US3178265A

US3178265A - Digestion and analysis apparatus and method

Info

Publication number: US3178265A
Application number: US112590A
Authority: US
Inventors: Jr Andres Ferrari
Original assignee: Technicon Instruments Corp
Current assignee: Bayer Corp
Priority date: 1961-05-25
Filing date: 1961-05-25
Publication date: 1965-04-13
Anticipated expiration: 1982-04-13
Also published as: BE618057A; DE1299910B; GB992648A; SE319628B; NL278868A; CH422387A; US3241921A; NL133959C

Description

April 13, 1965 A. FE JR 3,178,265

DIGESTION AND ANALYSIS APPARATUS AND METHOD Filed May 25, 1961 4 Sheets-Sheet 1 I n I 1 I, r

64 56 so 36 a s8 s4 40 BYWG,Q

April 13, 1965 A. FERRARI, JR 3,178,265

DIGESTION AND ANALYSIS APPARATUS AND METHOD Filed May 25, 1961 4 Sheets-Sheet 2 INVENTOR. 4%?

April 13, 1965 A. FERRARI, JR 3,173,265

DIGESTION AND ANALYSIS APPARATUS AND METHOD Filed May 25, 1961 4 Sheets-Sheet 3 1440965 Eve/1 1 am c2112.-

April 13, 1965 A. FERRARI, JR 3,173,255

DIGESTION AND ANALYSIS APPARATUS AND METHOD Filed May 25, 1961 4 Sheets-Sheet 4 INVENTOR. 1400/95; IZ- A I A TTQP/YEY United States Patent 3,178,265 DIGESTION AND ANALYSIS APPTUS AND METHGD Andres Ferrari, in, Scarsdale, N.Y., assignor to Technicon instruments (Corporation, (Ihauneey, N.Y., a corporation of New York Filed May 25, 1961, Ser. No. 112,590?

9 Claims. (Cl. 233-430) The present invention relates to a continuous digestion method and apparatus which, while useful for various purposes, is intended primarily for performing Kjeldahl types of total or partial nitrogen determinations In my prior US. Patent No. 3,020,130, issued February 6, 1962, there is disclosed a method and apparatus for digesting substances under investigation in a con tinuous manner and treating the digested substances for analysis. As described in said patent, prior to my invention, Kjeldahl type of nitrogen determinations were performed on one sample at a time in a discontinuous or batch process and required, for each determination, com plicated and expensive apparatus and procedures and the use of many articles of glassware and auxiliary apparatus. present invention, in performing nitrogen determinations, the material whose nitrogen content is to be determined and an acid, for example sulfuric acid, for digesting the material are introduced in the form of a liquid stream into the inlet end of a horizontal rotary vessel. The liquid is transmitted through the rotary member to its outlet end and is heated during its passage through said member. A stream of the liquid containing the digested material is withdrawn from the rotary member at its out let end while liquid is being introduced into the'rotary member at its inlet end and the withdrawn liquid is diluted with water. The diluted digested material is treated with an alkali, for example sodium hydroxide, which neutralizes the acid content of the liquid contain ing the digested material and liberates ammonia which immediately goes into solution in the water forming am monium hydroxide. The quantity of the ammonia, in the form of ammonium hydroxide, is used as a measure of the nitrogen in the sample introduced into the rotary member. The liquid containing ammonium hydroxide is treated with alkaline phenol and sodium hypochlorite which produces a blue color in proportion to the quan' tity of the ammonia present in the liquid and the blue color of the liquid stream is measured by a colorimeter of the flow cuvette type. It will be understood that the digestion of the material and its subsequent treatment for analysis is accomplished in a continuous fashion in contrast to the discontinuous or batch process employed heretofore in Kjeldahl type of nitrogen determinations.

Pursuant to the present invention, the method and apparatus embody the principles disclosed in my above mentioned application and represent further develop ments thereof in respect to certain features and forms of construction. 1

, The invention will be more fully understood from the following description of the presently preferred forms of the invention considered in connection with the accompanying drawings which are to be considered as illustrative of the invention but not in limitation thereof.

