Patent Publication Number: US-8992186-B2

Title: Suction arrangement for a refrigeration compressor

Description:
FIELD 
     The present disclosure refers to a constructive arrangement to be applied to the suction of hermetic refrigeration compressors in general. The arrangement is particularly directed to the suction of hermetic compressors used in refrigeration systems for commercial use, such as, for example, ice cube-making machines. 
     BACKGROUND 
     Hermetic refrigeration compressors (of small or medium size), such as those generally used in household refrigeration appliances, are also used in other refrigeration systems such as, for example, ice cube-making machines. In such systems, the periodic defrost of an evaporator of the refrigeration system is carried out by the refrigerant fluid itself in the form of heated gas, which leaves the discharge of the compressor. 
     In a refrigeration system (of small or medium size), return of liquid refrigerant in the suction system is common due to incomplete vaporization of the liquid refrigerant. In this case, if a liquid separating device is not provided in the refrigeration circuit, the compressor may be damaged. The most common causes for liquid return are: excess refrigerant load in the refrigeration system; inadequate refrigeration of the evaporator; and incorrect adjustment of the expansion device. The phenomenon of liquid return is more intense in commercial compressors of high capacity and low-evaporation temperature. 
     Some compressors (see  FIGS. 1 and 1A ) present an open suction, that is, a suction-inlet tube  1 , disposed through a wall of a shell  2 , is opened to the interior of the latter. With this construction, the refrigerant fluid—in the form of gas—which reaches the suction-inlet tube  1 , is admitted in the interior of the hermetic shell  2  of the compressor and is drawn from the internal environment of the shell  2  to the interior of a suction muffler  3  and, thence, to the interior of the compression chamber of the compressor. 
     In these known compressors, the suction-acoustic muffler  3  is provided in the interior of the hermetic shell  2 , spaced from and above the suction-inlet tube  1 . This suction arrangement allows the refrigerant fluid—in the form of gas—to be heated during its permanence in the interior of the shell  2 , due to its contact with hot components of the compressor, before being drawn to the interior of the suction muffler  3  and, subsequently, to the interior of the compression chamber. The heating of the refrigerant fluid in the interior of the shell  2  presents the inconvenience of reducing the volumetric pumping capacity and, consequently, the energetic efficiency of the compressor. An example of this construction is presented in JP2008-267365, in which the flow admitted in the interior of the shell  2 , through the outlet nozzle  1   a  of the suction-inlet tube  1 , is deflected by the head, before reaching the inlet nozzle  4  of the admission tube  5  of the suction muffler  3 , which is positioned spaced from the outlet nozzle  1   a  of the suction-inlet tube  1 . 
     There are also known direct-suction compressors (see  FIG. 1B ), in which the refrigerant fluid, in the form of gas, returning to the compressor by the suction-inlet tube  1 , is integrally directed to the interior of the suction muffler  3 , without being admitted in the interior of the hermetic shell  2 . In this type of suction arrangement, the refrigerant fluid is drawn to the compression chamber, through the suction-inlet tube  1  and through the suction muffler  3 , without being subjected to the hot components of the compressor of the open-suction arrangement and, thus, yields a higher energetic efficiency of the compressor. 
     However, a direct-suction arrangement ( FIG. 1B ) can only be used in applications in which there is no risk of the refrigerant fluid—in the liquid state—being admitted in the compression chamber of the compressor. Nevertheless, in certain refrigeration systems—such as those used in ice cube-making machines a defrost operation for removing ice that accumulates in the evaporator region should be periodically carried out by the operation of the compressor. In this type of defrost operation, an inversion is made in the circuit of the refrigerant fluid in the refrigeration system, so that the refrigerant gas compressed and heated by the compressor is directed to an inlet of the evaporator and not to an inlet of the condenser, as it would during normal operation of a conventional refrigeration cycle. 
     During the defrost operation—in which the refrigeration system is submitted to cycle inversion—the refrigerant fluid is at least partially condensed in the evaporator, passes to the liquid phase, and is returned to the compressor. The refrigeration system remains operating in the inverted cycle during a certain period of time, until the desired degree of defrost has been obtained. Once the degree of defrost is obtained, the refrigeration system operates in the conventional manner with the refrigerant fluid in the gas phase and compressed by the compressor—being directed to the condenser inlet. 
