Patent Publication Number: US-11384935-B2

Title: Combustion apparatus and hot water apparatus

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a combustion apparatus and a hot water apparatus. 
     Description of the Background Art 
     Japanese Utility Model Laying-Open No. 56-149251 describes a safety device for a gas burner, which includes a burner, a first detection element, a second detection element, and a controller. The burner produces flames upward. The first detection element is arranged above the burner. The second detection element is arranged above the first detection element. 
     During normal combustion of the burner, the first detection element is in contact with the flames produced at the burner, whereas the second detection element is not in contact with the flames produced at the burner. During abnormal combustion (incomplete combustion) of the burner, the flames produced at the burner are extended. As a result, the flames produced at the burner and the second detection element come into contact with each other. By detecting the contact between the flames produced at the burner and the second detection element, the controller detects abnormal combustion of the burner. 
     The higher the degree of abnormal combustion (the lower the oxygen concentration), the further the extension of flames produced from the burner. 
     SUMMARY OF THE INVENTION 
     Even during normal combustion of a burner, flames produced at the burner are extended by increasing output of the burner. In the construction of the safety device for a gas burner described in Japanese Utility Model Laying-Open No. 56-149251, it is impossible to distinguish between the extension of flames due to increase in output of the burner and the extension of flames due to abnormal combustion of the burner, and it is thus difficult to address a problem when the burner has variable output. 
     The present invention was made in view of the problem with conventional techniques as described above. More specifically, the present invention aims to provide a combustion apparatus capable of detecting abnormal combustion of a burner when the burner has variable output. 
     A combustion apparatus according to one aspect of the present invention includes a burner configured to produce flames, a first flame rod and a second flame rod, and a controller. The burner is configured to be controlled, by the controller, to be in a first output state, and a second output state in which output is smaller than in the first output state. 
     The first flame rod is arranged at a position where it makes contact with the flames produced at the burner in a normal combustion state when the burner is being controlled to be in the first output state and the second output state. The second flame rod is arranged at a position where it makes contact with the flames produced at the burner in the normal combustion state when the burner is being controlled to be in the first output state, and does not make contact with the flames produced at the burner in the normal combustion state when the burner is being controlled to be in the second output state. The controller is configured to determine that the burner is in an abnormal combustion state when, with the burner being controlled to be in the second output state, it is detected that the second flame rod and the flames produced at the burner are in contact with each other. 
     In the combustion apparatus, the controller may be configured to determine that the burner is in the normal combustion state when, with the burner being controlled to be in the first output state, it is detected that the first flame rod and the flames produced at the burner are in contact with each other and the second flame rod and the flames produced at the burner are in contact with each other. 
     In the combustion apparatus, the controller may be configured to determine that the burner is in the abnormal combustion state when it is detected that the first flame rod and the flames produced at the burner are not in contact with each other. 
     The combustion apparatus may further include a heat exchanger having a first sidewall. In plan view, a portion of the first flame rod that is farthest from the first sidewall may be located farther from the first sidewall than a portion of the second flame rod that is farthest from the first sidewall. 
     In the combustion apparatus, the heat exchanger may further have a second sidewall facing the first sidewall. The burner may have a plurality of burner ports through which the flames are produced. In cross-sectional view parallel to a direction from the first sidewall toward the second sidewall, the portion of the first flame rod that is farthest from the first sidewall may be located closer to the second sidewall than a virtual line obtained by extending a central axis of one of the burner ports that is closest to the first sidewall. In cross-sectional view parallel to the direction from the first sidewall toward the second sidewall, the portion of the second flame rod that is farthest from the first sidewall may be located closer to the first sidewall than the virtual line. 
     The combustion apparatus may further include a heat exchanger having a first sidewall and a second sidewall facing the first sidewall, and an insulator portion having the second flame rod inserted therein. The heat exchanger may further have a shell pipe attached to a surface of the first sidewall on a side of the second sidewall. The insulator portion may be inserted in the first sidewall below the shell pipe. A portion of the second flame rod overlapping the shell pipe in plan view may be covered with the insulator portion. 
     A hot water apparatus according to one aspect of the present invention includes a combustion apparatus. This combustion apparatus is the combustion apparatus described above. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a hot water apparatus  100  according to an embodiment. 
