HEAT EXCHANGER
20240280327 ยท 2024-08-22
Assignee
Inventors
Cpc classification
F28D9/0075
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D1/0333
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F3/044
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25B39/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F1/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F1/26
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F3/046
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F1/28
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A heat exchanger includes a plurality of fins each having an opening formed in an upper portion thereof and an opening formed in a lower portion thereof to allow a refrigerant to flow and being provided therein with a flow path through which the refrigerant flows, the plurality of fins being arranged at intervals in one direction; and a header formed at each of the upper portions and lower portions of the plurality of fins, the header being in communication with the flow path. At least one fin, among the plurality of fins, is configured such that at least one of the opening in the upper portion and the opening in the lower portion is closed.
Claims
1. A heat exchanger comprising: a plurality of fins defining a flow path for a refrigerant to flow, each fin having an opening located in an upper portion thereof and an opening located in a lower portion thereof to allow the refrigerant to flow, each fin having a flow path portion therein to allow the refrigerant to flow, the plurality of fins being arranged at intervals in one direction; and an upper header provided at the upper portion of the plurality of fins, and a lower header provided at the lower portion of the plurality of fins, each header being in communication with the flow path portion, wherein at least one fin, among the plurality of fins, is configured such that at least one of the opening in the upper portion and the opening in the lower portion is closed.
2. The heat exchanger of claim 1, wherein each header is defined by the openings of adjacent fins, of the plurality of fins, being coupled to one another in a successive manner.
3. The heat exchanger of claim 2, wherein each of the plurality of fins further comprises a fin collar to surround a corresponding one of the openings, the fin collar protruding a predetermined thickness, and wherein each header is defined by fin collars of the adjacent fins being coupled to one another in a successive manner.
4. The heat exchanger of claim 3, wherein the plurality of fins comprises at least two types of fins among a basic fin in which the opening in the upper portion and the opening in the lower portion are both open, a series flow fin in which only one of the opening in the upper portion and the opening in the lower portion is open, and a closed fin in which the opening in the upper portion and the opening in the lower portion are both closed.
5. The heat exchanger of claim 4, wherein the series flow fin is configured to change a flow of the refrigerant from a parallel flow to a series flow to thereby extend a length of the flow path for the refrigerant.
6. The heat exchanger of claim 5, wherein the series flow fin is disposed in a zone within the heat exchanger where refrigerant stagnation occurs.
7. The heat exchanger of claim 6, wherein the closed fin defines an end plate of the heat exchanger.
8. The heat exchanger of claim 7, wherein an entirety of the plurality of fins of the heat exchanger, except one series fin and one closed fin, consists of the basic fins.
9. The heat exchanger of claim 4, wherein a position of the series flow fin in the plurality of fins is selected depending on a role of the heat exchanger.
10. The heat exchanger of claim 9, wherein, when the heat exchanger is operated as a condenser, the flow path for the refrigerant is provided such that the flow of refrigerant is directed from top to bottom at an inlet of the heat exchanger and an outlet of the heat exchanger.
11. The heat exchanger of claim 10, wherein, when the heat exchanger is operated as the condenser, the series flow fin is disposed such that, in the flow path for the refrigerant, a section where refrigerant flows from top to bottom is greater than a section where refrigerant flows from bottom to top.
12. The heat exchanger of claim 11, wherein, when the heat exchanger is operated as the condenser, at least two series flow fins are disposed such that a portion of the flow path for the refrigerant flows from bottom to top.
13. The heat exchanger of claim 9, wherein, when the heat exchanger is operated as an evaporator, the flow path for the refrigerant is provided such that the flow of refrigerant is directed from bottom to top at an inlet of the heat exchanger and an outlet of the heat exchanger.
14. The heat exchanger of claim 13, wherein, when the heat exchanger is operated as the evaporator, the series flow fin is disposed such that, in the flow path for the refrigerant, a section where refrigerant flows from bottom to top is greater than a section where refrigerant flows from top to bottom.
