Device for injecting a plurality of liquids into a tank

Abstract: In a device for injecting a plurality of liquids into a tank, a plurality of liquid injecting valves (1,2,3) are connected by their pipe portions to form an extended common pipe which is communicated with one liquid injecting nozzle (5) which is inserted into the tank (4). Further in the device, a cleaning water supplying valve (7) is connected to one end of the extended common pipe to the other end of which the liquid injecting nozzle is coupled, a two-way valve (8) inserted between the liquid injecting nozzle and the extended common pipe, so that the extended common pipe can be connected to a waste liquid outlet when a liquid is to be discharged from the device. Owing to this construction, a plurality of liquids can be injected into the tank simultaneously or successively using only one liquid injecting nozzle.

Description: BACKGROUND OF THE INVENTION This invention relates to a device for injecting liquids into a mixing tank, and more particularly to a liquid injecting device suitable for injecting a plurality of liquids into a mixing tanks in a photo-sensitive material manufacturing industry. In a conventional method of injecting a plurality of liquids into one tank, liquid injecting inlets are provided as many as the number of kinds of liquids to be injected. That is, a number of liquid injecting inlets are provided above the tank, thus lowering the working efficiency. Furthermore, this construction makes it rather difficult to increase the number of liquid injecting inlets. The liquid injecting inlets thus provided obstruct the cleaning of the tank. A device for injecting a plurality of liquids according to the preamble of claim 1, is known from EP-A-0 097 458. This known device is an in-line blender for blending components in the form of liquids and comprises a pipeline, having a plurality of injection points. Each injection point is connected to a set of selector valves, which is connected to a separate source of a liquid. US-A-3 870 233 discloses an electrostatic spray system for spraying multiple colours of material through a single spraying gun. The spraying gun is connected by a plurality of valves to different reservoirs of paint and solvents. It is the object of the present invention to provide a device for injecting a plurality of liquids into a tank, in which it is easy to increase the number of liquid injecting inlets and which allows a cleaning of the device in an efficient way. This object is solved by the subject matter of claim 1. Since the cleaning water supplying valve provided with pipe portions having commonly connectable flanges with the liquid injecting valve is connected to one end of the liquid supplying common pipe the other end of which is coupled to the liquid injecting nozzle, and a two-way valve is provided at the position between the liquid injecting nozzle and the liquid supplying common pipe to discharge a waste liquid after washing from a waste liquid outlet valve in place of the liquid injecting nozzle, the device can be washed for every batch or for finishing supplying every liquid. In injecting a number of kinds of liquids at the same time, it is desirable to make the size of the outlet of the liquid injecting nozzle smaller than that of the liquid injecting valves, to prevent the entrance of air into the common pipe through the liquid supplying inlets, or the flow of a liquid into the inlets through which other liquids are supplied. Each pipe portion of the liquid injecting valves has the inner diameter in the same size and a common flange to comprise to extend the common pipe in the state of being connected. In addition, the valve of each liquid injecting valve system protrudes from the inner wall of the common pipe at the state of injecting a liquid, and the only smooth curved plane of the valve at the state of injecting no liquid so that the inner wall of the extended common pipe by connecting a plurality of liquid injecting valves never prevents other liquids or a cleaning water from flowing. The device thus constructed makes the kind of liquid increase only by connecting the units of some liquid injecting valves or some supplying valves of a cleaning water without increasing the liquid injecting nozzles in the tank. The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Fig. 1 is an explanatory diagram showing the arrangement of an example of a device for injecting a plurality of liquids into a tank Fig. 2 is an explanatory diagram showing the arrangement of another example of the device having a cleaning system according to the invention; and Fig. 3 is a sectional diagram showing a part of the device in which the liquid injecting valves are sanitary valves. DETAILED DESCRIPTION OF THE INVENTION Preferred embodiments of this invention will be described with reference to the accompanying drawings. A first example of a device for injecting a plurality of liquids into a tank as shown in Fig. 1 comprises: three liquid injecting valves 1, 2 and 3 for injecting three different liquid-phase liquids A, B and C, respectively, pipe portions of which are connected to form an extended common pipe 6; and a liquid injecting nozzle 5 which is inserted into a tank 4. Sanitary valves are used as the liquid