輸送堿液的柱塞計量泵不出液怎么辦？
柱塞式計量泵因其結構簡單、維護方便、效率高等優點在農業上得到了廣泛的應用，但也因其有時不能供水而帶來麻煩。
主要有三個原因
首先，VAREM柱塞計量泵的進氣管和柱塞計量泵中有空氣。
（1） 有些用戶在啟動泵前沒有充足水，有時似乎水已經從排氣孔溢出，但空氣在不旋轉泵軸的情況下完全排出，導致進氣管或泵體中殘留少量空氣。
（2） 與VAREM柱塞計量泵接觸的進水管水平段，在逆流方向上應有0.5%以上的下降坡度，與水泵進口連接的端部應為z高，不得完全水平。如果向上傾斜，空氣將留在進水管中，從而降低水管和水泵中的真空度，影響吸水。
（3） 由于長期使用，柱塞計量泵的填料已磨損或填料被壓得過松，導致填料與泵軸套之間的間隙有大量水噴出。因此，外部空氣從這些間隙進入泵內，影響水的提升。
（4） 由于水下長期存在潛勢，水泵運行后進水管水面不斷下降。當這些孔從水中出來時，空氣從這些孔進入進水管。（5） 進水管彎頭處的裂紋和進水管與水泵連接處的微小縫隙都可能導致空氣進入進水管。
二是變量活塞計量泵轉速過低
（1） 人為因素。由于原電機損壞，相當一部分用戶隨機配另一臺電機驅動，造成流量小、水頭低，甚至沒有供水。
（2） 傳動帶磨損。目前有許多大型水泵采用皮帶傳動，由于長期使用，傳動皮帶磨損松動，出現打滑現象，從而降低了水泵的轉速。
（3） 安裝不當。如果兩個皮帶輪中心距過小或兩軸不平行，則傳動帶緊邊安裝在其上，導致纏繞角過小，兩個皮帶輪直徑計算錯誤，耦合軸驅動的水泵兩軸之間偏心過大，水泵的速度會改變。
（4） 計量泵本身的機械故障。泵葉輪松動或軸軸承變形松動，可能與泵軸直接摩擦。
（5） 動力機器維護未記錄。由于繞組燒壞，電動機失去勵磁。檢修時改變繞組匝數、線徑、接線方式，或檢修中未完全消除的故障，也會改變水泵的轉速。
三是VAREM計量泵吸入揚程過大，有的液位較深，有的液位較平，忽視了泵的允許吸入壓頭，導致吸水量少或不吸水。必須知道，在泵的進水口處可以建立的真空度是有限度的。絕對真空下的吸入壓頭約為10 m水柱高，而VAREM計量泵無法建立絕對真空。而且真空度過大，容易使泵內的水氣化，不利于泵的工作。因此，每臺柱塞計量泵都有其z大的允許吸入壓頭，一般在3到8.5米之間。安裝泵時，不能簡單方便。
有時計量泵工作時，不能產生溶液。怎么了？下面讓上海龍亞泵閥制造有限公司的工作人員給我們詳細介紹一下：
（1） 檢查計量泵電機是否工作。如果不工作，說明馬達或電控電路有問題。注：一般情況下，由于二氧化氯發生器回路設有過載保護裝置，電動機不工作，電動機不損壞。此時，打開二氧化氯發生器方形控制器中的方形控制盒面板，按下下面一排右側熱繼電器上的藍色按鈕（復位按鈕），使計量泵正常工作；如果計量泵仍不能正常工作，合格的電工應根據制造商提供的二氧化氯發生器電路圖檢查相關電路。
（2） 檢查給藥管或藥管內有無雜質堵塞管路。如有雜質，應及時清除。
（3） 松開進藥管或出藥管的接頭，排出各自管路中的空氣。
How to do if the plunger metering pump can't discharge the liquid?
