficient manner.

As a result, the additional dry gas that passes through the regeneration pipe 30 moves through the second inlet 20 as regeneration air through the dryer 1 where this gas serves as a regeneration gas that will extract moisture from the drying medium 2.

After the regeneration gas leaves the regeneration zone through the second outlet 21, it will pass through an additional cooler 23 and a downstream condensate separator, which optionally, although not necessarily, can be built into the same housing as the cooler 23, to the suction hole 25 of the Venturi tube 24.

In accordance with the invention, the presence of a venturi tube is not strictly necessary, and a fan can also be used, for example, to combine the regeneration gas that exits the regeneration zone 14 with the hot compressed gas flow that passes from the heat exchanger 18 to the drying zone 8 through a pressure pipe 15.

As an alternative to the embodiment shown, aftercooler 19 and cooler 23 can be made as one element so that only one physical cooler is required.

FIG. 1B shows an alternative way of connecting the dryer 1 to the compressor element 12. FIG. 1B shows here a simpler design in which the compressed gas outlet 14 is divided, with part of the compressed gas moving directly as regeneration gas to the second inlet 20 of the dryer 1. Another part of the compressed gas is cooled in the cooler 19 and moved to the inlet 16 of the dryer for drying. The second outlet 21 of the dryer is also cooled in the cooler 23 and is combined through a venturi 24 or a small compressor element 24 with another cooling part.

While the above construction is advantageous, one skilled in the art will appreciate that the dryer 1 can be incorporated into the compressor in various ways for the purpose of drying the compressed gas. The outlet of the compressor element 12, for example, may be directly and completely connected through a cooler to the first inlet 16 and completely dried by the dryer 1. Here, an external air stream may be connected to the second inlet 20 to serve as a regeneration stream.

Figure 2 shows the drying device 1 in more detail. Figure 2 shows the drying medium 2 more specifically. The drying medium preferably has an internal structure with a plurality of narrow elongated small channels or tubes extending in the direction of axis 9. The walls of these elongated channels or tubes contain a material with a desired energy and moisture absorption capacity. In this way, a large contact surface is obtained between the air passing through the drying medium and the material, which ensures the exchange of energy and moisture. The drying environment is usually formed such that adjacent elongated small channels or tubes are closed off from each other so that air cannot pass from one channel or tube to another channel or tube. In other words, the air that passes into the drying medium in one small channel or tube will also exit the drying medium at the other end through the same channel or tube.

Regardless of the form it takes, this drying medium is divided into a plurality of 3 drying sections. The number of sections is a minimum of six. In figure 2, the sections are marked with the reference positions 3a, 3b, 3c, 3d, 3e and 3f. Preferably, about 25 regions are formed. When the drying medium is cylindrical, each section will preferably extend about 15 degrees. It should be understood that when the drying medium is formed with the above-described internal structure, each section 3 will have a plurality of small channels or tubes. However, the partitioning of the drying medium 2 also provides alternative designs. Thus, each section may be formed in a separate housing, or a plurality of cavities may be formed in one housing.

When the drying medium 2 is formed with an internal structure with a plurality of narrow elongated small channels or tubes, each channel or tube can itself be considered as a section in the drying medium 2, which then has a very large number of sections. However, through the formation of air chambers at the beginning and end of the elongated channels, these sections are operatively connected together, forming the above sections. The number of the above sections is significantly less than the number of elongated channels or tubes.

The drying medium 2 extends between the first connecting end 4 and the second connecting end 5. The drying medium 2 preferably extends upwards. In the embodiment of FIG. 2, the first connecting end 4 is formed at the top. In the embodiment of figure 2, the second connecting end 5 is formed at the bottom. In the position of the connecting ends 4 and 5, the air flows are controlled and distributed through the drying medium 2. Therefore, the first connecting end 4 has a first outlet 17 for the drying air flow and a second inlet 20 for the regeneration air flow. The second connecting end 5 has a first inlet 16 for the drying air flow and a second outlet 21 for the regeneration air flow.

The air flows are distributed over the sections 3. More specifically, the drying air flow and the regeneration air flow, and if necessary also the cooling air flow, will be distributed over the sections 3. Thus, the drying air flow will flow from the inlet 16 to the outlet 17, and the regeneration air flow will flow from the inlet 20 to the outlet 21. The drying air flow and the regeneration air flow preferably pass in opposite directions through the medium 2 for drying.

