Sampling and pre-processing device capable of cleaning on line of diaphragm type liquid level meter

Abstract

The invention relates to a diaphragm type liquid level meter. A sampling and pre-processing device capable of cleaning on line of the diaphragm type liquid level meter is mounted between a positive-pressure side sampling valve (5) and a positive-pressure side diaphragm (2) of the diaphragm type liquid level meter; the sampling and pre-processing device comprises a cavity with five end surfaces, wherein threads are arranged on each of a first end surface (101), a second end surface (102), a third end surface (103) and a fifth end surface (105); the first end surface is connected to the sampling valve through a flange; the positive-pressure side diaphragm is mounted on the second end surface through a flange; a cleaning ball valve (4) is mounted on the third end surface (103); a hole, which is equipped with transparent toughened glass, is formed in the fourth end surface (104) as a peep hole (6); the fifth end surface is connected to a dirt collecting tank (3) through an inlet valve (8) of the collecting tank; the bottom of the dirt collecting tank is connected to an outlet valve (8) of the collecting tank; and the fifth end surface is a bottom surface. The sampling and pre-processing device can timely find a fouling state of the diaphragm type liquid level meter, and realizes daily online decontamination.

Description

Technical field [0001] The invention relates to a diaphragm type liquid level gauge, in particular to a diaphragm type liquid level gauge sampling pretreatment device that can be cleaned online. Background technique [0002] Diaphragm level gauges are commonly used in automated inspection processes, such as cooling tower water tanks, water washing cooling towers, air cooling towers, etc. to detect the liquid level of the container 7 being inspected. The diaphragm liquid level gauge 11 calculates the pressure difference between the positive and negative sides by detecting the pressure values ​​of the diaphragms 12 and 13 on the positive and negative sides and sends them to the transmitter 14, and calculates the liquid level of the measured medium according to the liquid density, see figure 1 . Since the positive pressure side diaphragm 2 of the diaphragm level gauge 11 is directly installed on the sampling pipe 15 at the bottom of the container 7 to be tested via the sampling valv...

AI Technical Summary

Problems solved by technology

Since the positive pressure side diaphragm 2 of the diaphragm liquid level gauge 11 is directly installed on the sampling pipeline 15 at the bottom of the detected container 7 through the sampling valve 5, see figure 2 , so it is easy to cause silt fouling, clogging and other phenomena, so that the data detected by the liquid level gauge 11 cannot truly reflect the actual liquid level, resulting in a direct impact on production and equipment. However, cleaning and dredging the sampling pipeline requires dismantling the diaphragm, both The maintenance time is long, and it is easy to damage the diaphragm and damage the equipment

[0003] Since the diaphragm 12 on the positive pressure side of the diaphragm type liquid level gauge 11 must be in direct contact with the liquid at the bottom of the container 7 to transmit pressure, and this part of the liquid in the sampling pipeline 15 is not in circulation, therefore, the liquid in this part of the sampling pipeline It is very easy to deposit various impurities and sludge. The closer to the end of the sampling tube, that is, the end face of the diaphragm on the positive pressure side, the more likely to be clogged. When the clogged pressure cannot be transmitted, the data detected by the liquid level gauge will be wrong. If it is untrue, it will bring misjudgment to the operator and will have serious consequences

[0004] The existing solution is to add a blowdown valve 16 at the bottom of the positive pressure side sampling pipeline 15 end to carry out regular blowdown, see figure 1 , but it cannot effectively solve the problem, the precipitated dirt will completely adhere to the inner wall of the pipe, and it will become thicker and thicker along the inner wall of the pipe, and cannot be released through the blowdown valve 16

Moreover, when carrying out the blowdown operation, part of the liquid pressure on the positive pressure side is released. At this time, the detection value of the liquid level gauge 11 is a false value which is much lower than the actual liquid level. Although frequent blowdown operations can delay the occurrence of blockage, the , the liquid level is out of control every time the sewage is discharged, and the occurrence of clogging cannot be completely prevented under the condition of frequently increasing safety risks

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