Plunger metering pump is widely used in agriculture because of its simple structure, convenient maintenance and high efficiency, but it also brings trouble because it can not supply water sometimes.
There are three main reasons
First, there is air in the intake pipe and plunger metering pump of the varem plunger metering pump.
(1) Some users do not have enough water before starting the pump, sometimes it seems that the water has overflowed from the exhaust hole, but the air is completely discharged without rotating the pump shaft, resulting in a small amount of air remaining in the intake pipe or pump body.
(2) The horizontal section of the water inlet pipe in contact with the water pump should have a descending slope of more than 0.5% in the counter current direction, and the end connected with the water pump inlet should be Z high, not completely horizontal. If it tilts upward, the air will stay in the water inlet pipe, thus reducing the vacuum degree in the water pipe and water pump and affecting the water absorption.
(3) Due to long-term use, the packing of the pump has been worn or the packing has been pressed too loose, resulting in a large amount of water ejecting from the gap between the packing and the pump shaft sleeve. Therefore, external air from these gaps into the pump, affect the water lift. (4) Due to the long-term underwater potential, the water surface of the water inlet pipe continuously drops after the operation of the pump. When these holes come out of the water, air enters the inlet pipe through these holes. (5) The cracks at the elbow of the inlet pipe and the tiny gap between the inlet pipe and the water pump may cause the air to enter the inlet pipe.
Second, the speed of variable piston metering pump is too low
(1) Human factors. Due to the damage of the original motor, quite a number of users are randomly equipped with another motor drive, resulting in small flow, low water head, and even no water supply.
(2) The drive belt is worn. At present, many large water pumps adopt belt drive. Due to long-term use, the drive belt is worn and loose, resulting in sliding phenomenon, thus reducing the speed of the water pump.
(3) Improper installation. If the center distance of the two pulleys is too small or the two shafts are not parallel, the tight side of the drive belt is installed on it, resulting in too small winding angle, wrong calculation of the diameter of the two pulleys, too large eccentricity between the two shafts of the water pump driven by the coupling shaft, and the speed of the water pump will change.
(4) Mechanical failure of the pump itself. The pump impeller is loose or the shaft bearing is deformed and loose, which may cause direct friction with the pump shaft.
(5) Power machine maintenance is not recorded. The motor lost its excitation due to the burning out of the winding. During maintenance, changing the number of turns, wire diameter and wiring mode of the winding, or the faults not completely eliminated in maintenance, will also change the speed of the water pump.
Third, the suction head of varem metering pump is too large, some liquid level is deep, some liquid level is flat, and the allowable suction head of the pump is ignored, resulting in less or no water absorption. It must be known that there is a limit to the degree of vacuum that can be established at the water inlet of the pump. The suction head under absolute vacuum is about 10 m water column, while the varem metering pump cannot establish absolute vacuum. And the vacuum is too large, easy to make the water in the pump gasification, not conducive to the work of the pump. Therefore, each plunger metering pump has its own Z large allowable suction head, generally between 3 and 8.5 meters. It is not easy to install the pump.
Sometimes the VAREM solution pump can not work. What's up? Let's have a detailed introduction from the staff of Shanghai Longya pump valve manufacturing Co., Ltd
(1) Check whether the metering pump motor works. If it doesn't work, there is something wrong with the motor or electric control circuit. Note: in general, as the circuit of chlorine dioxide generator is equipped with overload protection device, the motor will not work and will not be damaged. At this time, open the square control box panel in the square controller of the chlorine dioxide generator, and press the blue button (reset button) on the right thermal relay of the lower row to make the metering pump work normally; if the metering pump still cannot work normally, the qualified electrician shall check the relevant circuits according to the circuit diagram of the chlorine dioxide generator provided by the manufacturer.
(2) Check whether there is any impurity in the dosing pipe. If there are impurities, they should be removed in time.
(3) Loosen the joint of the medicine inlet pipe or the medicine outlet pipe to discharge the air in their respective pipes.