injecting valves and the pipe portions of each liquid injecting valve are connected to extend the common pipe. With the device thus constructed, a number of kinds of liquids can be injected into the tank through only one liquid injecting nozzle. An example of the device according to the invention is arranged as shown in Fig. 2. That is, the device shown in Fig. 2 is formed by adding a cleaning system to the device shown in Fig. 1 so that a cleaning operation is carried out for every liquid injection. The arrangement and operation of the device shown in Fig. 2 will be described, assuming that three different liquid-phase chemicals A, B and C are to be injected into the tank 4. In the case of injecting the chemical A, a cleaning water supply valve 7, and all the liquid injecting valves 1, 2 and 3 which are provided for the chemicals A, B and C, respectively, are closed, and a two-way valve 8 as shown in Fig. 3 is operated to communicate with the liquid injecting nozzle 5 (its waste liquid outlet valve side being closed). Under this condition, the liquid injecting valve 1 for the chemical A is opened, so that the chemical A is injected into the tank 4 through the liquid injecting nozzle 5. Thereafter, the liquid injecting valve 1 is closed, and the two-way valve 8 is operated to communicate with the waste liquid discharging valve (its liquid injecting nozzle side being closed) not shown, and the cleaning water supply valve 7 is opened. As a result, the cleaning water flows into the extended common pipe 6, thus washing the liquid injecting valves 1, 2 and 3, and the liquid injecting nozzle side of the two-way valve 8 successively, and finally being discharged out of the device through the waste liquid discharging valve. Thereafter, similarly as in the above-described case, the chemicals B and C are injected into the tank, and the piping and the valves are cleaned. In the case where at least two of the chemicals A, B and C are injected simultaneously; for instance, in the case where the chemicals A and B are injected at the same time, the following problem is involved: Let us consider the case where the chemical A is foamable, and the injection of the chemical B is accomplished earlier than that of the chemical A because the quantity of the chemical B is smaller than that of the chemical A. In this case, the injection of the chemical A is continued even after the injection of the chemical B has been ended, and therefore air is caused to flow into the chemical A through the liquid supplying inlet for the chemical B, thus forming lots of bubbles. This difficulty can be eliminated by making the size of the outlet of the liquid injection nozzle 5 smaller than all the liquid injecting valves. With the liquid injection nozzle 5 thus modified, the chemicals A and B are mixed inside the extended common pipe 6; that is, the injections of the chemicals A and B are accomplished at the same time In this operation, no air will be mixed into the chemicals, and accordingly no bubbles are formed. Furthermore, the chemical A will not flow back into the pipe for the chemical B. Thus, a plurality of liquids can be injected into a tank through one liquid injecting nozzle. In the manufacture of a photographic material, it is difficult to predict the number of liquid injecting nozzles to be additionally used because the prescription is often changed or improved; that is, it is necessary to provide a number of liquid injecting nozzles to be additionally used. On the other hand, the device of the invention requires only a few liquid injection nozzles. Thus, with the device of the invention, the number of liquid injecting lines can be increased with ease when necessary. As was described above, with the device of the invention, a number of kinds of liquids can be injected into a tank simultaneously or successively using only one liquid injecting nozzle. Hence, even when the number of kinds of liquids to be injected is increased, the injection of the liquids can be achieved merely by adding liquid injecting valves with the number of liquid supplying inlets maintained unchanged.

Claims: A device for injecting a plurality of liquids into a mixing tank (4) comprising: a liquid injecting nozzle (5) inserted into said tank (4); a plurality of liquid injecting valves (1,2,3) which are provided with pipe portions having a common inner diameter and commonly connectable flanges so that said pipe portions are connected with each other to form an extended common pipe (6), characterized by a cleaning water supplying valve (7) connected to a source of cleaning water and to one end of said extended common pipe (6) to the other end of which said liquid injecting nozzle (5) is coupled; and a two-way valve (8) inserted between said liquid injecting nozzle (5) and said extended common pipe (6), so that said extended common pipe (6) can be connected to a waste liquid discharging valve when a liquid is to be discharged from said device.

Inventors: KABUTA YONEJI C O FUJI PHOTO F, WAKITA RYOZO C O FUJI PHOTO FI, KABUTA, YONEJI, C/O FUJI PHOTO FILM CO., LTD., WAKITA, RYOZO, C/O FUJI PHOTO FILM CO., LTD.
Applicants: FUJI PHOTO FILM CO LTD, FUJI PHOTO FILM CO., LTD.
Application year: 1991
Main classification: B01F15
IPC codes: B01F3, F17D1, G03D3, B01F15, B01F5