         FIG. 2  is a perspective view of a combustion apparatus  20  according to the embodiment. 
         FIG. 3  is a top view of combustion apparatus  20  according to the embodiment. 
         FIG. 4  is a cross-sectional view of combustion apparatus  20  according to the embodiment. 
         FIG. 5  is a block diagram of combustion apparatus  20  according to the embodiment. 
         FIG. 6  shows a schematic graph illustrating the effect of combustion apparatus  20  according to the embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be described with reference to the drawings. The same or corresponding parts are denoted by the same reference characters in the following drawings, and redundant description is not repeated. 
     (General Construction of Hot Water Apparatus According to Embodiment) 
     In the following, a general construction of a hot water apparatus  100  according to the embodiment is described. 
     As shown in  FIG. 1 , hot water apparatus  100  includes a housing  10 , a combustion apparatus  20 , pipes  40   a  to  40   g , a bypass pipe  41   a  and a bypass pipe  41   b , and a bypass servo  42 . 
     Combustion apparatus  20  includes a burner  21 , an ignition plug  22 , a first flame rod  23   a  (not shown in  FIG. 1 ) and a second flame rod  23   b  (not shown in  FIG. 1 ), and a primary heat exchanger  24 . Combustion apparatus  20  further includes a secondary heat exchanger  25 , a chamber  26 , a fan  27 , a duct  28 , a venturi  29 , an orifice  30 , and a gas valve  31 . 
     Burner  21 , ignition plug  22 , first flame rod  23   a  and second flame rod  23   b , primary heat exchanger  24  and secondary heat exchanger  25 , chamber  26 , fan  27 , duct  28 , venturi  29 , orifice  30 , gas valve  31 , pipe  40   a  to pipe  40   g , bypass pipe  41   a , bypass pipe  41   b  and bypass servo  42  are arranged in housing  10 . 
     Burner  21  is arranged below chamber  26 . Primary heat exchanger  24  is arranged below burner  21 . Ignition plug  22  is arranged below burner  21 . Ignition plug  22  is attached to primary heat exchanger  24 , for example. Secondary heat exchanger  25  is arranged below primary heat exchanger  24 . 
     Pipe  40   a  has one end from which fuel gas is supplied. Pipe  40   a  has the other end connected to gas valve  31 . Pipe  40   b  has one end connected to gas valve  31 . Pipe  40   b  has the other end connected to orifice  30 . Pipe  40   c  has one end connected to orifice  30 . Pipe  40   c  has the other end connected to venturi  29 . 
     Pipe  40   d  has one end connected to venturi  29 . Pipe  40   d  has the other end connected to fan  27 . Fan  27  is connected to chamber  26 . 
     Pipe  40   e  has one end from which water is supplied. Pipe  40   e  has the other end connected to secondary heat exchanger  25 . Pipe  40   f  has one end connected to secondary heat exchanger  25 . Pipe  40   f  has the other end connected to primary heat exchanger  24 . Pipe  40   g  has one end connected to primary heat exchanger  24 . Pipe  40   g  has the other end from which hot water exits. 
     Bypass pipe  41   a  has one end connected to pipe  40   e . Bypass pipe  41   a  has the other end connected to bypass servo  42 . Bypass pipe  41   b  has one end connected to bypass servo  42 . Bypass pipe  41   b  has the other end connected to pipe  40   g.    
     Gas valve  31  switches supply and stop of the fuel gas from pipe  40   a . The pressure of the fuel gas supplied to venturi  29  is thus regulated. 
     Venturi  29  is configured to take in air from the outside of housing  10 . Venturi  29  mixes the air taken in from the outside of housing  10  with the fuel gas supplied to venturi  29  through pipe  40   a , pipe  40   b , pipe  40   c , orifice  30  and gas valve  31  (the fuel gas mixed with the air is hereinafter referred to as mixed gas). 
     Exhaust from combustion apparatus  20  is discharged to the outside of housing  10  through duct  28 . Part of this exhaust, however, is taken in again through venturi  29 , which results in reduction in oxygen concentration in the mixed gas, causing abnormal combustion (incomplete combustion) which will be described later. 