Additional concentric elements are located in the position of the first connecting end 4 and the second connecting end 5 to distribute air flows over the sections 3. Figure 2 shows only the additional concentric features at the first connecting end 4. The person skilled in the art will understand that the same or similar additional concentric features are located at the position of the second connecting end 5.

Figure 2 shows the first concentric element 6. This first concentric element 6 has a cylindrical shape. A plurality of holes 8 are formed in the first concentric element 6. These holes 8 are connected to the drying sections 3. More specifically, each drying section 3 will be connected to at least one hole 8, so that the air that passes through this at least one hole 8 also passes through the corresponding drying section 3. The holes 8 pass along a rotating ring around the axis 9. The first concentric element 6 also passes around the axis 9.

Figure 2 also shows the second concentric element 7. The second concentric element 7 complements the first concentric element 6. More specifically, the second concentric element 7 can move relative to the first concentric element 6 so that air can be distributed. In this embodiment, the second concentric element also passes for this purpose around the axis 9 with a diameter corresponding to the diameter of the first concentric element 6. The second concentric element 7 has channels 10, which are located along a rotating ring around the axis 9. This rotating ring is the same as the rotating ring along which the holes 8 are formed. This leads to the fact that when the concentric elements 6 and 7 are installed, the channels 10 open into the holes 8.

Figure 2 shows two channels 10A and 10B. It will be appreciated by those skilled in the art that the first duct 10A is associated with the first air stream, the drying air stream, while the second duct 10B is associated with the second air stream, the regeneration air stream. The two channels open on a rotating ring around an axis 9. The channels 10A and 10B thus connect the first outlet 17 to a portion of the holes 8 and the second inlet 20 to the other portion of the holes 8 at the position of the first connecting end. Channels 10A and 10B thus distribute air from the first outlet 17 and the second inlet 20 into the holes. Since a similar or identical concentric element 7 is located in the position of the second connecting end 5, two air streams are formed which can pass through the drying medium 2 and which are almost completely separated from each other. It should be understood that most of the elements, including the drying medium and the first concentric elements 6, can assume a static form, i.e. be fixedly connected to the body (not shown in figure 2).

Figure 3 shows a practical embodiment of a dryer 1 according to an embodiment of the invention. The drawing shows that the medium 2 for drying is located in the housing 31. In the embodiment, the housing is cylindrical. It should be understood that since the drying medium 2 is fixed in the housing, other shapes are also possible, such as rectangular or divided shapes. The shaft 34 passes centrally through the housing 31 which physically connects the second concentric element 7 of the first connecting end 4 to the second concentric element 7 of the second connecting end 5. Due to their physical connection, these second concentric elements 7 always rotate in perfect synchrony.

Figure 3 shows that the first inlet 16 is directly connected to the second concentric element 7, so that air can pass through some of the holes 8 in the position of the first connecting end 4. This air passes through the drying medium 2 and, in the position of the second connecting end 5, passes through the holes 8 and the second concentric element 7 to the second outlet. Thus, the air flow can pass through the drying medium, more specifically through the second concentric elements 7 and a limited number of sections.

The air chambers 33 are arranged to allow air to pass through all the small channels or tubes of the drying medium section 2. The air chambers extend from the transverse surface of the respective portion of the drying medium to at least one respective opening. From the openings 8 the air chambers extend at least partially radially to allow air to pass from the openings which are formed in the first concentric elements with a small cross-sectional area to the drying medium which has a significantly larger cross-sectional area. The cross sections are seen to be perpendicular to axis 9. The air chambers thus ensure that air is distributed throughout the drying medium. Each air chamber is preferably associated with one drying section 3. The drying section 3 can also be associated with a plurality of air chambers, for example when the drying section 3 also has a plurality of openings 8.

Figure 3 further shows that the holes 8 are located not only on the cylindrical surface indicated by the reference position 8, but can also be located on the surface perpendicular to the axis 9, indicated by the reference position 8'. Each air chamber 33, and with it also each section 3, is thus associated with a first opening 8 and a second opening 8'. These additional holes 8' are closed at least partially by a lid 35 which forms part of the second concentric element 7. The second holes 8' form part of the first concentric element 6. The second holes 8' open at a position of a rotating ring that is significantly larger than the rotating ring of the first holes 8. The person skilled in the art will understand that the first and second concentric elements 6 and 7 still complement each other and are also still concentric. In this context, concentric is defined as elements that do not intersect each other and that are located around the same axis. Complementary is related to functionality and is defined as cooperating, to separate the air streams from each other. The concentricity ensures the rotation of the elements 6 and 7 relative to each other around the axis 9.

