KR200183853Y1 - Discharge pressure gauge of pumps - Google Patents

Abstract

This paper relates to a pressure gauge for measuring the discharge pressure of various liquid pumps used in water and sewage treatment plants.

The discharge pressure of various liquid pumps has a characteristic that the cycle is very short and the amplitude of the amplitude is large because of mechanical and fluid engineering reasons, and the indicator needle of the pressure gauge vibrates violently, while pumps for sewage or sludge are pumped. In addition to the above pressure fluctuations, the pressure gauge connector was blocked by foreign substances such as sludge, which was very inconvenient to use.This proposal eliminates spike-like seizing force for use in this application. The purpose of the present invention is to provide a pressure gauge which is prevented, and the pressure gauge is provided by installing a flexible pipe in the pump discharge side pipe, connecting an air reservoir at the end thereof, and installing a normal pressure gauge at the upper part of the air reservoir, and forming an air supply port at the upper side of the air reservoir. Supplies compressed air with constant pressure to the air flow meter It can be controlled by a control valve to continuously purge a small amount of air into the pump discharge pipe to prevent clogging caused by foreign substances and to absorb and remove pressure spikes by buffering action in the air cylinder. It is effective to measure the discharge pressure.

Description

Discharge pressure gauge of pumps}

The purpose of the present invention is to prevent the vibration of the pressure gauge needle due to the spike-like liquid pressure fluctuations and mechanical vibration generated at the discharge side pressure of the pump that pumps the liquid in the water / sewage treatment plant. It is to provide a pressure gauge on the discharge side of the pump which prevents the pressure gauge connecting pipe from being clogged by pressure or the like so that the pressure measurement cannot be made or is incorrect.

The present invention relates to the discharge pressure gauge of various liquid and sludge pumps used in water and sewage treatment plants.

Conventionally, a pipe tube pressure gauge or a diaphragm tube pressure gauge which is generally used to measure the discharge pressure of a pump that pumps liquid, sludge, sewage, etc. of the pump is connected to the discharge pipe of the pump using a metal pipe. The pressure gauge described above was installed at the end of the pipe to measure the discharge pressure of the pump.

However, since the discharge pressure of the pump for liquid pressure changes due to hydrodynamic causes and mechanical vibrations, the pressure fluctuates in a spike shape at a very high speed, so that the indicator needle of the pressure gauge has a very large amplitude at a high speed. It vibrated, making it difficult to know the actual pressure on the pump discharge side and causing the pressure gauge to fail. The pressure measuring tube is usually about 10 to 15 mm in diameter and stagnated in a space sealed by a pressure gauge. When used for sewage or sludge, the connecting tube is frequently blocked and the pressure is not measured or inaccurate.

The technical problem of this paper is to install an air tank on the discharge side of the pump for pumping liquid and purge the air to absorb the vibration caused by the pressure fluctuation of the pump discharge side so that the pressure gauge can indicate the correct pressure without vibrating and troubleshoot the pressure gauge. It is to prevent the pressure gauge connector from being clogged by air purge.

1 is an external view showing the configuration of the present invention

2 is a longitudinal sectional view showing a configuration of the present invention;

Explanation of symbols for important parts of the drawings

1.Reservoir Pedestal 1-1.Fixing Screw

2. Flexible Hose 2-1. Hose Connector

3. T-shaped connecting pipe

4. Shut-off valve

5. Reservoir 5-1. Upper air tab 5- 2. Flowmeter base

5-3. Fixing plate

6. Pressure gauge

7. Shut-off valve for pressure gauge 8.

9. Check valve 10. Air purge flow meter 10-1. Flow control knob

11.Air piping 12.Drain valve 13.Air valve

14. Air pressure regulator

Flange single pipe (B) in ordinary pumping equipment consisting of expansion pipe (B), flange single pipe (C), check valve (D), water valve (E), and discharge pipe (B) on the discharge side of pump (A) Weld and attach the connecting socket (2-1) so as to penetrate into the side of the) and connect the flexible flexible hose (2) to it and the T-shaped connecting pipe (3) at the other end of the flexible hose (2). Connect the shut-off valve (4) to the upper part of the T-shaped connecting pipe (3), connect the reservoir (5) with the appropriate capacity to the upper part, and connect the shutoff valve (7) for the pressure gauge to the reservoir (5). The pressure gauges 6 with needles were connected one after the other so that they could all penetrate each other inside.

