JPH0550354U - Fluid circulation bath - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a fluid reflux pump of a fluid reflux type thermostatic bath used in an automatic biochemical analyzer, and is particularly suitable for controlling a fluid flow velocity in a flow path to be constant. Flow rate control of a simple circulating constant temperature bath. [Structure] A reaction tank 100, a heating means 400, a temperature control circuit 420, a cooling means 500, a circulation pump 300, a variable control means 310, and a flow rate setting means 320 are main constituent elements. [Effect] Since there is no change in the discharge amount of the circulation pump due to the difference in the AC power supply frequency, there is no need to change the flow path corresponding to the power supply frequency for each destination, so that the manufacturing process can be unified.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluid circulation pump for a fluid circulation type thermostatic bath, and more particularly to a flow velocity control of a fluid circulation thermostatic bath suitable for controlling a fluid flow velocity in a flow path to be constant.

[0002]

[Prior Art]

 Conventionally, as this type of circulation type constant temperature bath, there is a constant temperature bath of the reaction tank of the biochemical automatic analyzer, and generally, water is used as the fluid, an electric heater is used as the heating means, and Freon is used as the cooling means. AC pumps are used as refrigerators and fluid transfer means using the above refrigerant. Then, the temperature of the water flowing back in the flow path is controlled to a constant temperature by appropriately heating and cooling with a heater and a refrigerator. A circulating pump having a flow rate of about 15 to 20 l / min is used, and a 40 to 50 W condenser type induction motor is used to drive the pump. In a biochemical automatic analyzer using a photometric method generally called a direct photometric method, a translucent container called a photometric cell is placed in the returning constant temperature water and filled in this container. The color of the sample to be measured is measured optically.

At this time, the constant temperature water that is refluxed has a uniform and stable temperature, and even if bubbles or the like are mixed, it adversely affects the photometric result. Therefore, these disturbances are one of the conditions that must be avoided. Is one.

[0004]

[Problems to be solved by the device]

 The prior art described above does not pay much attention to the flow velocity of the liquid circulating in the flow path of the constant temperature bath, and has the following problems.

That is, a change in flow velocity due to a change in flow passage resistance of a flow passage system and a change in flow velocity due to a change in frequency of an AC power source of a circulation pump.

[0006] The change of the flow velocity not only affects the uniformity of the temperature of the circulating constant temperature water and after stabilization, but also may cause the generation of bubbles, which is a very important problem in terms of photometric accuracy.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the circulation pump of the circulation constant temperature bath is changed from an AC power source drive motor to a DC power source drive motor, and the rotation speed of the DC motor can be set in multiple stages from outside the motor. By doing so, the flow velocity of the liquid in the constant temperature bath channel can be controlled in multiple stages and constantly.

This makes it possible to easily optimize the flow rate of the circulating constant-temperature water, has excellent temperature stability and uniformity, and can prevent the generation of bubbles due to turbulent flow or the like.

[0009]

[Action]

 The operation of each technical means will be described using an example of FIG. The reaction tank 100 is a container that forms a part of the flow path, and is filled with constant temperature water. The photometric cell 200 is a container in which the sample 210 to be measured is placed, and the sample in the container is colorimetrically measured by the photometer 600 while being immersed in the constant measuring water in the reaction tank.

The circulation pump 300 is a pump that circulates the constant temperature water 800 in the flow path, and its rotation speed is variable by the speed setting means 320 and the variable speed control means 310, whereby the flow speed of the circulating constant temperature water is optimum. Can be set to speed.

Further, as a modification of FIG. 1, as shown in FIG. 2, the flow velocity is automatically controlled by automatically controlling the pump rotation speed by adding a flow velocity detecting means 900 in the circulation flow path. It can also be configured to be controlled to.

[0012]

【Example】

 An embodiment of the present invention will be described with reference to FIG.

The reaction tank 100 is filled with constant temperature water 800 to keep the temperature of the sample 210 to be measured in the reaction cell 200 constant.

The photometer 600 disperses the amount of light (transmitted light amount) after passing through the measurement cell by the light source lamp 700 into monochromatic light for comparative measurement.

The heating means 400 is a means for heating constant temperature water, and an electric heater is generally used, and ON / OFF is controlled by outputs of the temperature detecting means 410 and the temperature control circuit 410.

The circulation pump 300 is a pump that circulates constant temperature water in the circulation flow path, and is driven by a DC motor. The rotation speed, that is, the flow velocity of the circulating water, is determined by the voltage set by the speed setting means 320 and the variable speed control means 310.

Here, the speed setting means is, for example, a digital signal by a plurality of switches, an analog signal by a variable resistor, or a control signal from a computer. The variable control means changes the voltage applied to the circulation pump drive motor according to the output from the speed setting means to control the circulation speed of the constant temperature water. For example, the inverter type variable control means is a suitable means. . The cooling means 500 cools the circulating water, and can be realized, for example, by passing a part of the flow path through a low temperature part such as cold water.

In this embodiment, the rotation speed setting means of the circulation pump is set so as to obtain the optimum flow velocity in the flow passage, and the optimum flow velocity is obtained. Since there is a difference and the liquid discharge capacity of the pump also differs from one solid to another, the flow velocity may not always be the same even if the rotation speed is specified.

FIG. 2 is a modified example for disregarding the above-mentioned individual differences of the devices, and the difference from the embodiment of FIG. 1 is the fluid detection means 900 for detecting the flow velocity of the constant temperature water in the flow path. Is added, and a feedback signal corresponding to the output is input to the variable control means, whereby the rotation speed of the pump is controlled and the flow velocity is constantly controlled to the set flow velocity.

The other components of FIG. 2 have the same function and operation as those of FIG. 1 described above, and therefore the description thereof will be omitted.

[0021]

[Effect of the device]

 According to the present invention, the number of revolutions of the circulation pump in the circulation constant temperature bath does not change due to the difference in the AC power supply frequency, so that it is not necessary to change the flow path according to the power supply frequency for each destination and the like, and the product can be unified. It will be possible. Further, since the flow velocity can be stabilized, the temperature in the reaction vessel can be made uniform and the effect of preventing bubbles can be improved.

As described above, the effect of the present invention is great in improving the work efficiency and the performance of the constant temperature bath.

[Brief description of drawings]

FIG. 1 is a block diagram of a circulating constant temperature bath according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a modified example of FIG.

[Explanation of symbols]

100 ... Reaction tank, 200 ... Photometric cell, 210 ... Measured sample, 300 ... Circulation pump, 310 ... Variable speed control means,
320 ... Flow velocity setting means, 400 ... Heating means (heater),
410 ... Temperature detecting means, 420 ... Temperature control circuit, 500
... Cooling means, 600 ... Photometer, 700 ... Light source lamp, 8
00 ... Constant temperature water, 900 ... Flow velocity detecting means.

Claims (1)

[Scope of utility model registration request] 1. A flow path is provided with a heating means such as a heater, a cooling means, a temperature detection means for detecting the temperature of a fluid circulating in the flow path, and a fluid transfer means such as a pump. A fluid circulation thermostatic bath characterized in that a variable control pump using an interverter is used as a liquid transfer means in a circulation thermostatic bath in which a liquid having a constant temperature is refluxed.