In the drawings:

FIG. 1 is a front elevational view of a digestion apparatus according to the present invention with portions cut away for the purposes of illustration;

FIG. 2 is a top plan view of the apparatus;

According to my prior patent and pursuant to the 3,i?3,2h5 Fatenteel Apr. 113, 1365 ice FIG. 6 is a vertical sectional view, on a larger scale, of I a portion of the apparatus taken in line 6--6 of FIG. 2;

FIG. 7 is an'end view looking in the direction of arrowlofFIG. 6; f

FIG. 8 is a sectional view taken on line 8. 8 of FIG. 1; r I

FIG. 9 he more or less diagrammatic view illustrative of the method and apparatus of the present invention;

FIG. 10 is a view of part of the apparatus on an en: larged scale;

FIG. 11 is a vertical sectional view of part of the apparatus showing a modification;

FIG. 12 is a sectional view taken on line 22-12 of FIG. 11;

FIG. 13 is a vertical sectional viewshowing another modification of a part of the apparatus; and

FIG. 14 is a more or less diagrammatic view of part of the apparatus illustrating another form of the invention.

Referring now to the drawings in detail and particularly to FIGS. 1 to 10, the digestion apparatus 10 comprises a liquid heating or digestion cylinder 12 which is mounted for rotation about a horizontal'axis in a heating oven 14. The oven is mounted on the op of a housing 15 which contains a motor 16 for rotating the digestion cylinder, heating controls 18, temperature indicating meter 20, and various other controls of the apparatus. The digestion cylinder is provided with a helical groove 22 along its inner surface coaxial with the axis of rotation of the cylinder so that the liquid which is supplied to the cylinder through its open inlet end 24 is caused to flow through the tube in Contact with the inner surface of the lower portion of the tube to the open outlet end 26.

During the flow of the liquid through the helical passage provided by groove 22, the lower portion only of the cylinder is heated by the electrical resistant heaters 28 which are disposed below and slightly spaced from the lower portion of the digestion cylinder, as best seen in FIGS. 1 and 8. The heaters comprise a series'of heatingrods 30 which extend longitudinally of the digestion cylinder and are symmetrically positioned about the vertical axis of the cylinder below its lower portion. As herein shown, there is a total of nine heating rods 30 comprising a first group of three rods positioned near the inlet end 'of the cylinder and two other groups of three rods positioned, respectively, at the center and near the outlet end of thecylinder. The first group of rods are operated together to provide a relatively high heatingtemperature at the inlet end of the cylinder and the remaining six rods are operated together to provide a somewhat lower heating temperature for the remaining portions of the digestion cylinder since a greater heating is required at the inlet end of-the cylinder. The ends of the heating rods 39 are supported in'brackets 32 and extending between the ends of the rods are reflectors 34 which are supported on brackets 36 that are secured to the top 38 of housing 16. Brackets 36 also support the. heater brackets 32. The undersurface, of each reflector is covered with an insulating layer 40 of a suitable material,

for example asbestos.

It is to be observed that the lower portion only of the digestioncylinder 12 is heated by the heating rods 36 and it is this portion of the, cylinder whose inner surface is covered by the liquid which is being conveyed through the helical passage of the cylinder due to its rotation. In this regard, it will be understood that the quantities of liquids which flow into and out of the cylinder are so regulated that the liquid flows only as a helical stream in the helical passage during rotation of the cylinder whereby mixing of successive portions of the liquid stream during its flow through the passage is prevented so that contamination of one portion of the stream by a preceding portion of a dilferent sample is prevented.

.The ends of the digestion cylinder 12 extend outwardly beyond the adjacent ends of, the oven 14, and each end of the cylinder is provided with a pair of clamping plates 42 which engage the outer surface of the cylinder to permit mounting of the rollers 44 on said extending ends of the cylinder. The drive for rotating the cylinder comprises a pinion 46 which is connected to the shaft of motor 16, a gear 48 engaged with said pinion, and a roller 50 which ismounted on the same shaft as gear 48 is and is provided with a peripheral groove 52 which the companion roller 44 engages. The motor and gear drive are provided at the inlet end of the apparatus and only the

companion rollers

44, 50 are provided at'the outlet end of the apparatus. The grooved rollers 50 are connected to each other by a horizontal'rotary shaft 54. A grooved idler roller 56 is provided at each end of the apparatus and engages the corresponding roller 44 for supporting the cylinder in its horizontal position. The upper half of the oven 14 is provided with a hinged transparent cover 58 to which a handle 60 is secured so that the, cover may be readily opened and the digestion cylinder easily removed from the apparatus.

The open inlet end 24 of the cylinder 12 is enclosed by an inlet cap 62 (FIGS. 1, 6 and 7) which is supported by a spring clip 63 which is connected to a bracket 64 that is connected to housing 15 and it is to be observed that the cap surrounds the inlet end of the cylinder and is spaced therefrom so as not to interfere with the rotation of the cylinder. The cap is provided with a plug 66 which supports an inlet tube 68 whose outlet end 70 is in communication with an endless cylindrical groove 72 provided at the inlet end of the cylinder 12 perpendicular to the axis of rotation of the cylinder. This groove 72 is in liquid communication with the helical groove 22 so that liquid is transmitted from the groove through the helical passage of the cylinder 12 by rotation of said cylinder. The cap is provided with a vent outlet 74 for the exhaust of fumes from the digestion cylinder 12 which results from the digestion operation and the lower portion of the cap is provided with a liquid outlet 76 for draining any liquid which may deposit in the bottom of the inlet cap.

