Patent Description:
The present disclosure relates to fluid sampling systems. More particularly, the disclosure relates to sampling systems for fluids having low boiling temperatures, such as ammonia.

Ammonia has many uses, including, for example, industrial cleaners and fertilizers. While ammonia is a gas at room temperature and atmospheric pressure, commercial ammonia is commonly shipped in liquid form, under pressure and/or at low temperatures. Because ammonia has a tendency to cause stress corrosion cracking in steel cargo tanks absent a minimal water content, the Department of Transportation (DOT) has promulgated regulations requiring a minimum water content of <NUM>% by weight for ammonia shipped in DOT specification MC-<NUM>/MC-<NUM> cargo tanks constructed of quenched and tempered steel (QT) and requiring periodic analyses for the prescribed water content in the ammonia.

CGA specification G-<NUM> provides guidelines for determining the water content in ammonia. In the system described in G-<NUM>, as shown in <FIG>, a regulated flow of liquid ammonia is drawn through an inlet tube <NUM>, past a stopper <NUM> into a glass residue tube <NUM> (having a wider upper body portion 10a and a narrower, graduated lower stem portion 10b) before sealing the inlet tube <NUM>. The ammonia in the residue tube <NUM> is allowed to evaporate or boil off at a temperature of up to <NUM>°F (<NUM>), leaving the unevaporated liquid water content of the ammonia sample in the graduated lower stem portion 10b of the residue tube, for visual inspection of the water content. The percent water by weight in the ammonia sample is calculated using the measured water residue in the graduated lower stem portion, multiplied by an evaporation factor (EF) calculated based on the temperature and pressure of the sampled ammonia.

The high pressure and/or low temperature conditions required to maintain the ammonia in a liquid state make sampling difficult, as the ammonia can be vulnerable to inadvertent flashing to gaseous form during preparation of the same, thereby affecting the accuracy of any water content measurements. Further, user handling of, or other interaction with, the ammonia can create safety hazards, causing irritation or caustic burns if inhaled or in contact with an individual's skin.

<CIT> discloses a liquid ammonia sampling analysis device composed of a box body and a stainless steel branch pipe liquid inlet set in the interior of the case, a liquid inlet electromagnetic valve, a stainless steel constant-volume pipe, vacuum pipe, liquid outlet electromagnetic valve, stainless steel liquid connecting pipe, a reducing connector, Li, susceptor, heat exchange sleeve, stainless steel hollow sphere, taper bottle, stainless steel first ball connecting pipe, stainless steel second ball connecting pipe, a first plug, a second plug, Pt sensor, a temperature regulator, a temperature adjustor connected with pipe and explosion-proof electric control box; the vacuum pipe is provided with a vacuum nozzle, the temperature regulator is composed of a heating pipe and axial flow fan. <CIT> discloses a method and apparatus for capturing a sample of a flowable material from a closed system inside a receptacle without exposing the sample to the ambient environment. <CIT> discloses a method and apparatus for measuring a water concentration in ammonia. <CIT> discloses a gasoline blend spot sampling system and method.

In accordance with the present invention, a sampling container assembly according to claim <NUM> is disclosed.

While the specific embodiments described herein relate to systems for sampling liquid ammonia and analyzing such samples for water content, the features of the present disclosure may additionally or alternatively be applied to other types of fluid sampling, processing, and containment systems, including systems for sampling other types of fluid and systems for analyzing sampled fluids for other fluid properties.

While various inventive aspects, concepts and features of the invention may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the invention as defined by the claims.

<FIG> schematically illustrates an exemplary fixture <NUM> for an ammonia sampling system, in which a sample receiving residue tube <NUM>, having a wider upper body portion <NUM> and a narrower, graduated lower stem portion <NUM>, is received in and surrounded by an inner pipe <NUM>, which is received in and surrounded by an outer pipe <NUM>. A heat transfer fluid H (e.g., glycol) is deposited in the inner pipe <NUM> in an inner cavity <NUM> between the residue tube <NUM> and the inner pipe <NUM>. An outer annulus <NUM> between the inner pipe <NUM> and the outer pipe <NUM> is filled with liquid ammonia A to cool the heat transfer fluid and the residue tube <NUM>. The cooled residue tube <NUM> is filled with an ammonia sample S, and a heater <NUM> (e.g., an aluminum heater block) beneath the residue tube <NUM> and inner and outer pipes <NUM>, <NUM> is powered to warm the heat transfer fluid and evaporate the ammonia (both the sample S in the residue tube and the cooling ammonia bath A in the outer annulus <NUM>). When the ammonia sample S has fully evaporated, the remaining water content in the graduated lower stem portion <NUM> of the residue tube <NUM> can be visually inspected and measured. The heater <NUM> may be controlled by a temperature switch <NUM> actuated by a container temperature probe <NUM> extending into the inner pipe <NUM> proximate the lower stem portion <NUM> of the residue tube <NUM>.

According to an exemplary aspect of the present application, a sampling system may be provided with a fluid distribution subassembly for controlled introduction, drainage, and purging of sample fluids and thermal control fluids into the sampling system, for example, to eliminate reliance on manual filling of samples and thermal fluids, and the risk of inconsistency and/or spillage that may result from such methods. In one such system, ammonia (both for sampling and for the cooling bath) and a purge gas (e.g., nitrogen) are supplied to a container subassembly of a sampling fixture from a fluid distribution subassembly from below a container mounting fixture block of the sampling fixture, with the fluids supplied through the fixture block and into a bottom end of the container subassembly. In one such embodiment, the ammonia in the cooling bath may be permitted to drain during testing of the ammonia sample, to reduce the amount of heating required to evaporate the ammonia sample.