     The refrigerant fluid in the liquid phase that leaves the evaporator and returns to the compressor during the defrost operation, has to be diverted from the normal-suction path to prevent it from being compressed by the compressor cylinder and causing a high inner pressure and consequent damages to the valves, gaskets and other parts of the compressor. Therefore, it is not possible to use a direct suction in these applications. 
     In order to prevent the liquid refrigerant fluid from entering into the suction chamber, some compressor constructions (particularly those for commercial application and which may be subjected to return of liquid during operation) present the suction muffler  3  provided with a refrigerant fluid inlet nozzle  4  spaced from the outlet nozzle  1   a  of the suction-inlet tube  1 , which outlet nozzle  1   a  is opened to the interior of the compressor shell  2 . 
     In the solution presented in JP2005-133707, the suction-acoustic muffler presents a refrigerant-fluid-admission tube provided spaced from the inner end of the suction-inlet tube. The admission tube presents a refrigerant-fluid-inlet nozzle substantially aligned with the inner end of the suction-inlet tube and conformed to incorporate a deflector defined for better admission of gaseous refrigerant fluid received through the suction-inlet tube. Nevertheless, during the suction, the spacing between the inner end of the suction-inlet tube and the inlet nozzle of the admission tube of the suction-acoustic muffler is not sufficient to prevent oil or refrigerant fluid in the liquid phase from being further drawn to the interior of the compressor, thereby damaging the latter. 
     In many hermetic compressor constructions (see  FIG. 1 ) to be used in ice cube-making machines or in other applications in which there is the risk of liquid-refrigerant fluid returning to the compression chamber, the suction-inlet tube  1  is provided spaced from the refrigerant-gas inlet nozzle  4  in the suction muffler  3 , generally opposed to each other in the interior of the shell  2 , according to the open suction arrangement. In this type of mounting arrangement although eliminating the risk of liquid-refrigerant fluid returning to the interior of the compression chamber the loss of energetic efficiency of the compressor is not avoided due to the heating of the refrigerant fluid, as the latter is admitted in the interior of the hermetic shell  2  before being drawn to the interior of the suction muffler  3  and, therefrom, to the interior of the compression chamber. 
     There are also known in the art some suction arrangements which aim at minimizing or suppressing the risk of liquid-refrigerant fluid (or even oil) returning to the suction muffler, without submitting the refrigerant fluid to an undesirable heating in the interior of the hermetic shell. Examples of these arrangements can be seen in patent JP2007-255245. 
     In the solution presented in JP2007-255245, the suction-inlet tube comprises an extension internal to the compressor shell and formed by a lower portion that is leveled with the suction-inlet tube for a temporary accumulation of the liquid-refrigerant fluid which by chance exists in the suction flow and by an upper portion that is elevated in relation to the suction-inlet tube to conduct only the gaseous-refrigerant fluid and having an outlet nozzle axially spaced in relation to the inlet nozzle of the suction muffler. The nozzle incorporates a deflector defined for better admission of the gaseous-refrigerant fluid received through the suction-inlet tube. It should be noted that the provision of the deflector is desirable due to the fact that the inlet nozzle of the suction muffler has its axis coplanar to the axis of the outlet nozzle of the upper portion of the inner extension of the suction-inlet tube, but forming with the latter an approximately right dihedral angle by reasons of space and to prevent any liquid refrigerant which reaches the upper portion of the inner extension from being supplied to the suction muffler. 
     In this previous solution, there is a semi-direct suction, according to which the liquid-refrigerant fluid which by chance reaches the liquid accumulator is stored therein until reaching a determined volume capable of activating a valve element—such as an articulated cover which opens under pressure of the accumulated liquid—that allows the liquid to be discharged in the interior of the shell, without being directed to the compression chamber. 
     Although the previous solution commented above minimizes or even impairs the admission of liquid-refrigerant fluid in the compression chamber of the compressor, it is complex and onerous to be carried out, requiring changes to be made in the construction of the suction-inlet tube, generally in the form of an additional piece having two distinct outlets. 
