JP2574859Y2 - Cavitation test equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cavitation experiment apparatus for examining a flow principle in relation between cavitation of a pump and pump performance, and can be used particularly for training and education in companies and schools.

[0002]

BACKGROUND ART In recent years, chemical plants including petroleum refining and petrochemical industries have become complex and large-scale using various kinds of apparatuses. For this reason, the operator who controls and manages the plant needs to fully understand and acquire pump cavitation and pump performance that are often experienced in an actual plant for plant management. Therefore, there has been a demand for an experimental apparatus that can easily and easily understand the cavitation and pump performance of such a pump in a short time.

[0003]

However, there are only a few such experimental devices for school teaching materials. In this experimental device for teaching materials, the device for pump performance experiment and the device for cavitation experiment are separately provided, and each experiment was performed separately. There is a problem that the behavior experienced in the actual plant cannot be reproduced, and it is not suitable for understanding and learning various behaviors and the like in the actual plant.

An object of the present invention is to provide a cavitation experiment apparatus which can reproduce the same behavior as that of an actual plant and can easily and quickly learn the cavitation of the pump and the performance of the pump.

[0005]

According to the present invention, there is provided a cavitation experiment apparatus comprising: a pressure reducing tank; a pressure reducing means for reducing the pressure in the pressure reducing tank; a pipe connected to the pressure reducing tank;
A pump for circulating a fluid through the piping and the pressure reducing tank, in order to eliminate bubbles in the pressure reducing tank.
Filter is provided, and the pump is operated for measurement on the front
The pump is fixed to the upper surface of a gantry provided with a panel .
A pressure measuring means for measuring a suction pressure and a discharge pressure of the pump, wherein the pressure reducing means is fixed to a lower portion of the gantry;
With a vacuum pump, with the flow rate measuring means for measuring the flow rate of the pipe is found provided on the pipe, said observation means
Is the observation window provided in a part of the pump and
And a stroboscope for observing the inside of the pump .

[0006]

[0007]

In the present invention, when the pressure inside the pressure reducing tank is reduced by the pressure reducing means, the pressure of the piping and the pump connected to the tank is also reduced. Since cavitation is likely to occur due to this reduced pressure, cavitation is generated by operating a pump, and observation is performed by an observation unit. In addition, since a pressure measuring means for measuring the suction and discharge pressures of the pump and a flow rate measuring means for measuring the flow rate are provided, not only can the state of cavitation be observed, but also the pump performance can be tested, and the cavitation state can be measured. The behavior of the actual plant, such as the pump performance, is reproduced, and the understanding can be easily and quickly acquired. At this time, an observation window is formed in a part of the pump so that the inside can be visually recognized, and the inside of the pump can be observed from the observation window using a stroboscope synchronized with the pump rotation speed, etc., so that the cavitation state is clear. Observation is possible. In addition, a filter is provided in the decompression tank to eliminate bubbles generated by the pump, so that water containing bubbles is not sucked into the pump and only cavitation generation by the pump can be tested. Becomes

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIGS. 1, 2 and 3 show a front view, a side view and a plan view of the cavitation experimental apparatus 1 of the present embodiment, and FIG. 4 shows a piping system diagram thereof.

The cavitation experiment apparatus 1 includes a gantry 2 on which various devices required for the experiment are mounted. The gantry 2 has a caster 3 for moving the apparatus 1 and a fixing section for fixing the apparatus 1 in a horizontal state. A level adjusting bolt (not shown) is provided. In addition, a measurement operation panel 4 provided with various instruments, switches, and the like is provided on the front surface of the gantry 2.

The cavitation test apparatus 1 includes two decompression tanks 5 and 6 and a cavitation pump 7. The pump 7 is driven by a motor 7A connected via a drive belt, and is fixed to a position on the upper surface of the gantry 2 where the pump 7 is easily visible. The side surface of the pump 7 is formed of an acrylic plate 7B so that the inside of the pump 7 can be visually recognized. Therefore, an observation window of the pump 7 is formed by the acrylic plate 7B. The discharge side of the pump 7 is connected to the pressure reducing tank 5 by a discharge side pipe 8, and the suction side is connected to the pressure reducing tank 6 by a suction side pipe 9. Further, the pressure reducing tanks 5 and 6 are connected by a pressure reducing tank piping 10.

