JPH0220695Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a COD (chemical oxygen demand) measuring device.

Measurement of COD in wastewater is generally required by law.
Although this was done according to the JIS analysis method, it was laborious and time consuming. For this reason, the present applicant first applied for the
No. 36039 (Utility Model No. 57-149453), COD
can be easily and quickly measured, and
We proposed a measuring device that can be made smaller.

In the above measurement device, a large number of arms, for example 36, extend radially from a rotating plate (turntable), and a reaction container containing sample water for COD analysis is removably attached to the tip of each arm. The arm is integrated with the turntable and moves intermittently around the circumference at a constant angle at regular intervals.
If this is installed, move the container at an angle of 10 degrees, inject the test solution into each container during the movement, immerse it in a water bath for 30 minutes, heat it, pull it out of the water bath again, and transfer it to the next COD. are being analyzed continuously.

The above application is a patent application filed in 1973, which is an even earlier application.
-98372 (Japanese Unexamined Patent Publication No. 53-23692), the configuration of attaching the reaction vessel to the conveyance chain shown in this patent application has been improved, and a large number of arms are provided radially across 360 degrees. This COD measurement device has a simple structure and can be made smaller in width and height by attaching a reaction container to the tip of the arm, but there are still points that need to be improved in this earlier application by the applicant. Ta.

That is, the reaction vessel, which is detachably attached to the tip of the arm and moves circumferentially at a certain height, descends a predetermined distance when immersed in the water bath, and rises again when removed from the water bath. . This requires two lifting devices, but after the lifting device stops operating due to a power outage, when the power is restored and it resumes operation, there is a difference between the intermittent rotation of the rotating plate arm and the timing of the lifting device. , there is a risk of the arm colliding with the lifting device.

The present invention has been proposed to solve the above-mentioned problems, and the conventional problems will be specifically explained below with reference to the drawings, followed by a description of the structure improved by the present invention.

Figures 1 to 4 show a COD measurement device according to the prior application, in which 1 is a rotary plate, which is connected to a drive source 2 such as a motor mounted on a base 3 via a shaft 1a, and is horizontally It is supported and rotated intermittently in the circumferential direction. 4 is a predetermined angular interval on the rotary plate 1;
That is, there are 36 arms arranged radially at 10° intervals, each of which has its base end pivotally supported on the rotary plate 1 via a mounting bracket 5 so as to be vertically rotatable.

At the tip of each arm 4, a holding spring piece 6 is attached so as to be able to freely rotate up and down within a predetermined range, for holding the neck of a reaction vessel F, such as a 200ml Erlenmeyer flask, containing sample water for COD measurement. ing.
Reference numeral 7 denotes a stopper fixed to the tip of the arm 1, and the holding spring piece 6 moves up and down within the range regulated by the opening. Reference numeral 8 denotes an inverted U-shaped stopper fitting that restricts the upward movement of each arm 4, and is fixed on the rotary plate 1.

Reference numeral 9 denotes a water bath, which is placed on the base 3 and positioned on the rotation locus of the reaction container F. The water bath 9 is filled with water, and a heater 10 is provided at the bottom to keep the water in the water bath at a temperature of 100°C. 11 is rotating plate 1
an arc-shaped first rail 12 that guides each arm 4 while holding it at a predetermined height at a position other than the position extending in the direction of the water bath 9 when rotating intermittently;
is a second rail that guides each arm 4 while maintaining it at a predetermined height in the direction of the water bath 9; the second rail 12 is provided lower than the height of the first rail 11; Both ends of the rail 12 are slightly overlapped concentrically about the axis 1a.

Reference numerals 13 and 14 indicate first and second lifting devices provided at the overlapping ends of the first and second rails 11 and 12, and each lifting device 13 and 14 supports each arm 4 so as to be able to rise and fall freely. rail parts 13a and 14a,
A threaded portion 13b integral with the rail portions 13a and 14a,
14b, and main body portions 13c, 14c which are attached to support portions 3a, 3b integral with the base 3, have members screwed into threaded portions 13b, 14b, and drive sources for rotating the screwed portions. 52 is the axis 1a
It is a lid member attached to the top of the.