     SUMMARY 
     As a function of the inconveniences commented above and also other disadvantages of the known constructive solutions, it is one of the objects of the present disclosure to provide a refrigeration compressor—of the type having a suction muffler mounted in the interior of a hermetic shell with a suction arrangement that minimizes or even impedes the admission of refrigerant fluid in a liquid phase into the compression chamber of the compressor, without submitting the refrigerant fluid in a gaseous phase being drawn by the compressor to an undesirable heating in the interior of the hermetic shell that could impair the energetic efficiency of the compressor in its normal refrigeration operation. 
     Another object of the present disclosure is to provide a suction arrangement that presents a reduced cost and does not require providing additional pieces in the interior of the compressor. 
     The suction arrangement of the present disclosure may be applied to a refrigeration compressor of the type that includes a hermetic shell carrying a suction-inlet tube that is provided with an outlet nozzle opened to the interior of the shell and through which a refrigerant-fluid flow containing at least one of the gaseous and liquid phases is expelled to the interior of the shell; a cylinder block mounted in the interior of the shell and defining a compression chamber with an end closed by a valve plate; a suction muffler mounted to the cylinder block and externally incorporating: an admission tube provided with an inlet nozzle turned to the suction-inlet tube; and an outlet tube for the refrigerant fluid, having an end nozzle maintained in communication with the compression chamber, through the valve plate. 
     In the arrangement of the present disclosure, the inlet nozzle of the admission tube may be provided adjacent and external to the axial projection of the contour of the outlet nozzle of the suction-inlet tube and turned to a shell region disposed between the outlet nozzle and the inlet nozzle. The inlet nozzle may admit under at least one of the conditions of underpressure in its interior or deflection of the flow in the interior of the shell the gaseous phase, if existing in the refrigerant-fluid flow, whereas the liquid phase, if existing in the refrigerant-fluid flow, is directed to a shell region external to the inlet nozzle. 
     In a particular aspect of the present disclosure, the inlet nozzle of the admission tube is positioned externally to the axial projection of the contour of the outlet nozzle of the suction-inlet tube and turned according to a direction orthogonal to the axis of the axial projection to a region of the latter provided in front of the inlet nozzle. 
     In another aspect of the present disclosure, the inlet nozzle of the admission tube is turned to a direction inclined in relation to the axis of the axial projection of the contour of the outlet nozzle of the suction-inlet tube and to an inner region of the shell, defined between the outlet nozzle and the inlet nozzle and in which the refrigerant-fluid flow is admitted. 
     Still in another aspect of the present disclosure, the inlet nozzle of the admission tube is turned according to a direction parallel to the axis of the axial projection of the contour of the outlet nozzle of the suction-inlet tube. 
     Still according to another aspect of the present disclosure, the suction arrangement includes a deflecting means provided in the interior of the shell, adjacent to the inlet nozzle of the admission tube, facing the outlet nozzle of the suction-inlet tube and configured to interfere with the refrigerant-fluid flow. The deflection means deflecting the liquid phase if existing in the refrigerant-fluid flow to the interior of the shell and its gaseous phase, if existing, to the inlet nozzle of the admission tube. In a particular aspect, the deflecting means is carried by one of the parts of shell, cylinder block and suction muffler. According to another particular aspect of the present disclosure, the deflecting means may be defined by at least one of the parts of cylinder block and a deflecting flange carried by any of the parts of cylinder block and shell. In a particular constructive variation, the deflecting means may be defined by a deflecting flange projecting arcuately outwardly from the admission tube, in the region of its inlet nozzle, adjacent to and facing the outlet nozzle of the suction-inlet tube and configured to receive, from the latter, the refrigerant-fluid flow, directing its gaseous phase, if existing, in a non-descending curved path, into the inlet nozzle of the admission tube, and directing, gravitationally, any liquid phase, if existing, outwardly from the admission tube and to the interior of the shell. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a schematic representation of a compressor incorporating a prior-art suction muffler; 
