Pump Knowledge

Pump Knowledge

Advantages Of A Pneumatic Diaphragm Pump In Comparison With A Centrifugal Pump.

Pneumatic diaphragm pump uses air as its power, so the flow is automatically adjusted with the change in backpressure (outlet resistance) changes; it is suitable for medium-high viscosity fluid. The working point of the centrifugal pump is set based on water. If it’s used for a slightly higher viscosity of the liquid, a frequency converter is needed. The cost will be significantly increased. The same logic is applied for gear pumps.

1: Pneumatic diaphragm pump can be used for conveying chemical that has a relatively unstable chemical nature such as photosensitive material, flocculation. This is because of the low shear force of the pneumatic pump, the physical impact of the material is small.

2: In the harsh environment, such as construction sites, industrial and mining wastewater discharge, due to a large amount of impurities and complex composition in the sewage, the pipeline is easily blocked, causing the electric pump to have high load and increased temperature on the motor. Pneumatic diaphragm pump can be adjusted according to the particles. When the flow to the pipe is blocked, it will stop automatically to avoid unobstructed.

3: In the treatment of hazardous and corrosive material, the material can be separated from the outside world, or in some tests to ensure that no impurities contaminate the raw materials.

4: The pneumatic diaphragm pump is reliable due to its low cost in a flammable and explosive environment. , such as fuel, gunpowder, explosives, because: firstly, it is impossible to generate sparks after grounding; secondly, there will not be heat generated while it is working, the machine will not overheat; third, the fluid will not overheat because the pneumatic diaphragm pump has minimum agitation to the fluid.

5: The volume of the pneumatic diaphragm pump is small and easy to move; it does not need any foundation; floor area is small and easy to install. It can also be used as a mobile material transfer pump.

Science And Technology To Enhance The Magnetic Pipeline Pump To Ease The Pressure.

The magnetic pump is a new type of pump that uses the working principle of magnetic coupling to transfer torque without contact. When the motor drives the outer magnetic rotor to rotate, the magnetic pipeline pump drives the inner magnetic rotor and the impeller to rotate synchronously through the action of the magnetic field, to achieve the purpose of pumping liquid because the liquid is enclosed in a stationary isolation sleeve, the magnetic pump is a fully sealed, leak-free pump type. The magnetic pipeline pump cancels the use of a mechanical seal of the pump and completely eliminates the inevitable running, emitting, dripping, and leakage of the problems of the mechanical seal in a centrifugal pump. The magnetic pump is the best choice for leak-free factories. Because the flow parts of the magnetic pump are made of stainless steel and engineering plastics, the purpose of corrosion resistance is achieved. The magnetic coupling of the magnetic pump is integrated with the pump body, so it has a compact structure, convenient maintenance, safe and energy-saving. The magnetic coupling of the magnetic pump can protect the transmission motor from overload.

Magnetic pipeline pumps are fully sealed, leak-free, and corrosion-resistant. Magnetic pipeline pumps are widely used in petroleum, chemical, pharmaceutical, electroplating, environmental protection, water treatment, film and television printing, defense, and other departments to pump flammable, explosive, Toxic, and precious liquids, the magnetic pump is an ideal pump for creating a civilized workshop and a civilized factory without leakage and pollution.

Working conditions of the magnetic pump. The density of the medium conveyed by the magnetic pipeline pump is not more than 1300kg/m3, and the viscosity is not more than 30×10-6m3/S liquid without ferromagnetism and fiber. The rated temperature of the magnetic pump is metal or F46 lining. The maximum working temperature is 80℃ and the rated pressure is 1.6MPa; the operating temperature of the magnetic pump is ≤350℃; the magnetic pump body is made out of non-metallic material, the highest temperature does not exceed 60℃, and the rated pressure is 0.6MPa.

For liquids with a density greater than 1600kg/m3, the magnetic coupling needs to be designed separately. The bearings of the magnetic pump are lubricated and cooled by the conveyed medium, and the magnetic pump is strictly prohibited from running without load.

Five main points of using a magnetic pump:

1. Commissioning work: check whether the connecting parts are loose; turn the coupling by hand to make the rotor rotate several times, and see whether the unit rotates flexibly, whether there are noise and unevenness of light and weight. To judge whether there are foreign objects in the pump or whether the shaft is bent, whether the seal is installed correctly, etc.; check whether the clean lubricating oil in the sealed cavity is filled with 1/2 cavity space; whether the surface of the magnetic pump unit is clean; Turn to no-load test.