<FIG> schematically illustrates an exemplary ammonia sampling system <NUM> including a sampling fixture <NUM> in fluid communication with a fluid distribution system <NUM>. The sampling fixture <NUM> includes first and second sample container subassemblies 1105a-b, for simultaneous testing of two separate ammonia samples. In other exemplary embodiments, a different number of sample container subassemblies may be provided (e.g., one subassembly, or three or more subassemblies).

Each sample container subassembly 1105a-b includes a sample receiving residue tube <NUM>10a-b, having a wider upper body portion 1111a-b and a narrower, graduated lower stem portion 1112a-b, an inner pipe 1120a-b sealingly mounted to the fixture block <NUM> and surrounding the residue tube to define an inner cavity 1125a-b, and an outer pipe 1130a-b sealingly mounted to the fixture block and surrounding the inner pipe to define an outer annulus 1135a-b. Container caps 1170a-b are assembled with, and seal against, the upper ends of the outer pipes 1130a-b.

The fixture block <NUM> is thermally connected to an aluminum heater block <NUM> electrically connected to a controller <NUM> and operable to heat the fixture block, for heating the heat transfer fluid in the inner cavity 1125a-b. A fixture block temperature probe <NUM> is disposed within the fixture block <NUM> and electrically connected to the controller <NUM> to provide a signal indicating the temperature of the fixture block, for accurate controlled heating of the fixture block to a desired temperature (e.g. about <NUM>°F or <NUM>). A container temperature probe 1106a-b (e.g., resistance temperature detector or RTD) is installed through the fixture block <NUM> to extend into the inner cavity 1125a-b to measure the temperature of the heat transfer fluid. The container temperature probe 1106a-b is electrically connected with the controller <NUM>, for measurement of the temperature of the heat transfer fluid, to a desired temperature for controlled evaporation of the ammonia sample (e.g., about <NUM>°F or <NUM>). Drain passages 1108a-b may be provided in the fixture block <NUM> to drain the heat transfer fluid from the inner cavities 1125a-b to a drain port <NUM> (e.g., for maintenance and/or period replacement of the fluid), which may be provided with a removable plug <NUM> for selective drainage. Alternatively (not shown), a valve may be connected to the drain port for selective drainage of the heat transfer fluid.

The fluid distribution system <NUM> includes an ammonia supply line <NUM> for supplying ammonia from an ammonia supply <NUM> (e.g., tank) to the sampling fixture <NUM>, a purge gas supply line <NUM> for supplying purge gas (e.g., nitrogen) to the sampling fixture, a drain line <NUM> for draining fluid from the containers, a residue tube line <NUM> for supplying ammonia and purge gas to the residue tubes, a cold bath line <NUM> for supplying ammonia to, and draining ammonia and purge gas from, the outer annuli 1135a-b, and an overflow line <NUM> for draining excess ammonia from the outer annuli.

The ammonia supply line <NUM> may be configured to continuously recirculate ammonia in the supply line to the ammonia supply <NUM> to provide for quicker sampling of the fluid (i.e., a "fast loop" arrangement), and to maintain the valves and conduits in a chilled condition. As shown, the ammonia supply line <NUM> may include a shutoff valve <NUM>, a temperature indicator <NUM>, first and second branch valves <NUM>, <NUM>, a pressure gauge <NUM>, and a regulating valve <NUM>. The shutoff valve <NUM> provides for isolation of the system from the ammonia supply, for example, to facilitate system maintenance. The branch valves <NUM>, <NUM> provide for selective and independent flow control to each of the residue tubes and the cold baths, respectively. The regulating valve <NUM> may be operated to reduce flow and increase pressure, for example, to ensure the ammonia remains in a liquid state.

The purge gas supply line <NUM> may be configured to direct purge gas from a purge gas supply <NUM> (e.g., tank) to an enclosure purge, for example, to purge stray vapors from the enclosure (both the control enclosure and sampling enclosure) to the surrounding atmosphere. As shown, the purge gas supply line <NUM> may include a shutoff valve <NUM>, a check valve <NUM>, a pressure regulator <NUM>, a pressure gauge <NUM>, a supply regulating valve <NUM>, and a purge regulating valve <NUM>. The shutoff valve <NUM> provides for isolation of the system from the purge gas supply, for example, to facilitate system maintenance. The check valve <NUM> prevents backflow in the purge gas supply line, and the pressure regulator <NUM> reduces the purge gas pressure to an appropriate pressure for purging the system (e.g., <NUM> psig), as monitored by the pressure gauge <NUM>. The supply and purge regulating valves <NUM>, <NUM> may be provided with flowmeters to facilitate regulation of the purge gas.

The drain line <NUM> includes a drain conduit <NUM> extending to a drain <NUM>, an open drain branch <NUM> permitting free flow to the drain conduit, and a relief drain branch <NUM> permitting pressurized flow to the drain conduit (as limited by a low pressure check valve <NUM>) for draining fluid from the cold bath line <NUM> and the overflow line <NUM>, as discussed in greater detail below.

