US 3857409 A
An aspirating mixing apparatus wherein a first and second component of a given composition is mixed with water in desired proportions and deposited within a first reservoir tank, a third, fourth and fifth component of a particular composition is mixed with water and is deposited in a second reservoir tank, a mixing block is used in each mixing system wherein a plurality of particularly sized orifices are employed and arranged in such a way so as to closely approximate the desired proportions, restricted type of flow control valves are located within the conduits of each of the components so as to adjust the volume flow of the particular component to its mixing block, the mixed liquid of the first mixing block is conducted into the first reservoir, the mixed liquids of the second mixing block are conducted into the second reservoir tank, each of the reservoir tanks include a float, each of the floats being connected to separate solenoid valves, each solenoid valve to control supply of water to its respective said mixing block.
Description (OCR text may contain errors)
United States Patent 91 Dec. 31, 1974 Aubrey et al.
[ LIQUID MIXING APPARATUS  Inventors: William B. Aubrey, 8424 Yolander Ave., Northridge, Calif. 91324; Angelo A. Giordano, 21716 Napa St.; Raymond Giordano, 7815 Vicky Ave., both of Canoga Park, Calif. 91304 221 Filed: Mar. 26, 1973 211 App1.No.:345,004
3/1970 l-lawes, Jr. 137/604 X Primary Examiner-Robert G. Nilson Attorney, Agent, or FirmRobert E. Geauque [5 7] ABSTRACT An aspirating mixing apparatus wherein a first and second component of a given composition is mixed with water in desired proportions and deposited within a first reservoir tank, a third, fourth and fifth component of a particular composition is mixed with water and is deposited in a second reservoir tank, a mixing block is used in each mixing system wherein a plurality of particularly sized orifices are employed and arranged in such a way so as to closely approximate the desired proportions, restricted type of flow control valves are located within the conduits of each of the components so as to adjust the volume flow of the particular component to its mixing block, the mixed liquid of the first mixing block is conducted into the first reservoir, the mixed liquids of the second mixing block are conducted into the second reservoir tank, each of the reservoir tanks include a float, each of the floats being connected to separate solenoid valves, each solenoid valve to control supply of water to its respective said mixing block.
11 Claims, 6 Drawing Figures PATENTED DECS 1 I974 SHEET 2 OF 3 PATENTEDBEBB I 1914 3,857. 409
sum 3 or 54 BACKGROUND OF THE INVENTION All hospitals and most doctors offices have X-ray equipment. X-rays must be developed and it is common for each hospital and doctors office to have an automatic X-ray processor. An X-ray processor is a device which is basically composed of a chemical developer bath and a chemical fixer bath. The undeveloped X-ray film is placed automatically within the developer bath for a certain period of time until the X-ray image is developed. At that time, the X-ray film is moved to the fixer bath where the image is cleared and fixed. The film is then advanced through a wash tank to remove chemical residue and lastly through a dryer section where the film is dried, completing the processing cycle.
The three major components which make up the developer are Part A (hydroquinone and a mild alkali), Part B (acetic acid) and Part C (aldehydes). A common percentage composition by volume of working developer solution is 25 percent of Part A, percent of Part B, 5 percent of Part C and 65 percent water. Component make-up, number of parts, and relative volumes of each may vary slightly according to brand of chemistry used.
An example make-up of the fixer is an ammonium thiosulfate (Part A) composition and a tannic acid composition (Part B). The desired volumetric breakdown of the fixer composition is about 25 percent Part A, about percent Part B, and 65 percent water. This fixer also may change slightly in composition and relative volume according to brand of chemistry used. The mixing apparatus has structure to make it compatible with all major chemistry suppliers.
As an X-ray film is developed, a portion of the chemicals are used requiring that additional chemicals be resupplied to maintain chemical strength before the insertion of another film. The same is true for the fixer solution. In actual practice for a normal size of X-ray film (14 by 17 inches), it has been found that as each film is developed, the fixer must be replenished with approximately 1 10 cubic centimeters of new fixer solution, with the developer bath to be replenished with approximately 65 cubic centimeters of new developing solution. Volumes may vary slightly as per chemical brand requirements and number of films processed per unit of time, type of processor used and type of film being developed.