         FIG. 1A  is a schematic representation of a compressor incorporating a prior-art suction muffler; 
         FIG. 1B  is a schematic representation of a compressor incorporating a prior-art suction muffler; 
         FIG. 1C  is a schematic representation of a compressor incorporating a suction-acoustic muffler in accordance with the principles of the present disclosure; 
         FIG. 2  is a partial sectional view of a compressor incorporating a suction muffler in accordance with the principles of the present disclosure; 
         FIG. 2A  is a schematic representation of an inlet nozzle of the suction muffler of  FIG. 2  in a first position relative to an inlet of the compressor of  FIG. 2 ; 
         FIG. 2B  is a schematic representation of an inlet nozzle of the suction muffler of  FIG. 2  in a second position relative to the suction inlet of the compressor of  FIG. 2 ; 
         FIG. 2C  is a schematic representation of an inlet nozzle of the suction muffler of  FIG. 2  in a third position relative to the flow inlet of the compressor of  FIG. 2 ; 
         FIG. 3  is a perspective view of a suction muffler according to the principles of the present disclosure; 
         FIG. 3A  is a partial perspective view of the suction muffler of  FIG. 3  incorporated into a compressor and showing a position of an inlet of the suction muffler relative to an inlet of the compressor; 
         FIG. 4  is a perspective view of a suction muffler according to the principles of the present disclosure; and 
         FIG. 4A  is a partial perspective view of the suction muffler of  FIG. 4  incorporated into a compressor and showing a position of an inlet of the suction muffler relative to an inlet of the compressor. 
     
    
    
     DETAILED DESCRIPTION 
     As illustrated in the enclosed  FIGS. 1C to 4A , the present disclosure provides a suction arrangement for a refrigeration-system compressor of the type including a hermetic shell  10 ; a cylinder block  11  mounted internally to the shell  10  and defining a compression chamber CC housing a reciprocating piston  12  and having an end closed by a valve plate  13  and by a head  14 ; and a suction muffler  20  mounted to the cylinder block  11  and externally incorporating: an admission tube  21  provided with an inlet nozzle  22 ; and an outlet tube  23  for the refrigerant fluid, having an end nozzle  24  maintained in communication with the compression chamber CC through the valve plate  13 . In the illustrated construction, the outlet tube  23  is mounted in the head  14 , attached to the cylinder block  2  through the valve plate  13  and in which at least one discharge chamber (not illustrated) is defined. 
     The shell  10  carries a suction-inlet tube  15  provided with an outlet nozzle  15   a  opened to the interior of the shell  10  and through which it is admitted, in the interior of the shell  10 , a refrigerant-fluid flow which can contain—depending on the operational condition of the refrigeration system—only a gas phase, only a liquid phase, or both liquid and gas phases. 
     In the illustrated construction, the outlet nozzle  15   a  is defined as an opening in the shell  10  of the compressor, although the suction-inlet tube  15  could be provided extending through the interior of the shell  1 . The suction-inlet tube  15  is generally mounted to a circuit of a refrigeration system (not illustrated) and which includes the compressor. 
     The suction muffler  20  may include a generally two-piece hollow body provided with the admission tube  21  and outlet tube  23 . 
     In some compressor constructions, the body of the suction muffler  20  may be disposed inferiorly to the outlet nozzle  15   a  of the suction-inlet tube  15 . In this case, the refrigerant fluid admitted in the suction muffler  20  is initially downwardly directed to the interior of the hollow body of the suction muffler  20 , before being conducted to the outlet tube  23  and, thence, to the compression chamber CC. 
     It should be understood that the present disclosure is not restricted to a construction of suction muffler  20  of the type illustrated herein. The disclosure can also be applied to suction mufflers admitting refrigerant fluid parallelly to the axis of the outlet nozzle  15   a  of the suction-inlet tube  15  or above the latter. 
     According to the suction arrangement of the present disclosure, the inlet nozzle  22  of the admission tube  21  is provided adjacent but external to the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15  and turned to a region of the shell  10  that is disposed between the outlet nozzle  15   a  and the inlet nozzle  22 . The inlet nozzle  22  may admit—under at least one of the conditions of underpressure in its interior or deflection of the flow in the interior of the shell  10  the gaseous phase of the flow. 