15. The heat exchanger of claim 13, wherein, when the heat exchanger is operated as the evaporator, at least two series flow fins are disposed such that a portion of the flow path for the refrigerant flows from top to bottom.
16. The heat exchanger of claim 1, wherein each fin includes: a first panel having a plurality of first grooves protruding outward from the first panel and extending in a direction inclined with respect to a longitudinal direction of the first panel, the plurality of first grooves being arranged along the longitudinal direction of the first panel, and a second panel coupled to the first panel, the second panel having a plurality of second grooves protruding outward from the second panel and extending in a direction intersecting the plurality of first grooves while being inclined with respect to a longitudinal direction of the second panel, the plurality of second grooves being arranged along the longitudinal direction of the second panel to face the plurality of first grooves to thereby define the flow path portion.
17. The heat exchanger of claim 16, wherein each fin includes a fin collar to surround a corresponding one of the openings, each fin collar including: a first fin collar on the first panel; and a second fin collar on the second panel.
18. The heat exchanger of claim 17, wherein the first panel comprises a first bending section where the first grooves are bent in a first direction with respect to an air flow direction, and wherein the second panel comprises a second bending section where the second grooves are bent in a second direction opposite to the first direction at a position corresponding to the first bending section.
19. The heat exchanger of claim 18, wherein the first bending section and the second bending section are arranged parallel to a longitudinal direction of the fin.
20. A heat exchanger comprising: a plurality of fins provided therein with a flow path through which a refrigerant is configured to flow, the plurality of fins being arranged at intervals in one direction; and an upper header provided at an upper portion of the plurality of fins, and a lower header provided at a lower portion of the plurality of fins, each header being in communication with the flow path, wherein each of the plurality of fins has an opening in the upper portion and the lower portion thereof, and wherein each header is defined by the openings of adjacent fins, of the plurality of fins, being coupled to one another in a successive manner.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0037]
[0038]
[0039]
[0040]
[0041]
[0042] (a) of
[0043]
[0044]
[0045]
DETAILED DESCRIPTION
[0046] The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the exemplary embodiments to those skilled in the art. The same reference numerals are used throughout the drawings to designate the same or similar components.
[0047] Spatially relative terms such as below, beneath, lower, above, upper, etc., can be used to easily describe the correlation between one component and another component as shown in the drawing. Spatially relative terms should be understood as including different directions of components at the time of use or operation in addition to the directions shown in the drawing. For example, when reversing a spherical element shown in the drawing, a component described as below or beneath of another component may be placed above another component. Thus, the illustrative term below may include both the lower and the above directions. Components can also be oriented in different directions, so that spatially relative terms can be interpreted according to the orientation.
[0048] The terms herein are merely used to describe various embodiments of the present disclosure but are not intended to limit the present disclosure. Singular forms are intended to include plural forms unless the context clearly indicates otherwise. The terms comprise and/or comprising used in this specification do not exclude presence or addition of one or more other constituents, steps and/or operations in addition to the stated constituent, step, and/or operation.
[0049] Unless otherwise defined herein, all terms (including scientific and technical terms) used in the present specification may have meanings commonly understood by those skilled in the art. Such terms as those defined in a generally used dictionary are to be interpreted to have the same meanings as the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.
[0050] In the drawings, the thickness or size of each constituent is exaggerated, omitted, or schematically illustrated for ease description and clarity. In addition, the size or area of each constituent does not completely reflect the real size or area thereof.
[0051] In addition, angles and directions referred in description of structures of embodiments are based on the illustrations of the drawings. In the case that a reference point or a reference position for an angle is not clearly stated in description of structures forming the embodiments, refer to the relevant drawings.
[0052] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings.
[0053]
[0054] As shown in
[0055] In this embodiment, two indoor units 20 are connected to one outdoor unit 40. However, this is merely an example, and the present disclosure is not limited thereto. That is, one indoor unit 20 may be connected to one outdoor unit 40, or three or more indoor units 20 may be connected to one outdoor unit 40.