Previous to this invention it has been known to manually mix a quantity of replenishing fixer solution and developer solution in separate large drums. A pump is connected to the developer bath and a pump is connected to the fixer bath in the normal X-ray processor. When a film is placed within the processor, a switching mechanism is activated which pumps the required amount of fluid into the particular bath from its storage tank. In this way the baths are automatically replenished. However, there are certain disadvantages such as it is required to periodically make up the storage solution. Besides the inconvenience of having to make up the solution, the solution tends to neutralize itself in time. The life expectancy is approximated at 2 weeks for the mixed solutions. Further, because a substantial quantity of each solution is used in most instances, a substantial quantity must be made up in each storage drum. Substantial amount of space is required to store such large size drums which contain about two-thirds water by composition.
SUMMARY OF THE INVENTION It is the primary objective of this invention to eliminate the aforementioned problems by eliminating the use of large storage drums and eliminating the need for manually premixing the developer solution and the fixer solution. The apparatus of this invention is composed of a housing which is divided into a first reservoir tank and a second reservoir tank. A discharge line extends from the first reservoir tank to the developer bath pump of the X-ray processor with a discharge line extending from the second reservoir tank to the fixer bath pump. A float is mounted within each of these reservoir tanks and is operatively connected through a rod to, respective solenoid valves. Each solenoid valve has water supplied to it from a conventional water source. Upon activation of one of the valves, water is conducted to a first mixing section and upon activation of the other of the valves, water is to be conducted to a second mixing section.
The first mixing section comprises a block, of plexiglass or the like, which has formed therein a plurality of orifices and conduits. The second mixing section is similarly constructed. The first mixing section divides the water into two separate channels. Also formed within the block is an inlet for ammonium thiosulfate (Part A fixer concentrate) and also an inlet for tannic acid (Part B fixer concentrate). The water is applied under a pressure of approximately 25 pounds per square inch to the water inlet into each of the channels. Within each of the channels is located a venturi. The inlet for the Part A fixer intersects one of the water channels just downstream of its venturi. The inlet for the part B fixer intersects the other of the water channels just downstream of its venturi. The intersection angle of each is to be an acute angle at approximately 45. It is found that when the angle is acute, a greater amount of the concentrate portion is intermixed with the water within its respective water channel. The combined Part A fixer and water is then conducted exteriorly of the mixing section and into the fixer reservoir tank. The same is true for the Part B fixer and its mixed water. A similar mixing arrangement is achieved through the second mixing block with the developer components being deposited into the developer reservoir tank.
The supply conduits for each of the developer components and the fixer components include a flow control valve which permits precise adjustment of the volume of flow of each of these components into its respective mixer section. In this way, precise amount of each component within the final mixer can be closely controlled as per manufacture recommendations.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the apparatus of this invention;
FIG. 2 is a side view of the apparatus of this invention taken along line 2-2 of FIG. 1;
FIG. 3 is a top view of the apparatus of this invention taken along line 33 of FIG. 2;
FIG. 4 is a side view of the apparatus of this invention taken along line 44 of FIG. 3;
FIG. 5 is an exploded isometric view of the developer mixing section showing in more detail the internal orifice arrangement; and
FIG. 6 is a view similar to FIG. 5 but of the fixer mixing section.
DETAILED DESCRIPTION OF THE SHOWN EMBODIMENT Referring particularly to the drawings, there is shown the mixing apparatus 10 of this invention which is basically composed of a housing 12, a first mixing section 14 and a second mixing section 16. The housing 12 is to be constructed of a plurality of vertical walls 18 interposed between a top plate 20 and a bottom plate 22. The vertical walls 18 cooperate between the top 20 and the bottom 22 to form a pair of spaced apart enclosed chambers 24 and 26. The chambers 24 and 26 are to be fluid-tight and capable of retaining a supply of a liquid. The material of construction of the walls 18, plate 20 and bottom 22 are shown to be of a substantially transparent plexiglass material. However, the material of construction could be readily varied, if desired.
Formed within one of the walls 18 and adjacent the bottom 22 and communicating with the chamber 24 is an opening 28. In a similar manner, an opening 30 communicates with the chamber 26. Screw threadingly attached within the opening 28 is a connector 32 and in a similar manner a connector 34 cooperates within the opening 30. A conduit 36 is attached to connector 32 with a conduit 38 being attached to connector 34. The free end (not shown) of the conduit 38 is to extend within the fixer bath of an X-ray processor. The conduit 36 is to extend within the developer bath of the X-ray processor (not shown).