2. Manual start: prime the pump (for the first time), slightly open the outlet valve, start the motor, the pressure rises, and confirm that the centrifugal pump unit is running smoothly and gradually open the outlet valve to the working conditions.

3. Operation inspection: When the pump is operating normally at the power frequency (frequency conversion), check and record the readings of the pump set’s ammeter, voltmeter, inlet, and outlet vacuum gauge, pressure gauge, and flowmeter. Whether the vibration, noise and temperature rise of the unit is normal. There should be no obvious aviation fuel leakage at the shaft seal.

4. Normal stop: close the discharge valve, make the pump load lighter, and stop the motor.

5. Emergency stop conditions:

a. The working current meter of the pump motor indicates abnormality (too large or too little); the magnetic pump system makes an abnormal sound.

b. The pump inlet vacuum pressure gauge and outlet pressure gauge indicate abnormally, and the magnetic pump body vibrates greatly and makes abnormal noises, and its performance is seriously degraded.

c. The pump motor produces a peculiar smell, aviation oil leaks from the shaft seal, and the bearing temperature exceeds 75℃.

Magnetic pumps can be widely used in chemical, pharmaceutical, petroleum, electroplating, food, film photo finishing, scientific research institutions, national defense industry, and other units to pump acids, lyes, oils, rare and valuable liquids, venoms, volatile liquids, and water circulation supporting equipment and filter. Magnetic pumps are especially suitable for pumping leaky, flammable, and explosive liquids. This magnetic pump is more ideal.

The Magnetic Pump Is A Fusion Of The World’s Most Advanced Manufacturing Processes.

The magnetic pump refers to the water pump that can be directly installed on the pipeline. Centrifugal pumps are mostly used to connect the pipeline with flanges. The rotation of the internal warrant makes the water rise, and the internal pressure becomes smaller. Due to the atmospheric pressure, the water enters the warrant part again. Magnetic pumps are often used to increase water pressure on water pipes with insufficient water pressure, and can also be used in other water circulation systems. Generally composed of: motor housing, motor stator, motor rotor, sealing sleeve, water pump housing, water pump impeller, end cover, motor shaft, filter, end cover groove, sealing rubber ring, and graphite bearing, the characteristics of a magnetic pump are the seal sleeve separates the motor stator and the motor rotor and seals it with a sealing rubber ring. There is a filter in the end cover, the end cover has an end cover groove, the bearing is made of graphite sliding bearings, the water pump impeller is made out of cast iron, and the magnetic pump The motor shell is made out of die-cast aluminum alloy or cast iron.

1. Installation and debugging of magnetic pipeline pump

(1) The magnetic pump should be installed horizontally. Before starting the magnetic pump, check the lubricating oil level of the cooling tank. If the oil level is too low, it should be refilled in time. Before starting the pump, the valve should be opened first. The opening of the inlet pipe valve should be adjusted according to the temperature of the cooling outlet pipe after the pump is working normally.

(2) When the suction liquid level is higher than the pump axis line, just open the suction pipe valve before starting. If the suction liquid level is lower than the pump axis line, the pipeline needs to be equipped with a bottom valve.

(3) The pump should be inspected before use. The motor blades should rotate flexibly. There should be no jamming or abnormal noise. All fasteners should be tightened.

(4) Check whether the rotating direction of the motor is consistent with the steering mark of the magnetic pump.

(5) After the motor starts, slowly open the discharge valve. After the pump enters the normal working state, adjust the discharge valve to the required opening for the magnetic pump. Before the pump stops working, first close the discharge valve, then cut off the power supply, and then close the cooling water pipe valve.

2. Precautions for using magnetic pipeline pump:

1. Since the cooling and lubrication of the magnetic pump bearing depends on the medium to be transported, idling rotation is forbidden, and at the same time avoids idling operation caused by restarting after a power cut in the middle of the work.

2. In the conveyed medium, if the magnetic pump contains solid particles, a filter should be added to the pump inlet: if it contains ferromagnetic particles, a magnetic filter should be added.