[0056] The outdoor unit 40 includes an outdoor heat exchanger 41 configured to exchange heat between outdoor air and a refrigerant, an outdoor blower 42 configured to allow the outdoor air to pass through the outdoor heat exchanger 41, a compressor 46 configured to compress a refrigerant, a four-way valve 44 configured to guide the refrigerant discharged from the compressor 46 to one of the outdoor unit 40 and the indoor units 20, an outdoor expansion valve 43 configured to decompress and expand the refrigerant, and an accumulator 45 configured to separate a liquid refrigerant from the refrigerant introduced into the compressor 46 to allow the liquid refrigerant to be vaporized and introduced into the compressor 46.
[0057] The outdoor unit 40 further includes a controller 47 to control the operation of the outdoor blower 42, the outdoor expansion valve 43, the compressor 46, and the four-way valve 44. The controller 47 may be configured as a micro-computer or the like.
[0058] The indoor unit 20 includes an indoor heat exchanger 21 configured to exchange heat between indoor air and a refrigerant, an indoor blower 22 configured to allow the indoor air to pass through the indoor heat exchanger 21, and an indoor expansion valve 23 configured to decompress and expand the refrigerant.
[0059] A refrigerant pipe 30 includes a liquid refrigerant pipe 31 through which a liquid refrigerant passes, and a gaseous refrigerant pipe 32 through which a gaseous refrigerant passes. The liquid refrigerant pipe 31 allows the refrigerant to flow between the indoor expansion valve 23 and the outdoor expansion valve 43.
[0060] The gaseous refrigerant pipe 32 guides the refrigerant to flow between the four-way valve 44 of the outdoor unit 40 and the gas side of the indoor heat exchanger 21 of the indoor unit 20.
[0061] Any one of HC refrigerant, HC mixed refrigerant, R32, R410A, R407C, and carbon dioxide may preferably be used as a refrigerant in the air conditioner.
[0062]
[0063] Referring to
[0064] A header 20 may be provided in pair, and the pair of headers 20 may be disposed at opposite end portions of the plurality of fins 10. The opposite end portions may be an upper end portion and a lower end portion in an up-and-down or vertical direction. The header 20 may be in communication with the flow paths formed in the plurality of fins 10.
[0065] Accordingly, a refrigerant may be introduced into one header 20 of the pair of headers 20, then may pass through the flow paths in the respective plurality of fins 10, and then may be discharged to the other header 20 of the pair of headers 20. Air may exchange heat with the flowing refrigerant that passes between the plurality of fins 10 and between the pair of headers 20.
[0066] Referring to
[0067] A fin collar 12 may be provided in pair, and the pair of fin collars 12 may surround the pair of openings 11, respectively. The fin collar 12 may extend in a direction in which the plurality of fins 10 are arranged. The fin collar 12 may have a circular shape surrounding the opening 11. The fin collar 12 may be in communication with the opening 11. When the plurality of fins 10 are arranged, the fin collar 12 may be connected between each of the plurality of fins 10 to thereby define a header 20 (see
[0068] A refrigerant may flow in the opening 11 inside the fin collar 12. The refrigerant may be introduced into the fin 10 through the fin collar 12 or may be discharged from the fin 10 through the fin collar 12.
[0069] Referring to
[0070] As shown in (b) of
[0071] The groove 14 may be formed between a pair of fin collars 12 in one fin 10. The groove 14 may protrude to an outside of the fin 10, so that a flow path through which a refrigerant flows is formed inside the fin 10. The flow path defined by the groove 14 may be in communication with the opening 11.
[0072] The groove 14 may extend in a direction inclined with respect to a longitudinal direction of the fin 10. The groove 14 may extend in a direction inclined with respect to an air flow direction. The plurality of grooves 14 may be arranged along the longitudinal direction of the fin 10.
[0073] Each of the plurality of fins 10 may be formed by coupling a first panel 110 and a second panel 120. The first panel 110 and the second panel 120 may be bonded together at an outer portion 15 formed around an edge of the fin 10.
[0074] The first panel 110 and the second panel 120 may each have the shape of a plate elongated vertically. The first panel 110 and the second panel 120 may be coupled so that flat portions thereof face each other. A flow path through which a refrigerant flows may be formed between the first panel 110 and the second panel 120.