Extending within the chamber 24 is a float 40 and in a similar manner extending within the chamber 26 is a float 42. The floats 40 and 42 are of conventional construction and adapted to float within a liquid having a density similar to water.
Float 40 is screw threadingly attached to a rod 44 with the float 42 being threadingly attached to a rod 46. Rod 44 extends through the top plate 20 and is connected to an actuating arm 48. In a similar manner the rod 46 extends through the top 20 and is connected through a nut to an actuating arm 50. A protective shield 52 surrounds the arm 48 and is fixedly secured to a switch housing 54. In a similar manner a protective shield 56 surrounds the actuating arm 50 and is permanently affixed to a switch housing 58. Within each of the switch housings 54 and 58 is located a conventional electrical switch which is activated upon the float 40 or float 42 being moved downwardly a predetermined distance determined by the level of liquid within its respective chamber 24 or 26. Electrical power is supplied to the switches through an electrical conduit 60 and through a connecting conduit 62 which interconnects switches located within the housings 54 and 58. It is to be understood that the housings 54 and 58 are fixedly mounted upon the top plate 20.
Upon activation of the switch located within the housing 54, a solenoid valve is activated which is located within the solenoid valve housing 64. In a similar manner, if the switch located within housing 58 is activated, a solenoid valve is also activated which is located within the housing 66. Water is to be supplied under pressure through inlet conduit 68 through a T connector 70 to water conduits 72 and 74. The water is supplied in a constant pressure of approximately 25 p.s.i. into conduit 68. However, this pressure could be varied if desired. It is to be understood that there would be a water pressure regulator upstream of conduit 68 adjacent the source, not shown. A typical source could be the water lines within a building.
Conduit 72 connects with the housing 66. Conduit 74 connects with the housing 64. With the valve located within the housing 66 being closed, water is not permitted to pass from conduit 72 through the solenoid valve housing 66 and into conduit 76. In a similar manner, if the solenoid valve within the housing 64 is closed, water is not capable of being conducted from conduit 74 through the housing 64 and into the conduit 78. If the valve located within housing 66 is open, water does pass into conduit 76 through elbow 80 into conduit 82 and into opening 84 formed within the solid block of material 92 which makes up the first mixing section 14. In a similar manner, if the valve located within valve housing 64 is open, water is permitted to pass from con duit 74 into conduit 78 and through elbow 86 into conduit 88 and into opening 90 of the solid block of mate rial 94 which makes up the second mixing section 16.
Within the block 92 the opening 84 connects with a cross opening 96. Normally it is envisioned that the size of the opening 96 will be approximately one-fourth inch in diameter. In each end of the opening 96, a pair of orifices 98 and 100 connect therewith in a transverse manner. The size of orifice 98 is to be envisioned to be l/32 of an inch in diameter with the size of orifice 100 to be l/l6 of an inch in diameter. The reason for the differences in sizes will become more apparent further on in the description. Orifice 98 connects with a larger sized orifice 102 which is envisioned to be sized l/l6 of an inch in diameter. Orifice 100 connects with enlarged orifice 104 which is envisioned to be approximately l/8 of an inch in diameter. Because the water is being forced from an enlarged opening 96 into smaller diametered openings 98 and 100, the velocity of the water increases. Once the water reaches orifices 102 and 104, a decrease in velocity occurs and also a drop in pressure. This drop in pressure tends to create a vacuum at the junction of orifice 98 with orifice 102 and at the junction of orifice 100 with orifice 104. As a result a venturi action is created. At the junction of orifices 98 and 102, a third orifice 106 communicates therewith at a 45 angle. The size of orifice 106 will be approximately l/l6 of an inch for reasons which will be described further on in the specification. At the junction of orifices 100 and 104, a third orifice 108 connects therewith at also a 45 angle. The size of the third orifice is 1/8 of an inch. Orifice 106 connects with conduit 110 with orifice 108 connecting with conduit 112. Conduit 112 connects with opening 114 in the solid plexiglass block 116.
