JPH0434083B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tank-stored liquid measuring device for measuring the liquid level, temperature, density, etc. of a tank-stored liquid.

For measuring physical quantities such as the height, temperature, and density of liquid stored in this type of tank,
US Pat. No. 4,056,887 is widely known. Also,
A product based on this U.S. patent was sold by Scientific Instruments, Inc., the holder of the patent, as the 6280LTD device.
The device was published in the Japanese magazine "Oil and Petrochemicals"
It is described in detail in VoL24, No. 10 (1980), pages 54 to 60, in the explanation of ``Advances in technology for measuring liquid level, temperature, and density for LNG tanks.''

This conventional example uses two probe guide support cables connected to a weight, and the liquid level, temperature, density, etc. that moves up and down within the stored liquid while being guided along these two probe guide support cables. It consists of a probe with measurement functions, a drive mechanism with a support drive cable that moves the probe up and down, and a digital display section that displays measured values.

By the way, in this conventional measuring device,
In terms of safety, the following major problems arose. In other words, (1) When the two probe guide support cables are lowered to the bottom of the tank by the gravity of the weights, the weights hit the bottom of the tank violently and locally strike the bottom of the tank in a state close to a so-called collision. This caused the inconvenience of damaging the bottom of the tank.

(2) a drive mechanism that moves the support drive cable connected to the probe up and down by forward and reverse rotation of the roll;
Since the electrical connection to the digital display section that displays measured values is done through a slip connection, operation becomes unstable due to damage and abrasion, as well as explosion-proof hazards and inconveniences such as sparks. Ta.

This invention was made by focusing on the points mentioned above, and its first feature is that the weight is vertically divided into two parts, and when the weight hanging downward lands on the bottom of the tank, The system detects a change in the tension of the probe guide support cable and immediately stops the descending motion of the cable to prevent the landing phenomenon of the weight hitting the ground. The cables are incorporated as a plurality of cables connected between each roll of a plurality of roll groups of two or more stages, and a spring that gradually reduces the amount of rotation of the roll group and expands and contracts in a linear direction in the final stage roll. An object of the present invention is to provide a measuring device for liquid stored in a tank, characterized in that it is non-sliply connected to a digital display section for measuring values that is connected to a mechanism and works by electrical connection.

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

Reference numeral 1 denotes a weight, which is vertically divided into two halves 1a and 1b, and connected by a required number of strings 2 at intervals. 3 is a frame attached to the upper weight 1b and pulley 4
Equipped with. Reference numerals 5 and 5 denote probe guide support cables, and one end of the guide cables 5 and 5 is connected from inside the connecting pipe 7 via guide rolls 10 and 10 of the tension detection mechanism 9 of the operation housing 8 provided above the tank 6. Winding drum 1 via rolls 11, 11
2 and 12, respectively. The other ends of the guide cables 5, 5 are passed through guide tubes 21, 21, which will be described later, and are wound around the pulley 4 a plurality of times.

By the way, the tension detection mechanism 9
The guide rolls 10, 10 are fixed to one end of a lever 14 supported by a coaxial shaft 15, and the other end is
A coil spring 16 corresponding to the weight of the weight 1 is attached, and a tension detector 17 is provided to detect changes in the tension of the coil spring 16.

18 is a drive shaft for the winding drums 12, 12;
9 is a drive motor.

First, we will discuss the action of the above structure when the weight descends.

When the weight 1 initially located in the connecting pipe 7 of the tank 6 receives an operation to lower the weight, the drive motor 19 is activated and rotates the drive shaft 18 to rotate the winding drums 12,1.
2 in the unwinding direction.

The probe guide support cable 5 wound around the winding drums 12, 12 is connected to the intermediary rolls 11, 11.
The weight 1 is then sent out one after another through the guide rolls 10, 10, and the weight 1 also gradually descends in accordance with the action thereof. Here, the plurality of rolls including the guide rolls 10, 10, intermediary rolls 11, 11, etc. are referred to as a plurality of first guide rolls.

By the way, from when the weight 1 begins to descend until it reaches the level of the stored liquid, the guide rolls 10, 10 of the tension detection mechanism 9 are equipped with a lever 14 supported by a fulcrum 13 to receive the weight of the weight 1. The maximum tension is acting on the coil spring 16 through the coil spring 16, but in the process of the weight 1 first descending into the stored liquid, the lever 14 moves in the direction of the solid line arrow about the fulcrum 13. Rotates slightly.