In the embodiment of figure 3, two concentric elements 7 will separate the channels from each other, but the second concentric elements 7 will not necessarily contain two channels. The reason is that the first channel will pass through the second concentric elements 7. This first channel opens into the first holes 8 while the cover closes the respective second holes 8'. The delimitation is thus carried out by the second concentric elements 7 of the air chambers 33 and thus also by the sections 3 that are associated with the openings 8. More specifically, the second concentric elements 7 will delimit these sections by isolating these sections from the surrounding area. Thus, the first channel may be formed through the second concentric elements 7 and the portions connected thereto, while the second channel is formed around the second concentric elements 7. In this embodiment, the holes that are connected to the first channel will be called the first hole selection, and the holes that are connected to the second channel will be called the second hole selection. The second concentric elements contain a channel that opens into the first holes of the first choice, while the cover closes the second holes of the first choice. The second concentric elements are also formed so as not to cover the second holes of the second choice, and to cover the first holes of the second choice. It should be understood that for both closing the second holes of the first choice and closing the first holes of the second choice, it is not necessary to close each hole separately, although it is necessary that the holes be shielded together from the other channel so that air from the first channel cannot pass into the second channel and vice versa.

In the embodiment of figure 3, the connection of channels is simple and is as follows. At the top and bottom, the second concentric element can be directly rotatably connected to the regeneration air inlet 20 and outlet 21. Through the rotation of the second concentric elements, the regeneration air alternately passes through the different sections of the drying medium. The housing 31 may be positioned at the top and bottom of the outlet 17 and the inlet 16 so that the second airflow may be passed around the second concentric members. In other words, the second concentric elements shield the drying medium zone to allow the regeneration flow to pass in the opposite direction to the drying flow. The drying flow passes through the body of the dryer through the areas using the holes 8', except for the areas that are closed by the second concentric elements.

Figure 4 shows an embodiment of additional concentric elements. More specifically, Fig. 4A shows a first concentric element and Fig. 4B shows a second concentric element. The first concentric element in figa has a cylindrical shape in the Central zone and has holes 8, which extend over the surface of the cylinder. The person skilled in the art will appreciate that the cylinder shape is only one embodiment, and that other shapes, such as a cone shape, optionally truncated, may also be used. Further, in the embodiment of FIG. 4A, the partitioning walls 36 are shown. The partitioning walls 36 extend radially from the central region of the first concentric member 6. When the dryer 1 is configured as shown in FIG. 3, the partitioning walls 36 extend to a diameter that is substantially equal to that of the drying medium. The dividing walls 36 form air chambers 33 for distributing air to all the small channels or tubes of the drying section 3. The dividing walls 36 are located at least opposite the drying medium 2, preferably partly in the drying medium 2. This ensures that the air is sealed between the separating walls 36 and the material of the drying medium. The location of the separating walls 36 partially in the drying medium 2 makes it possible to still reliably use the drying medium 2 with a treatment that is rough and not perfectly smooth. When the drying medium 2 rotates relative to the air distributors, as in the prior art, it is important that the drying medium 2 has a very smooth sanding finish.

The partition walls can be closed at the top (not shown) so that air can only be distributed between the regions through the holes 8. In the embodiment shown, the partition walls are open at the top so that additional holes 8' are formed on a surface substantially perpendicular to the axis 9. The second concentric element then preferably comprises a lid which fits snugly over the additional holes 8' so that some of the additional holes 8' can be covered. Thus, different air streams can move to different areas.