Conduit 110 connects with opening 118 in block 116. Located upon the outer surface of the block 116 is indicia beside each opening 114 and 116 representing a series of numbers from zero to fifteen in each instance. To be located within each opening 114 and 116 is a solid element (normally metal) 120 which tends to be displaced vertically within its respective tapered opening dependent upon the flow of liquid through the opening. As the flow of liquid increases, the greater the vertical displacement of the element 120. The particular numeral of the indicia located which is directly adjacent the element 120 gives an indication of the volumetric flow being conducted into its respective conduit 110 or 112. The amount of flow can be controlled within each opening 114 or 118 by manual adjustment of a restrictor type of valve 122. It is to be understood that there will be a valve 122 for each opening 114 and 118. Fluid will be supplied to the valve 122 through supply conduits 124 and 126. Conduit 124 will supply fluid into opening 114 with conduit 126 supplying fluid into opening 118. It is envisioned that conduit 112 will supply Part A fixer, an ammonium thiosulfate composition, with conduit 110 supplying a tannic acid composition, Part B fixer.
Referring in particular to the first mixer section 14 shown in FIG. 6 of the drawing, the Part A fixer is conducted from conduit 112 into orifice 108. Due to the venturi action at the connection between orifices 100 and 104, Part A fixer is drawn and intermixed with the water passing through orifices 100 and 104. Because of the particular selecting of orifice size, the approximate desired quantity of Part A fixer solution is intermixed with the water. It has been found that with the orifice size shown, the quantity of Part A fixer which is conducted within orifice 104 would be approximately onethird of the total volume of liquid within orifice 104. This resultant mixture is conducted through discharge conduit 128, through a T connector 130 and is deposited within chamber 26.
The Part B fixer which is supplied through conduit 110 is passed into orifice 106 and hence is sucked into orifice 102 due to the venturi action between orifices 98 and 102. Because of the proper selecting of the orifice sizes, the amount of Part B fixer which is intermixed with water is approximately forty percent within the orifice 102. It is to be noted that the orifice sizes 98, 102 and 106 are substantially smaller in area by a factor of four than orifices 100, 104 and 108. As a result, the volume of fluid which is conducted within orifice 104 is approximately four times the volume of fluid which is conducted within orifice 102. The resultant solution within orifice 102 is conducted into conduit 132 and into T connector 130 and also is deposited within chamber 26. The resultant overall mixture within the chamber 26 should closely approximate percent in volume of Part B fixer, 25 percent in volume of Part A fixer and 65 percent in volume of water (or adjusted as per chemical manufacturers specifications). The precise adjustment of this resultant overall solution can be controlled by manually operating a restrictor valve 122 to control the volume of flow of the solution being conducted through conduits 110 and 112. The volume of water which is being conducted into the apparatus does not vary but is maintained constant as a function of water pressure. It has been found that once the desired adjustment of the valves 122 is accomplished, the correct volumetric flow relationship is maintained within the mixed product located within chamber 26.
It has been found to be necessary to dilute the tannic acid and the sodium thiosulfate prior to intermixing of the two directly together. If the two are mixed directly together, the sulfates will be caused to precipitate out as a solid. This precipitation can be avoided by first diluting the tannic acid and then depositing such in the chamber 26, and also diluting the Part A fixer and supplying such in the chamber 26. After they have been diluted and then intermixed within chamber 26, there is no precipitate formed.
Referring particularly to the second mixing section 16, you will note that there is no problem of any precipitate being formed and therefore direct intermixing of all the components is accomplished. The water is supplied through conduit 88 into opening and into restricted orifice 134 of H16 inch in diameter. Orifice 134 connects with enlarged orifice 136 of H8 inch in diameter. The same venturi phenomenon is created at the junction of the orifices 134 and 136.
Intersecting adjacent this junction at a 45 angle is an orifice which is also 1/8 of an inch in diameter. Orifice 135 communicates with conduit 138 which in turn connects with opening 140 in the block 116. Opening 140 is a tapered opening similar to openings 114 and 118 and also includes an element 120 and a restrictor valve 122. A conduit 142 is to supply an aldehyde solution past the restrictor valve 122, into the opening 140 and into conduit 138. The solution within conduit 138 is then deposited within orifice 135 and is caused to be conducted within orifice 136 and intermixed with water therein.
