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(11) | EP 0 075 027 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 158(3) EPC |
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| (54) | FLUID CIRCUIT FOR TREATMENT DEVICE |
| (57) A fluid circuit in a treatment device in which a treatment liquid (6) in a storage
tank (2) is supplied to a heat exchanger (7) to control its temperature, one part
of the treatment liquid (6) is supplied to a treatment tank (1), and the liquid remaining
in the tank (1) is returned to the storage tank (2) where part of the conduit feeding
the liquid (6) from the tank (2) to the tank (1) is common to that used by the conduit
returning the liquid (6) from the heat exchanger (7) to the tank (2). |
Technical Field
[0001] The present invention relates to a fluid circuit for a photosensitive material treatment device or other treatment devices.
Background Art
[0002] Generally, in conventional photosensitive material treatment device a treatment solution is always recirculated from the reservoir to the treatment tank to regulate the solution temperature even when no material is treated. But in recent years, in view of the oxidation of treatment solution and of power saving, an increasing number of fluid circuits are coming into use, in which the treatment liquid is recirculated through the liquid temperature regulation circuit when no photosensitive materials are being treated. One of such fluid circuits employs solenoid valves in the recirculation circuit which changes over so that when no material is treated the solution is recirculated in the temperature regulation circuit and when the material comes into the treatment tank the treatment liquid is made to flow to the treatment tank. In this type of fluid circuit, however, a pump of large delivery capacity must be operated at all times resulting in not a small power consumption. Further since the pump capacity is large, the solenoid valve is required to have a large orifice. Moreover the system requires one three-way solenoid valve or two two-way solenoid valves. In other fluid circuits, two pumps are used, one dedicated to deliverying the treatment solution through the temperature regulation circuit and the other for deliverying the solution through the treatment tank circuit. This kind of fluid circuit can achieve the object of power saving, but when applied to the treatment device equipped with a cartridge type reservoir intended to facilitate the supply and recovery of the treatment solution, the piping becomes complex and insertion opening on the reservoir becomes large in outer diameter. This makes it impossible to use polyethylene containers available on the market as a cartridge reservoir.
Disclosure of the Invention
[0003] Accomplished in the light of the above drawbacks, the present invention has a primary object to provide a fluid circuit for treatment devices which does not employ solenoid valves and has simple piping and small power consumption.
[0004] To achieve this object the fluid circuit of this invention comprises: a treatment liquid temperature regulating circuit for regulating the temperature of treatment liquid in the reservoir by supplying the liquid by a first pump to a heat exchanger; and a treatment tank circuit in which a second pump with a greater delivery capacity than the first pump supplies the treatment liquid to the treatment tank to treat the material in the tank and the used liquid collected at the bottom of the treatment tank is returned to the treatment liquid reservoir; whereby that part of the delivery pipe of the treatment tank circuit which is located near the reservoir and that part of the return pipe of the treatment liquid temperature regulating circuit which is located near the reservoir are formed by the same pipe.
Brief Description of the Drawings
[0005]
Figure 1 is a cross section showing one embodiment of the fluid circuit for treatment devices according to this invention;
Figure 2 is a schematic diagram showing the flow of fluid through the treatment liquid temperature regulat-- ing circuit when no material is treated; and
Figure 3 is a schematic diagram showing the flow of fluid through the treatment tank circuit when a material is being treated.
Best Mode for Carrying Out the Invention
[0007] Figure 1 is a cross section of a fluid circuit for treatment devices embodying this invention. Figure 2 is a schematic diagram showing the fluid circulation for regulating the temperature when no treatment is performed. Figure 3 is a schematic diagram showing the circulation of treatment solution when treatment is performed. In Figures 1 through 3, reference numeral 1 denotes a treatment tank below which is installed a cartridge type treatment solution reservoir 2 which is communicated with the lower part of the treatment tank 1 through a fluid pipe 3. Denoted 4 is a first pump which sends the treatment solution 6 through a delivery pipe 8 to a heat exchanger 7 from which the liquid is returned to the reservoir 2 through the return pipe 8. Designated 9 is a second pump which has a larger capacity (for instance more than two times greater) than the first pump 4. Reference numeral 10 represents a filter and 11 a spray nozzle. The spray nozzle 11, filter 10, second pump 9 and the reservoir 2 are interconnected by a delivery pipe'12. A part of the delivery pipe 12 located near the reservoir 2 (to the right of the branch point A of Figure 1) and a part of the return pipe 8 located near the reservoir 2 (to the right of the branch point A of Figure 1) are formed with a single and the same pipe. Designated 13 are rollers for feeding material to be treated and 14 a frame for supporting the treatment tank 1. The circuit for regulating the temperature of the treatment solution 6 in the reservoir 2 consists of the first pump 4, the delivery pipe 5, the heat exchanger 7 and the return pipe 8. The treatment tank circuit for supplying the treatment liquid to the treatment tank and returning the used liquid to the reservoir 2 is made up of the second pump 9, filter 10, spray nozzle 11 and delivery pipe 12 and the used liquid recovery pipe 3.
[0008] The operation of the fluid circuit of this invention will be explained in the following. Firstly when no treatment is performed, the treatment solution 6 in the reservoir 2, as shown in Figure 2, is delivered by the first pump 4 to the heat exchanger 7 where it is heated (or temperature-regulated) to a certain temperature, after which the treatment solution is returned through the return pipe 8 to the reservoir 2. In this case the second pump 9 is not operating. Next, as the material to be treated is fed into the treatment tank 1, a sensor not shown detects the material and activates the second pump 9. The second pump 9 has a larger delivery capacity than that of the first pump 4, so that as shown in Figure 3 the treatment liquid 6 delivered from the heat exchanger 7 and the liquid 6 from the reservoir 2 are both drawn by the second pump 9 and after combining together at the branch point A will be passed through the filter 10 into the spray nozzle 11 from which the liquid is sprayed against the material. The treatment solution 6 that was sprayed from the nozzle 11 collects at the bottom of the treatment tank 1 from which it is guided by the used liquid recovery pipe 3 into the reservoir 2.
[0009] The fluid circuit with the above construction has only three pipes inserted into the treatment solution reservoir 2 and these pipes can also be inserted into the openings of a polyethylene container available on the market which therefore can be used as a cartridge tank. When no treatment is being performed, only the first pump which has small delivery capacity is operating and therefore the electric power consumption is kept minimum. The fluid circuit of this invention has another advantage that since no solenoid valve is used the circuit is free from problems associated with the solenoid valve.
[0010] While in the above embodiment the first and second pumps 4, 9 are installed upstream of the heat exchanger 7 and the filter 10, they may of course be installed downstream. The filter 10 may be omitted.
Industrial Applicability
A fluid circuit for treatment devices comprising:
a treatment liquid temperature regulation circuit for regulating the temperature of treatment liquid in the reservoir by supplying the liquid by a first pump to a heat exchanger; and a treatment tank circuit in which a second pump with a greater delivery capacity than the first pump supplies the treatment liquid to the treatment tank to treat the material and the used liquid collected at the bottom of the treatment tank is,returned to the treatment liquid reservoir; whereby that part of the delivery pipe of the treatment tank circuit which is located near the reservoir and that part of the return pipe of the treatment liquid temperature regulating circuit which is located near the reservoir are formed by the same pipe.