     According to the present disclosure, the inlet nozzle  22  of the admission tube  21  may be positioned somewhat spaced from the outlet nozzle  15   a  of the suction-inlet tube  15 , so as to make the refrigerant-fluid flow travel a certain extension of the inner space of the shell  10  and to allow the gaseous phase of the flow to be deflected to the interior of the inlet nozzle  22  of the admission tube  21 , by one or both means defined by the underpressure condition in the inlet nozzle  22  of the admission tube  21  and by a deflector  25  positioned in the interior of the shell  10  and which can be carried, for example, by the cylinder block  11 . When the directioning of the gaseous phase to the interior of the inlet nozzle  22  is affected only by the underpressure reigning in the interior of the latter, the flow of gaseous phase admitted in the interior of the shell  10  through the outlet nozzle  15   a  of the suction-inlet tube  15  is deviated from its path upon leaving the outlet nozzle  15   a  by the suction imparted thereto by the inlet nozzle  22  of the admission tube  21 . 
     According to a first construction for the suction arrangement of the present disclosure illustrated in  FIG. 2A  the inlet nozzle  22  of the admission tube  21  is mounted in the interior of the shell  10 , turned according to a direction A substantially horizontal and orthogonal to the axis X of the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15 , that is, turned to a region of the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15  that is provided in front of the inlet nozzle  22  of the admission tube  21 . 
     In a particular aspect of this construction for the suction arrangement of the present disclosure, the inlet nozzle  22  of the admission tube  21  has a contour substantially tangent to the contour of the refrigerant-fluid flow. 
     The advantage of the first construction of the arrangement of the present disclosure is that, by positioning the admission tube  21  at a certain distance from the outlet nozzle  15   a  as shown in  FIG. 2A  it is possible to initially obtain a considerable reduction around 80% of the suction of the liquid phase of the refrigerant-fluid flow to the interior of the inlet nozzle  22  of the admission tube  21 . This position allows the gaseous phase of the refrigerant-fluid flow to enter into the inlet nozzle  22  of the admission tube  21 , by means of a semi-direct suction. In this mounting condition, the gaseous phase of the refrigerant fluid is deviated to the interior of the inlet nozzle  22  of the admission tube  21  by means of the underpressure reigning in the interior of the latter and/or with the aid of a deflector to be described ahead. 
     In high-efficiency commercial compressors, a deflector ( FIG. 3 ) may be employed to direct the gaseous phase of the refrigerant-fluid flow to the inlet nozzle  22  of the admission tube  21 , thus increasing the capacity of the compressor without the risk of admitting the liquid phase into the suction muffler  20 . The deflector  25  may be defined by a compressor component internal to the shell  10 , or by an additional component mounted in the region of the inlet nozzle  22  to deviate the gaseous phase of the refrigerant-fluid flow to the interior of the inlet nozzle  22 , but without allowing the liquid phase to be admitted into the suction muffler  20 . The deflector  25  may be capable of directing the liquid phase of the refrigerant-fluid flow to an internal region of the shell  10  external to the inlet nozzle  22  of the admission tube  21 . 
     According to a second construction for the suction arrangement of the present disclosure illustrated in  FIG. 2B  the inlet nozzle  22  of the admission tube  21  is turned according to a direction B inclined in relation to the axis X of the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15  and to an inner region of the shell  10 , for admitting the refrigerant-fluid flow and which is defined between the outlet nozzle  15   a  and the inlet nozzle  22 . 
     In a first particular construction of this second suction arrangement of the present disclosure, the inlet nozzle  22  of the admission tube  21  has its contour substantially tangent to the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15 , as illustrated in  FIG. 2B . 
     Although not specifically illustrated in the drawings herein, it should be understood that the inlet nozzle  22  of the admission tube  21  may have its contour substantially tangent to the contour of the refrigerant-fluid flow, in situations in which this contour extrapolates, radially, the limits of the contour of the axial projection of the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     The second construction commented above has the advantage of increasing the mass of the gaseous phase of the refrigerant-fluid flow drawn by the inlet nozzle  22  of the admission tube  21 , consequently increasing the efficiency of the compressor. 