Connecting at a 90 angle at the junction of the orifices 134 and 136 are orifices 144 and 146. Both orifices 144v and 146 are shown to be 1/ 16 in size in diameter. Another orifice 148 intersects at a right angle with orifice 144 and is also l/l6 inch in diameter. In a similar manner an orifice 150 intersects at a right angle with orifice 146 and is also l/l6 inch in diameter. Orifice 148 connects with conduit 152. Orifice 150 connects with conduit 154. Conduit 152 connects with tapered opening 156 formed within block 116. Conduit 154 connects with tapered opening 158 located within block 116. It is to be understood that each of the openings 156 and 158 has located therebeside it certain indicia to represent the quantity of flow through these openings. Additionally, each of the openings 156 and 158 also includes an element 120 and also a restrictor valve 122. A conduit 159 is to supply an acetic acid solution within the opening 156. A conduit 160 is to supply an activator solution into opening 158. It is to be understood that each of the supply conduits I24, 126, 142, 159 and 160 will be connected to appropriate sources of supply which will normally be located in a 1 gallon container, a 5 gallon container or a 20 gallon container.
Referring particularly to FIG. 5 of the drawings, the overall mixture which is produced within the orifice 136 will be conducted to discharge conduit 162 and into chamber 24. Because the orifice 135 is located at a 45 angle with respect to the water orifice 134 and orifice 136 is larger than the water orifice, it has been found that approximately 25 percent by volume of the aldehyde solution will be produced with respect to the overall volume of solution. Because the solution being conducted through orifices 144 and 146 are at a right angle with respect to orifice 134 and are also the same size as orifice 134, it has been found that approximately 5 percent in volume of each solution as compared to the overall solution will be conducted within orifice 136. Therefore, the overall volumetric relationship of the solution being deposited within chamber 24 will be approximately 25 percent aldehyde solution, approximately 5 percent acetic acid solution, approximately 5 percent activator solution and approximately 65 percent water. Again, the final adjustment of the activator solution, the acetic acid solution and the aldehyde solution is accomplished through its particular restrictor valve 122 associated with its respective tapered opening. Final ratios are to be determined from chemical manufacturers specifications.
It is readily apparent that the operation of the apparatus of this invention is to install such in combination with an X-ray processing apparatus. The appropriate lines are connected and electrical power is transmitted to the solenoid valves located within solenoid valve housings 64 and 66. During the time of initial activation, the setting of the restrictor valve 122 is accomplished to achieve the desired amount of flow through each of the tapered openings of the particular solution being passed through that opening. Once established, there should be no need to change this setting.
As each film is processed within the film processor and the appropriate pump is activated within the film processor to replenish the particular bath, the fluid will be pumped from each of the chambers 24 and 26. When the fluid within these chambers reaches a sufficiently low level, the respective float 40 or 42 will cause activation of its respective float switch located within either housing 54 or 58. Once the respective switch is activated, the respective solenoids located within the solenoid housing 64 or 66 is activated. Upon activation of its respective solenoid, the water is to be supplied to its respective mixing block 16 or 14. As a result, as was previously described, the desired mixture would then be produced and supplied within its appropriate chamber 24, 26 to replenish the loss of solution within the particular chamber. It is envisioned that in most instances one chamber will be replenished while the other chamber is not being replenished. This is due to the fact that with the developing of each X-ray plate, only approximately 65 cubic centimeters of developer solution is used where approximately 110 cubic centimeters of fixer solution is used.
It is considered to be within the scope of this invention to employ other means in order to determine the level of the fluid within the fixer reservoir tank or the developer reservoir tank. For example, the floats 40 and 42 need not be connected to their respective rods 44 and 46. The floats 40 and 42 could include a permanent magnet attached to the upper surface of each of the floats. The rods 44 and 46 would be eliminated as well as the actuating arms 48 and 50 with the mechanical switches within the housings 54 and 58 also being eliminated. A magnetic proximity sensor would be mounted within the housings 54 and 58 directly above their respective float. Once the float reaches the predetermined lower level, the magnetic proximity sensor will be activated causing admission of water through its respective valve.
It is also considered to be within the scope of this invention to employ an electrical probe arrangement which extends down into each of the reservoir tanks. Since each of the fluids within each of the tanks is capable of carrying a small electric current, upon the current reaching a predetermined level based on the level of fluid within its respective tank, a switch is activated. The switches would be located in the respective housings 54, 58.
It is further considered to be within the scope of this invention to supply both the fixer solution and the developer solution directly into the X-ray processor. When such an arrangement is employed and the film is put within the processor, the respective valve is actuated for the particular type of fluid for a certain period of time for which it is known that the desired quantities of particular fluids will be supplied. In this arrangement, there is no requirement for any reservoir tanks or the use of any replenisher pump.