[0075] As shown in
[0076] The second panel 120 may include a plurality of second grooves 124. The second groove 124 may be formed by protruding outward from the second panel 120. The second groove 124 may extend in a direction inclined with respect to a longitudinal direction of the second panel 120. The plurality of second grooves 124 may be arranged along the longitudinal direction of the second panel 120.
[0077] The second groove 124 may protrude in a direction opposite to the first groove 114. The second groove 124 may extend in a direction intersecting the first groove 114. When the first panel 110 and the second panel 120 are coupled to each other, the first groove 114 and the second groove 124 may face each other to thereby define therein a flow path through which a refrigerant flows.
[0078] A plurality of dimples 116, 126 may be formed in the respective grooves 114 and 124 of the first panel 110 and the second panel 120.
[0079] The plurality of dimples 116, 126 may be configured as circular recessed portions, each having a diameter greater than a width of the groove 114, 124. At least two dimples (116, 126), and preferably, four dimples (116, 126) may be formed in one groove (114, 124).
[0080] That is, for one groove (114, 124), a dimple (116, 126) may be provided at each of its ends, and two dimples (116, 126) may be further provided at its middle portion at an interval from each other.
[0081] Meanwhile, the pair of fin collars 12 may include a pair of first fin collars 112 formed on the first panel 110 and a pair of second fin collars 122 formed on the second panel 120.
[0082] As shown in
[0083] As for the first panel 110, a first flat portion 113 may be formed between the first grooves 114. The first flat portion 113 may be formed on the same plane as a first outer portion 115. The first groove 114 may protrude outward relative to the first flat portion 113. The first groove 114 and the first flat portion 113 may be alternately arranged along the longitudinal direction of the first panel 110.
[0084] As for the second panel 120, a second flat portion 123 may be formed between the second grooves 124. The second flat portion 123 may be formed on the same plane as a second outer portion 125. The second groove 124 may protrude outward relative to the second flat portion 123. The second groove 124 and the second flat portion 123 may be alternatively arranged along the longitudinal direction of the second panel 120.
[0085] The first panel 110 and the second panel 120 may be coupled to each other at the first outer portion 115 and the second outer portion 125. The first outer portion 115 and the second outer portion 125 may be bonded to each other to define the outer portion 15.
[0086] Referring to
[0087] The first panel 110 may include a first bending section B1 where the first groove 114 is bent with respect to the air flow direction. The second panel 120 may include a second bending section B2 where the second groove 124 is bent with respect to the air flow direction. The first bending section B1 and the second bending section B2 may be disposed at positions corresponding to each other.
[0088] The first groove 114 may be bent at the first bending section B1. The first groove 114 may be inclined with respect to the longitudinal direction of the first panel 110, while being reversely inclined from the first bending section B1.
[0089] For example, the first groove 114 may be inclined upward to the first bending section B1 along the air flow direction, and then may be inclined downward from the first bending section B1.
[0090] The second groove 124 may be bent at the second bending section B2. The second groove 124 may be inclined with respect to the air flow direction, while being reversely inclined from the second bending section B2.
[0091] For example, the second groove 124 may be inclined downward to the second bending section B2 along the air flow direction, and then may be inclined upward from the second bending section B2.
[0092] The first groove 114 and the first flat portion (113a, 113b) may be alternatively arranged along the longitudinal direction of the first panel 110. The second groove 124 and the second flat portion (123a, 123b) may be alternatively arranged along the longitudinal direction of the second panel 120.
[0093] The first groove 114 and the second groove 124 may face each other to thereby define a flow path. The first groove 114 and the second groove 124 may be disposed to be inclined in a direction intersecting each other.
[0094] The first bending section B1 and the second bending section B2 may be disposed in parallel with each other. The first bending section B1 and the second bending section B2 may be disposed parallel to the longitudinal direction of the fin 10.