3. The ambient temperature of the pump should be less than 40℃, and the temperature rise of the motor should not exceed 75℃.

4. The conveyed medium and its temperature should be within the allowable range of the pump material (see attached table for details). The operating temperature of the engineering plastic pump is <60℃, the operating temperature of the metal pump is <100℃, the suction pressure is not more than 0.2mpa, the maximum working pressure is 1.6mpa, the density is not more than 1600kg/m3, and the particle size is not more than 30 × 10-6m2/s The liquid without hard particles and fibers.

5. Pumps should be cleaned in time after the use of the magnetic pump for the medium that is easy to precipitate and crystallize, drain the liquid accumulation in the pump.

6. After the pump has been running for 6 hours, the wear of the bearing and the end face moving ring should be disassembled, and the worn parts that are not suitable for reuse should be replaced.

7. The internal and external magnetic couplings of the magnetic pump adopts high-performance permanent magnet materials, which may cause potential harm to the following devices. Please keep the following devices away from this series of pumps.

The Innovation Of Self-suction Magnetic Pump For Technology.

The self-priming magnetic pump is a successful new product based on the CQ-type magnetic pump based on the latest foreign technology and repeated research and experimentation by our engineers and technicians. The performance of the self-priming magnetic pump has reached similar foreign products—advanced level in the decade. The self-priming magnetic pump replaces the dynamic seal with a static seal so that the flow-through parts of the self-priming magnetic pump are in a completely sealed state, completely solving the disadvantages of running, emitting, and dripping that cannot be avoided by other pump mechanical seals. The self-priming magnetic pump body and The materials of the flow parts are made of corrosion-resistant stainless steel, corundum ceramics, tetrafluoro graphite, and other materials. The self-priming magnetic pump not only has the function of the CQ type magnetic pump but also integrates self-priming. It does not need a bottom valve and irrigation water—the self-priming height (4m).

The self-priming magnetic pump has a compact structure, beautiful appearance, small size, low noise, reliable operation, convenient use, and maintenance. The self-priming magnetic pump can be widely used in petroleum, chemical, pharmaceutical, electroplating, printing and dyeing, food, scientific research, and other units to pump acid and alkali, Oils and rare precious liquids, venoms, volatile liquids, and circulating water equipment, especially the pumping of leaky, flammable, and explosive liquids. Therefore, self-priming magnetic pumps have a wide range of uses. We sincerely recommend this new product.

Self-priming magnetic pumps can be widely used in petroleum, chemical, pharmaceutical, electroplating, printing and dyeing, food, scientific research, and other units to pump acids, alkalis, oils and rare precious liquids, venoms, volatile liquids, and supporting circulating water equipment, especially Pumping of leaky, flammable and explosive liquids.

The self-priming magnetic pump applies the working principle of the permanent magnet coupling to the self-priming centrifugal pump. The self-priming magnetic pump adopts an external mixing axial water pump structure. The pump body is composed of a liquid suction chamber, a liquid storage chamber, a volute, and a return hole. , Gas-liquid separation chamber, and other components. The design is reasonable and the technology is advanced. The self-priming magnetic pump has the characteristics of full sealing, no leakage, and corrosion resistance. The performance of the self-priming magnetic pump has reached the advanced level of similar foreign products. The magnetic pump has a compact structure, beautiful appearance, small size, low noise, reliable operation, and convenient use and maintenance. Self-priming magnetic pumps can be widely used in chemical, pharmaceutical, petroleum, electroplating, food, film photo finishing, scientific research institutions, national defense industry, and other units to pump acids, lyes, oils, rare and precious liquids, plating liquids, volatile liquids, and Supporting circulating water equipment. Especially for the pumping of flammable, explosive, and volatile liquids, the working principle of the self-priming magnetic pump is that after the pump is started, under the action of centrifugal force, the remaining liquid in the suction chamber and the air in the liquid inlet pipe are stirred by the impeller. Gas-water mixture, the mixture enters the gas-liquid separation chamber through the volute. As the speed slows down, the gas and water separate. The air is discharged from the pump outlet and the liquid returns to the pump through the return hole. After multiple cycles, the inlet pipe in the pump is exhausted to form a certain degree of vacuum in the pump to achieve self-priming.