When the divided weight 1a on the lower side of the weight 1 lands on the bottom of the tank, the guide roll 10,
The tension that was acting on 10 is weakened, so the lever 14
rotates around the fulcrum 13 in the direction of the solid line arrow,
Since the displacement is reliably detected by the tension detector 17, the drive motor 18 is stopped and the upper weight 1b is suspended via the string 2, and the upper weight 1b is in a landed state. The probe guide support cable 5 stretched by the lower weight 1a is connected to the tank 6.
It can be stably installed vertically within the interior.

Incidentally, in order to lift the weight 1 to the information of the tank 6, it is sufficient to drive and rotate the drive motor 19 in the opposite direction.

Next, the configuration and operation of the drive mechanism of the probe 20 will be described in detail.

21 is a guide tube provided on both sides of the probe 20, through which the probe guide support cable 5 is inserted;
The probe 20 is moved up and down along the cable 5. Reference numeral 22 denotes a support drive cable having a conductive function, with one end tied to the top of the probe 20, and the other end passing through the connecting tube 7, passing through the guide roll 24 of the tension detection mechanism 23 of the operation housing 8, and then being connected to the drive roll 25. Large diameter first winding roll 26
is fixed to. 27 is a pressing roll of the driving roll 25 and has a spring 28. 29 is a first small-diameter roll 30 coaxial with the first winding roll 26; 31 is a large-diameter first auxiliary cable 32 having a conductive function, one end of which is fixed to the first small-diameter roll 29; A second winding roll, 33 is the second winding roll 3
1 and a second small-diameter roll coaxial with 34; 35, a large-diameter third take-up roll fixed to the other end of a second auxiliary cable 36 having a conductive function, one end of which is fixed to the second small-diameter roll 33; and 37, the Third winding roll 35
The third small-diameter roll 39 coaxial with the third small-diameter roll 38 has one end fixed to the third small-diameter roll 37, and the other end of a third auxiliary cable 40 having a conductive function is fixed, using a spring mechanism using a coil spring. Here, the guide roll 24, the drive roll 25, the rolls 26, 31, 3
6, etc. are called a plurality of second guide rolls.

The amount of vertical and reciprocating movement of the support drive cable 22, which connects the probe 20 with the many large diameter rolls, small diameter rolls, and many auxiliary cables mentioned above, is as follows:
It can be reduced by a kind of deceleration rotating drum system, and can be taken out as an extremely small expansion/contraction stroke amount of the final stage spring mechanism 39.

In addition, each cable is directly electrically connected to each roll, so that the electrical signal detected by the probe 20 can be taken out from the third auxiliary cable 40 at the final stage by so-called non-slip coupling.

By the way, the tension detection mechanism 23 has the same configuration as the tension detection mechanism 9 described above, and the guide roll 24 is fixed by a shaft 43 to one end of a lever 42 supported by a fulcrum 41, and the other end has the following: A coil spring 44 corresponding to the weight of the probe 20 is attached, and a tension detector 45 is provided to detect the tension of the support drive cable 22 by detecting the displacement of the lever 42.

46 is a motor for lowering the support drive cable 22 and is provided on the drive shaft 47 of the drive roll 25. 48
A cable winding motor is connected to the first winding roll 26 via a drive shaft 49 and a reduction gear mechanism 50. 51 is a measurement display section.

Based on the above configuration, the vertical movement of the probe 20 will be described.

Note that this probe 20 is equipped with a sensor that measures the liquid level, a sensor that measures temperature, a sensor that measures density, etc. that can measure various physical properties of the stored liquid, and the measured values are transmitted through the cable. It is designed so that it can be electrically displayed on the measurement display section 51 via.

The probe 20 guided by the probe guide support cable 5 descends within the tank 6 under the action of the lowering motor 46, and reaches above the frame 3 of the weight 1 at the bottom of the tank from the level of the stored liquid.

When the probe 20 lands on the frame 3, the tension acting on the cable 22 decreases, so the tension detection mechanism 23 sensitively detects the change, and the tension detector 45 operates to stop driving the lowering motor 46. do. Next, when the cable winding motor 48 operates, the first winding roll 26 performs a winding action and pulls up the cable 22 via the drive shaft 49 and the deceleration mechanism 50, so that the probe 20 rises in the stored liquid. Therefore, the temperature, density, etc. inside the liquid can be measured during the rising process. When the probe 20 reaches the surface of the stored liquid, the tension acting on the cable 22 changes, so the tension detection mechanism 23 operates the tension detector 45 via the lever 42 according to the change in tension. The drive of the cable winding motor 48 is stopped.