The reservoir (5) was firmly fixed to the reservoir holder (1) fixed to the bottom by fixing screws (1-1) to secure the position and to prevent movement.

In addition, an air inlet (5-1) is integrally welded and attached to the upper side of the air tank (5), and a check valve (9) and an air purge flow meter (10) are connected and installed in this order. 10) The lower inlet side is connected to the air pipe 11, the air pipe 11 is connected to the shut-off air valve 13 and the air pressure regulator 14, the air pressure regulator 14 is connected to the compressed air supply source Connected.

On the other hand, a drain valve 12 for discharging sludge or the like is provided at the end of the pipe facing downward of the T-shaped connecting pipe 3.

The air purge flowmeter 10 has a flow control knob 10-1 attached thereto, and the air purge flowmeter 10 is screwed to the flowmeter pedestal 5-2 formed integrally with the bottom side outer wall of the air cylinder 5. Fixed so as not to move.

On the other outer wall of the reservoir 5, a fixing support plate 5-3 is formed integrally with the reservoir 5 so that the reservoir 5 can be fixed to the reservoir holder 1.

The pump discharge pressure measuring device works as follows.

First, the air supplied from the air air source (not shown) is lowered to an appropriate pressure in the air pressure regulator 14, and the air of a constant pressure is supplied through the air pipe 11 and the air flow meter. The air flows through the connecting pipe and flows into the flange single pipe (C) on the pump discharge side through the connecting pipe.

When the pump is operated and the discharge-side pipe is filled with liquid, pressure is applied to the pipe, and this pressure causes a very large amplitude spike-like vibration pressure due to hydrodynamic reasons and mechanical vibration. 2) This pressure is transmitted to the reservoir (5) through the flexible hose (2) and the T-shaped connecting pipe (3), but the compressed air is filled in the reservoir (5) so that the liquid from the pump is discharged into the reservoir (5). You cannot enter any more than).

In addition, if the air purge amount is made very small by adjusting the flow control knob 10-1 of the air purge flowmeter 10, the pressure in the air cylinder 5 is equal to the liquid pressure on the pump discharge side (in theory, very little The pressure is high, but in reality it can be ignored.) A small amount of purge air continues to flow into the flange short pipe (c) on the pump discharge side.

In this case, the cross-sectional area of the air cylinder 5 is much smaller than the cross-section of the pressure measuring connection pipe (usually 1/100 or less), so that a very rapid pressure fluctuation on the spike is absorbed and removed from the air layer in the air cylinder 5, and is actually applied to the pump discharge side pipe. Only the pressure of the liquid is displayed on the pressure gauge 6 provided on the reservoir 5, so that the indicator needle of the pressure gauge 6 is stable and can accurately measure the liquid pressure on the pump discharge side without vibrating.

For example, assuming that the pump discharge side pressure is 5 kgf / ㎠ and the pressure fluctuation range is ± 30%, a pressure fluctuation of ± 5 × O.3 = ± 1.5 kgf / ㎠ occurs due to the actual pump pressure. The movable flow rate and flow rate are as follows.

V = 0.7 × (2gh) ^

Where V: flow rate m / s

0.6: Flow coefficient at the inlet of the hose connector (2-1)

g: acceleration of gravity 9.8 m / s ^ 2

h: pressure head; Pump discharge pressure (kgf / ㎠) × 10m

= 0.6 × (2 × 9.8 × 1.5 × 10) ^ = 10.3 m / s

Q = A1 × V = 3.14 × D ^ ² × 12/4

Where Q is the flow rate at the inlet of the hose connector (2-1), ㎥ / s

A1: Pipe cross section of connecting hose, ㎡

D: Diameter of connecting hose, 0.1m

= 3.14 × 0.01 ^ ² × 1O.3 / 4 = 0.00081㎥ / s

If the frequency of the pressure change of the pump discharge pressure is 5 times / s, the flow rate between one cycle of pressure change Q1 = Q / (Pressure change frequency × 2) = O.00081 / 10 = 0.00008 ㎥ / time