1: Self-priming magnetic pump problems caused by cavitation: the main causes of pump cavitation are the large resistance of the pump inlet pipe, the more gas phase of the conveying medium, the insufficient filling of the pump, and the insufficient inlet energy of the self-priming magnetic pump. Cavitation is the most harmful to the pump. When cavitation occurs, the pump vibrates violently and the balance is severely damaged, which will cause damage to the pump bearings, rotor, or impeller. This is a common cause of a failure of self-priming magnetic pumps.

2: No medium or small flow of conveying medium: dry friction between the rotor main shaft and the stable bearing, burning the bearing. The self-priming magnetic pump is lubricated and cooled by the conveying medium to the sliding bearing. Without opening the inlet valve or outlet valve, the sliding bearing will be damaged due to high temperature due to no lubrication and cooling of the conveying medium.

3: Isolation sleeve damage: The magnetic coupling of the magnetic pump is cooled by the medium conveyed by the pump. If there are hard particles in the medium, it is easy to cause the isolator sleeve to be scratched or pierced. Sometimes if the maintenance method is improper, it may also cause the isolator sleeve to damage.

4: Prevent particles from entering
(1) No ferromagnetic impurities or particles are allowed to enter the magnetic drive and bearing friction pairs.

(2) After transporting the medium that is easy to crystallize or precipitate, flush it out (pour clean water into the pump cavity after stopping the pump, and drain it after 1 minute of operation) to ensure the service life of the sliding bearing.

(3) When transporting media containing solid particles, install a filter at the inlet of the pump flow pipe.

5: Self-priming magnetic pump to prevent demagnetization
(1) The magnetic torque cannot be designed too small.

(2) It should be operated under the specified temperature conditions, and the medium temperature is strictly prohibited from exceeding the standard. A platinum resistance temperature sensor can be installed on the outer surface of the isolating sleeve of the self-priming magnetic pump to detect the temperature rise in the annulus area so that it can alarm or shut down when the temperature exceeds the limit.

6: Prevent dry friction
(1) No idling is allowed.

(2) It is strictly forbidden to evacuate the medium.

(3) When the outlet valve is closed, the continuous operation time of the pump shall not exceed 2min to prevent the magnetic actuator from overheating and failing.

Attention In The Use Of Magnetic Pump.

1. Problems caused by cavitation of the magnetic pump: The main reasons for the cavitation of the pump are the large resistance of the pump inlet pipe, the more gas phase of the conveying medium, the insufficient filling of the pump, and the insufficient energy head of the pump inlet. Cavitation is the most harmful to the pump. When cavitation occurs, the pump vibrates violently and the balance is severely damaged, which will cause damage to the pump bearings, rotor, or impeller. This is a common cause of magnetic pump failure.

2. No medium or small flow of conveying medium: dry friction between the rotor main shaft and the stable bearing, burning the bearing. The magnetic pump is lubricated and cooled by the conveying medium to the sliding bearing. Without opening the inlet valve or the outlet valve, the sliding bearing is damaged due to high temperature due to the lack of lubrication and cooling of the conveying medium.

3. Isolation sleeve damage: The magnetic coupling of the magnetic pump is cooled by the medium conveyed by the pump. If there are hard particles in the medium, it is easy to cause the isolator sleeve to be scratched or pierced. Sometimes if the maintenance method is improper, it may also cause the isolator sleeve to damage.

4. Prevent particles from entering 

(1) Do not allow ferromagnetic impurities and particles to enter the magnetic drive and bearing friction pairs.

(2) After transporting the medium that is easy to crystallize or precipitate, flush it out (pour clean water into the pump cavity after stopping the pump, and discharge it after 1 minute of operation) to ensure the service life of the sliding bearing.

(3) When transporting media containing solid particles, filter at the inlet of the pump flow pipe. 

5. Prevent demagnetization   

(1) The magnetic torque cannot be designed too small.

(2) It should be operated under the specified temperature conditions, and the medium temperature is strictly prohibited from exceeding the standard. A platinum resistance temperature sensor can be installed on the outer surface of the magnetic pump isolation sleeve to detect the temperature rise in the annulus area, and send an alarm or shut down when the temperature exceeds the limit. 

6. Prevent dry friction   

(1) No idling is allowed.

(2) It is strictly forbidden to evacuate the medium.

(3) When the outlet valve is closed, the continuous operation time of the pump should not exceed 2 min to prevent the magnetic actuator from overheating and failing.