In this way, the probe 20 can be moved up and down within the storage liquid.

In addition, the cables 22, 32, which are connected in multiple stages,
36 and 40 are directly connected without slipping by a combination of a large-diameter roll and a small-diameter roll, and the amount of movement of each cable gradually decreases in sequence, and is tensioned by a spring mechanism 39, so that the cable can be moved forward or backward. No relaxation occurs regardless of movement.

Incidentally, the lowering motor 46 and the hoisting motor 48 can be easily driven by a normal control mechanism (not shown) provided in the operation housing 8, and the display section 50 can also display digital or analog display as desired. .

In the figure, reference numeral 51 denotes a known feeding mechanism provided to ensure the alignment of the cables wound around each roll, and is also provided on the rolls 12, 12, although not shown. 52 is an air brake, 53 is a clutch, 54 is a torque tender, 5
5 is a rotation detector, and 56 is a gate provided on the connecting pipe 7.

As described above, by constantly detecting the minimum value of the tension acting on the guide cable and the support drive cable, equipment failures resulting from cable breakage can be detected early, and equipment safety can be ensured. It has the effect of achieving

In addition, we connected the weight divided into two halves with a string and suspended it with a guide cable.
With a simple configuration, a weight can be placed on the tank floor. The guide cable can be stabilized. Furthermore, the support drive cable for the probe guided by the guide provided on the guide support cable was divided into two or more cables, and they were directly connected to each other in a non-slip configuration using a plurality of decelerated roll configurations.
The electrical signal detected by the probe can be safely and reliably transmitted by converting the large displacement of the vertically moving probe into a small displacement on the auxiliary cable side.

[Brief explanation of drawings]

FIG. 1 is an explanatory cross-sectional view of the main parts of an embodiment of the tank-stored liquid measuring device according to the present invention, FIG. 2 is an explanatory plan view of the inside of the same operation case, and FIG. FIG. 3 is a side view of a main part. 1...It is vertically divided into two parts 1a and 1b, and the string 2
Weight connected with 5... Probe guide support cable, 6... Tank, 8... Operation housing, 9, 23
...Tension detection mechanism, 14, 42...Rice lever, 17, 45...Tension detector, 20...
Probe, 22... Support drive cable, 26...
First winding roll, 29...First small diameter roll, 32
...First auxiliary cable, 39...Spring mechanism, 51
...Measurement display section.

Claims (1)

[Claims] 1. A guide support cable with a weight wrapped around the tip,
Driven by a motor in a housing placed on the roof of the storage tank, a support drive cable with a probe fixed to the tip for measuring physical quantities such as liquid level, temperature, density, etc. is guided inside the tank by a drive mechanism along the guide support cable. In a device that measures the physical quantity of liquid stored in a tank by moving the weight up and down, the weight is divided into upper and lower halves, the halves of the weight are connected vertically with a string, and the upper weight is It is suspended by a frame body, a pulley is rotatably attached to the frame body, one end of the guide support cable is wound and fixed to a winding drum via a plurality of first guide rolls, and the other end is attached to the pulley. the winding drum is connected to a drive shaft of a motor, a tension detection mechanism for the guide and support cable is attached to the first guide roll position of the plurality of first guide rolls, and the probe is attached to one end of the support. The other end of the drive cable is attached to a first take-up roll of the plurality of second guide rolls, a tension detection mechanism of the support drive cable is attached to the first guide roll position of the plurality of second guide rolls, and the tension detection mechanism of the support drive cable is attached to the first take-up roll of the plurality of second guide rolls. 1. A measuring device for a liquid stored in a tank, characterized in that the tension of the probe support drive cable and the guide support cable caused by vertical movement of the probe support cable and the guide support cable is constantly detected to drive and control the guide support cable and the support drive cable. 2. A part of the plurality of second guide rolls is configured by combining a stepped drum in multiple stages, each consisting of a large diameter part of the drum for winding the support drive cable and a small diameter part coaxially connected to the drum, and 2. The device for measuring liquid stored in a tank according to claim 1, wherein the amount of movement of the support drive cable on the side of the plurality of second guide rolls is smaller than the amount of movement of the probe.