Each of the pressure reducing tanks 5 and 6 is provided with a level meter 11 for measuring a water level in the tank 5 or 6. In each of the tanks 5 and 6, a filter 12 formed of a wire mesh or the like is disposed. In the filter 12, a pipe on the suction side in each of the tanks 5 and 6, that is, a pipe 8 in the tank 5 and a tank 6 In, the pipe 10 is arranged,
When bubbles are contained in the water supplied to the tanks 5 and 6, the bubbles can be eliminated.

Each of the pressure reducing tanks 5 and 6 has a valve 1.
A vacuum pump 16 as a pressure reducing means is connected via the vacuum pumps 3 and 14 and the vacuum valve 15 so that the pressure in the tanks 5 and 6 can be reduced. Further, between the tanks 5 and 6 and the valves 13 and 14, valves 17 and 18 for opening the inside of the tanks 5 and 6 to the atmosphere are provided.

The vacuum pump 16 is a water-sealed vacuum pump and is driven by a motor 16A. The pump 16 includes a strainer and a valve 19 for supplying water into the pump 16.
Is connected to a water supply pipe 21 provided with a water supply valve 20. The pump 16 is also connected to a drain pipe 22 for draining water. The water supply pipe 21 and the drain pipe 22 are connected to a water supply / drain pipe 24 via a water supply valve 20 and a drain valve 23. The water supply / drainage pipe 24 is connected to each of the pressure reducing tanks 5 and 6 via valves 25 and 26, the discharge side pipe 8, and the suction side pipe 9, so that water can be supplied to and drained from the tanks 5 and 6.

A nozzle 30 and a flow control valve 31 are provided in the pressure reducing tank pipe 10. In the nozzle 30,
A U-tube manometer 32 for measuring the differential pressure of the nozzle 30 is connected. The decompression tank 6 is provided with a thermometer 33 for measuring the water temperature and a compound meter 34 for measuring the suction head of the pump 7.

[0015] A compound gauge 35 and a vacuum gauge 36 for measuring the discharge pressure and the suction pressure of the pump 7 are connected to the pipes 8 and 9 on the discharge side and the suction side of the cavitation pump 7. Moreover, each piping 8-before and behind the decompression tanks 5 and 6
In 10, compound gauges 37, 38, 39, and 40 for measuring pressure losses in the tanks 5 and 6 are provided, respectively. Further, a suction valve 41 and a discharge valve 42 for flow rate verification are provided in the suction side pipe 9 and the pipe 10 between the pressure reducing tanks.
Are provided in a branched manner. That is, in this embodiment, the flow rate is detected by measuring the differential pressure of the nozzle 30 with the manometer 32. In order to verify whether the detected flow rate is correct, water is supplied from the suction valve 41 and the nozzle 30 is supplied. Through the discharge valve 42 to measure the actual flow rate.
The flow rate verification is performed by comparing with the flow rate detected from the differential pressure of 0.

The gantry 2 is provided with a stroboscope 43 for intermittently irradiating light toward the acrylic plate 7B of the pump 7. Further, the measurement operation panel 4 includes a tachometer 44 for measuring the number of revolutions of the pump 7, a voltmeter 45 for measuring the voltage and power of the pump, a wattmeter 46, and switches 47 and 48 for the cavitation pump 7 and the vacuum pump 16. Is provided.

Next, an experimental procedure using such a cavitation experimental apparatus 1 will be described. First, the cavitation observation experiment for observing the cavitation state in the pump 7 is performed by the valves 20, 25, 26, 31 and the valves 13, 14, 17, 18 connected to the vacuum pump 15.
And open valves 19, 23 and valves 41,
Close 42. And from the water supply pipe 21 to each decompression tank 5,
Supply water to 6. The water level in the tanks 5 and 6 is monitored by the level meter 11, and when water is supplied to a height of about 80%, the valves 20, 25 and 26 are closed to terminate the water supply.