The residue tube line <NUM> is connected to the ammonia supply line <NUM> and to the purge gas supply line <NUM> by a residue tube supply valve <NUM> operable to open the residue tube line to a selected one of the ammonia supply line and the purge gas supply line. The residue tube line <NUM> includes a source conduit <NUM> and branch supply conduits 1242a-b each extending through the fixture block <NUM> and outer annulus 1135a-b for connection with the residue tube 1110a-b through inlet ports 1192a-b in a sealed cap subassembly 1180a-b on each residue tube, to supply ammonia or purge gas (e.g., nitrogen) to the residue tubes. As shown, shutoff valves 1243a-b may be provided with each of the branch conduits 1242a-b to shut off ammonia flow to a selected one of the residue tubes, for example, in the event only one sample is desired.

The cold bath line <NUM> is connected to the ammonia supply line <NUM> by a cold bath supply valve <NUM> operable to open the cold bath line to the ammonia supply line. The cold bath line <NUM> includes a source conduit <NUM> and branch conduits 1252a-b extending through the fixture block <NUM> and into the outer annulus 1135a-b to supply ammonia to the outer annulus (thereby providing a cold bath surrounding the heat transfer fluid in the inner cavity). The cold bath line <NUM> is connected to the open drain branch <NUM> of the drain line <NUM> by a cold bath drain valve <NUM> operable (in combination with the closing of the cold bath supply valve <NUM>) to drain ammonia and purge gas from the outer annulus 1135a-b.

The overflow line <NUM> is connected to the relief drain branch <NUM> of the drain line <NUM> for draining ammonia overflow from the outer annulus 1135a-b. The overflow line includes a main conduit <NUM> and branch conduits 1262a-b each extending into the outer annulus 1135a-b. The overflow line branch conduits 1262a-b may be arranged to terminate at a height selected to limit the volume of the cold bath, with excess ammonia added to the outer annulus draining through the branch conduits to the main conduit <NUM>, and to the relief drain branch <NUM> of the drain line <NUM>. An overflow drain valve <NUM> may be positioned between the relief drain branch <NUM> and the open drain branch <NUM> and may be selectively closed to block flow from the open drain branch to the overflow line <NUM>, thereby preventing drain backflow to the overflow line, for example, when the system is inactive.

In an exemplary operation of the sampling system <NUM>, the residue tube supply valve <NUM>, cold bath supply valve <NUM>, cold bath drain valve <NUM>, and overflow drain valve <NUM> (collectively the "system switching valves") may be collectively operated to place the system in a selected one of an inactive ("OFF") condition, a cold bath filling ("CHILL") condition, a sample filling ("SAMPLE") condition, and a system purging ("PURGE") condition.

In the inactive ("OFF") condition, as shown in <FIG>: the residue tube supply valve <NUM> is in the closed position to shut off flow from the ammonia and purge gas supply lines <NUM>, <NUM> to the residue tube line <NUM>; the cold bath supply valve <NUM> is in the closed position to shut off flow from the ammonia supply line <NUM> to the cold bath line <NUM>; the cold bath drain valve <NUM> is in the closed position to prevent back pressure from the drain <NUM> into the cold bath line; and the overflow drain valve <NUM> is in the closed position to prevent back pressure from the drain into the overflow line <NUM>. This valve arrangement may be maintained when the sampling system is not in use.

In the cold bath filling ("CHILL") condition, as shown in <FIG>: the residue tube supply valve <NUM> is in the closed position to shut off flow from the ammonia and purge gas supply lines <NUM>, <NUM> to the residue tube line <NUM>; the cold bath supply valve <NUM> is in the open position to permit flow from the ammonia supply line <NUM> to the cold bath line <NUM>; the cold bath drain valve <NUM> is in the closed position to prevent flow from the ammonia supply line <NUM> to the drain <NUM>; and the overflow drain valve <NUM> is in the open position to permit cold bath overflow to drain from the overflow line <NUM> to the drain <NUM>. This valve arrangement is utilized when the cold bath (outer annulus) is being filled and may be maintained (with excess ammonia passing through the overflow line) until the container temperature probe 1106a-b indicates that the heat transfer fluid is at a desired temperature for receiving the sample.

In the sample filling ("SAMPLE") condition, as shown in <FIG>: the residue tube supply valve <NUM> is in a first switching position permitting flow between the ammonia supply line <NUM> and the residue tube line <NUM>; the cold bath supply valve <NUM> is in the open position to supply ammonia from the ammonia supply line <NUM> to the cold bath line <NUM> to supply new liquid ammonia to the cold bath for continued cooling of the heat transfer fluid, which cools the sample; the cold bath drain valve <NUM> is in the closed position to retain cooling ammonia; and the overflow drain valve <NUM> is in the open position to permit cold bath overflow to drain from the overflow line <NUM> to the drain. This valve arrangement is utilized as the sample is being collected in the residue tube 1110a-b, until the supplied sample has reached a desired fill line in the upper body portion <NUM>1a-b of the residue tube and begins spilling into the cold bath.

In the system purging ("PURGE") condition, as shown in <FIG>: the residue tube supply valve <NUM> is in a second switching position permitting flow between the purge gas supply line <NUM> and the residue tube line <NUM>; the cold bath supply valve <NUM> is in the closed position to shut off flow from the ammonia supply line <NUM> to the cold bath line <NUM>; the cold bath drain valve <NUM> is in the open position to permit ammonia in the outer annulus to drain through the cold bath line <NUM> to the drain; and the overflow drain valve <NUM> is in the open position to permit purge gas and purged fluids to evacuate from the container through the overflow line <NUM> to the drain. This valve arrangement is utilized as the heat transfer fluid is heated by the heater block <NUM> (through the fixture block <NUM>), allowing the cold bath to drain for more efficient evaporation of the ammonia sample, and may be maintained until the ammonia has fully evaporated, at which time the valve arrangement may be actuated to the inactive condition.