     Fan  27  includes a fan case, an impeller arranged in the fan case, and a motor for driving the impeller to rotate. When the motor drives the impeller to rotate, fan  27  suctions the mixed gas produced at venturi  29  through pipe  40   c . The suctioned mixed gas is supplied to burner  21  through chamber  26 . 
     The mixed gas is ejected downward through burner ports  21   a  provided in a lower surface of burner  21 . The ejected mixed gas is burned by being ignited by ignition plug  22 , and turned into combustion gas. The combustion gas is ejected downward (i.e., toward primary heat exchanger  24 ). 
     The water supplied to secondary heat exchanger  25  through pipe  40   e  exchanges heat with latent heat of the combustion gas at secondary heat exchanger  25 , to thereby have an increased temperature. The water which has passed through secondary heat exchanger  25  is supplied to primary heat exchanger  24  through pipe  40   f . The water supplied to primary heat exchanger  24  exchanges heat with sensible heat of the combustion gas at primary heat exchanger  24 , to thereby have a further increased temperature. The water which has passed through primary heat exchanger  24  flows through pipe  40   g.    
     Part of the water flowing through pipe  40   e  flows to bypass pipe  41   a . A flow rate of water flowing from bypass pipe  41   a  to bypass pipe  41   b  is controlled by bypass servo  42 . The water flowing through bypass pipe  41   b  is mixed with the water flowing through pipe  40   g . That is, the temperature of the water exiting from the other end of pipe  40   g  is adjusted by bypass servo  42  controlling the flow rate of the water flowing from bypass pipe  41   a  to bypass pipe  41   b.    
     Water produced by condensation of water vapor in the combustion gas in primary heat exchanger  24  (this water is hereinafter referred to as drainage water) is discharged to the outside of housing  10  through duct  28 . 
     (Detailed Construction of Combustion Apparatus According to Embodiment) 
     In the following, a detailed construction of combustion apparatus  20  according to the embodiment is described with reference to  FIGS. 2, 3 and 4 . Secondary heat exchanger  25 , fan  27 , duct  28 , venturi  29 , orifice  30  and gas valve  31  are not shown in  FIGS. 2 to 4 . Chamber  26  is also not shown in  FIG. 3  in order to clarify an internal structure of combustion apparatus  20 . 
     Primary heat exchanger  24  has a first sidewall  24   a , a second sidewall  24   b , a third sidewall  24   c , and a fourth sidewall  24   d . First sidewall  24   a  and second sidewall  24   b  face each other in a first direction DR 1 . Third sidewall  24   c  and fourth sidewall  24   d  face each other in a second direction DR 2  intersecting with first direction DR 1 . Third sidewall  24   c  is continuous with first sidewall  24   a  and second sidewall  24   b , and fourth sidewall  24   d  is continuous with first sidewall  24   a  and second sidewall  24   b.    
     Primary heat exchanger  24  has a shell pipe  24   ea , a shell pipe  24   eb  and a shell pipe  24   ec . Shell pipe  24   ea , shell pipe  24   eb  and shell pipe  24   ec  are attached along inner wall surfaces of first sidewall  24   a , second sidewall  24   b  and third sidewall  24   c.    
     The inner wall surface of first sidewall  24   a  refers to a surface of first sidewall  24   a  on a side of second sidewall  24   b , and the inner wall surface of second sidewall  24   b  refers to a surface of second sidewall  24   b  on a side of first sidewall  24   a . The inner wall surface of third sidewall  24   c  refers to a surface of third sidewall  24   c  on a side of fourth sidewall  24   d , and the inner wall surface of fourth sidewall  24   d  refers to a surface of fourth sidewall  24   d  on a side of third sidewall  24   c.    
     Shell pipe  24   eb  is arranged below shell pipe  24   ea . Shell pipe  24   ea  and shell pipe  24   eb  are spaced from each other in an up-down direction. Shell pipe  24   ec  is arranged below shell pipe  24   eb . Shell pipe  24   eb  and shell pipe  24   ec  are spaced from each other in the up-down direction. 