     On the other hand, positioning of the inlet nozzle  22  in relation to the refrigerant-fluid flow admitted in the shell  10  requires a larger spacing of the inlet nozzle  22  in relation to the contour of the refrigerant-fluid flow, in order to reduce the risk of admitting the liquid phase in the interior of the inlet nozzle  22  of the admission tube  21 . However, the reduction of the risk leads to loss of efficiency in admitting the gaseous phase of the refrigerant-fluid flow that is being released through the suction-inlet tube  15  to the interior of the shell  10 . 
     In order to minimize the risks of admitting the liquid phase in the suction muffler  20  without reducing the efficiency in admitting the gaseous phase a deflector  25  may be employed, as already described in relation to the first construction for the mounting arrangement ( FIG. 2A ). 
     According to a third construction for the suction arrangement of the present disclosure—illustrated in FIG.  2 C—the inlet nozzle  22  of the admission tube  21  is turned according to a direction C substantially parallel to the axis X of the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     In a first particular way of carrying out the third construction of the present disclosure ( FIG. 2C ), the inlet nozzle  22  of the admission tube  21  has its contour substantially tangent to the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     Although not being specifically illustrated in the drawings, it should be understood that, for the third construction of the suction arrangement of the present disclosure, the inlet nozzle  22  of the admission tube  21  may have its contour substantially tangent to the contour of the refrigerant-fluid flow in situations in which this contour radially extrapolates the limits of the contour of the axial projection of the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     The third constructive arrangement may be used when there is insufficient space in the interior of the shell  10  from the constructions shown in  FIGS. 2A and 2B  and/or when there is no possibility of using other component parts as a deflector. 
     For low-capacity compressors, the third solution is adequate and sufficient to avoid the suction of the liquid phase of the refrigerant-fluid flow through the inlet nozzle  22  of the admission tube  21 . However, in high-capacity compressors, efficiency can be impaired. It should be understood that because the refrigerant-fluid flow can present a certain dispersion after passing through the outlet nozzle  15   a  until reaching the inlet nozzle  22  of the admission tube  21 , a tangential condition of the inlet nozzle  22  in relation to the contour of the axial projection can result in determined distances between the inlet nozzle  22  of the admission tube  21  and the outlet nozzle  15   a  of the suction-inlet tube  15 , in a secant condition of the inlet nozzle  22  in relation to the contour of the refrigerant-fluid flow. 
     It should be understood that, in the constructive options commented above and exemplarily illustrated in  FIGS. 2A ,  2 B and  2 C, the inlet nozzle  22  of the admission tube  21  may be arranged in different positions around the axial projection of the contour of the outlet nozzle  15   a  of the suction-inlet tube  15 . The position of the inlet nozzle  22  of the admission tube  21  (distance, laterality)—in relation to the outlet nozzle  15   a  of the suction-inlet tube  15  may be defined as a function of the inner space in the shell  10  of the compressor that is available for mounting the suction muffler  20 , the design characteristics of the compressor, and the refrigeration system to which it is coupled. 
     The present solution may further provide a misalignment between the inlet nozzle  22  of the admission tube  21  and the outlet nozzle  15   a  of the suction-inlet tube  15 , so that at least a substantial part of the liquid phase of the refrigerant-fluid flow passes through the region of the inlet nozzle  22  of the admission tube  21 , without being admitted therein in an amount that can be harmful to the operation of the compressor. 
     In one of the ways of carrying out the present disclosure, the gaseous phase of the refrigerant-fluid flow may be directed to the interior of the suction muffler  20  due to the depression caused by the difference of pressure between the interior of the shell  10  and the interior of the suction muffler  20  during the suction cycle of the compressor, as the inner pressure of the suction muffler  20  is lower than in the interior of the shell  10 , due to the suction cycles during operation of the compressor. With pressure reduction, the suction muffler promotes suction of the gaseous phase of the refrigerant-fluid flow. The low pressure that draws the gas from the refrigerant-fluid flow is not sufficient—together with the positioning of the inlet nozzle  22  of the admission tube  21  to draw the liquid phase of the refrigerant-fluid flow which is at a high velocity when entering into the interior of the shell  10  from the outlet nozzle  15   a  of the suction-inlet tube  15 . The underpressure in the interior of the suction muffler  20  acts as a non-physical deflecting means for the gaseous phase of the refrigerant-fluid flow. In this case, the liquid phase of the refrigerant-fluid flow is directed, for example, gravitationally and/or inertially, to the interior of the shell  10 , as its velocity decreases. A deflector is not necessarily provided to act on the flow to modify the path of its liquid phase in order to prevent it from being admitted in the inlet nozzle  22  of the admission tube  21  in any amount that can be harmful to the compressor. 