The system switching valves <NUM>, <NUM>, <NUM>, <NUM> may each be independently operated by a user between the positions corresponding to the system maintaining, cold bath filling, sample filling, and system purging conditions, as described above. According to another aspect of the present disclosure, as schematically shown in <FIG> and <FIG>, the system <NUM> may include a valve arrangement <NUM> in which a single handle or other such actuator <NUM> may be operated for simultaneous actuation of the system switching valves <NUM>, <NUM>, <NUM>, <NUM>, such as, for example, a single manual or electromechanical operation. In one such exemplary embodiment, as described in greater detail below, the single actuator may include a manually rotatable handle and a gear mechanism configured to operate all four valves, with a first position of the handle corresponding to the system maintaining condition, a second position of the handle corresponding to a cold bath filling condition, a third position of the handle corresponding to a sample filling condition, and a fourth position of the handle corresponding to a system purging condition.

Many different suitable sampling systems may be provided in accordance with one or more of the exemplary features of the sampling system <NUM> schematically illustrated in <FIG>. <FIG> illustrates various views of an exemplary ammonia sampling system <NUM> including several features in accordance with exemplary aspects of the present disclosure. In the exemplary system <NUM>, an ammonia sampling fixture <NUM> and fluid distribution system <NUM> are enclosed within an outer box or cabinet <NUM>, for example, to protect and support the various components of the system. The sampling fixture <NUM> includes first and second sample container subassemblies 2105a-b mounted to and supported by a fixture block <NUM>, for simultaneous testing of two separate ammonia samples. In other exemplary embodiments, a different number of sample container subassemblies may be provided (e.g., one subassembly, or three or more subassemblies).

As shown in <FIG>, each sample container subassembly 2105a-b includes a sample receiving residue tube 2110a-b, having a wider upper body portion 2111a-b and a narrower, graduated lower stem portion 2112a-b, an inner pipe 2120a-b sealingly mounted to the fixture block <NUM> by inner mounting arrangements 2140a-b and surrounding the residue tube to define an inner cavity 2125a-b for retaining a heat transfer fluid (e.g., glycol), and an outer pipe 2130a-b sealingly mounted to the fixture block by outer mounting arrangements 2150a-b and surrounding the inner pipe to define an outer annulus 2135a-b for receiving and retaining an ammonia cold bath. Container cap subassemblies 2170a-b are assembled with, and seal against, the upper ends of the outer pipes 2130a-b.

As shown in <FIG>, the fixture block <NUM> is thermally connected to an aluminum heater block <NUM> electrically connected to a controller <NUM> (shown in <FIG> and <FIG> and described in greater detail below) and operable to heat the fixture block, for heating the heat transfer fluid in the inner cavity 2125a-b. A fixture block temperature probe <NUM> is disposed within the fixture block <NUM> and may be electrically connected to the controller <NUM> to provide a signal indicating the temperature of the fixture block, for accurate controlled heating of the fixture block to a desired temperature (e.g. about <NUM>°F or <NUM>). Insulation material <NUM> (e.g., a Buna/PVC closed cell foam) may be applied over the heater block <NUM> and fixture block <NUM> to prevent heat loss to the atmosphere, and a cover <NUM> (e.g., stainless steel cover) may be fitted over the insulation material, for example, to neatly contain the insulation. The cover <NUM> may be attached to the fixture block <NUM>, for example, using nylon bolts.

As shown in <FIG>, a container temperature probe 2106a-b is installed through the fixture block <NUM> to extend into the inner cavity 2125a-b to sense the temperature of the heat transfer fluid. The container temperature probe 2106a-b may be electrically connected with the controller <NUM>, which is configured to selectively power the heater block <NUM> to achieve a desired temperature of the heat transfer fluid, as measured by the temperature probe, for controlled evaporation of the ammonia sample. Drain passages 2108a-b may be provided in the fixture block <NUM> to drain the heat transfer fluid from the inner cavities 2125a-b to a drain conduit <NUM> (e.g., for maintenance and/or period replacement of the fluid), which may be provided with a removable plug <NUM> for selective drainage. In the illustrated example, the container temperature probe 2106a-b is installed through the drain passage 2108a-b. As shown, a counterbore 2008a-b may be provided in the fixture block, surrounding the drain passage, to provide a lower well in the inner cavity 2125a-b, for example, to increase surface exposure of the fixture block <NUM> to the heat transfer fluid, and/or to reduce the height of the inner cavity 2125a-b.

<FIG> and <FIG> illustrate an exemplary controller <NUM> of the illustrated embodiment, which includes an enclosure <NUM> attached (e.g., welded) to the side of the cabinet <NUM>. While the enclosure <NUM> may be an explosion proof (e.g., heavy-duty cast) enclosure, in some embodiments, the enclosed electrical components may be rated for hazardous areas, allowing for a standard (e.g., <NUM> stainless steel) enclosure. The enclosure <NUM> encloses a microcontroller <NUM> with wiring (not shown) electrically connected to the heater block <NUM>, container temperature probes 2106a-b, and fixture block temperature probe <NUM>. The cabinet <NUM> may be provided with conduits plumbed to the interior of the cabinet for enclosing and protecting the wiring. The microcontroller <NUM> is connected to a user interface <NUM> (e.g., touchscreen and/or button controls) for display of system conditions (e.g., temperature, elapsed time) and/or user input of desired sample collecting and test conditions, for example, chilling and heating temperatures, sample testing durations, etc. In other embodiments, the microcontroller <NUM> may additionally or alternatively be configured to communicate wirelessly to a remote device (e.g., computer, smartphone) to display system conditions and/or receive operating inputs. An external power source (e.g., hard-wired with an electrical conduit of an electrical system) may provide power to the controller for powering the heater block and temperature probes.