     Primary heat exchanger  24  further has a shell pipe  24   ed  and a shell pipe  24   ee . Shell pipe  24   ed  and shell pipe  24   ee  are attached to an outer wall surface of fourth sidewall  24   d . The outer wall surface of fourth sidewall  24   d  refers to a surface of fourth sidewall  24   d  on a side opposite the side of third sidewall  24   c . Shell pipe  24   ee  is located below shell pipe  24   ed . Shell pipe  24   ed  and shell pipe  24   ee  are spaced from each other in the up-down direction. 
     Shell pipe  24   ed  has one end connected to one end of shell pipe  24   ea . The other end of shell pipe  24   ea  is an end of shell pipe  24   ea  on a side of a water outlet  24   h . Shell pipe  24   ed  has the other end connected to one end of shell pipe  24   eb . Shell pipe  24   ee  has one end connected to the other end of shell pipe  24   eb . Shell pipe  24   ee  has the other end connected to one end of shell pipe  24   ec.    
     Primary heat exchanger  24  further has a pipe  24   f . Pipe  24   f  is connected at its one end to the other end of shell pipe  24   ec , and is connected at its other end to a water inlet  24   g . A number of fins are attached to pipe  24   f.    
     Primary heat exchanger  24  further has water inlet  24   g  and water outlet  24   h . Water inlet  24   g  is connected to the other end of pipe  24   f . Water outlet  24   h  is connected to one end of pipe  40   g . Water inlet  24   g  and water outlet  24   h  are connected to each other through shell pipe  24   ea  to shell pipe  24   ee  and pipe  24   f.    
     Chamber  26  has an intake port  26   a . The mixed gas supplied from fan  27  is supplied into chamber  26  through intake port  26   a . Burner  21  is attached below chamber  26 . 
     The lower surface of burner  21  is provided with the plurality of burner ports  21   a , as described above. The mixed gas supplied into chamber  26  is ejected through burner ports  21   a . The lower surface of burner  21  is curved in a downwardly convex manner in cross-sectional view along first direction DR 1  (cross-sectional view orthogonal to second direction DR 2 ). A line obtained by extending a central axis of burner port  21   a  that is closest to first sidewall  24   a  will be referred to as a virtual line VL. 
     Ignition plug  22  is arranged below burner  21 , as described above. Ignition plug  22  is composed of a first electrode  22   a  and a second electrode  22   b . First electrode  22   a  and second electrode  22   b  each have a tip end arranged inside combustion apparatus  20 , and each have the other end arranged outside combustion apparatus  20 . 
     The tip ends of first electrode  22   a  and second electrode  22   b  face each other. The tip ends of first electrode  22   a  and second electrode  22   b  are located below the lower surface of burner  21 . By passing a current between first electrode  22   a  and second electrode  22   b , sparks are generated between the tip end of first electrode  22   a  and the tip end of second electrode, leading to ignition of the mixed gas ejected through burner ports  21   a.    
     Ignition plug  22  (first electrode  22   a  and second electrode  22   b ) is inserted in first sidewall  24   a . More specifically, ignition plug  22  is inserted in first sidewall  24   a  between shell pipe  24   ea  and shell pipe  24   eb.    
     First flame rod  23   a  is inserted in chamber  26 . First flame rod  23   a  has a tip end arranged inside combustion apparatus  20 , and has the other end arranged outside combustion apparatus  20 . The other end of first flame rod  23   a  is electrically connected to a controller  5  which will be described later. 
     The tip end of first flame rod  23   a  (portion that is farthest from first sidewall  24   a ) is located below burner  21 . Preferably, in cross-sectional view along first direction DR 1 , the tip end of first flame rod  23   a  (portion that is farthest from first sidewall  24   a ) is located closer to second sidewall  24   b  than virtual line VL. First flame rod  23   a  is arranged at a position where it makes contact with the flames produced at burner  21  in a normal combustion state when burner  21  is being controlled to be in a first output state and a second output state which will be described later. 
     That burner  21  is in a normal combustion state means that incomplete combustion has not occurred in the fuel gas ejected through burner ports  21   a . That burner  21  is in an abnormal combustion state, on the other hand, means that incomplete combustion has occurred in the fuel gas ejected through burner ports  21   a . Here, the incomplete combustion means that carbon monoxide concentration in exhaust gas from the combustion apparatus is equal to or higher than the concentration that has an effect on the human body. 