The helical passage 22 of the'digestion cylinder extends from cylindrical groove 72 to the open outlet end 26 of the cylinder so that the liquid is conveyed by the rotation of the cylinder through said open outlet end. An' outlet end cap 78 (FIGS. 1, 4 and encloses the outlet end of the cylinder and is supported on the side of the housing by a spring clip 63 and bracket 64 in a manner similar to the described support for the inlet cap 62. The lower portion 82 of the end cap. is funnel-shaped and receives the liquid which flows from the outlet end 26 of the cylinder. .An overflow liquid outlet 84 is provided in the funnel above its outlet end 86. The outlet end cap is also provided with a fume exhaust 88 which includes a tube 90 which extends endwise through the open end 26'of the cylinder 12 for exhausting fumes from said cylinder through tube 92. The end caps are preferably made of glass and it will be understood that the digestion cylinder 12 is also preferably made of, a glass which is highly resistant to heat.

The fume outlets of the end caps are connected by suitable tubing 93 (FIG. 2) to the ends 94, respectively, of a fume exhaust manifold 96 which is connected to an aspirator 98 via tube 106, as indicated in FIG. 9. The aspirator is of a well known type which is operated by means of a stream of water for withdrawing the fumes resulting from the heating of the acid in cylinder 12 and for diluting the acid constituents of the fumes sutficiently to produce a weak acid solution which may safely be transmitted through the outlet 102 of the aspirator for disposal in a waste pipe.

The operation of the digestion apparatus 10 will now be more fully described with respect to FIG. 9 which shows the apparatus with a separate liquid receiving funnel 104 in lieu of the integral funnel and end cap'78 previously described. The successive samples which are to. be investigated or analyzed in accordance with the present invention are supplied to the pump tube 106 of a proportioning pump 168 from a sample supply device 110 which comprises a horizontal rotary plate 112 and mounts a series of receptacles or cups 114 for the different samples, the cups being preferably. arranged in a circular row. Plate 112 is intermittently rotated and an off-take tube 116 is connected to the pump tube 106 and is pivotally moved in timed relation to the intermittent rotation of plate 112 for moving its inlet end into and out of each of the receptacles 114 in succession during the dwell periods of the plate. This supply device 110 may be of the construction shown and described in US. Patent No. 3,038,340, issued June 12, 1962.

The proportioning pump 108, which is schematically illustrated, may be of any suitable type although it is preferablyof the type described .in US. Patent No. 2,935,028, issued May 3, 1960. Briefly described, the

r pump comprises a plurality of resiliently flexible tubes which are compressed progressively along their lengths for the pumping operation by the engagement therewith of a plurality of pressure rollers which move longitudinally of the pump tubes to fully close said tubes progressively along their lengths and thus propel the liquids or other fluids for transmitting them from sources of supply to points of delivery.

As herein shown, the sample to be digested is transmitted by the pump tube 106, the acid is transmitted by the pump tube 118 and air or other inert gas is transmitted by the pump tube 120. The fluids mix with each other at fitting 122 and form a segmented stream consisting of a series of liquid segments containing the sample and the acid separated by a series of intervening gas segments. The segmented stream passes through a horizontal glass helical mixing coil 124 wherein the constituents of each liquid segment are mixed together and the segmented stream is transmitted from the mixing coil, via conduit 126, to the inlet tube 68, which is connected to the conduit, for introducing the acid and sample into the digestion cylinder 12. The air segments of the introduced stream escape from the digestion cylinder through the fume vent 74. The provision of the intervening segments of gas help maintain the tubular passages of the apparatus clean to avoid contamination of one liquid sample by a preceding liquid sample. The proportioning pump is operated continuously so that when the off-take aspirating tube 116 of the sample supply device 110 is not immersed in the liquid in the cups 114, air is transmitted through the off-take tube as well as through tube and as acid is being continuously supplied through pump tube 118 due to the continuous action of the pump, each succeeding sample is separated from the other by an intervening air-segmented stream of acid whereby contamination of one sample by a preceding sample is eliminated or reduced to a tolerable degree. It is to be observed that due to the operation of the sample supply device 110 and pump 108, a series of separate liquid samples and a stream of acid are introduced into the digestion cylinder 12 during spaced intervals of time and a stream of acid without said liquid samples is introduced into the cylinder between said spaced intervals of time.