<FIG> illustrates the exemplary inner and outer mounting arrangements 2140a-b, 2150a-b. As shown, ring gaskets 2141a-b, 2151a-b (e.g., <NUM>/<NUM>" thick EPDM gasket) may be provided between the bottom surfaces 2121a-b, 2131a-b of the container pipes and an upper surface of the fixture block. Inner and outer clamp rings 2142a-b, 2152a-b are tightened against lower flange portions 2122a-b, 2132a-b of the container pipes by bolts 2149a-b, 2159a-b installed through holes in the clamp rings and into threaded mounting holes in the fixture block, to compress the ring gaskets between the pipe ends and the fixture block to effect a seal. As shown, the clamp rings may include a plastic (e.g., PVC) flange engaging insert 2143a-b, 2153a-b, providing loaded elastic engagement between the clamp rings and the pipe flanges, and a metal (e.g., <NUM> stainless steel) collar 2144a-b, 2154a-b restricting an outer diameter of the plastic inserts, for example, to restrict radial extrusion of the plastic inserts. Belleville washers 2148a-b, 2158a-b may be installed on the bolts 2149a-b, 2159a-b to effect a live-loaded seal.

As shown in <FIG> and <FIG>, the illustrated exemplary container cap subassembly 2170a-b includes a ring gasket 2171a-b, clamp ring 2172a-b, cap ring 2173a-b, cap gasket 2176a-b, cap 2177a-b, and hinged clamp 2178a-b. As shown in <FIG>, the ring gasket 2171a-b (e.g., <NUM>/<NUM>" thick [material] gasket) is provided between the top surface 2136a-b of the outer pipe 2130a-b and a lower flange portion 2174a-b of the cap ring 2173a-b. The cap ring and clamp ring 2172a-b are tightened against an upper flange portion 2137a-b of the outer pipe by bolts 2139a-b installed through holes in the cap ring 2173a-b and into threaded mounting holes in the clamp ring 2172a-b, to compress the ring gasket between the outer pipe and the cap ring to effect a seal. As shown, the clamp ring 2172a-b may include a plastic (e.g., PVC) flange engaging insert 2178a-b, providing loaded elastic engagement between the clamp ring and the pipe flange, and a metal (e.g., <NUM> stainless steel) collar 2179a-b restricting an outer diameter of the plastic insert, for example, to restrict radial extrusion of the plastic insert. The cap 2177a-b is secured to an upper flanged portion 2175a-b of the cap ring 2173a-b by the hinged clamp 2178a-b, with the cap gasket 2176a-b compressed between the upper flanged portion and the cap to provide a leak tight seal. The upper flanged portion 2175a-b may be welded to the lower flange portion 2174a-b of the cap ring 2173a-b. Belleville washers 2138a-b may be installed on the bolts to provide a live-loaded seal.

As shown in <FIG>, the fluid distribution system <NUM> includes an ammonia supply line <NUM> for supplying ammonia from an ammonia supply (not shown) to the sampling fixture <NUM>, a purge gas supply line <NUM> for supplying purge gas (e.g., nitrogen) to the sampling fixture, a drain line <NUM> for draining fluid from the containers, a residue tube line <NUM> for supplying ammonia and purge gas to the residue tubes, a cold bath line <NUM> for supplying ammonia to, and draining ammonia and purge gas from, the outer annuli, and an overflow line <NUM> for draining excess ammonia from the outer annuli.

The ammonia supply line <NUM> may be configured to continuously recirculate ammonia in the supply line to the ammonia supply to provide for quicker sampling of the fluid (i.e., a "fast loop" arrangement). As shown, the ammonia supply line <NUM> may include a shutoff valve <NUM>, a temperature indicator <NUM>, first and second branch valves <NUM>, <NUM>, a pressure gauge <NUM>, and a regulating valve <NUM>. The shutoff valve <NUM> provides for isolation of the system from the ammonia supply, for example, to facilitate system maintenance. The branch valves <NUM>, <NUM> provide for selective and independent flow control to each of the residue tubes and the cold baths, respectively. The regulating valve <NUM> may be operated to reduce flow and increase pressure, for example, to ensure the ammonia remains in a liquid state. As shown, the ammonia supply line may be provided with insulation material to minimize heat gain in the recirculating ammonia. In other embodiments (not shown), the temperature indicator and the pressure gauge may be electrically connected to the controller for electronic monitoring of the ammonia supply line temperature and pressure.

The purge gas supply line <NUM> may be configured to direct purge gas from a purge gas supply (not shown) to an enclosure purge, for example, to purge stray vapors from the enclosure (both the control enclosure and sampling enclosure) to the surrounding atmosphere. As shown, the purge gas supply line <NUM> may include a shutoff valve <NUM>, a check valve <NUM>, a pressure regulator <NUM>, a pressure gauge <NUM>, a supply flowmeter <NUM>, and a purge flowmeter <NUM>. The shutoff valve <NUM> provides for isolation of the system from the purge gas supply, for example, to facilitate system maintenance. The check valve <NUM> prevents backflow in the purge gas supply line, and the pressure regulator <NUM> reduces the purge gas pressure to an appropriate pressure for purging the system (e.g., <NUM> psig), as monitored by the pressure gauge <NUM>. In other embodiments (not shown), the pressure gauge and flowmeters may be electrically connected (e.g., wired or wireless connection) to the controller for electronic monitoring of the purge gas supply line pressure and flow rate.