     First flame rod  23   a  is made of heat-resistant steel, for example. Since molecules forming the fuel gas are ionized in the flames produced at burner ports  21   a , the flames exhibit electrical conductivity. Thus, when first flame rod  23   a  is in contact with the flames produced at burner ports  21   a , a current flows between first flame rod  23   a  and an electrode (not shown) provided on a side of burner  21 . By detection of this current, it can be detected that first flame rod  23   a  and the flames produced at burner ports  21   a  are in contact with each other. 
     Second flame rod  23   b  is inserted in first sidewall  24   a . More specifically, second flame rod  23   b  is inserted in first sidewall  24   a  between shell pipe  24   ea  and shell pipe  24   eb . Second flame rod  23   b  has a tip end arranged inside combustion apparatus  20 , and has the other end arranged outside combustion apparatus  20 . The other end of second flame rod  23   b  is electrically connected to controller  5  which will be described later. 
     The tip end of second flame rod  23   b  (portion that is farthest from first sidewall  24   a ) is located below the tip end of first flame rod  23   a  (portion that is farthest from first sidewall  24   a ). As will be described later, burner  21  is controlled by controller  5  to be in the first output state, and the second output state in which the output is smaller than in the first output state (the flames produced at burner  21  are shorter than in the first output state). The control of the output state of burner  21  is performed by, for example, varying a flow rate of the mixed gas supplied to burner  21 . 
     Second flame rod  23   b  is arranged at a position where it makes contact with the flames produced at burner  21  in the normal combustion state when burner  21  is being controlled to be in the first output state, and does not make contact with the flames produced at burner  21  in the normal combustion state when burner  21  is being controlled to be in the second output state. 
     In cross-sectional view along first direction DR 1 , the tip end of second flame rod  23   b  (portion that is farthest from first sidewall  24   a ) is preferably located closer to first sidewall  24   a  than the tip end of first flame rod  23   a  (portion that is farthest from first sidewall  24   a ). That is, in cross-sectional view along first direction DR 1 , the tip end of first flame rod  23   a  (portion that is farthest from first sidewall  24   a ) is preferably located farther from first sidewall  24   a  than the tip end of second flame rod  23   b  (portion that is farthest from first sidewall  24   a ). More specifically, in cross-sectional view along first direction DR 1 , the tip end of second flame rod  23   b  (portion that is farthest from first sidewall  24   a ) is preferably located closer to first sidewall  24   a  than virtual line VL. 
     Second flame rod  23   b  is made of heat-resistant steel, for example. When second flame rod  23   b  is in contact with the flames produced at burner  21 , a current flows between second flame rod  23   b  and the electrode (not shown) provided on a side of burner  21 . By detection of this current, it can be detected that second flame rod  23   b  is in contact with the flames produced at burner  21 . 
     Combustion apparatus  20  may further include an insulator portion  6 . Insulator portion  6  is made of an insulating material. Insulator portion  6  is attached to first sidewall  24   a . More specifically, insulator portion  6  is inserted in a through hole provided in first sidewall  24   a  between shell pipe  24   ea  and shell pipe  24   eb . That is, insulator portion  6  and second flame rod  23   b  are located below shell pipe  24   ea.    
     Insulator portion  6  has a first through hole, a second through hole and a third through hole. Second flame rod  23   b  is inserted in the first through hole. First electrode  22   a  and second electrode  22   b  are inserted in the second through hole and the third through hole, respectively. 
     Second flame rod  23   b  is inserted in insulator portion  6  in such a way that a portion of second flame rod  23   b  overlapping shell pipe  24   ea  in plan view is covered with insulator portion  6 . Similarly, ignition plug  22  (first electrode  22   a  and second electrode  22   b ) is inserted in insulator portion  6  in such a way that a portion of ignition plug  22  overlapping shell pipe  24   ea  in plan view is covered with insulator portion  6 . 
     (Operation of Combustion Apparatus According to Embodiment) 
     In the following, the operation of combustion apparatus  20  according to the embodiment is described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , fan  27 , first flame rod  23   a  and second flame rod  23   b  are connected to controller  5 . Controller  5  is composed of a microcontroller, for example. 