Next, the air bleed valve of the pump 7 is opened to evacuate the air inside the pump, and then filled with water. At this time, by rotating the pump 7, air can be removed from the pipes 8, 9, and 10. In addition, water is filled in the pipe of the manometer 32,
Inject mercury. Air release from the pipe of the manometer 32 can be performed by opening the pressure equalizing valve and opening the nozzle cock during operation of the pump 7.

Then, the valves 20 and 19 are opened to supply water to the vacuum pump 16. A predetermined amount of water is constantly supplied to the vacuum pump 16 during operation. Next, the valves 13, 14, 15
Is opened, the valves 17 and 18 are closed, and the vacuum pump 16 is operated to reduce the pressure in the decompression tanks 5 and 6 to a predetermined degree of vacuum, and then the valves 13, 14 and 15 are closed.

The cavitation pump 7 is set to the starting position and the switch 47 is pressed to operate. Motor 7A
The rotation speed of the pump 7 is adjusted to a predetermined rotation speed by the rotation speed adjustment handle 7C. Further, the valve 31 is opened to circulate water. When cavitation occurs with the rotation of the pump 7, the cavitation state is observed by the stroboscope 43 from an observation window provided with the acrylic plate 7A of the pump 7. When the degree of vacuum in the decompression tanks 5 and 6 does not change, the vacuum pump 16 may be stopped.

Along with the observation of the cavitation, the number of revolutions of the cavitation pump 7, suction pressure, discharge pressure, pressure of the pressure reducing tanks 5 and 6, pressure difference of the nozzle 30, water temperature, and the like are measured using various measuring devices. Then, the flow rate, the flow rate in the pump 7, and the cavitation coefficient are calculated from these measurement data, and the cavitation state corresponding to the cavitation coefficient is observed and recorded.

On the other hand, in the pump performance experiment, after supplying water and bleeding air in the same manner as in the cavitation observation experiment, the valve 31 is slightly opened to operate the pump 7.
The discharge pressure, suction pressure, input power, and rotation of the pump 7 when the flow rate is changed by adjusting the opening degree of the valve 31 based on the rotation speed of the pump 7 or when the rotation speed of the pump 7 is changed. The number, the differential pressure and the fluid temperature of the nozzle 30, the pressure of the decompression tank 6, and the water levels of the decompression tanks 5 and 6 are measured using each measuring device. And from these measured data, the flow rate,
Pump total pressure, pump output, pump input, pump efficiency, N
Calculate PSH (effective suction head). The standard pump performance experiment was performed without operating the vacuum pump 16, and the pump performance when the vacuum pump 16 was operating or when cavitation occurred was compared with the pump performance in the standard state. Experiments may be performed.

When the experiment is completed, the cavitation pump 7 is returned to the starting position, the pump 7 is stopped, and the piping system and the pumps 7, 16 are drained as necessary.

According to the present embodiment, a cavitation observation experiment and a pump performance experiment can be performed by one cavitation experiment apparatus 1. For this reason, it is possible to perform experiments more efficiently than in the case where each experiment is performed by a separate device, and to perform a pump performance experiment in a state equivalent to the actual plant such as pump performance in a cavitation state. Can easily and quickly learn the pump cavitation state and pump performance experienced in

In the cavitation experiment apparatus 1, the equipment necessary for the experiment is arranged on the gantry 2, thereby saving space. In addition, since the assembly work such as connection of each equipment is not required in the experiment, the experiment is simplified. You can do it too. Furthermore, since the experimental device 1 is provided with the casters 3 and the level adjustment bolts, the experimental device 1 can be used while being moved, and even when the floor or the like is inclined, the experimental device 1 can be used for horizontal experiments. Can also. Therefore, the laboratory can be used more effectively, and accurate experimental results can be obtained.

Furthermore, since the pump 7 is fixed to the upper surface of the gantry 2 and the observation window made of the acrylic plate 7B is provided so as to be easily visible, each experimenter can easily observe the cavitation state even if there are many experimenters. be able to. Further, since the stroboscope 43 for intermittently applying light corresponding to the rotation speed of the pump 7 is provided, the cavitation state can be clearly observed even when the pump 7 is rotating at high speed.