[0095] The first bending section B1 and the second bending section B2 may each be provided in plurality. The plurality of first bending sections B1 and the plurality of second bending sections B2 may be arranged along the air flow direction.
[0096] The first groove 114 may be bent at each of the plurality of first bending sections B1. The second groove 124 may be bent at each of the plurality of second bending sections B2.
[0097] Accordingly, the area where the air and refrigerant flowing between the plurality of grooves 14 exchange heat may be increased.
[0098] In addition, the plurality of dimples 116, 126 may be configured as circular recessed portions, each having a diameter greater than a width of the groove 114, 124. At least two dimples (116, 126), and preferably four dimples (116, 126) may be formed in one groove (114, 124).
[0099] That is, for one groove (114, 124), a dimple (116, 126) may be provided at each of its ends, and two dimples (116, 126) may be further provided at its middle portion at an interval from each other to be symmetrical with respect to the bending section (B1, B2).
[0100] Thus, four dimples (116, 126) provided in one groove (114, 124) of each panel (110, 120) are formed symmetrically with respect to the bending section (B1, B2).
[0101] Due to the dimples 116, 126, pressure loss may be reduced.
[0102] As the header and the flow path are formed by the plurality of fins 10 stacked one another, a header-fin-flow path integrated heat exchanger is achieved.
[0103] Here, the heat exchanger of the present disclosure may change the flow path by employing various fins 10 as necessary, as shown in
[0104]
[0105]
[0106] The heat exchanger according to an embodiment of the present disclosure includes various shapes of fins available for changing the flow path, depending on the role of the heat exchanger or the installation environment.
[0107] As for the various shapes of fins of
[0108] In the case of a basic fin 10a of
[0109] In the case of a series flow fin 10b of
[0110] As some of the plurality of fins 10 are connected serially in a parallel refrigerant flow arrangement, an extension of the flow path is achieved, thereby preventing refrigerant distribution imbalance due to an increase in size of the heat exchanger.
[0111] By connecting the series flow fin 10b to a position in which the refrigerant is stagnant without flowing, the direction of the flow path is changed to cause the stagnant refrigerant to be pushed, thereby addressing the refrigerant imbalance.
[0112] In the case of a closed fin 10c of
[0113] As such, by variously arranging fins of different shapes depending on the purpose of their use, the flow path may vary according to the role (or function) of the heat exchanger.
[0114] In one example, the heat exchanger of the present disclosure may have different arrangements and configurations of fins when used as a condenser and when used as an evaporator.
[0115] This will be described below with reference to
[0116]
[0117] In the case of
[0118] Here, an opening 11 at the upper left side may be used as a refrigerant inlet (in), and an opening 11 at the lower left side may be used as a refrigerant outlet (out).
[0119] Meanwhile, as shown in
[0120] When the refrigerant inlet (in) and the refrigerant outlet (out) are formed on the same side, as shown in
[0121] Accordingly, the refrigerant flows from the other side to the outlet (out) through the header 20.
[0122] Meanwhile, when the refrigerant inlet (in) and the refrigerant outlet (out) are formed on different sides, fins on the respective sides provided with the inlet (in) and the outlet (out) are both configured as a series flow fin 10b, as shown in
[0123] All fins, except the series flow fin 10b or the closed fin 10c of
[0124] When the heat exchanger is used as a condenser, a refrigerant exchanges heat with low temperature outside air, and accordingly, the specific volume decreases as heat of the refrigerant is released as the heat exchange progresses. Thus, when a flow of refrigerant directed from bottom to top is formed, the specific volume is further reduced, causing an increase in refrigerant pressure loss due to gravity.
[0125] Therefore, when the heat exchanger is used as a condenser, a flow path directed from top to bottom is formed.
[0126] In addition, due to an increase in size of the heat exchanger, the refrigerant flow rate on the refrigerant inlet (in) side of
[0127] In order to prevent such refrigerant flow rate imbalance, the series flow fin 10b is inserted into a part of the heat exchanger.