     Burner  21  is controlled to be in the first output state and the second output state by controller  5  controlling fan  27 . Burner  21  may be controlled to be in an output state different from the first output state and the second output state by controller  5  controlling fan  27 . 
     When burner  21  is being controlled to be in the second output state by controller  5 , and when burner  21  is in the normal combustion state, then first flame rod  23   a  makes contact with the flames produced at burner  21 , whereas second flame rod  23   b  does not make contact with the flames produced at burner  21 . 
     However, even when burner  21  is being controlled to be in the second output state by controller  5 , the flames produced at burner  21  and second flame rod  23   b  make contact with each other when burner  21  is in the abnormal combustion state. For this reason, controller  5  determines that burner  21  is in the abnormal combustion state when burner  21  is being controlled to be in the second output state, and when it is detected that second flame rod  23   b  is in contact with the flames produced at burner  21  (that is, a current flowing through second flame rod  23   b  is detected). 
     When burner  21  is being controlled to be in the first output state by controller  5 , second flame rod  23   b  makes contact with the flames produced at burner  21  even when burner  21  is in the normal combustion state. For this reason, controller  5  determines that burner  21  is in the normal combustion state when it is detected that first flame rod  23   a  is in contact with the flames produced at burner  21  and the second flame rod is in contact with the flames produced at burner  21  (a current flowing through first flame rod  23   a  and second flame rod  23   b  is detected). 
     When burner  21  is in the abnormal combustion state, the base of the flames produced at burner  21  may be separated from the lower surface of burner  21 , making it impossible to detect the contact between first flame rod  23   a  and the flames produced at burner  21 . For this reason, controller  5  determines that burner  21  is in the abnormal combustion state when it is detected that first flame rod  23   a  is not in contact with the flames produced at burner  21  (that no current is flowing through first flame rod  23   a ). 
     (Effect of Combustion Apparatus According to Embodiment) 
     In the following, the effect of combustion apparatus  20  according to the embodiment is described. 
     As described above, in combustion apparatus  20 , controller  5  determines whether or not burner  21  is in the abnormal combustion state by considering whether or not second flame rod  23   b  is in contact with the flames produced at burner  21 , and the control state of burner  21  (whether it is in the first output state or in the second control state). 
     In combustion apparatus  20 , therefore, it is possible to distinguish between the contact of the flames produced at burner  21  with second flame rod  23   b  due to large output of burner  21 , and the contact of the flames produced at burner  21  with second flame rod  23   b  due to abnormal combustion of burner  21 . In this manner, according to combustion apparatus  20 , the abnormal combustion of burner  21  can be detected even when burner  21  has variable output. 
     In combustion apparatus  20 , by adjusting the distance between the tip end of first flame rod  23   a  and the tip end of second flame rod  23   b  in plan view, the degree of abnormal combustion of burner  21  that can be detected can be changed (see  FIG. 6 ). By positioning the tip end of second flame rod  23   b  closer to first sidewall  24   a  than the tip end of first flame rod  23   a , therefore, it is possible to detect abnormal combustion of a degree that is difficult to detect using only first flame rod  23   a.    
     When second flame rod  23   b  is located below shell pipe  24   ea , water droplets produced due to condensation on a surface of shell pipe  24   ea  may drop to second flame rod  23   b  from shell pipe  24   ea  located above second flame rod  23   b . These water droplets cause an electric leakage in second flame rod  23   b.    
     When the portion of second flame rod  23   b  overlapping shell pipe  24   ea  in plan view is covered with insulator portion  6 , however, the contact between these water droplets and second flame rod  23   b  is suppressed. 
     Although the embodiment of the present invention has been described as above, the embodiment described above can be modified in various manners. In addition, the scope of the present invention is not limited to the embodiment described above. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the meaning and scope equivalent to the terms of the claims. 
     INDUSTRIAL APPLICABILITY 
     The embodiment described above is applied particularly advantageously to a combustion apparatus and a hot water apparatus. 
     Although the embodiment of the present invention has been described, it should be understood that the embodiment disclosed herein is illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the meaning and scope equivalent to the terms of the claims.