What is claimed is:
1. A liquid mixing apparatus comprising:
a first mixing section and a second mixing section, each of said mixing sections being mounted upon said housing;
said first mixing section having a first inlet and a second inlet and a water inlet, said first mixing section having first means to intermix the liquid of said first inlet with a portion of said water and conduct such into a first conduit, said first mixing section having second means to intermix the liquid of said second inlet with a portion of said water and conduct such into a second conduit, both said first conduit and said second conduit extend exteriorly of said first mixing section and deposit both the respective liquids into a first reservoir tank;
said second mixing section having a third inlet and a fourth inlet and a fifth inlet and a water inlet, said second mixing section having third means to intermix said water and the liquids of said third, fourth and fifth inlets and conduct such into a third conduit, said third conduit extends exteriorly of said second mixing section and deposits its liquid into a second reservoir tank; and
means for separately removing the liquids from said first and said second reservoir tanks.
2. Apparatus as defined in claim 1 wherein:
both said first mixing section and said second mixing section comprising a solid block of material having a plurality of conduits formed therein, within said block of said first mixing section said water inlet being divided into a pair of spaced apart water conduits, one of said water conduits being located adjacent said first inlet and the other of said water conduits being located adjacent said second inlet, the angular spacing between said first inlet and its respective said water conduit being an acute angle, the angular spacing between said second inlet and its respective said water conduit being an acute angle.
3. Apparatus as defined in claim 2 wherein:
each of said acute angles comprising substantially 4. Apparatus as defined in claim 2 wherein:
each of said water conduits including a venturi, said first inlet intersecting its respective said water conduit just downstream of its respective said venturi, said second inlet intersecting said water conduit just downstream of its respective said venturi, conduits of said third inlet and said fourth inlet and said fifth inlet intersect the water conduit of said second mixing section just downstream of its respective said venturi.
5. Apparatus as defined in claim 4 wherein:
said third inlet being located substantially at a 45 angle with respect to said water inlet, said fourth and fifth inlets being located substantially at a angle with respect to said water inlet.
6. Apparatus as defined in claim 1 wherein:
restrictor valve means to control the flow of liquid into said first, said second, said third, said fourth and said fifth inlets, said restrictor valve means capable of being individually operated for each said inlet so as to individually control the volume of liquid being conducted to said inlet.
7. Apparatus as defined in claim 1 wherein: a first float located within said first reservoir tank, a
second float located within said second reservoir tank, said first float being operatively connected to a first solenoid valve, said second float being operatively connected to a second solenoid valve, upon the level of liquid within either of said reservoir tanks falling below a certain level the movement of said float by gravity causes activation of its respective said solenoid valve, upon said first solenoid valve being activated water is permitted to be conducted into said first mixing section, upon said second solenoid valve being activated water is permitted to be conducted into said second mixing section.
8. A liquid mixing apparatus comprising: a first mixing section and a second mixing section,
said first mixing section having a first inlet and a second inlet and a water inlet, said first mixing section having first means to intermix the liquid of said first inlet with a portion of said water and conduct such into a first conduit, said first mixing section having second means to intermix the liquid of said second inlet with a portion of said water and conduct such into a second conduit;
said second mixing section having at least a third inlet and a water inlet, said second mixing section having a third means to intermix said water and the liquid of said third inlet and conduct such into a third conduit; and
both said first mixing section and said second mixing section each comprise a solid block of material having a plurality of conduits formed therein, within said block of said first mixing section said water inlet being divided into a pair of spaced apart water conduits, one of said water conduits being located adjacent said first inlet and the other of said water conduits being located adjacent said second inlet, the angular spacing between said first inlet and its respective said water conduit being an acute angle, the angular spacing between said second inlet and its respective said water conduit being an acute angle.
9. Apparatus as defined in claim 8 wherein:
each of said acute angles comprising substantially 10. Apparatus as defined in claim 8 wherein:
each of said water conduits including a venturi, said first inlet intersecting its respective said water conduit just donwstream of its respective said venturi, said second inlet intersecting said water conduit just downstream of its respective said venturi.
11. Apparatus as defined in claim 10 wherein:
restrictor valve means to control the flow of liquid into said first, said second and said third inlets, said restrictor valve means capable of being individually operated for each said inlet so as to individually control a volume of liquid being conducted to a