The filter 12 is provided in the decompression tanks 5 and 6.
Is provided to eliminate bubbles generated in the cavitation pump 7, so that even when water is circulated by the pump 7, water without bubbles can be sucked into the pump 7. For this reason, since cavitation is generated only by the rotation of the pump 7, a cavitation observation experiment can be accurately performed.

Further, the flow rate in the pipe 10 can be easily detected by measuring the differential pressure of the nozzle 30 with the manometer 32, and the suction valve 41 and the discharge valve 41 are provided so that the nozzle 30 can be verified by the gravimetric method. Since 42 is provided, an accurate flow rate can always be measured, and the experiment can be performed with high accuracy also from this point.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved. For example, in the above embodiment, two decompression tanks 5 and 6 were provided,
Only one decompression tank may be provided. However, if two decompression tanks 5 and 6 are provided, defoaming can be performed even in the second tank 6. Therefore, cavitation-generating materials such as wings are provided between the tanks 5 and 6, and other than the pump 7. There is an advantage that the cavitation generation state of the object can be observed. Also, the pump 7 can be replaced,
By preparing various types of pumps and replacing them sequentially,
The difference in the cavitation generation state of each pump may be observed.

Further, the flow rate measurement is not limited to the one using the nozzle 30 and the manometer 32 as in the above-described embodiment, but may use an appropriate flow rate detecting means. Further, as the pressure detecting means for detecting the pressures of the pump 7 and the pressure reducing tanks 5 and 6, an appropriate pressure detecting means may be used. Further, the depressurizing means is not limited to the water-sealed vacuum pump 15 of the above embodiment, but an appropriate depressurizing means may be used. Further, a computer which can process measurement data by using a computer as the flow rate detecting means and the pressure detecting means may be used. Also, the computer or the like may control each device of the cavitation experiment apparatus so that automatic measurement can be performed.

[0031]

According to the cavitation experiment apparatus of the present invention, it is possible to reproduce the same behavior as that of an actual plant and to learn the cavitation of the pump and the performance of the pump easily and in a short time.

[Brief description of the drawings]

FIG. 1 is a front view showing a cavitation test apparatus according to an embodiment of the present invention.

FIG. 2 is a side view showing the cavitation test apparatus of the present embodiment.

FIG. 3 is a plan view showing the cavitation test apparatus of the present embodiment.

FIG. 4 is a piping diagram of the cavitation test apparatus of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cavitation experiment apparatus 2 Stand 4 Measurement operation panel 5, 6 Decompression tank 7 Cavitation pump 7B Acrylic plate 8 Discharge side pipe 9 Suction side pipe 10 Pipe between decompression tanks 12 Filter 16 Vacuum pump 30 Nozzle 32 Manometer 34, 35, 37, 38 , 39,40 Compound gauge 36 Vacuum gauge 43 Stroboscope

──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiichi Shinbayashi 26, Anesaki Beach, Ichihara-shi, Chiba Idemitsu Kosan Co., Ltd. Incorporated (72) Inventor Etsushi Kajita 2-11-5 Kugahara, Ota-ku, Tokyo Tokyo Meter Co., Ltd. (56) References Japanese Utility Model Sho-57-83289 (JP, U) (58) Fields surveyed (58) Int.Cl. ⁶ , DB name) F04B 51/00 F04B 11/00 F04D 29/66

Claims (1)

(57) [Scope of request for utility model registration] A pressure reducing tank, pressure reducing means for reducing the pressure in the pressure reducing tank, a pipe connected to the pressure reducing tank,
A pump for circulating fluid through the piping and the pressure reducing tank, and a filter for eliminating bubbles is provided in the pressure reducing tank.
The pump is provided on the top of a gantry having a measurement operation panel on the front.
The pump is provided with observation means for observing the internal cavitation state, and pressure measurement means for measuring the suction pressure and discharge pressure of the pump, and the pressure reduction means is a vacuum pump fixed to the lower part of the gantry. Equipment
For example, with the flow rate measuring means for measuring the flow rate of the pipe is <br/> et al provided in the pipe, it said observation means includes an observation window provided at a part of the pump this
A stroboscope for observing the inside of the pump from the observation window
Cavitation experimental apparatus characterized in that it comprises.