Next, to explain the operation, first, measure an appropriate amount of sample water from the subject (COD cannot be estimated), for example 20ml, 40ml.
ml, 80ml, 200ml capacity reaction containers _F1 to _F3 ,
Add distilled water to each reaction vessel F ₁ to _{F 3} to make a total volume of 100
ml, and adjust the water test. Next, the rotating plate 1 is driven at intervals of 5 minutes by the intermittent drive of the driving source 2.
Rotate in 10° increments. Therefore, the arm 4 slides on the first rail 11, and the reaction vessel _F1 also moves in sequence.
Pause for 5 minutes at the position shown in Figure 1. At this time, the water in the water bath 9 is heated by the heater 10.
It is heated to 100℃, and each automatic pipette 7, 2
1, 25, and 29, a first reagent tank 15 containing a 10% silver nitrate solution, and a sulfuric acid solution (1:
2H ₂ SO ₄ ), a third reagent tank 23 containing N/40 potassium permanganate solution, and a fourth reagent tank 27 containing N/40 sodium oxalate solution. Each reagent is connected to a conduit 16, 20,
24 and 28, each 10 ml is measured. At this position, the reaction vessel F ₁ is supplied with 10 ml of silver nitrate solution from the conduit 16 and then moved to the next position. In this position, reaction vessel F ₁ is supplied with 10 ml of sulfuric acid solution from conduit 20 and 10 ml of potassium permanganate solution from conduit 24, and a first stirring device 34 is inserted into reaction vessel F ₁ . Water and each solution are stirred and mixed.

At this time, the arm 4 that already supports the reaction vessel _F1
is on the rail member 13a of the first lifting device 13, so the rail portion 13a is moved by the drive source of the arm 4.
The arm 4 descends with the
2, the reaction vessel F ₁ is placed on the water bath 9
immersed in it. As shown in Figure 5, the reaction vessel
Before F ₁ is immersed in the water bath 9, the holding spring piece 6 comes into contact with the lower part of the stopper 7, and _{the reaction vessel F 1 is} held in a horizontal position. In this case, the buoyant force applied to the reaction vessel F ₁ causes it to come into contact with the upper part of the stopper 7, and the reaction vessel F ₁ is still maintained in a horizontal position.

After the reaction container F ₁ is transported in the water bath 9 for 30 minutes, the arm 4 supporting the reaction container F ₁ is pushed up onto the rail portion 14a of the second lifting device 14, and soon the arm 4 is moved again to the first rail 1
1 and the reaction vessel F ₁ is also placed on the water bath 9
be raised from. As shown in FIG _. 4, a second stirring device 35,
Conduits 28, 43 and metal electrodes 44 are inserted, and conduit 28 supplies 10 ml of sodium oxalate solution. Further, the motor 39 is switched on by lowering the metal electrode 44, and the potassium permanganate solution in the cylinder 38 is supplied from the conduit 43 to the reaction vessel _F1 , and is stirred and mixed by the second stirring device 35.

The supply of the potassium permanganate solution is continued until the metal electrode 44 senses an increase in the redox potential at the end of the titration of sodium oxalate and potassium permanganate in the solution in the reaction vessel _F1 . That is, at the time of this sensing, a current flows, this current is amplified by the amplifier 47, and the relay 49 is operated by this amplified current.
This causes the motor 39 to stop, the cylinder 38 to stop operating, and the supply of potassium permanganate solution to stop. In addition, the operation of the relay 49 also turns on the arithmetic circuit 50 to automatically calculate the amount of potassium permanganate consumed, that is, the COD.
The COD is indicated by a bar graph by the recorder 51.
The support fitting 42 rises to its original position after a predetermined period of time has elapsed.

The COD of the sample water in reaction vessels F ₂ and F ₃ is also measured in the same manner as above. In this example, the amount of water tested in each reaction vessel F ₁ to F ₃ was changed into three stages.
Among the measured values of COD, measured values within an appropriate range can be adopted.

According to the above device, the base end is pivoted to a rotary plate that is intermittently rotated in the horizontal direction, and each reaction container containing the test water at the tip of a large number of arms arranged radially is intermittently rotated. Since the device is continuously immersed in a water bath and then pulled up, the distance between each container can be reduced, resulting in effects such as miniaturization of the COD measurement device and improvement in measurement efficiency.

However, according to the above COD measuring device, the first
A large number of reaction vessels is provided by the second lifting device 13 and 14.
Although a mechanism is adopted in which F ₁ and F ₂ are continuously immersed in the water bath 9 and pulled up, various troubles may occur when power is restored after a power outage.