Figure 4B shows a second concentric element 7. The second concentric element is cylindrical and has a diameter which is such that the second concentric element fits snugly against the first concentric element 6. The length of the second concentric element 7, measured in the direction of the axis 9, is at least large enough to pass essentially the entire first concentric element 6. In Fig.4B, the second concentric element 7 has two channels 10A and 10B. Channels 10A and 10B open into different openings 8 when concentric members 6 and 7 are fitted. FIG. 4B shows the interface between channels 10A and 10B. This boundary surface defines the channel boundary 37 and separates the two channels 10A and 10B from each other in the position of the rotating ring. The channel boundary 37 has a width that is preferably at least equal to, preferably slightly greater than, the width of the holes 8. A channel boundary 37 with this width prevents the first channel 10A and the second channel 10B from opening into the same hole 8. In FIG. Thus, the first air stream and the second air stream can be separated from each other in a simple way by two complementary concentric elements 6 and 7.

Fig. 5 shows an element of an embodiment of the first connecting end of the dryer and shows how the complementary concentric elements cooperate to separate the two air streams from each other in the drying medium 2. Figure 5 shows the drying medium 2 and shows how the partition walls 36 form air chambers 33 at the top. Figure 5 also shows that the air chambers 33 have holes 8 in the central area and have additional holes 8' at the top. On the left side of the drawing, additional holes 8' are covered with a cover. The air of the second air stream 39 may pass through the channel 10A through a part of the sections 3. More specifically, the second air stream 39 passes through the sections that are associated with the holes 8 into which the channel 10A opens. The air chambers associated with these areas are closed at the top with a cover 35. The first air flow 38 passes through additional holes 8', which are not closed on the right side of the drawing. It will be appreciated by those skilled in the art that the first air stream 38 does not pass through the holes 8 to any appreciable extent, but passes through additional holes 8'. In this way, the openings 8, which are associated with the areas through which the first air flow 38 passes, can be closed. In this embodiment, the drying medium 2 and the first concentric element 6 containing holes 8, additional holes 8' and separating walls 36 preferably assume a static shape. This means that the last indicated elements are rigidly connected to the housing. In this embodiment, the second concentric element 7, which contains the channels 10A and the cover 35, can be rotated. To synchronize the rotation of the second concentric element 7 of the first and second connecting ends 4 and 5, the shaft 34 which mutually connects the second concentric elements 7 preferably passes through the dryer 1.

Figure 6 shows the principle of operation of the flow 40 of the cooling air. The cooling air stream 40 forms a third air stream which, in addition to the first air stream 38 and the second air stream 39, passes through at least one portion of the drying medium. The first air stream 38 is a drying air stream. The second air flow 39 preferably runs in the opposite direction and is a regeneration air flow 39 . By returning part of the drying air flow to at least one section of the drying medium, cooling of this section is achieved. Therefore, the cooling air stream preferably extends from the end of the first air stream 38, where the first air stream 38 exits the drying environment, to the end of the second air stream 39, to be there combined with the second air stream that exits the drying environment. Thus, it is not necessary to actively connect the third airflow to the concentric members, but a cooling airflow can be obtained in the drying environment by predetermined timing and positioning of the channels at the position of the first and second connecting ends 4 and 5. Tests have shown that providing a cooling airflow further improves the efficiency of the dryer.

Fig. 7 shows a cross-section of the second concentric element 7. Fig. 7A shows here the second concentric element in the position of the first connecting end 4, and Fig. 7B shows the second concentric element 7 in the position of the second connecting end 5. The concentric elements 7 in Figs. 7A and 7B are not identical, but compatible. More specifically, the dimensions of the channels 10A and 10B are not the same, resulting in the above-described cooling air flow.

On figa shows the second concentric element 7 with the first channel 10A, which extends for about 90°. The second channel 10B extends for about 240°. Channel boundaries are formed between channels 10A and 10B and extend for about 15°.

On figv shows the second concentric element 7 with the first channel 10A, which extends for about 105°. The second channel 10B extends for about 225°. Channel boundaries are formed between the channels 10A and 10B and extend for about 15°.

Where indicated above a given number of degrees, this number will be interpreted as approximately +/-20%, preferably as +/-15%, more preferably as +/-10%, most preferably as +/-5%. One skilled in the art will appreciate that this percentage change should be chosen such that the total number of degrees of the different channels and boundaries is 360 degrees.