     In a way of carrying out this aspect of the present disclosure, the inlet nozzle  22  of the admission tube  21  may be positioned at a determined distance from the outlet nozzle  15   a  of the suction-inlet tube  15 , so that the liquid phase of the refrigerant-fluid flow has its path modified by the loss of velocity of this refrigerant-fluid flow. 
     According to another particular aspect of the present disclosure, the liquid phase of the refrigerant-fluid flow has its path interrupted in the internal environment of the shell  10 , by a deflector  25  provided in the interior of the shell  1 . The deflector  25  may be positioned adjacent to the inlet nozzle  22  of the admission tube  21 , facing the outlet nozzle  15   a  of the suction-inlet tube  15  and configured to receive, from the latter, the refrigerant-fluid flow, interfering with the path of the liquid phase of the refrigerant fluid and gravitationally directing any liquid phase, if existing, to the interior of the shell  10 . The deflector  25  may be used when it is not possible to use only the underpressure and the relative positioning between the inlet nozzle  22  of the admission tube  21  and the outlet nozzle  15   a  of the suction-inlet tube  15  as a separating element between the gaseous and liquid phases of the refrigerant-fluid flow. 
     The deflector  25  may be carried by one of the parts of shell  10 , cylinder block  11  and suction muffler  20  and may be defined, for example, by an element of the suction muffler  20  or of the compressor. In particular, the deflector  25  may be defined as an adjacent and confronting inner wall portion of the shell  10 . 
     In a way of carrying out the present disclosure, the deflector  25  may be defined by the cylinder block  11  of the compressor, such as the head  14  generally seated against the valve plate  13  and which defines at least one of the suction and discharge chambers of the compressor (not illustrated), in fluid communication with the compression chamber CC in the cylinder block  11 . 
     The deflector  25  may be positioned close to the inlet of the suction muffler  20 , adjacent thereto and relative to the inlet nozzle  22  of the admission tube  21  so that the liquid phase of the refrigerant-fluid flow is received by the deflector  25  and inertially and/or gravitationally directed to the interior of the shell  10 . 
     The deflector  25  may be defined by at least one of the parts of cylinder block  11  and by a deflecting flange carried by any of the parts of cylinder block  11  and shell  10 , or also by a deflecting flange  25   a  ( FIGS. 3 and 3A ), projecting arcuately outwardly from the admission tube  22  in the region of its inlet nozzle  22 , adjacent to and facing the outlet nozzle  15   a  of the suction-inlet tube  15 . The deflector  25  is configured to receive, from the outlet nozzle  15   a  of the suction-inlet tube  15 , the refrigerant-fluid flow, directing its gaseous phase, in a non-descending curved path, into the inlet nozzle  22  of the admission tube  21  and gravitationally and/or inertially directing any liquid phase, if existent, outwardly from the admission tube  21  and to the interior of the shell  10 . 
       FIGS. 3 and 3A  show, schematically, the refrigerant fluid flow impinging a deflecting flange  25   a , which is positioned in order to allow the gaseous phase (plain arrows) of the refrigerant fluid flow to be suctioned into the inlet nozzle  22 , while blocking and deflecting the path of the any liquid phase (dotted arrows), allowing it to be gravitationally and or inertially directed into the shell  10 . 
     The deflecting flange  25   a  of the present disclosure receives, directly, the refrigerant-fluid flow admitted in the interior of the shell  10  through the outlet nozzle  15   a  of the suction-inlet tube  15 , actuating as a baffle for the refrigerant fluid in the liquid phase, which, after reaching the deflecting flange  25   a , gravitationally and/or inertially flows from the latter, precipitating to the interior of the shell  10  towards the bottom thereof. 