The residue tube line <NUM> is connected to the ammonia supply line <NUM> and to the purge gas supply line <NUM> by a residue tube supply valve <NUM> operable to open the residue tube line to a selected one of the ammonia supply line and the purge gas supply line. The residue tube line <NUM> includes a source conduit <NUM> and branch conduits 2242a-b (a portion of which may include flexible plastic tube, such as Tygon®) each extending through a passage 2102a-b in the fixture block <NUM> and into the outer annulus 2135a-b for connection with an inlet port 2192a-b in a sealed cap subassembly 2180a-b of the residue tube 2110a-b, to supply ammonia or purge gas (e.g., nitrogen) to the residue tube. While any suitable arrangement of the source conduit <NUM> and branch supply conduits 2242a-b may be utilized, in the illustrated embodiment, the branch conduits extend substantially symmetrically from the central source conduit, for example, to promote consistent, uniform flow to outer annuli of the two containers. As shown in <FIG>, shutoff valves 2243a-b may be provided with each of the branch conduits 2242a-b to shut off ammonia flow to a selected one of the residue tubes, for example, in the event only one sample is desired.

As shown in <FIG>, the drain line <NUM> includes a drain conduit <NUM> extending to a drain <NUM> (e.g., a waste disposal system, sewer, or a vessel where the drained ammonia can collect until it warms up and evaporates), an open drain branch <NUM> permitting free flow to the drain conduit, and a relief drain branch <NUM> permitting pressurized flow to the drain conduit (as limited by a low pressure check valve <NUM>) for draining fluid from the cold bath line <NUM> and the overflow line <NUM>, as discussed in greater detail below.

The exemplary residue tube cap subassembly 2180a-b, as shown in <FIG> and <FIG>, includes a male threaded sleeve 2187a-b received around the residue tube 2110a-b in abutment with an outer lip 2113a-b at an upper end of the residue tube, and a female threaded cap 2184a-b in threaded engagement with the sleeve to compress a gasket 2189a-b against the upper lip. A bottom end of the sleeve 2187a-b may be configured to extend over or engage a top surface of the inner container pipe 2120a-b to prevent or impede fluid ingress between the outer annulus 2135a-band the inner cavity 2125a-b.

The cap 2184a-b includes a female threaded cap nut 2191a-b defining an inlet port 2192a-b with an attached inlet connector 2194a-b (e.g., quick-connect coupling) for connection with a branch conduit 2242a-b of a residue tube line <NUM>, and an outlet port 2193a-b with an attached outlet connector 2195a-b that receives a U-shaped outlet tube 2196a-b defining an outlet passage 2183a-b extending into the residue tube 2110a-b and an overflow passage 2197a-b extending into the outer annulus 2135a-b. As shown, the inlet port 2192a-b in the cap nut 2191a-b may be provided with a necked down flow restriction, for example to provide increased pressure for ensuring the supplied ammonia remains in a liquid state. As shown, the inlet port 2192a-b may include a bent end portion 2182a-b (e.g., tube end, port connector) oriented to direct the flow of fluid from the residue tube line <NUM> against the interior wall surface of the residue tube 2110a-b, for example, to minimize disruption to the surface of the fluid in the residue tube, to allow for a more accurate and consistent fill level. While any suitable materials may be used, in an exemplary embodiment, the cap nut and sleeve are provided in PVC.

The vertical position of the outlet tube 2196a-b may be adjusted to adjust the ammonia fill level of the residue tube. In such an embodiment, the outlet tube 2196a-b is adjusted such that the end of the outlet passage 2183a-b is aligned with a desired fill line of the residue tube 2110a-b, such that the outlet passage functions as a dip tube, with excess ammonia flowing up the outlet passage and through the overflow passage 2197a-b to the cold bath in the outer annulus 2135a-b. The overflow passage 2197a-b may extend below the upper end of the inner container pipe 2120a-b to further impede ingress of the ammonia into the inner cavity 2125a-b. The bottom end of the outlet passage 2183a-b may include an angled edge 2185a-b to allow purge gas to be drawn into the outlet passage without carrying liquid ammonia from the surface.

Referring back to <FIG>, the cold bath line <NUM> is connected to the ammonia supply line <NUM> by a cold bath supply valve <NUM> operable to open the cold bath line to the ammonia supply line. The cold bath line <NUM> includes a source conduit <NUM> and branch conduits 2252a-b extending to the fixture block <NUM> to supply ammonia to a lower end of the outer annulus 2135a-b (thereby providing a cold bath surrounding the heat transfer fluid in the inner cavity 2125a-b). While any suitable arrangement of the source conduit <NUM> and branch conduits 2252a-b may be utilized, in the illustrated embodiment, the branch conduits extend substantially symmetrically from the central source conduit <NUM>, for example, to promote consistent, uniform flow to outer annuli 2135a-b of the two containers 2105a-b. Further, while many different supply passages may be provided, in the illustrated embodiment, the branch conduits 2252a-b surround the residue tube line branch conduits 2242a-b and are connected with the fixture block passages 2102a-b, thereby providing concentric passages for supplying ammonia to the residue tubes and cold baths. This arrangement may facilitate maintaining a sufficiently cold, liquid condition of the ammonia in both lines. The cold bath line <NUM> is connected to the open drain branch <NUM> of the drain line <NUM> by a cold bath drain valve <NUM> operable (in combination with the closing of the cold bath supply valve <NUM>) to drain ammonia and purge gas from the outer annulus 2135a-b.