In other words, although the proposed COD measuring device automatically performs the process using sequence control, if there is a power outage, all relays are cleared and it becomes impossible to know how far the process has progressed. Therefore, when the power is restored, it is necessary to proceed with a certain predetermined process, for example, by manually switching the process to the starting state, or to remember the process even if the power goes out. . In the method of proceeding with the process using a manual switch, this device has complicated movements, so there is a risk of erroneous operation, which may cause damage to the device.

This will now be explained with reference to FIG. 5 and subsequent figures. In each figure, the symbols ~...〓〓 indicate the positions to which the reaction vessels F... are sequentially moved intermittently. In this case, the rails 11 and 12 are placed on the circumference to support the arm 4 between positions other than the water bath 9, but one rail 12 supports the reaction vessel _F1 within the water bath 9. The water bath 9 is provided at a position slightly lower than the other rail 11 to accommodate the length of the water bath 9.

Therefore, in order to move the reaction vessels F from the position to the position shown in FIG. 6 and from the position to the position shown in FIG.

Analyzing this operation, it can be divided into the following four steps.

Lower from the position of the first step to the position ''. At the same time, raise it from the previous position to the ′ position. For this purpose, lifting devices 13 and 14 are used. At the position , the arm 4 is separated from the rail 11 and rests on the rail portion 13a. next,'
It is still on the rail portion 13a at the position.
At the position ', the arm 4 is still separated from the rail 11 and rests on the rail portion 14a.

2nd process Arm 4 rotates slightly to the left by the drive source,
At this time, the arm 4 that was at the position ' leaves the rail part 13c and rides on the rail 12. Also, the arm 4 that was at the position '
leaves the rail portion 14a and rides on the rail 11.

Third step: The rail portion 13a of the lifting device 13 returns to the position from '', and the rail portion 14a of the lifting device 14 returns to the position from ''.

4th process The arm 4 that was at ``moves to the position'' The arm 4 that was at ``moves to the position'', and at the same time the arm 4 that was at ``moves to'', and the arm that was at '' moves to 9. Above, the first process ~ One movement is completed in the fourth step, and each of these steps is controlled by a limit switch or the like.

However, according to the above steps, there is a problem if there is a power outage between the first step and the fourth step, that is, while the reaction vessel F ₁ ... is being moved to the next fixed position. In other words, when the power is restored after a power outage, conventional limit switches do not memorize the process and start operating from the beginning of the process, which disrupts the operating order of each limit switch.
~ Each of the fourth steps is operated one by one using a manual switch, but there is a risk of malfunction at this time. for example,
If a power outage occurs in the middle of the third process, the operation when the power is restored is that the rail parts 13a, 14a of the lifting devices 13, 14 must be moved from ' to ' to ', respectively, as a continuation of the third process. Must not be. However, if the fourth step is performed before the rail parts 13a and 14a reach the predetermined positions due to a manual malfunction, the arm 4 at ``
Come to the position and stop. Therefore, the lifting device 1
Even if the rail portion 14a of 4 is attempted to be lowered to the position from '', it collides with the arm 4 and cannot be lowered, making it impossible to continue the predetermined operation thereafter.

Furthermore, in some cases, there is a risk of damaging the device. In addition to power outage countermeasures, it is necessary to manually move reaction vessel F for maintenance even during normal times, but at that time, to prevent malfunction,
It must be possible to move it with simple operations.

The present invention solves the above problems and will be explained below with reference to FIG. First, in the present invention, four limit switches 53, 54, 55, 5 are used to detect the upper and lower limit positions of the rail portions 13a, 14a of the first and second lifting devices 13, 14.
6, the first step and the second step are called step A, and the third step and the fourth step are called step B, then a keep relay A (or stepping relay) that stores step A and step B is used. A keep relay B (or stepping relay) is provided to store the memory, so that when the power is restored, the lifting devices 13 and 14 resume operation from the state before the power outage, thereby eliminating the possibility that the timing of the arm 4's operation will be shifted. The keep relays A and B are connected in an electric circuit between the drive motor of the lifting device 13 and the drive motor of the rotary plate 1, and are operated by the keep relays A and B and the limit switches 53, 54, 55, and 56. The order is as shown in Figure 8. Start switch 5
By pressing 2, process A is activated with keep relay A.
(that is, the first step or the second step), and if YES, the limit switch 53 is activated to control the rail portions 13a, 14a of the lifting devices 13 and 14.
It is determined whether the rails 13a and 14a have reached the lower limit position and the upper limit position, respectively, and if the rail parts 13a and 14a are not at the upper limit position or the lower limit position, respectively, they are moved to that position. When the limit switches 53 and 54 determine that the rail portions 13a and 14a of each lifting device 13 and 14 have moved to the lower limit position and upper limit position, respectively, the arm 4 is moved to the position shown in FIG. 6'→''.