     According to a way of carrying out the disclosure, as illustrated in the appended drawings, the inlet nozzle  22  of the admission tube  21  presents a pair of side edges  26  and an upper edge  27  that are contained in a plane substantially parallel to the axis of the admission tube  11  and secant to the contour of the latter, in order to provide, to the inlet nozzle  22 , a cross section with an area at least equal to the cross sectional area of the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     The illustrated inlet nozzle  22  of the admission tube  21  presents a pair of side edges  26  and an upper edge  27  that are contained in a plane substantially parallel to the axis X of the outlet nozzle  15   a  of the suction-inlet tube  15 . The plane maintains, with the axis of the admission tube  21 , a constant distance defined so as to provide, to the inlet nozzle  22  of the admission tube  21 , a cross section with an area at least equal to the cross sectional area of the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     The deflecting flange  25   a  may be incorporated, in a single piece, to a side edge of the pair of side edges  26  of the inlet nozzle  22  of the admission tube  21 , occupying, for example, the whole extension thereof. The deflecting flange  25   a  may be rectilinear and coplanar to a plane containing the opposite side edges  26  of the inlet nozzle  22  of the admission tube  21 , and can be slightly inclined to the plane, so as to facilitate the down-flow of the liquid reaching the face of the deflecting flange  25   a  turned to the suction-inlet tube  15  and which receives the refrigerant-fluid flow admitted by the suction-inlet tube  15 . 
     According to a preferred form of the present disclosure, the curved path imparted to the gaseous phase of the refrigerant-fluid flow during its admission through the inlet nozzle  22  of the admission tube  21 , presents only one direction. In the illustrated construction, the refrigerant fluid, in the gaseous phase, is submitted to a substantially horizontal curved path between the outlet nozzle  15   a  of the suction-inlet tube  15  and the inlet nozzle  22  of the admission tube  21 , and then the refrigerant fluid, in gaseous phase, is forced, by the suction, to change the direction of its path, which becomes orthogonal to the direction of admission in the inlet nozzle  22  of the admission tube  21 , and which, in the illustrated construction, is vertical and downwardly inclined. 
     However, it should be understood that other solutions are possible within the concept presented herein, in which the positioning of the inlet nozzle  22  or even of the admission tube  21  in relation to the outlet nozzle  15   a  of the suction-inlet tube  15  can provoke a path for the refrigerant fluid—in its gaseous phase—with more than one change of direction, in the same plane of admission of the refrigerant-fluid flow being admitted by the suction-inlet tube  15 , or defining a helical path for this refrigerant-fluid flow. 
     According to the present disclosure, the deflecting flange  25   a  presents a dimension in the axial direction of the admission tube  21  at least equal to the dimension, in the same direction, of the inlet nozzle  22  of the admission tube  21  and of the cross section of the outlet nozzle  15   a  of the suction-inlet tube  15 . According to a particular aspect of the present disclosure, the deflecting flange  25   a  projects radially outwardly from the contour of the admission tube  21 , defining a volute portion. 
     According to the illustration in  FIG. 3 , the admission tube  21  may present, in a way of carrying out the present disclosure, a first portion, which is adjacent to the inlet nozzle  22  and substantially parallel to the outlet tube  23 , and a second portion, inferiorly positioned in relation to the first portion and which extends to the hollow body of the suction muffler  20 , being angularly positioned in relation to the first portion. In one configuration, the position is calculated to define a desired spacing between the inlet nozzle  22  of the admission tube  21  and the outlet nozzle  15   a  of the suction-inlet tube  15 . 
     Although not illustrated, the deflecting flange  25   a  may be dimensioned so that the volute defines a larger or smaller path extension for the gas being admitted, maintaining its function of blocking and deflecting the liquid phase of the refrigerant fluid. 
     In the preceding configurations, a predetermined distance may be maintained between the outlet nozzle  15   a  of the suction-inlet tube  15  and the inlet nozzle  22  of the admission tube  21 , originating a semi-direct suction that provides high efficiency to the compressor. The use of a deflector optimizes the efficiency of the arrangement because it better directs the liquid phase of the refrigerant fluid beyond the reach of the inlet nozzle  22  of the admission tube  21  of the suction muffler  20 . The deflector can be the head  11  or in other parts of the compressor that are adjacent to the outlet nozzle  15   a  of the suction-inlet tube  15 .