As the cylinder rotates, the introduced liquid stream is transmitted from the peripheral groove 72 and flows progressively in the helical groove 22 in contact with the inner surface of the lower portion of the cylinder longitudinally of the cylinder through its open outlet end 26 and into the funnel 104. In the'course of the passage of the liquid through the digestion cylinder 12 the digestiblematerial in the sample which is being investigated or analyzed is digested by the heated acid and is in a highly concentrated condition by the time it reaches the outlet end 26 of the cylinder. The outlet end 86 of the end cap 78 or of the funnel 104 is connected to conduit 128 which is connected to a pump tube 130 and the liquid is transmitted through said conduit and pump tube by the action of the pump to fitting 132 where it joins a stream of air or other inert gas which is introduced through pump tube 134 and subdivides the liquid stream into a series of liquid segments spaced from each other by intervening gas segments. It will be understood that pump tube 13%} is made of a resiliently flexible material highly resistant to the heated concentrated acid nature of the digested material. A suitable material, for example, is sold under the trademark Fluran 5000 and is manufactured by the US. Stonewall Co. of Akron, Ohio. Further description of the pump tube 13% and its material is not considered necessary as it does not, per se, form part of the invention. The use of special material for pump tube 13d can be avoided by diluting the digested material before it reaches the pump as shown in FIGS. 11, 13 and 14, which will be explained hereinafter. i

A diluent, for example, water, is introduced into the segmented stream via pump tube 136 and the diluted segmented stream is then cooled by passing through the cooling coil 138 which is immersed in a water cooling bath 140. Since the liquid contains sulfuric acid in a highly concentrated condition, only a relatively small quantity of water is added to the liquid and after it has been cooled an additional quantity of water is added to the liquid through pump tube 142 and the resulting mixture is passed through an air-cooled helical mixing coil 144. An additional quantity of water is added through pump tube 146 and the resulting mixture is mixed in another air cooled helical mixing coil 148. The nature of the resulting diluted and cooled liquid is such as to have no serious detrimental effects on the parts and tubes of the apparatus. The cooling effect provided by the

coolers

140, 144 and 148 reduces the quantity of diluent required to a minimum so that the apparatus performs with a high degree of sensitivity.

The diluted liquid is then transmitted through conduit 159 and pump tube 152, respectively, to a fitting 154- where it mixes with air and sodium hydroxide which are introduced through

pump tubes

156 and 15 8, respectively. As explained above, the air serves to segmentize the resulting liquid stream which consists of liquid segments containing the digested liquid and sodium hydroxide. The constituents of the liquid segments of the stream are mixed together in a helical mixing coil 16% and from the helical mixing coil, the mixed segmentized liquid stream joins a stream of a liquid containing alkaline phenol, one of the substances of the above-described color reagent, which is introduced through pump tube 162. The resulting stream is transmitted to a mixing coil 164 and the other of the above described color reagents, namely sodium hypochlorite, which is introduced through pump tube 1-56, joins the mixed stream from mixing coil 1(4 and the resulting liquid stream is mixed in mixing coil 163. From coil 16 3 the liquid passes to the heating bath 176 wherein the color is fully developed and from said heating bath the liquid passes through the cooling coil 172; and then through the flow cuvette of a colorimeter 174 which operate a recorder 175 for recording the results of the color measurement. Since the details of construction of the colorimeter and recorder are not per se part of the invention, a further description of these instruments is considered unnecessary. The measured liquid is discharged from the flow 'cuvette of the colorimeter through outlet 176.

As described above, acid fumes are removed by suction from the open ends of the cylinder 12 and are thus prevented from contaminating the air in the workroom or laboratory, said acid fumes being diluted with water and discharged to waste through the outlet ltlZ of the asp-irator 9'8. Also, as indicated above, the overflow outlet 84 of the funnel 194 discharges any excess liquid which rises to the level of said overflow outlet.

The method and apparatus of the present invention can be used for partial digestion of a substance under investigation when said substance is homogeneous, ie when it has only one source of nitrogen in its composition. In this connection, it will be understood that total digestion is employed in accordance with a well known practice when the substance is not homogeneous, i.e. when it includes more than one source of nitrogen in its composition and the rates of digestion of said nitrogen sources are not relatively the same. Also it will be understood that while the method and apparatus of the present invention are intended primarily for performing Kjeldahl types of quantitative analysis with respect to the nitrogen content of a substance, the principles of the method and apparatus of the present invention are not limited to such determina tions, and may be used for other punposes.

Referring now to FIGS. 11 and 12, there is shown a modification of the outlet end of the digestion apparatus 19 wherein the digested material is aspirated from the digestion cylinder 12 in lieu of being transmitted through the open outlet end 26 of the cylinder to a funnel 82 which is integral with an end cap 78, as shown in FIG. 4 for example, or in lieu of being transmitted to a separate funnel 1164, as shown in FIG. 9. More specifically, an outlet end cap 178 is provided, enclosing the open outlet end 25 of the digestion cylinder and is provided with a plug 18d which supports a liquid off-take tube 182 and a liquid inlet tube 134 which supplies a diluent, for example water, to the digested material while said material is in the digestion cylinder. The diluent reduces the detrimental nature of the hot concentrated acid and eliminates the necessity of special pump tubing material, as explained previously. The out-let end of the digestion cylinder is provided with cylindrical grooves 185, herein shown as two, connected to each other by the helical groove 22, and each groove is in liquid-flow communication with the helical groove 22 and is provided with projecting vanes or mixing members 186 for mixing the digested material and the diluent introduced through inlet tube 184. Grooves 135 are at right angles to the axis of rotation of the cylinder 1-2. The outlet end 1-37 of the inlet tube is positioned in the groove upstream of the inlet end 11% of the oft-take tube 182 and is adjacent to groove 185 in which end 188 of the ofi-take tube is positioned or may be spaced one or more turns upstream from said inlet end. The inlet end of the off-take tube is preferably positioned vclose to the bottom of the groove adjacent the end 26 of the digestion cylinder.

Tubes

182 and 184 are connected by suitable conduits to pump tubes of the proportioning pump Hi8 so that during the operation of the pump the diluting liquid is introduced into the digestion cylinder through tube 184 and the mixed digested material and diluent are aspirated from the digestion cylinder through tube 182 and from the latter to the cooling bath 14%? which may be accomplished by connecting the aspirating tube 182 to conduit 128. In this case, if desired or it necessary, pump tube 136 may be eliminated. The end cap 173 is provided with the previously described fume exhaust outlet 92 and overfiowdrain outlet 34.

In FIG. 13 there is shown another form of the outlet end cap. As here shown, the outlet end cap 1% includes a plug 192 which supports three tubes, namely, an inlet tube 194 for introducing a diluent into the digestion cylinder, as previously described, an aspirating or off-take tube 196 for aspir-ating liquid from the cylinder and an overfiow tube 198 for aspirating excessive liquid from the cylinder. The digestion cylinder 12' is similar to the di- 'gestion cylinder previously described with respect to FIG. 11 but has, in addition, an endless cylindrical groove 200 at the outlet end of the cylinder which is in liquid communication with the helix 22 and is perpendicular to the horizontal axis of the cylinder. The groove 20%) has a greater volume than a groove of the helix or groove 185 and acts as a reservoir or liquid receiver into which the digested liquid and diluent is introduced from the helix. The inlet end 262 of the overfiow tube is above the inlet end 204 of the off-take tube 196. Tube 198is connected to one of the pump tubes (not shown) of the proportioning pump so that it is apparent that when the liquid rises in groove 209 to the level of inlet end 262, the overflow tube 198 aspirates the excessive liquid from the digestion cylinder. It is to be observed that since diluent is being added to the digested mixture, the quantity of the liquid in the digestion cylinder at its outlet end is greater than that at its inlet end and groove 200 provides a reservoir for this excessive liquid. With respect to the end cap 178, as shown in FIGS. 11 and 12, the overflow outlet 84 removes any excessive liquid which may occur due to the introduction of the diluent at the outlet end of the cylinder. End cap 190 is also provided with the previously described fume exhaust outlet 92.

Referring now to FIG. 14, there is also shown a modification of the invention which permits the introduction of the diluting water into the liquid containing the digested material before said material is transmitted through the pump and in this manner eliminates the necessity of providing special acid-resistant pump tubes resistant to the concentrated acid nature of the liquid, as previously mentioned. As shown in FIG. 14, the liquid flows from the outlet 86 of the funnel 104 and water is added to the outflowing liquid through pump tube 206 and conduit 2458 and the diluted liquid is passed through the water cooled mixing coil 138. Additional Water is supplied through pump tube 210 and conduit 212 and is added to the outfiowing cooled diluted liquid from mixing coil 138 and the resulting liquid is transmitted through the air cooled mixing coil 144- and the liquid from said mixing coil is mixed with additional Water supplied through pump tube 214. The resulting liquid is mixed in air cooled mixer 148 and thereafter is transmitted to the previously mentioned pump tube 152 for subsequent treatment, as previously described. It will be observed that before the digested material is transmited to any of the pump tubes, it has been diluted with Water and cooled so that when it arrives at the pump it is no longer in a condition which may have adverse effects on the pump tubes or other parts of the apparatus.

While I have shown and described the preferred embodiment of my invention, it will be understood that the invention may be embodied otherwise than as herein specifically illustrated or described, and that certain changes in the form and arrangement of parts and the specific manner of practicing the invention may be made Without departing from the underlying ideas or principles of this invention within the scope of the appended claims.

What is claimed is:

1. Continuous liquid-treatment and analysis apparatus, comprising a horizontally mounted longitudinally extending rotary member having means defining a helical passage therein disposed coaxially of the axis of rotation of said member for the flow of liquid therein from a point of liquid supply to a liquid-delivery point downstream from said point of supply, means for rotating said member about said axis for the flow of the liquid in said helical passage to said point of delivery, means for heating said member during its rotation whereby to heat the liquid, means during spaced intervals of time into said rotary member at said point of liquid supply for treatment in said memher, during the flow'of said samples to said point of delivery, means for introducing a reagent liquid into said rotary member at a point upstream of said liquid delivery point for treating said liquid samples while said samples flow in said member toward said delivery point, said reagent being heated during its flow in said member whereby the samples are subjected to the action of said heated reagent liquid, during the flow toward said delivery point, means for introducing a diluent into said rotary member at a point upstream from said liquid delivery point and downstream from said reagent delivery point, means for receiving the diluted liquid from said rotary member in the form of a stream containing the treated liquid samples spaced from each other longitudinally of the stream by other intervening, liquid, and means for treating the treated liquid samples in said last mentioned stream during the fiow thereof for examination in respect to a particular substance therein.

2. Continuous liquid-treatment and analysis apparatus, comprising a horizontally mounted longitudinally extending rotary member having means defining a helical passage therein disposed coaxially of the axis of rotation of said member for the flow or" liquid therein from a point of liquid supply to a liquid-delivery point'downstream from said point of supply, means for rotating said member about said axis for the how of the liquid in said helical passage to said point of delivery, means for heating said member during its rotation whereby to heat the liquid, means operable to introduce a series of separate liquid samples during spaced intervals of time into said rotary member at said point of liquid supply for treatment in said member, during the flow of said samples to said point of delivery, means for introducing a reagent liquid into said rotary member at a point upstream of said liquid delivery point for treating said liquid samples while said samples flow in said member toward said delivery point, said reagent being heated during its flow in said member whereby the samples are subjected to the action of said heated reagent liquid during the flow toward said delivery point, means for introducing a diluent into said rotary member at a point upstream from said liquid delivery point and downstream from said reagent delivery point, means for receiving the diluted liquid from said rotary member in the form of a stream containing the treated liquid samples spaced from each other longitudinally of the stream by other intervening liquid, means for treating the treated liquid samples in said last mentioned stream during the flow thereof for examination in respect to a particular substance therein, and analysis means including a colorimeter having a flow cuvette through which said stream of treated samples and intervening liquid between said treated samples is transmitted for said examination of said treated samples.

3. Continuous liquid-treatment and analysis apparatus, comprising a horizontally mounted longitudinally extending rotary member having means defining a helical passage therein disposed coaxially of the axis of rotation of said member for the flow of liquid therein from a point of liquid supply to a liquid-delivery point downstream from said point of supply, means for rotating said memher. about said axis for the flow of the liquid in said helical passage to said point of delivery, means for heating said member during its rotation whereby to heat the liquid, means operable to introduce a series of separate liquid samples during spaced intervals of time into said rotary member at said point of liquid supply for treatment in said member, during the flow of said samples to said point of delivery, said rotary member having an outlet opening at said delivery point and said helical passage extending to said outlet opening whereby the liquid flows directly from said helical passage through said outlet opening, means for introducing a reagent liquid into said rotary member at a point upstream of said liquid delivery point for treating said liquid samples while said samples flow in said member toward said delivery point, said reagent being heated during its flow in said member whereby the samples are subjected to-the' action of said heated reagent liquid, during the flow toward said delivery point, means for introducing a diluent into said rotary member at a point upstream from said liquid delivery point and downstream from said reagent delivery point, means for receiving the diluted liquid from said rotary member in the form of a stream containing the treated liquid samples spaced from each other longitudinally of the stream by other intervening liquid, and means for treating the treated liquid samples in said last mentioned stream during the flow thereof for examination in respect to a particular substance therein.

4. Continuous liquid-treatment apparatus, comprising a heating vessel mounted for rotation about a horizontal axis, means for rotating said vessel about said axis, means for heating said vessel during its rotation, liquid inlet means in liquid flow communication with said vessel for introducing a stream of liquid into said vessel during its rotation, said vessel having a helical groove along its inner surface coaxial with the axis of rotation of said vessel for causing the liquid to flow in contact with the lower portion of said inner surface from said inlet means to a position downstream from said inlet means, liquid outlet means for the delivery of liquid from said vessel at said downstream position and while the liquid is being introduced into said vessel through said inlet means, and means positioned upstream of said outlet means and downstream of said inlet means for transmitting another liquid to said first mentioned liquid before the latter is delivered from said vessel, said vessel having projecting means extending from the inner surface of said vessel at the position of said liquid transmitting means for mixing said other liquid and said first mentioned liquid during the rotation of said vessel.

5. Continuous liquid-treatment apparatus, comprising a heating vessel mounted for rotation about a horizontal axis, means for rotating said vessel about said axis, liquid inlet means in liquid flow communication with said vessel for introducing a stream of liquid into said vessel during its rotation, said vessel having a helical groove along its inner surface coaxial with the axis of rotation of said vessel with side walls of adequate height for causing the liquid to flow in and along said groove between said side walls in contact with the lower portion of said inner surface from said inlet means to a position downstream from said inlet means, an endless cylindrical groove in liquid flow communication with said helical groove at said downstream position for receiving the liquid from said helical groove, said cylindrical groove having a volume which is greater than the volume of a turn of said helical groove, liquid outlet means in communication with said cylindrical groove for delivering liquid therefrom and while the liquid is being introduced into said vessel through said inlet means, means for heating said vessel during its rotation; and means downstream of said liquid inlet means and upstream of said liquid outlet means for transmitting another liquid to said first mentioned liquid before the latter is delivered from said vessel.

6. Continuous liquid-treatment and analysis apparatus, comprising a liquid-heating vessel mounted for rotation about a horizontal axis, means for rotating said vessel about said axis, liquid-inlet means in liquid flow communication with said vessel for introducing a stream of liquid into said vessel during its rotation, said vessel having a helical groove along its inner surface coaxial with the axis of rotation of said vessel for causing the liquid to flow in contact with the lower portion of said inner surface from said inlet means to a position downstream from said inlet means, means for heating said vessel during its rotation, liquid outlet means in liquid flow com munication with said vessel for the delivery of liquid from said vessel at said downstream position during the rotation of said vessel and while the stream of liquid is being introduced into said vessel through said inlet means, means inliquid flow communication with said vessel posi tioned upstream of said outlet means and downstream of said inlet means for transmitting another liquid to said first mentioned liquid before the latter is delivered from said vessel, means for receiving from said outlet means and for treating the withdrawn liquid for analysis, analysis means, and means for transmitting a stream of said treated liquid to said analysis means from said treating means. i

7. Continuous liquid-treatment and analysis apparatus, comprising a liquid-heating vesselmounted for rotation about a horizontal axis, means for rotating said vessel about said axis, liquid-inlet means in liquid flow communication with said vessel for introducing a stream of liquid into said vessel during its rotation, said vessel having a helical groove along its inner surface coaxial with the axis of rotation of said vessel for causing the liquid to flow in contact with the lower portion of said inner surface from said inlet means to a position downstream from said inlet means, means for heating said vessel during its rotation, liquid outlet means in liquid flow communication with said vessel for the delivery of liquid from said vessel at said downstream position during the rotation of said vessel and while the stream of liquid is being introduced into said vessel through said inlet means, means in liquid flow communication with said vessel positioned upstream of said outlet means and downstream of said' inlet means for transmitting another liquid to said first mentioned liquid before the latter is delivered from said vessel, said vessel having means for mixing said other liquid and said first mentioned liquid during their passage through said vessel, means for receiving from said outlet means and for treating the withdrawn liquid for analysis, analysis means, and-means for transmitting a stream of said treated liquid to said analysis means from said treating means.

8. Continuous liquid-treatment and analysis apparatus, comprising a liquid-heating vessel mounted for rotation about a horizontal axis, means for rotating said vessel about said axis, liquid-inlet means in liquid flow communication with said vessel for introducing a stream of liquid' into said vessel during its rotation, said vessel having a helical groove along its inner surface coaxial with the axis of rotation of said vessel for causing the liquid to flow in contact with the lower portion of said inner surface from said inlet means to a position downstream from said inlet means, means for heating said vessel during its rotation, liquid outlet means in liquid flow communication with said vessel for the delivery of liquid from said vessel at said downstream position during the rotation of said vessel and while the stream of liquid is being introduced into said vessel through said inlet means, means in liquid flow communication with said vessel for introducing a diluting liquid into said vessel upstream from said downstream position and downstream from said inlet means, said vessel having means for mixing said diluting liquid and said first mentioned liquid during their passage through said vessel, means for receiving from said outlet means for adding liquid to said mixed liquids after their delivery from said vessel, means coupled to said receiving means for further treating the diluted liquid mixture for analysis, analyzing means, and means for transmitting a stream of said treated liquid to said analyzing means from said treating mean-s.

9. A continuous digestion and analysis method according to which there is provided a horizontal rotary member provided with a liquid passage extending helically around the axis of rotation of said member, said method comprising rotating said member about said axis and heating said member during its rotation, introducing into said liquid passage at a predetermined position a stream of liquid containing the substance to be digested and an acid 1 l l 2 for digesting said substance, introducing a diluting liquid References Cited by the Examiner. into said-liquid passage at a position downstream from UNITED STATES PATENTS said first mentioned position, withdrawing from said rotary v I member during the rotation'thereof and at a position 222: donta to th 't' f'td g 'dd'lt' r w s re m r m e posi 10H 0 1n r0 11cm sai 1 u mg 5 3020130 2/62 Ferrari 23 230 liquid a stream of the liquid containing thevdiluted digested substance, regulating the quantity of said liquids which T flow into and out of said member so that the liquid flows 2 FOREIGN A ENTS' in said helical passage only duringthe rotation of said O4067 1/57 Francemember to prevent mixin of successive portions of the 10 liquid stream during its- 50w through said passage, and MORRIS WOLK Primary Examiner treating the withdrawn liquid stream during its flow for MAURICE A. BRINDISI, ANTHONY SCIAMANNA, quantitative analysis in respect to said digested substance. Examiners.

Claims

1. CONTINUOUS LIQUID-TREATMENT AND ANALYSIS APPARATUS, COMPRISING A HORIZONTALLY MOUNTED LONGITUDINALLY EXTENDING ROTARY MEMBER HAVING MEANS DEFINING A HELICAL PASSAGE THEREIN DISPOSED COAXIALLY OF THE AXIS OF ROTATION OF SAID MEMBER FOR THE FLOW OF LIQUID THEREIN FROM A POINT OF LIQUID SUPPLY TO A LIQUID-DELIVERY POINT DOWNSTREAM FROM SAID POINT OF SUPPLY, MEANS FOR ROTATING SAID MEMBER ABOUT SAID AXIS FOR THE FLOW OF THE LIQUID IN SAID HELICAL PASSAGE TO SAID POINT OF DELIVERY, MEANS FOR HEATING SAID MEMBER DURING ITS ROTATION WHEREBY TO HEAT THE LIQUID, MEANS OPERABLE TO INTRODUCE A SERIES OF SEPARATE LIQUID SAMPLES DURING SPACED INTERVALS OF TIME INTO SAID ROTARY MEMBER AT SAID POINT OF LIQUID SUPPLY FOR TREATMENT IN SAID MEMBER, DURING THE FLOW OF SAID SAMPLES TO SAID POINT OF DELIVERY, MEANS FOR INTRODUCING A REAGENT LIQUID INTO SAID ROTARY MEMBER AT A POINT UPSTREAM OF SAID LIQUID DELIVERY POINT FOR TREATING SAID LIQUID SAMPLES WHILE SAID SAMPLES FLOW IN SAID MEMBER TOWARD SAID DELIVERY POINT, SAID REAGENT BEING HEATED DURING ITS FLOW IN SAID MEMBER WHEREBY THE SAMPLES ARE SUBJECTED TO THE ACTION OF SAID HEATED REAGENT LIQUD, DURING THE FLOW TOWARD SAID DELIVERY POINT, MEANS FOR INTRODUCING A DILUENT INTO SAID ROTARY MEMBER AT A POINT UPSTREAM FROM SAID LIQUID DELIVERY POINT AND DOWNSTREAM FROM SAID REAGENT DELIVERY POINT, MEANS FOR RECEIVING THE DILUTED LIQUID FROM SAID ROTARY MEMBER IN THE FORM OF A STREAM CONTAINING THE TREATED LIQUID SAMPLES SPACED FROM EACH OTHER LONGITUDINALLY OF THE STREAM BY OTHER INTERVENING LIQUID, AND MEANS FOR TREATING THE TREATED LIQUID SAMPLES IN SAID LAST MENTIONED STREAM DURING THE FLOW THEREOF FOR EXAMINATION IN RESPECT TO A PARTICULAR SUBSTANCE THEREIN.