7A and 7B show line 42 as a timing line to explain the operation of the concentric members 7. In the installed position and during operation of the dryer 1, the timing lines run in parallel. The direction of rotation is also shown in FIGS. 7A and 7B with an arrow 41. FIG. 7 shows one drying section 3A. This drying section 3A extends from the first connecting end 4 to the second connecting end 5, and air can pass through this drying section 3A. In the position shown, the drying air flow will flow through the drying section 3A, since the drying section 3A borders the second channel 10B at the position of both the first and second connecting ends 4 and 5. It is assumed here that the drying air flow passes through the second channels 10B in this embodiment. The person skilled in the art will understand that by rotating the concentric elements 7, the drying section 3A is first closed by the boundary 37 of the channels, and then abuts the first channels 10A. At this point, the regeneration air flow will pass through the drying section 3A. Since the concentric members 7 are not identical, the dryer section 3A will initially be closed at the first end position by the channel boundary 37 while the dryer section still borders the first channel 10A at the second end position. The dryer section 3A will then abut the second channel 10B at the position of the first connection end 4, while the dryer section abuts the first channel 10A at the position of the second connection end 5. At this point, the cooling air flow will begin to flow through the dryer section 3A. This cooling air stream passes between the end of the drying air stream and the end of the regeneration air stream. With further rotation of the concentric elements 7, the drying section will be closed by the boundary of the channels at the position of the second connecting end 5, so that the flow of cooling air is stopped. Then the process is repeated again. The plurality of sections 3 will be provided alternately in the method described above with a drying air flow, a regeneration air flow and a cooling air flow due to the design of the channels 10A and 10B. The ratio of the drying air flow, the regeneration air flow and the cooling air flow may be determined by the number of sections and the design of the second concentric elements.

It should be understood that the direction of rotation shown in FIGS. 7A and 7B and used above in the accompanying explanation cannot be construed as limiting, and that it is possible to rotate the concentric members 7 in different directions. It should also be understood that the rotation speed may vary depending on the speed of the air flow passing through the dryer 1 and based on the temperatures of the flows 38 and 39.

Fig. 8 shows a cross section of a portion of the first connecting end 4 of the dryer 1. Fig. 8 shows how an air chamber 33 is formed above the drying medium 2. The drying medium 2 contains small channels and/or tubes which extend in an upward direction. On the upper side, the drying medium 2 may have some roughness or rough finish. The separating walls 36 are pushed at least partially into the medium 2 for drying. In FIG. 8, about 1/3 of the separating wall 36 has been pressed into the medium 2 for drying. The separating walls 36, however, are flat at the top so that the lid 35 can seal tightly against the walls to optimize sealing. Figure 8 shows how the air box 33 is used to distribute the air coming from the hole 8 and indicated by the arrow 43, between small channels and/or tubes of the drying medium, indicated by the arrows 44. The person skilled in the art will understand that the air flow in the opposite direction can be provided in a similar way.

By pressing the partitioning walls 36 at least partially into the drying medium on either side of the drying medium 2, the drying medium 2 can be separated into drying zones 3 and air can selectively pass through the openings 8 from and to the drying zones 3.

Figure 9 shows a top view of an alternative implementation of the dryer. In this embodiment, the drying medium 2 is formed in the rectangular housing 31, and the drying medium comprises eight sections 3a to 3h. The sections have substantially the same surface area in cross section, resulting in the sections at the corners of the rectangle, 3b, 3d, 3f and 3h, being narrower than the other sections 3a, 3c, 3e and 3g. Each section is associated with an opening in the first concentric element 6. This first concentric element 6 is compatible with the second concentric element 7. The second concentric element 7 rotates in the first concentric element 6 and has two channels 10A and 10B. In the position as shown in FIG. 9, the first channel 10A is connected to sections 3a and 3h. The second channel 10B is connected to sections 3c, 3d, 3e and 3f. Sections 3b and 3g are closed by the boundaries of 37 channels. The openings 8 are preferably the same size as the channel borders 37 so that the channel border 37 can completely cover the opening. In Fig.9 the first concentric element 6 is located in the center of the dryer. It should be understood that the first concentric element 6 can also be decentralized.

10 shows an embodiment in which each drying section 3 is formed separately and has its own body. Each dryer section 3 is here connected via connection 45 to a second concentric element 7. The second concentric element has holes 8 (not shown in Fig. 10) to which connections 45 are connected, so that when air passes through the holes, this air can pass through the respective drying sections 3. Since each dryer section 3 has its own housing, air leakage from one section to another is almost impossible. This provides a cheaper drying medium, such as a chamber with granules whose surfaces have desired properties.