Referring to <FIG>, the overflow line <NUM> is connected to the relief drain branch <NUM> of the drain line <NUM> for draining ammonia overflow into the outer annulus 2135a-b. The overflow line includes a main conduit <NUM> and branch conduits 2262a-b each extending into the outer annulus 2135a-b. While any suitable conduit/porting arrangement may be utilized, in the illustrated embodiment, the main conduit <NUM> may be attached (e.g., by a fitting connection) to a branching passage <NUM> in the fixture block <NUM>, with the overflow line branch conduits 2262a-b installed in branch ports 2104a-b of the branching passage <NUM>. In the illustrated embodiment, O-rings 2263a-b installed in the fixture block branch ports 2104a-b provide for sealing and retention of the overflow line branch conduits (e.g., plastic tubes, such as Tygon®). As shown, the overflow line branch conduits are arranged to terminate at a height selected to limit the volume of the cold bath, with excess ammonia added to the outer annulus 2135a-b draining through the branch conduits to the main conduit <NUM>, and to the relief drain branch <NUM> of the drain line <NUM>. An overflow drain valve <NUM> may be positioned between the relief drain branch <NUM> and the open drain branch <NUM> and may be selectively closed to block flow from the open drain branch to the overflow line <NUM>, thereby preventing drain backflow to the overflow line, for example, when the system is inactive.

In an exemplary operation of the sampling system <NUM>, the residue tube supply valve <NUM>, cold bath supply valve <NUM>, cold bath drain valve <NUM>, and overflow drain valve <NUM> (collectively, the "system switching valves") may be collectively operated to place the system in a selected one of an inactive ("OFF") condition, a cold bath filling ("CHILL") condition, a sample filling ("SAMPLE") condition, and a system purging ("PURGE") condition, as described in the embodiment of <FIG> above.

In the illustrated embodiment, as shown in <FIG> and <FIG>, the system switching valves <NUM>, <NUM>, <NUM>, <NUM> are operated by a single handle <NUM> for simultaneous actuation of the valves. While many different arrangements may be utilized, in the illustrated example, the wheel-shaped handle <NUM> (sized, for example, to provide adequate torque), is directly connected to the overflow drain valve <NUM>, and by geared arrangements (wheel gears <NUM>, <NUM>, <NUM>, <NUM>) to the residue tube supply valve <NUM>, cold bath supply valve <NUM>, and cold bath drain valve <NUM>. In such an arrangement, a first rotational position of the handle <NUM> corresponds to the inactive ("OFF") condition, a second rotational position corresponds to the cold bath filling ("CHILL") condition, a third rotational position corresponds to the sample filling ("SAMPLE") condition, and a fourth rotational position corresponds to the system purging ("PURGE") condition. While a variety of arrangements may be used to identify the orientation of the handle <NUM> (and the corresponding valve conditions), in an exemplary embodiment, as shown in <FIG>, indicia (e.g., OFF, CHILL, SAMPLE, and PURGE) may be provided on the handle, for example, on an indicator plate <NUM> identifying the four handle positions corresponding to the four system conditions. A position marker <NUM> (e.g., arrow-shaped tab) may be attached to the cabinet <NUM> to align with indicia corresponding to the selected handle position. While the handle may be configured to permit <NUM>° rotation between the four handle positions (e.g., spaced at <NUM>° increments), in other embodiments, the handle <NUM> may be configured to be limited, for example, to <NUM>° rotation between the four handle positions, for example, blocking rotation from the "OFF" position to the "SAMPLE" position, and vice versa. In the illustrated embodiment, as shown in <FIG>, a cam plate <NUM> is secured to the handle <NUM>, with a first edge of the cam plate engaging a stop pin <NUM> (secured to the cabinet <NUM>) in the "OFF" position of the handle, and a second edge of the cam plate engaging the stop pin in the "SAMPLE" position. Additionally or alternatively, the valve handle arrangement may be provided with detents corresponding to each of the four conditions of the system switching valves, to facilitate user operation of the handle to these positions. In the illustrated embodiment, the cam plate <NUM> may be provided with holes or other such recesses that align with a ball detent with the valve handle <NUM> is in the "CHILL" and "PURGE" positions to provide a tactile detect condition at these intermediary positions.