[0128] When a series flow fin 10b is disposed between basic fins 10a, as shown in
[0129] As such, the refrigerant introduced into an inlet (in), as shown in
[0130] When the first and the second series flow fins 10b are provided, the length of the refrigerant flow path is increased twice as long as that of the original flow path.
[0131] Thus, the refrigerant may flow evenly or uniformly without any refrigerant stagnant zone.
[0132] In addition, the series flow fin 10b is also provided at each of one side and the other side, so that the one side is provided with a refrigerant inlet (in) and the other side is provided with a refrigerant outlet (out).
[0133] When the heat exchanger is used as a condenser, the position of the series flow fin 10b is adjusted such that a length of the flow path through which the refrigerant flows from top to bottom is greater than that of the flow path through which the refrigerant flows from bottom to top.
[0134]
[0135] In the case of
[0136] Here, an opening 11 at the lower left side may be used as a refrigerant inlet (in), and an opening 11 at the upper left side may be used as a refrigerant outlet (out).
[0137] Meanwhile, as shown in
[0138] When the refrigerant inlet (in) and the refrigerant outlet (out) are formed on the same side, as shown in
[0139] Accordingly, the refrigerant flows from the other side to the outlet (out) through the header 20.
[0140] Meanwhile, when the refrigerant inlet (in) and the refrigerant outlet (out) are formed on different sides, fins on the respective sides provided with the inlet (in) and the outlet (out) are both configured as a series flow fin 10b, as shown in
[0141] All fins, except the series flow fin 10b or the closed fin 10c of
[0142] When the heat exchanger is used as an evaporator, a refrigerant exchanges heat with high temperature outside air, and accordingly, the specific volume increases as the heat exchange progresses. Thus, when a flow of refrigerant directed from top to bottom is formed, a lighter gaseous refrigerant becomes stagnant at the top without flowing downward, causing obstruction in the flow. In order to prevent such refrigerant stagnation, a flow path through which the refrigerant flows from bottom to top is formed.
[0143] Meanwhile, due to an increase in size of the heat exchanger, the refrigerant flow rate on the refrigerant inlet (in) side of
[0144] In order to prevent such refrigerant flow rate imbalance, the series flow fin 10b is inserted into a part of the heat exchanger.
[0145] When a series flow fin 10b is disposed between basic fins 10a, as shown in
[0146] As such, the refrigerant introduced into an inlet (in), as shown in
[0147] When the first and the second series flow fins 10b are provided, the length of the refrigerant flow path is increased twice as long as that of the original flow path.
[0148] Thus, the refrigerant may flow evenly or uniformly without any refrigerant stagnant zone.
[0149] In addition, the series flow fin 10b is also provided at each of one side and the other side, so that the one side is provided with a refrigerant inlet (in) and the other side is provided with a refrigerant outlet (out).
[0150] When the heat exchanger is used as an evaporator, the position of the series flow fin 10b is adjusted such that a length of the flow path through which the refrigerant flows from bottom to top is greater than that of the flow path through which the refrigerant flows from top to bottom.
[0151] The heat exchanger of the present disclosure has one or more of the following effects.
[0152] The present disclosure can provide a fin-tube integrated heat exchanger that is easy to assemble, has high heat efficiency, and has low air flow resistance, which also enables a fin-tube-header integrated heat exchanger to be achieved.
[0153] Accordingly, a more compact heat exchanger can be implemented. In addition, various flow path designs are available by selectively opening an opening portion, which defines a header, of at least a part of a plurality of fins.
[0154] Thus, refrigerant flow imbalance can be suppressed or reduced, and the flow path can vary according to the role (or function) of the heat exchanger, thereby increasing the heat exchange efficiency.
[0155] In addition, as the position of a refrigerant inlet and a refrigerant outlet vary depending on the configuration of an inner space in which the heat exchanger is installed, an optimized heat exchanger can be provided.
[0156] Further, as fins with both headers closed are disposed at opposite ends to serve as end plates, the space utilization can be achieved without a dummy component, and the heat exchange efficiency can be improved.
[0157] Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this disclosure. Therefore, the above detailed description should not be construed as restrictive in all respects and should be considered as illustrative.