Technical Characteristics Of Fluorine Plastic Magnetic Pump.

The magnetic pump refers to the water pump that can be directly installed on the pipeline. Centrifugal pumps are mostly used to connect the pipeline with flanges. The rotation of the internal warrant makes the water rise, and the internal pressure becomes smaller. Due to the atmospheric pressure, the water enters the warrant part again. Magnetic pumps are often used to increase water pressure on water pipes with insufficient water pressure, and can also be used in other water circulation systems. Generally composed of: motor housing, motor stator, motor rotor, sealing sleeve, water pump housing, water pump impeller, end cover, motor shaft, filter, end cover groove, sealing rubber ring, and graphite bearing, the characteristics of a magnetic pump are the seal sleeve separates the motor stator and the motor rotor and seals it with a sealing rubber ring. There is a filter in the end cover, the end cover has an end cover groove, the bearing is made of graphite sliding bearings, the water pump impeller is made out of cast iron, and the magnetic pump The motor shell is made out of die-cast aluminum alloy or cast iron.

1. Installation and debugging of magnetic pipeline pump

(1) The magnetic pump should be installed horizontally. Before starting the magnetic pump, check the lubricating oil level of the cooling tank. If the oil level is too low, it should be refilled in time. Before starting the pump, the valve should be opened first. The opening of the inlet pipe valve should be adjusted according to the temperature of the cooling outlet pipe after the pump is working normally.

(2) When the suction liquid level is higher than the pump axis line, just open the suction pipe valve before starting. If the suction liquid level is lower than the pump axis line, the pipeline needs to be equipped with a bottom valve.

(3) The pump should be inspected before use. The motor blades should rotate flexibly. There should be no jamming or abnormal noise. All fasteners should be tightened.

(4) Check whether the rotating direction of the motor is consistent with the steering mark of the magnetic pump.

(5) After the motor starts, slowly open the discharge valve. After the pump enters the normal working state, adjust the discharge valve to the required opening for the magnetic pump. Before the pump stops working, first close the discharge valve, then cut off the power supply, and then close the cooling water pipe valve.

2. Precautions for using magnetic pipeline pump:

1. Since the cooling and lubrication of the magnetic pump bearing depends on the medium to be transported, idling rotation is forbidden, and at the same time avoids idling operation caused by restarting after a power cut in the middle of the work.

2. In the conveyed medium, if the magnetic pump contains solid particles, a filter should be added to the pump inlet: if it contains ferromagnetic particles, a magnetic filter should be added.

3. The ambient temperature of the pump should be less than 40℃, and the temperature rise of the motor should not exceed 75℃.

4. The conveyed medium and its temperature should be within the allowable range of the pump material (see attached table for details). The operating temperature of the engineering plastic pump is <60℃, the operating temperature of the metal pump is <100℃, the suction pressure is not more than 0.2mpa, the maximum working pressure is 1.6mpa, the density is not more than 1600kg/m3, and the particle size is not more than 30 × 10-6m2/s The liquid without hard particles and fibers.

5. Pumps should be cleaned in time after the use of the magnetic pump for the medium that is easy to precipitate and crystallize, drain the liquid accumulation in the pump.

6. After the pump has been running for 6 hours, the wear of the bearing and the end face moving ring should be disassembled, and the worn parts that are not suitable for reuse should be replaced.

7. The internal and external magnetic couplings of the magnetic pump adopts high-performance permanent magnet materials, which may cause potential harm to the following devices. Please keep the following devices away from this series of pumps.

Concept And Characteristics Of Magnetic Pump

Overview of Magnetic Pump

The magnetic drive pump is composed of three parts: pump, magnetic drive, and motor. The key component of the magnetic drive consists of an outer magnetic rotor, an inner magnetic rotor, and a non-magnetic isolation sleeve.

When the motor drives the outer magnetic rotor to rotate, the magnetic field can penetrate the air gap and non-magnetic materials, driving the inner magnetic rotor that is connected to the impeller to rotate synchronously, generating contactless transmission of power, and convert the dynamic seal into a static seal. Because the pump shaft and inner magnetic rotor are completely enclosed by the pump body and the isolating sleeve, the problem of “running, emitting, dripping and leaking” is completely eliminated, and the leakage of flammable, explosive, toxic, and harmful media in the refining and chemical industry through the pump seal is eliminated. The potential safety hazards effectively ensure the physical and mental health and safe production of employees.