Figure 10 further shows how the first concentric element can be made with two connections 16 and 21, and the first concentric element can be made from the inside, so that the first channel 10A is always connected for passage with connection 16, while the second channel 10B is always connected for passage with connection 21. Such an internal design is described in US7077187 and is included here by reference.

Figure 11 shows an alternative implementation of the concentric additional elements 6 and 7. In the shown embodiment, the second concentric element 7 is made of two parts 7a and 7b. The first part 7a is located inside the first concentric element 6 and has a first channel 10A, which is directed to the holes 8 in the position of the inner border of the first concentric element 6. The second part 7b is located outside the first concentric element 6 and has a second channel 10B, which is directed to the holes 8 in the position of the outer border of the first concentric element 6. Air can be distributed over the sections 3 with the help of such additional concentric elements 6 and 7.

The specialist should understand based on the above description that the invention can be embodied in various ways and based on different principles. The invention here is not limited to the above-described embodiments. The embodiments and drawings described above are illustrative only and serve only to improve the understanding of the invention. Therefore, the invention is not limited to the embodiments described herein, but is defined in the claims.

Claims (15)

1. A drying device (1) containing a drying medium (2) with a predetermined number of drying sections (3a, 3b, ... 3f) that pass adjacent to each other and are connected to at least one hole (8) at each of the first connecting end (4) and the second connecting end (5), with the specified number greater than six, and each connecting end contains the first and second concentric elements that are rotatable relative to each other around the axis (9), the holes being formed in the first concentric elements along the rotating ring around the axis, and each of the second concentric elements limits at least two channels (10A, 10B) that open in the position of said rotating ring, so that the corresponding channels of the first and second connecting ends are connected to each other through holes and drying sections to provide the first air flow and the second air flow through the dryer. 2. The dryer according to the previous claim, wherein each of the second concentric elements is formed at least a first channel, which opens at the position of said rotating ring in the first selection of holes to provide a first air flow through the first channel and the corresponding areas. 3. The dryer according to the previous claim, wherein each of the second concentric elements is further formed to leave a second selection of holes, different from the first selection, open to define the second channel around the second concentric elements to provide a second air flow through the second channel and the corresponding areas. 4. A drying device according to any of the previous paragraphs, in which each said at least one hole contains the first hole (8) located along the rotating ring, and contains the second hole (8') located along the other rotating ring, and the second concentric elements are formed to close the second holes (8'), where the first channel opens into the first holes (8), and to leave the second holes (8') open, where the first holes (8) are closed. 5. A dryer according to any one of the preceding claims, wherein the apertures are of substantially constant size and spaced at a substantially constant intermediate distance from each other along a rotating ring. 6. Drying device according to claim 4, wherein when the openings (8) are closed, the drying sections and the first concentric elements are statically shaped and the second concentric elements are rotatable. 7. A dryer according to any one of the preceding claims, wherein the set amount is less than 50, preferably less than 40, more preferably less than 30, and wherein the set amount is preferably greater than 10, more preferably greater than 15, and most preferably greater than 20. 8. A dryer according to any one of the preceding claims, wherein the second concentric elements are operatively connected to rotate synchronously with respect to the first concentric elements. 9. The dryer according to the previous claim, in which the working connection is formed by a shaft that physically connects the second concentric elements to each other. 10. A dryer according to any one of the preceding claims, in which two channels are formed to allow the passage of the first air flow through the sections X and to allow the passage of the second air flow through the sections Y, and X is greater than Y. 11. A dryer according to any one of the preceding claims, wherein the dryer is configured to provide a first airflow and a second airflow in opposite directions. 12. A dryer according to the preceding claim, wherein the device is configured to provide a third air stream that extends between the end of the first air stream on one side and the end of the second air stream on the other. 13. A dryer according to claim 10, or 11, or 12, in which two channels are formed to ensure the passage of a third air flow through sections Z, and Z is less than Y. 14. A dryer according to any one of the preceding claims, wherein each drying section has an air chamber on either side of the drying medium for distributing air between the at least one opening and the drying medium. 15. A compressor for compressing a gas, the compressor comprising at least one compressor element with a compressed gas outlet, said compressed gas outlet being connected to a dryer according to any one of the preceding claims.

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