Membrane protection system

Abstract

The invention belongs to the technical field of membrane protection of a membrane pump and particularly relates to a membrane protection system. The invention provides the membrane protection system which can be operated stably and reliably and has a long service life. The membrane protection system comprises a rubber membrane, wherein the rubber membrane comprises an iron core; and the iron core is connected with the rubber membrane by a guided transverse metal non-magnetic guide rod. The membrane protection system is structurally characterized in that a permanent magnet is mounted on the non-magnetic guide rod; magnetic signal sensors are arranged corresponding to a transverse movement track of the permanent magnet; signal output ports of the magnetic signal sensors are connected with a signal input port of a PLC (Programmable Logic Controller); an oil supplementing and discharging signal output port of the PLC is connected with a control signal input port of an oil supplementing and discharging part of a membrane chamber; and the two magnetic signal sensors are arranged along the transverse direction of the membrane chamber.

Description

technical field [0001] The invention belongs to the technical field of diaphragm protection of diaphragm pumps, and in particular relates to a diaphragm protection system. Background technique [0002] Diaphragm pump, as a commonly used pipeline conveying equipment in the industrial field, has been widely used in solid-liquid two-phase medium conveying occasions due to its high conveying pressure, stable conveying flow rate, and isolation between conveying materials and pistons. Among them, rubber diaphragms are used as An important part of the diaphragm pump structure plays an irreplaceable role in isolating the conveyed material from the piston. The service life of the rubber diaphragm of the diaphragm pump directly determines the continuous operation time and equipment operation rate of the diaphragm pump. Therefore, in the diaphragm pump manufacturing and control technology Among them, diaphragm protection technology and diaphragm damage detection technology are the top ...

AI Technical Summary

Problems solved by technology

[0008] 1. The oil quantity detection method in the diaphragm chamber is backward: the oil quantity detection device of the diaphragm pump oil quantity control system currently on the market is a qualitative detection scheme, which can only judge the oil quantity in the diaphragm chamber through the magnetic signal detection probe, and obtain The detection result is a digital quantity of 1bool, in which 0 means that the oil volume is insufficient, and 1 means that the oil volume is exceeded, but it is not possible to further judge the lack or excess of the oil volume in the diaphragm chamber. From this characteristic, it can be seen that the old diaphragm The oil volume control system can only perform qualitative detection of the oil volume in the diaphragm chamber, but cannot quantitatively detect the oil volume in the diaphragm chamber

[0009] 2. Oil replenishment and oil discharge actions are uncontrollable: the oil replenishment and discharge hydraulic system of the diaphragm chamber in the current market has already adopted a quantitative replenishment and discharge oil control strategy when making oil replenishment or oil discharge to the diaphragm chamber, that is, The oil volume in the diaphragm chamber is controlled by oil replenishment and oil discharge at a fixed time. This control method is relatively backward and is greatly affected by external influences. It lacks the necessary closed-loop control strategy for oil replenishment and discharge flow detection, resulting in oil replenishment and oil discharge. The efficiency is low. For example, assuming that the time for a single oil replenishment is t1, and the amount of oil in a single oil replenishment is V1, due to the difference in oil replenishment pressure and the periodic and technological changes in the pressure of the diaphragm chamber, the amount of oil replenished in a single time will inevitably lead to V1 is different every time. At this time, the diaphragm pump will alternately perform multiple oil replenishment and oil discharge operations, and adjust the oil volume in the diaphragm chamber to the best state through the difference between the sum of the oil replenishment volume and the oil discharge volume. It can be seen that in In this oil replenishment and discharge control system, the efficiency of oil replenishment and discharge is low, the system oscillates for a long time, and the stability is poor

Summarizing the above phenomena, it can be seen that the oil replenishment and discharge hydraulic system plays a role in controlling the oil volume of the oil replenishment action and the oil discharge action. The hydraulic system cannot control the amount of oil replenished at a time through closed-loop feedback

[0010] 3. The failure of the oil replenishment and discharge hydraulic system of the diaphragm chamber cannot be judged: in industrial situations, the environment is harsh, chemical acid gas, external impact, mechanical vibration, dust and other complex factors act on the hydraulic system of the diaphragm chamber replenishment and discharge oil, resulting in the diaphragm chamber replenishment and discharge There is an unexpected failure in the oil hydraulic system. At this time, the rubber diaphragm will be damaged because the oil supply valve or the oil discharge valve cannot be effectively opened or closed. The failure of the oil supply and discharge hydraulic system in the diaphragm chamber can be roughly divided into the following aspects:

[0011] The oil replenishment valve cannot be opened effectively, so that the oil replenishment action cannot compensate for the lack of hydraulic oil in the diaphragm chamber, or the oil discharge valve cannot be effectively closed, so that the oil discharge valve continues to discharge excessive oil to the diaphragm chamber. These two situations will cause the diaphragm chamber to The lack of oil, the pressure drop, the diaphragm is in a state where the material pressure is greater than the oil pressure of the diaphragm chamber, resulting in damage to the rubber diaphragm. At the same time, due to the lack of oil in the diaphragm chamber, the iron core of the rubber diaphragm will hit the back of the diaphragm chamber during each reciprocating cycle. end, causing mechanical damage

[0012] The oil discharge valve cannot be opened effectively, so that the oil discharge action cannot discharge the diaphragm chamber that is already in an overfilled state of hydraulic oil, or the oil replenishment valve cannot be effectively closed, resulting in the oil replenishment valve continuing to replenish the diaphragm chamber with excessive oil. It will cause too much oil in the diaphragm chamber, the pressure will increase, and the diaphragm will be in a state where the material pressure is lower than the oil pressure in the diaphragm chamber, resulting in damage to the rubber diaphragm

[0013] Combining the above two aspects and a total of four situations, it can be seen that the failure of the hydraulic system for replenishing and discharging oil in the diaphragm chamber is harmful to the operation of the rubber diaphragm, but the current hydraulic system for replenishing and discharging oil in the diaphragm chamber cannot identify its own faults, and it is difficult to protect the rubber diaphragm. for purposes of device security

[0014] 4. No detection measures for rubber diaphragm damage: as the key control and protection object of the diaphragm pump, the rubber diaphragm plays an important role in isolating materials and hydraulic oil. The main pipeline transportation principle of the diaphragm pump is to reciprocate in the diaphragm chamber through the rubber diaphragm Elastic movement, extruding the material to provide pipeline delivery pressure, the damage of the rubber diaphragm will cause the material isolation effect of the rubber diaphragm to decrease, resulting in the mixing of the material and the hydraulic oil. When the pressure increases, the material flows into the rubber diaphragm through the damaged gap, and finally enters the conveying pipeline, resulting in the waste of hydraulic oil and the pollution of the pipeline process. After the hydraulic oil enters the conveying pipeline, it will cause the hydraulic system to detect the diaphragm chamber Insufficient oil volume in the chamber, and then oil replenishment action occurs

When the rubber diaphragm is sucking material, because the pressure of the hydraulic oil in the diaphragm chamber decreases, the pressure of the material is higher than the pressure of the hydraulic oil in the diaphragm chamber, causing the material to flow into the diaphragm chamber and mix with the hydraulic oil. Too much oil, and then the oil discharge action occurs. At this time, the hydraulic oil in the diaphragm chamber is a mixture of material particles and hydraulic oil. During the oil discharge action, the material particles will enter the oil discharge pipeline with the hydraulic oil and finally flow into the hydraulic oil tank. Blocking the oil discharge pipeline will pollute a large amount of hydraulic oil in the hydraulic oil tank. At the same time, the hydraulic oil contains a large amount of particulate matter, which will cause the piston in the diaphragm chamber to grind, affect the life of the equipment and even cause major accidents

From the above technical facts, it can be seen that the main reason for the above hidden dangers is that the current diaphragm pump lacks an effective diaphragm damage detection device, which cannot timely judge and control the pollution of hydraulic oil by materials at the initial stage of diaphragm damage.

[0015] Judging from the current existing problems in the operation of the diaphragm pump mentioned above, the currently adopted diaphragm pump oil replenishment and discharge scheme and diaphragm protection strategy mainly rely passively on the natural elastic tensile strength of the rubber diaphragm, and the control method is relatively vague and cannot be used. Quantitative detection and compensation of hydraulic oil volume does not properly detect faults in the oil supply system, and lacks a fault control mechanism at the initial stage of diaphragm damage, which is likely to cause pollution and damage expansion

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