The Working Principle Of The Magnetic Pump

n pairs of magnets (n is an even number) are assembled on the inner and outer magnetic rotors of the magnetic drive in a regular arrangement so that the magnet parts form a complete coupled magnetic system. When the inner and outer magnetic poles are opposite each other, that means the displacement angle between the two magnetic poles is Φ=0, the magnetic energy of the magnetic system is lowest at this time; when the magnetic poles rotate to the same pole, the displacement angle between the two magnetic poles is Φ=2π /n, the magnetic energy of the magnetic system is maximum at this time. After removing the external force, since magnetic poles of the magnetic system repel each other, the magnetic force will restore the magnet to the lowest magnetic energy state. Then the magnet moves and drives the magnetic rotor to rotate.

 Structural features

 1. Permanent magnets

made of rare earth permanent magnet materials have a wide operating temperature range (-45-400℃), high coercivity, and good anisotropy in the direction of the magnetic field. Demagnetization will not occur when the same poles are close. The phenomenon is a good source of a magnetic field.

 2. Isolation sleeve

When a metal isolating sleeve is used, the isolating sleeve is in a sinusoidal alternating magnetic field, which induces eddy currents in the cross-section perpendicular to the direction of the magnetic force and converts them into heat. The expression of eddy current is: where Pe-eddy current; K-constant; n-rated speed of the pump; T-magnetic transmission torque; F-pressure in the spacer; D-inner diameter of the spacer; resistivity of a material;-material The tensile strength. When the pump is designed, n and T are given by the working conditions. To reduce the eddy current, only F and D can be considered. The isolation sleeve is made of non-metallic materials with high resistivity and high strength, which is very effective in reducing eddy current.

 3. Cooling lubricating fluid flow control 

When the pump is running, a small amount of liquid must be used to flush and cool the annular gap area between the inner magnetic rotor and the isolating sleeve and the friction pair of the sliding bearing. The coolant flow rate is usually 2%-3% of the pump design flow rate. The annular gap area between the inner magnetic rotor and the isolating sleeve generates high heat due to eddy currents. When the cooling lubricant is insufficient or the flushing hole is not smooth or blocked, the temperature of the medium will be higher than the working temperature of the permanent magnet, and the inner magnetic rotor will gradually lose its magnetism and the magnetic drive will fail. When the medium is water or water-based liquid, the temperature rise in the annulus area can be maintained at 3-5°C; when the medium is hydrocarbon or oil, the temperature rise in the annulus area can be maintained at 5-8°C.

 4. Sliding bearings

Magnetic pump sliding bearings are made of impregnated graphite, filled PTFE, engineering ceramics, etc. Because engineering ceramics have good heat resistance, corrosion resistance, and friction resistance, the sliding bearings of magnetic pumps are mostly made of engineering ceramics. Because engineering ceramics are very brittle and have a small expansion coefficient, the bearing clearance must not be too small to avoid shaft hung accidents. Since the sliding bearing of the magnetic pump is lubricated by the conveyed medium, different materials should be used to make the bearings according to different media and operating conditions.

 5. Safeguard

When the driven part of the magnetic drive is running under overload or the rotor is stuck, the main and driven parts of the magnetic drive will automatically slip off to protect the pump. At this time, the permanent magnet on the magnetic drive will produce eddy loss and magnetic loss under the action of the alternating magnetic field of the active rotor, which will cause the temperature of the permanent magnet to rise and the magnetic drive to slip and fail.

Compared with centrifugal pumps using mechanical seals or packing seals, magnetic pumps have the following advantages.

 1. The pump shaft changes from a dynamic seal to a closed static seal, completely avoiding medium leakage.

 2. Independent lubrication and cooling water are not required, which reduces energy consumption.

 3. From coupling transmission to synchronous drag, there is no contact and friction. The power consumption is small, the efficiency is high, and it has the effect of damping and vibration reduction, which reduces the influence of motor vibration on the pump and the influence on the motor when the pump occurs cavitation vibration.

 4. When overloaded, the inner and outer magnetic rotors will slip relatively, which will protect the motor and pump.