as one example , the multi - cartridge membrane contactor of the instant invention may be used as a multi - cartridge degassing module . in this embodiment , as shown , for example , in fig1 , a gas sweep and / or vacuum may be achieved on the lumen side of the membrane in a conventional way with the fibers open on each end of the cartridges . the lumen fibers of the first cartridge in series may communicate to the lumen fibers of the second cartridge due to the seal between the spool piece and the central plate . this provides a zone that may act as a gas equalizing gap by mixing the gas flow from the lumens of the first cartridge before entering the second cartridge . this step may be advantageous because oxygen which may be absorbed in the sweep stream may lose its driving force before reaching the end of the lumen length . referring to fig1 , there is shown an exemplary multi - cartridge membrane contactor 10 according to at least one embodiment of the invention . contactor 10 , as shown , but not so limited , generally comprises at least two longitudinal sections 12 / 14 , and head spaces 16 / 18 at the ends of sections 12 / 14 . sections 12 / 14 are detachably fastened together ( gas and liquid tight ) in any conventional manner , for example , via bolted flange . sections 12 / 14 may have side ports 13 / 15 . section 12 is shown in fig1 with a fluid inlet 21 and section 14 is shown in fig1 with a fluid outlet 23 . head spaces 16 / 18 are fastened together ( gas and liquid tight ), detachably or fixedly , to the ends of the longitudinal sections 12 / 14 in any conventional manner , for example , via bolted flange or welding or gluing . any number of sections maybe joined together , 2 , 3 , 4 , 5 , or more . head spaces 16 / 18 include end ports 17 / 19 . on head space 16 , the port 17 is shown as a fluid outlet 17 , and on head space 18 , the port 19 is shown as a fluid inlet . depending on the desired flow path , each port 13 , 15 , 17 , or 19 may be an inlet or an outlet and may be operatively connected in series or parallel to another contactor or device . an end plate 36 is located between head space 16 and section 12 , and an end plate 34 is located between head space 18 and section 14 . a central plate 24 is located between sections 12 , 14 . each section 12 / 14 includes a plurality of cartridges 28 ( in section 12 ) and 30 ( in section 14 ), the cartridges will be discussed in greater detail below . the number of cartridges in each section is not limited , but typically , there will be at least 2 and there may be as many as 10 . the number of cartridges in each section should be the same , so that the longitudinal axis of a cartridge in one section aligns with the longitudinal axis of a mating cartridge in the next section ( as shown ). end plates 34 / 36 may be provided with nesting positions 35 / 37 respectively for holding the ends of the cartridges . the nesting positions may be configured in any manner , so long as the end of the cartridge is held in a sealed ( gas and liquid tight ) manner against the end plate and a major portion of the terminal end of the cartridge is in fluid communication with the head space . these nesting positions hold the ends of the cartridges in sealed ( gas and liquid tight ) manner ( for example , an o - ring may be used to effect the seal ). additionally , the nesting positions should be sufficiently large to allow a major portion of the terminal ends of the cartridges to be in fluid communication with their respective head spaces 16 / 18 . the number of nesting positions should correspond to the number of cartridges in the section . as an example , in fig1 , the nesting positions are shown as holes through the end plates . central plate 24 is positioned between each section ( but not between a section and its head space . as shown in fig1 , there is only one central plate , but if more than two sections are joined together , there will be a central plate between each of those sections . central plate 24 may be provided with nesting positions 26 for holding the end of the cartridge . the nesting positions may be configured in any manner , so long as the end of the cartridge is held in a sealed ( gas and liquid tight ) manner against the central plate and a major portion of the terminal end of the cartridge is in fluid communication with a mating cartridge in the adjoining section . these nesting position hold the ends of the cartridge in sealed ( gas and liquid tight ) manner ( for example , an o - ring may be used to effect the seal ). additionally , the nesting positions should be sufficiently large to allow a major portion of the terminal ends of the cartridges to be in fluid communication with their mating cartridge in the adjoining section . the number of nesting positions should correspond to the number of cartridges in the section . as an example , in fig1 , the nesting positions 26 are shown as holes through the central plate . a zone 27 may be provided within in the nesting position 26 of the central plate 24 . this zone acts as an equalization gap between cartridges 28 / 30 . the zone allows fluid traveling through the hollow fibers of the cartridges to pass from one cartridge to the next . a spool member 32 may be provided between cartridges 28 / 30 . the spool member interconnects the perforated center tube of the cartridges in each section , so that fluid may freely pass between the sections . spool member 32 may include a stop ( shown as a raised annular ring at the center of the central portion of the spool member in fig1 ), so that when the cartridges are fit into the nesting positions of the central plate , space of the zone 27 may be provided . spool member 32 may also include an axial hole 33 therethrough , thereby effecting fluid communication between the perforated center tubes of the cartridges of the respective sections . referring to fig2 - 4 , various exemplary cartridges are illustrated . the cartridges are hollow fiber membrane cartridges . these hollow fiber membrane cartridges generally comprise : a perforated center tube 50 , a plurality of hollow fiber membranes , and tube sheets 54 at both ends of the cartridge . the hollow fiber membrane may be any hollow fiber membrane , for example , celgard ® hollow fibers commercially available from celgard , llc of charlotte , n . c . the fibers are formed into an array ( e . g ., a flat mat where the individual fibers are held in parallel alignment with threads ), and then the array is wound around the center tube 50 so that the longitudinal axis of the tube is parallel with the longitudinal axis of the fibers . the tube sheets may be formed as the array is wound around the center tube , as is well known . after completion of winding and solidification of the tube sheets , a terminal portion of the tube sheets are removed to ensure that the terminal ends of the hollow fibers are open for free fluid communication , as is well known . fig2 shows cartridge 28 of section 12 . cartridge 28 includes a block 56 at the left end of and within center tube 50 . this block prevents the flow of fluid from this end of the center tube . referring to fig1 , the block is positioned adjacent end plate 36 . fig3 shows cartridge 30 of section 14 . cartridge 30 includes a block 56 at the right end of and within center tube 50 . this block prevents the flow of fluid from this end of the center tube . referring to fig1 , the block is positioned adjacent end plate 34 . fig4 shows a cartridge 60 that may be used if more than two sections are used ( not shown in fig1 ) or may be used in place of cartridges 28 and 30 if a block 56 is added at one end . in this cartridge 60 , the block 56 is shown at the midpoint between tube sheets 54 , however , the block may be placed at any position between the tube sheets 54 and is not limited to the midpoint ( alternatively , there may be no block in this cartridge ). additionally , the cartridges may include one or more baffles , as is well known . for example , a baffle may be added at block 56 in cartridge 60 . in operation , contactor 10 may be expanded ( lengthened ) or collapsed ( shortened ) by removal of sections and central plates . once configured to the desired length , a first fluid ( for example a gas ) is flowed through contactor 10 by , for example , introducing that fluid to inlet 19 where it enters head space 18 . this fluid then enters the lumens of the hollow fibers and passed through the length of the hollow fibers , passes through the zone 27 and then on through the length of the lumens of the next cartridge . finally , the fluid exits the contactor 10 by passing from the hollow fibers of the last cartridge into the head space 16 and out via outlet 17 . as the first fluid passes through the length of the contactor , it may pick - up or deposit a component from or into the other fluid ( this operation is governed by diffusion ). the first fluid &# 39 ; s travel path is typically referred as the lumen ( or tube ) side . simultaneously with the passage of the first fluid , a second fluid enters one of the sections 12 / 14 via inlet 21 and passes over the exterior surface of the hollow fibers and into the perforated center tubes of the cartridges , the second fluid passes into the perforated center and is directed through the spool member into the next cartridge , in the next cartridge , the second fluid leaves the perforated center tube , passes over the exterior surface of the hollow fibers , and exits the section via outlet 23 . as the second fluid passes through the contactor , it may pick - up or deposit a component from or into the first fluid ( this operation is governed by diffusion ). the second fluid &# 39 ; s travel path is typically referred as the shell side . the first and second fluids may be flowed through the contactor in either a concurrent or countercurrent fashion . the fluids may be either a gas or a liquid . in one possibly preferred embodiment , the first fluid is a gas , sweep gas , or vacuum , and the second fluid is a liquid to degassed , debubbled , or gasified . the present invention may be embodied in other forms without departing from the spirit and the essential attributes thereof , and , accordingly , reference should be made to the appended claims , rather than to the foregoing specification , as indicating the scope of the invention . additionally , the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein .