LIQUID TREATING APPARATUS AND METHOD

72 '176 '1 This invention relates to a liquid treating apparatus and method and comprises a measuring tank for accurately measuring a predetermined quantity of granular liquid treating material, means for transferring to said tank said predetermined quantity of granular liquid treating material, means for draining liquid from said tank without loss of granular liquid treating material, optional means for regenerating said liquid treating material in said tank» and means for discharging said predetermined quantity of granular liquid treating material from said tank.

i0 It is an object of this invention to provide a liquid treating apparatus and method to accurately measure predetermined quantities of granular liquid treating material discharging from or entering into a vessel such as an ion exchange unit. It is a further object of this invention to provide a liquid treating apparatus and method in which liquid may be treated in a vessel continuously without interruption for regenerating or reconditioning. Another object of this invention is to provide a liquid treating apparatus having a treatment or storage vessel and a measuring tank with means for transferring periodically a predetermined quantity of liquid treatment material from said treatment or storage vessel to said measuring tank.

The manner in which the foregoing objects are achieved is shown in the appended drawings in which:

Figure i is a diagrammatic view of an apparatus according to my. invention; Figure 2 is a view of a modified portion of the apparatus shown in Figure l and Figure 3 is a diagrammatic view of another embodiment of my invention.

Referring now to Figure l, there is shown an ion • i A y27176 exchange vessel 15 containing a screened collector 14 and a body of cation exchanger 16. Located in the bottom of said ion exchange vessel 15 is an underdrain consisting of a distributor 17 embedded in a gravel subfill 27. Communicating with the bottom of the ion exchange vessel 15 is a pipe 42 connected by a tee 43 to a hard water inlet pipe 29 provided with a valve 28, and to a line 31 provided with a valve 30. The collector 14 is connected to a pipe 13 extending through the top of the ion exchange vessel and connected by a tee 46 to a treated water outlet line i0 i0 provided with a valve ii» and to a transfer inlet line 18 provided with a valve 12 and leading to a pump 19. Extending from the side of the ion exchange vessel 15, at a level adjacent to but above the gravel subfill 27 is a discharge tube 21 provided with a valve 20 and extending downwardly into a closed measuring or receiving tank 33 to a level 34 as required to measure a predetermined quantity of cation exchanger 35. A transfer outlet line 22, provided with a valve 23, interconnects the top of the ion exchange vessel 15 and the top of the measuring tank 33. The measuring tank 33 is located at a lower elevation than the ion exchange vessel 15 to permit gravity flow of ion exchanger from vessel l5 to tank 33. An underdrain consisting of a screen support 36 with holes small enough to prevent loss of the cation exchange material 35 is located near the bottom of the measuring tank 33, and extends over its entire cross-sectional area. A pipe 37 leads from the bottom of the measuring tank 33 through a tee 45 to a drain line 38. A pipe 48 provided with an elbow 49 connects the outlet of pump 19 with the tee 45 and thus constitutes a continuation of the transfer inlet line 18. The drain line 38 is provided with a valve 39 and leads to a sump 40, The llne 31 is further connected by a tee 44 to a pipe 47 and to a brine line 41, provided with a valve 24. The pipe 47 enters the top of the measuring tank 33 where it is connected to a - :2 - ,: i i. « $ j ?...

iL i ii¸ L ï i l0 7271 ç6 distributor 32. The brine line 41 is further connected to a brine container 25 which holds a quantity of saturated brine 26.

In operation, initially all valves with the exception of valves 28 and ll are closed and the pump 19 is stopped. Hard water flows through valve 28 and hard water inlet llne 29, and enters the ion exchange vessel 15 through pipe 2 and the distributor 17. The hard water then flows upwardly through the body of cation exchanger 16, where it is softened by ion exchange, and is collected by the collector 14 and discharged through the pipe 13, valve ll, and the treated water outlet line l0 to a point of use. The exchange capacity of the body of cation exchanger 16 is being exhausted as water passes through it, and the exchanger must be regenerated periodically. Because the water being treated flows upwardly through the ion exchange vessel 15, the bottom portion of the body of cation exchanger 16 becomes exhausted first, and therefore, is in need of regeneration before the upper portions. For regeneration, an exhausted portion of cation exchanger from the lower part of the body 16 is withdrawn from the ion exchange vessel without interrupting the treatment of water in vessel which is carried on with the remaining portion of the body 16.

In order to initiate the withdrawal of cation exchanger from the body 16, valves 20 and 39 are opened. Now a slurry of cation exchanger from the body 16 flows by gravity through the discharge tube 21 and open valve 20 into the measuring tank 33, open valve 39 permitting water to drain through the screen support 36 and out through the drain line 38 into sump 40. Draining of the measuring tank 33 during this operation aids in settling the cation exchanger in the measuring tank 33. When the top of the cation exchanger settling in the measuring tank 33 has reached the level 34 even with the end of the discharge tube 21, the flow of cation exchanger automatically stops because the cation exchanger k 2.. , ili not rise higher than the level 34. The level 34 accordingly defines in the measuring or receiving tank 33 a lower measuring space and an upper free and unobstructed rising space. Thus, a constant and predetermined quantity of cation exchanger 35 is measured out in the measuring tank 33, equal in volume to that of the measuring tank 33 as measured from the top of the screen support 36 to the level 34.

Next, valve 20 is closed and valves 24 and 30 are opened, permitting saturated brine 26, entering through pipe 41, and lO dilution water entering through line 31 to mix in tee 44, producing the dilute brine solution required to regenerate the cation exchanger. This dilute brine solution enters tank 33 through pipe 47 and distributor 32, and then passes down through the body of measured cation exchanger 35, regenerating it, and finally flows through distributor 36, pipe 37, and drain line 38 into the sump 40. When the required quantity of brine has been introduced in this manner, valve 24 is closed, shutting off the supply of saturated brine. Hard water is permitted to continue to flow through valve 30 and the line 31 into the tee 44, thence continuing along the same path previously taken by dilute brine. This rinse operation is continued until the body of the cation exchanger has been rinsed substantially free of spent and excess brine.

Then the hard water rinse is followed by a soft water rinse.

To this end valve 30 is closedand valve 23 opened» allowing soft water from the vessel 15 to flow into the top of the measuring tank 33 to displace through the cation exchanger the hard water remaining in the tank 33 above the level 34 at the end of the previous rinse step. As this hard water enters the cation exchanger 35 it becomes softened by ion exchange.

When this has been accomplished the soft water rinse is terminated and the transfer of ion exchanger is initiated. For this purpose valve 39 is closed» the pump 19 is started» and valve 12 is opened (valve 23 remaining open). The pump 19 now circulates soft water at a high rate of flow from vessel lit¸ lO 7271 76 through collector l pipe 13, tee 46, transfer inlet line 18, pipe 48, tee 4%, pipe 37, upwardly through the tank 33, through valve 23, and transfer outlet llne 22 back into vessel l The high rate of flow of water carries the body of regenerated and rinsed cation exchanger 3% out of the measuring tank 33 and through the transfer outlet llne 22 into the top of the ion exchange vessel 1%, depositing it on top of the body 16. When this is completed the pump 19 is stopped, and valves 12 and 23 are closed.

Softening of water now continues with all the cation exchanger in the body 16. This goes on until the lower portion of the body 16, at least equal in volume to the quantity 35, has again become exhausted, when the above described cycle of operations is repeated.

The provision of the measuring tank 33 in accordance with my invention makes it possible to accurately measure out uniform and predetermined quantities of cation exchanger.

Furthermore, softening of water in a single unit continues indefinitely without interruption for purposes of regeneration.

The cation exchanger is moved with a minimum of attrition, not being required to pass through a pump. The use of soft water to return the cation exchanger to vessel 15 avoids any contamination er the effluent from vessel 15 during such return, and due to the reclrculatlon of this soft water this is accomplished without any waste of soft water.

In Figure 2, the apparatus of Figure 1 is modified as follows. The transfer outlet llne 22 is extended to a level in the measuring tank 33 adjacent to and above the screen support 36, as indicated at 0. The elbow 9 is replaced by a tee 51 connected by a pipe 52 with a tee 53 inserted in llne 31. A valve 54 is provided in pipe 48, and a valve 55 in pÆpe 52.

The operation of the modification shown in Figure 2 • p :iI i, 7 7176 differs from that described above in connection with Figure i in the following respects. In the soft water rinse step valve 23 remains closed, but valve 55 is opened so that the rinse water enters the measuring tank 33 via the transfer line 18, pump 19, tee 51, pipe 52 with valve 55, tee 53, part of pipe 31, tee 44, pipe 47 and distributor 32 (instead of through line 22). Thence the rinse water follows the same path as in Figure i. In the next following transfer step valve 39 is closed.

Valve 55 remains open, and valves 23 and 54 are also opened.

i0 The soft water discharged by pump 19 thus is divided in tee 51 into two separate streams, a smaller portion entering tank 33 through pipe 48, tee 45» and pipe 37, fluidizing the exchanger 35, and a larger portion entering tank 33 through •pipe 52, tee 53, part of pipe 31, tee 44, pipe 47 and distributor 32, pushing the exchanger 35 down toward the end of the transfer outlet line at 50. The fluidized resin and water pass through line 22 into the top of the ion exchange vessel, as in Figure I.

The arrangement of Figure 2 is advantageous particularly for relatively large equipment because there is less tendency çOr exchanger particles to linger in tank 33 at the end of the transfer step than there is in the arrangement shown in Figure i.

Regeneration and rinsing of the liquid treating material in the measuring tank is an attractive but not necessary feature of my invention. If desired» the measuring tank may be used for the sole purpose of accurately measuring a predetermined quantity of granular liquid treating material which is then transferred elsewhere through the transfer outlet line for further use or processing. Such an arrangement is shown in Figure 3.

Referring now to Figure 3» there is shown by way of example a reactor 127, a regenerator 131, a storage tank or vessel ll0, and £i I E lO a measuring tank ll8. The reactor 127 and the regenerator 131 are provided with the usual connections for liquid to be treated and for regeueratlon liquids, respectively (not shown). A pipe 128, provided with a valve 129 and a pump 130 is connected to and extends from the reactor 127 to the regenerator 131. A pipe 132 provided with a valve 134 is connected to and extends from the regenerator 131 to the storage tank llO. The storage tank llO contains liquid and a body of regenerated granular liquid treating material lll, and is provided with an air vent 135, and an underdraln comprising a distributor I14 imbedded in a gravel subfill ll3 and connected with a valved drain ll5.

At the bottom of the storage tank llO, and extending upwardly into said storage tank llO to a level adjacent to and above the gravel subfill ll3 is a plurality of outlets ll2. These outlets ll2 are connected to a common pipe ll6, provided with a valve llT. At the bottom of the measuring tank ll8 is an underdrain consisting of a collector 123 imbedded in a gravel subfill 122 and connected with a pipe 136 leading to a tee 137 which in turn is connected with a drain pipe 138 provided with a valve 139 and a supply llne 140 provided with a valve l l. At the bottom of said measuring tank ll8 and extending upwardly to a level 133 adjacent to and above the top of the gravel subfill 122 is a plurality of outlets which are connected by a fitting 124 to a pipe 125 provided with a valve 126 and connected to the top of the reactor 127. The pipe ll6 extends downward into the measuring tank 118 to a level ll9 between the top of the gravel subfill 122 and the top of the measuring tank ll8. The measuring tank I18 is adapted to measure out a predetermined quantity of liquid treating material 120 having a volume equal to that of tank ll8 between the levels 133 and llg.

In operation of the apparatus shown in Figure 3, when a substantial portion of the liquid treating material in the r lO reactor 127 has been exhausted it is transferred as a slurry to the regenerator 131 by opening valve 129 and operating pump 130. In the regenerator 131 the liquiŒE treating material is regenerated and rinsed in a conventional manner and then allowed to flow by gravity in the form of a slurry into the storage tank llO where it is added to and comes to rest on top of the body of regenerated liquid treating material lll.

Periodically, a predetermined quantity of liquid treating material is transferred from the storage tank llO through the measuring tank ll8 to the reactor 12T. This is accomplished in the following manner. First, valves I17 and 139 are opened. The liquid treating material now flows as a slurry by gravity through outlets 112 and pipe 116 into the measuring tank 118 where it settles on the gravel subfill 122, the excess liquid draining off through collector 123 and pipes 136 and 138. As soon as the liquid treating material has reached the level 119 its flow stops automatically because the liquid treating material flowing as a slurry will not rise above the level 119 at which the end of pipe 116 is located. Thus, in each such transfer operation, the measuring tank I16 is filled with liquid treating material up to the same level ll9 predetermined by the location of the end of the pipe ll6.

When the liquid treating material 120 in the measuring tank ll8 has thus reached the level llg, valves liT and 139 are closed and valves 126 and l l are opened. Liquid from a suitable source now flows through pipes lhO and 136 into the collector 123 and then upwardly through the gravel subfill 122 into the settled liquid treating material 120. The entering liquid stirs up the lower portion of the material 120 and transforms it into a free flowing slurry which passes through outlets 121, fitting 12 and pipe 125 into the reactor 127. This flow of slurry stops automatically when all liquid treating material i iÚ E ï V i I r 72 71. 7 6 above the level 133 has been removed from the measuring tank 118. Then valves 126 and 141 are closed.

In this manner a uniform quantity of liquid treating material 120, predetermined by the location of levels 119 and 133, has been transformed from the storage tank II0 to the reactor 127 and such transfer operation is repeated periodically as required.

While I have shown and described several embodiments of my invention as applied to specific types of liquid treating plants, this has been done merely by way of example and not for purposes of limitation. My invention may, of course, also be used for other types of treatment of water and for treatment of other liquids employing a granular liquid treating material which requires periodic regeneration or reconditioning, such as anion exchange material, activated carbon, or granular adsorbent.

Modifications other than those described may be made without departing from the spirit of my invention, and reference is, therefore, made to the following claims for a definition of the scope of my invention.

T}H EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS :

i. A liquid treating apparatus comprising a storage vessel and a measuring tank adjacent to said storage vessel, an intermediate level in said measuring tank defining therein a lower measuring space of predetermined volume substantially smaller than the volume of said storage vessel and a free and unobstructed rising space above said level» a pipe extending from the lower portion of said storage vessel downwardly into said measuring tank and terminating at said level, a transfer outlet pipe leading from said measuring tank to a point of use, a transfer inlet pipe and a drain pipe connected with said measuring tank, and a valve in each of said pipes.

2. In the apparatus of claim i, said point of use being a reactor, a connection from said reactor to said storage vessel, and a valve in said connection.

3. In the apparatus of claim i, a pump in said transfer inlet line, said transfer inlet line being in communication with said storage vessel.

4. A method of treating liquid by contact with granular liquid treating material including the measuring out of successive batches of liquid treating material of equal volume which comprises (a) maintaining a storage zone containing a body of liquid treating material and a receiving zone, maintaining in said receiving zone below a predetermined level therein a measuring space of predetermined volume substantially smaller than the volume of said storage zone, and above said predetermined level therein a free and unobstructed rising space, (b) establishing a flow of fluid slurry consisting of liquid and a batch of liquid treating material from said body from said storage zone to said receiving zone at said predetermined level, settling said fluid slurry in said measuring space while simultaneously draining I 0