As a result, we moved from process A (first process and second process) to process B (third process and fourth process), so
Keep relay A is cleared and keep relay B is made. In response to a signal from keep relay B or a No signal from keep relay A, limit switches 55 and 56 determine whether rail portions 13a and 14a of lifting devices 13 and 14 are at the upper limit position and lower limit position, respectively. If it is at each position, it will output that signal, and if it is not, the rail section 13
a to the upper limit position, and move the rail portion 14a to the lower limit position. Set this position to limit switch 55,5
After the detection at 6, the arm 4 is moved to the position from ''.

As a result of the above, the state returns to the state before the power outage, keep relay A is made again, keep relay B is cleared, and rotary plate 1, arm 4, and lifting devices 13, 1
4 starts working normally and synchronously, and each reaction vessel
Reagents are injected into F ₁ , F _{2 . .} . and automatic COD analysis is performed.

As explained above, according to the present invention, when the power is restored after a power outage during automatic COD analysis while moving a reaction vessel, a keep relay or stepping relay is used to control the lifting device and arm at each step before the power outage. Since the information is stored in memory, there is no need to worry about the switch malfunctioning when the power is restored, unlike in the past, and there is no risk of damage to the equipment. Furthermore, when manually moving the reaction vessel during maintenance, the four steps from the first to the fourth steps can be performed with just one operation switch, eliminating the risk of erroneous operation. As the keep relay or stepping relay, a relatively inexpensive commercial item can be used.

[Brief explanation of drawings]

Figure 1 is an overall explanatory diagram of the COD measuring device according to the present invention, and Figures 2 and 3 are respectively related to the present invention.
A plan view of the reaction vessel transporting device portion of the COD automatic analyzer and a view of the same as seen from the A-O-B line, FIG. 4 is a front view of the vicinity of the second stirring part of the COD automatic analyzer according to the present invention, Fig. 5 is an explanatory diagram showing the movement relationship of the reaction vessels attached to multiple arms in the present invention, Fig. 6 is a side explanatory view showing the relationship between the lifting and lowering of the elevating device and the movement of the arms, and Fig. 7 is a plan view of the same. FIG. 8 is a flowchart explaining the operating sequence of the arm and the lifting device. 1... Rotating plate, 4... Arm, F... Reaction container, 9... Water bath, 11... First rail,
12... Second rail, 13... First lifting device, 1
4...Second lifting device, 13a, 14a...Rail portion, 53-56...Limit switch.

Claims (1)

[Claims for Utility Model Registration] A drive motor is connected to a rotating plate that is driven intermittently,
The base ends of multiple arms to which reaction vessels containing sample water for COD measurement are removably attached are pivoted, a water bath is placed on the rotation trajectory of the reaction vessels, and a water bath is placed at a predetermined position other than the water bath. A first rail is provided for guiding the arm at a position other than the water bath, and a first rail is provided for guiding the arm at a position other than the water bath, in order to inject the reagent, immerse the reaction vessel therein at the front position of the water bath, and pull it up at the rear position of the water bath; A second rail is provided that is lower than the first rail that guides each arm when the reaction container is immersed in a water bath, and a first rail that lowers each arm while supporting each arm as it moves from the first rail to the second rail.
a lifting device; and a second lifting device that supports and raises each arm when it moves from the second rail to the first rail; lowering the arm while supporting it, and lifting the arm from the second rail at the rear position while supporting it with a second elevating device; A step of moving the first arm to the first rail, a step of raising and lowering the first and second lifting devices and returning them to their original positions, and a step of intermittently driving the rotary plate to move the next arm to the second rail using the first and second moving devices. In a COD measurement device that measures COD by a step of moving the COD to a rail and a first rail, each of the first and second lifting devices is provided with a limit switch that detects an upper limit position and a lower limit position,
In addition, the series of steps described above is divided into a plurality of steps, and a keep relay or stepping relay is provided for each step to memorize the step being moved in the event of a power outage, and the relay is used to drive the drive motor of each lifting device and the rotating plate. It is characterized by being inserted into the electric circuit of the motor and incorporated into the sequence control circuit, so that when the power is restored, the sequence control circuit restarts the operation from the memorized process to prevent malfunctions when the power is restored.
COD automatic analyzer.