In operation, the switching handle <NUM> is actuated from the inactive ("OFF") position to the cold bath filling ("CHILL") position to supply ammonia to a cold bath in the outer annulus 2135a-b of each container 2105a-b, and the temperature of the heat transfer fluid is monitored using the temperature probe 2106a-b. Once the heat transfer fluid has reached a desired chilled temperature (e.g., about -<NUM>°F to <NUM>°F or about -<NUM> to -<NUM>), the switching handle <NUM> is actuated to the sample filling ("SAMPLE") position, in which ammonia is supplied to the residue tube 2110a-b (for collecting the samples) and to the outer annulus 2135a-b (for maintaining a chilled liquid ammonia cold bath). Once the residue tube 2110a-b has been filled to the fill line, coinciding with the lower end of the outlet passage 2183a-b (e.g., as visually identified by the operator or when excess ammonia is passing through the overflow passage 2197a-b), the switching handle <NUM> is actuated to the system purging ("PURGE") position, in which the cold bath ammonia is drained from the outer annulus 2135a-b, as facilitated by the purge gas supplied to the residue tube cap subassembly 2180a-b and through the outlet tube 2196a-b. The heater block <NUM> is operated to heat the fixture block <NUM> (e.g., to about <NUM>°F or <NUM>), for example, by user operation of the user interface <NUM> on the controller <NUM>, which heats the heat transfer fluid to a desired temperature sufficient to boil off the ammonia but not the water content in the liquid ammonia (e.g., <NUM>°F or <NUM>, per CGA G-<NUM>). The controller <NUM> may be configured to heat the heat transfer fluid to the desired temperature, as monitored by the container temperature probes 2106a-b, and then maintaining the heat transfer fluid at this temperature for a time period selected to ensure boiling of all ammonia in the sample (e.g., <NUM> minutes, per CGA G-<NUM>). The controller may provide an alert (e.g., audible and/or visual, or an electrical signal to a remote device) to the operator to visually inspects the residue tube to measure the amount of water in the graduated lower stem portion 2112a-b of the residue tube. After this measurement, the switching handle <NUM> is actuated to the inactive ("OFF") position, shutting off the supply of purge gas to the residue tube supply line. The residue tube 2110a-b may then be removed from the container 2105a-b, by releasing the hinged clamp 2178a-b, removing the cap 2177a-b, disconnecting the residue tube line branch conduit 2242a-b from the inlet connector 2194a-b, and withdrawing the capped residue tube from the container. The water may then be removed from the residue tube 2210a-b before reinstalling the residue tube in the container.

<FIG> and <FIG> illustrate an alternative arrangement for a residue tube cap subassembly 3180a-b including a male threaded sleeve 3187a-b received around the residue tube in abutment with an outer lip <NUM>13a-b at an upper end of the residue tube, and a female threaded cap 3184a-b assembled with the sleeve. The cap 3184a-b includes a female threaded nut 3188a-b in threaded engagement with an upper portion of the sleeve 3187a-b, and a ported plug 3181a-b extending through the nut and received in the upper body portion 3111a-b of the residue tube 3110a-b. An O-ring 3189a-b (or other gasket seal) is clamped between the nut 3188a-b and the residue tube lip 3113a-b for sealing engagement between the residue tube and the plug 3181a-b. A bottom end of the nut 3188a-b may be configured to extend over or engage a top surface of the inner container pipe (not shown) to prevent or impede fluid ingress between the outer annulus and the inner cavity.

The exemplary ported plug 3181a-b includes an adapter plate 3191a-b assembled with a plug body 3190a-b, for example, by threaded fasteners 3186a-b. In other embodiments, the adapter portion may be welded to or integral with the body of the ported plug. The adapter plate 3191a-b includes an inlet port 3192a-b aligned with an inlet passage 3182a-b of the ported plug, and an outlet port 3193a-b aligned with an outlet passage 3183a-b of the ported plug, with O-ring seals 3198a-b between the inlet/outlet ports and the inlet/outlet passages. An inlet connector 3194a-b (e.g., quick-connect coupling) is attached to the inlet port 3192a-b (e.g., welded) for connection with the branch conduit of the residue tube line, as described above. An outlet connector 3195a-b is attached to the outlet port 3193a-b (e.g., welded), and includes upward and downward oriented branch ports 3196a-b, 3197a-b. As shown, the inlet port 3192a-b in the adapter plate 3191a-b may be provided with a necked down flow restriction, for example to provide increased pressure for ensuring the supplied ammonia remains in a liquid state. Similar necked down restrictions may additionally or alternatively be provided in the inlet passage of the ported plug. While any suitable materials may be used, in an exemplary embodiment, the plug, sleeve, and nut are provided in PVC, and the cap is provided in stainless steel.

According to an exemplary aspect of the present disclosure, the vertical position of the ported plug 3181a-b may be adjusted in the residue tube 3110a-b to adjust the ammonia fill level of the residue tube. In such an embodiment, the ported plug is adjusted such that a bottom surface of the plug is aligned with a desired fill line of the residue tube, such that the outlet passage 3183a-b functions as a dip tube, with excess ammonia flowing up the outlet passage and through the downward oriented branch port 3197a-b to the cold bath in the outer annulus. The downward oriented branch port may extend below the upper end of the inner container pipe to further impede ingress of the ammonia into the inner cavity. The bottom surface of the plug 3181a-b may include a channel 3185a-b extending between the inlet and outlet passages 3182a-b, 3183a-b, to allow purge gas to pass to the outlet passage without carrying liquid ammonia from the surface.

Claim 1:
A sampling container assembly comprising:
a sample receiving residue tube (1110a-b, 2110a-b, 3110a-b);
a residue tube cap (1180a-b, 2180a-b, 3180a-b) assembled with the residue tube and defining inlet and outlet ports (1192a-b, 2192a-b, 3192a-b; 2193a-b, 3193a-b);
a fixture block (<NUM>, <NUM>);
an inner pipe (1120a-b, 2120a-b) having a lower end sealingly mounted to the fixture block and surrounding the residue tube to define an inner cavity (1125a-b, 2125a-b) for receiving a heat transfer fluid;
an outer pipe (1130a-b, 2130a-b) having a lower end sealingly mounted to the fixture block and surrounding the inner pipe to define an outer annulus (1135a-b, 2135a-b;
a container cap (1170a-b, 2170a-b) sealingly assembled with an upper end of the outer pipe; and
a supply conduit (1242a-b, 2242a-b) extending through the fixture block and the outer annulus and connected with the inlet port of the residue tube cap for providing a sample fluid to the residue tube;
wherein the fixture block (<NUM>, <NUM>) defines a passage extending to the outer annulus for supplying a chilling fluid to the outer annulus for chilling the heat transfer fluid in the inner cavity.