If the diameter of the reservoir 5 is 0.15m and the length is 0.3m, the volume of the reservoir 5 is

Va = 3.14 × D ^ ² × L / 4 = 3.14 × 0.15 ^ ² × 0.3 / 4 = O.0053 ㎥

Since air is a compressible fluid, the air in the air cylinder 5 is isothermally compressed and expanded. P1 × v1 = P2 × v2

Where P1 is the actual absolute pressure of the pump (initial absolute pressure); 6 kgf / cm 2

P2: Absolute pressure in the reservoir changed by the movement of liquid

v1: volume of the reservoir; 0.0053㎥

v2: volume of air in the reservoir changed by the movement of the liquid;

0.0053-0.00008 = 0.00522 ㎥

In summary

P2 / P1 = v1 / v2 = 0.0053 / 0.00522 = 1.015 = 101.5%

From the above calculation result, it can be seen that the rate of change of pressure indicated on the pressure gauge is 101.5-100 = 1.5%, that is, the range of fluctuation of the indicated value with respect to the actual pressure is ± 1.5%. The fluctuation range was reduced to 1/20, and the actual indication value was 5 × 1.5 / 100 = 0.075 kgf / ㎠, and the pressure gauge's indication was actually 0.25 mm to 0.5 kgf / ㎠. The value hardly fluctuates and can be said to indicate a constant value.

In addition, the compressed air continuously flows into the pump discharge-side pipe through the pressure measuring connection pipe little by little, so that the connecting pipe for pressure measurement is not blocked and mechanical vibration is caused by the action of the flexible hose (2). Absorbed and blocked in 2), it is not delivered to the pressure gauge.

The drain valve 12 is installed for a preliminary purpose for regular cleaning or inspection and is not prepared for clogging.

In another embodiment, the air valve 13 used in the above embodiment is used as the solenoid valve for a short time periodically by a timer or a program (when the air in the air is dissolved in the liquid and the air layer volume is reduced below a certain amount). By supplying compressed air to the air cylinder 5, a certain air layer is formed in the air cylinder 5, so that the fluctuation of the pump discharge pressure can be absorbed and buffered by the complete action of the air layer (not shown).

In addition, the effect of absorbing and absorbing pressure fluctuations is the same even when the pressure gauge 6 having the indicator needle used in the above embodiment is used as a pressure gauge having an electric transmitter.

The main purpose of this paper is to fill the air in the cylinder 5 which has a relatively large cross section and volume and to absorb and reduce the fluctuation of liquid pressure by using the compressibility of the air. It prevents severe mechanical vibration of the indicator needle by blocking mechanical vibration, so it can measure the correct pressure and prevents vibration of the indicator needle. It prevents the failure of the pressure gauge in advance. Since it flows into the inside, it is possible to prevent the blockage of the pipe such as the pressure gauge connecting hose caused by foreign substances such as sludge, so that the maintenance is easy.

Claims (2)

The pressure measuring hose which is installed on the discharge side of the pump for pumping liquid and integrally fixed to the side of the flange end pipe (C) so as to penetrate therethrough and installed therein (2) and the other end of this hose to the T-shaped tube (3), to the T-shaped tube (3) to the upside of the reservoir (5) and above the reservoir (5) for the pressure gauge The pressure gauge 6 was connected via a shutoff valve 7. The upper side of the reservoir (5) is integrally formed to penetrate the upper air tab (5-1) and connected to the air purge flow meter (10) through a connecting pipe to the flow meter (5) integrally with the reservoir (5) It is fixed not to move to the formed flowmeter support (5-2), and the air reservoir (5) is firmly fixed to the airtight support (1) fixedly installed on the floor with a fixing screw (1-1), and the air purge flowmeter (10) The inlet side of the pump is connected to the air pressure regulator 14 through the air pipe (11) and the discharge pump of the pump characterized in that the flow control knob (10-1) is attached to the air purge flowmeter 10 is adjustable Pressure measuring device. An apparatus for measuring the discharge pressure of a pump according to claim 1, wherein the compressed air is periodically supplied by a timer or the like by using the air valve as the solenoid valve.