The role of underwater pumps in low level transportation
When a centrifugal water pump is blocked by waste, it is necessary to pull the pump up in order to sort it, which is very inconvenient and therefore rarely used in practical activities. Therefore, using a submerged pump to carry out low-level transportation solves the problem of low-level transportation.
However, due to the use of a short shaft and the uneven axial force of the centrifugal impeller, all shafts are of a suspended wall structure, resulting in significant stiffness at the end of the centrifugal impeller during flipping. The longer the axis, the greater the stiffness. In order to solve this problem, the equipment on the shaft has bearings. However, because the whole shaft is a Flexible shaft, the bearing continues to suffer from unilateral damage, with a high wear rate, strong bearing shaking, and accelerated damage rate. Therefore, the underwater pump has a high frequency of damage. And the shaft is not suitable for making too long, usually within 2 meters. The bearings of the submerged pump are cooled and polished by water using the medium transported by the pump. If the medium of underwater concrete does not freeze and clean the bearings (such incidents can occur when the pump is empty and the inlet is blocked by dirt), it will cause burning of the tiles or even the motor.
The repair equipment of the submerged pump is very laborious. When transporting corrosive media, it is impossible to complete without lifting items. When a centrifugal water pump is transporting liquid, when the liquid level gauge is less than, it is required to fill the pump in order to produce water. Therefore, it is necessary to install a water pump bottom valve at the pump inlet. Over time, if the bottom valve of the water pump is corroded or stuck, exchange or repair is required, making the application inconvenient. Submersible pumps are generally used to transport cold water and rivers, but when used to transport corrosive liquids such as strong acids and alkalis, they are prone to motor erosion and power loss, making them very unsafe. After all, the submerged pump solves the problem of low level transportation, but it also incurs many difficulties in applications. The column type self priming pump is designed specifically for the transportation of low level liquids due to the aforementioned defects of the submerged pump. It can replace a long axis underwater pump on the road, with a naturally aspirated aspect ratio of up to 8 meters. It can be used as a bottom pump and a cabin cleaning pump in ships.
Requirements for arrangement of centrifugal submersible pumps!
Centrifugal submersible pump is a type of submersible pump. With the development of the water pump industry and continuous technological innovation, centrifugal pumps are favored by many customers due to their high efficiency and safety advantages. However, there are still many customers who are limited by their professional knowledge and do not have a good understanding of it, resulting in various problems during the operation and even layout of centrifugal pumps.
1. The pump group should be arranged neatly, and the editor suggests aligning it with the outlet centerline of the water pump.
2. The electrical and process disciplines should be coordinated in a timely manner. When possible, the motor part of the water pump should be as far away from the explosion-proof zone as possible to save investment.
3. The water pump should be as close as possible to the liquid supply equipment to prevent small NPSHa.
4. The power side and pump side of the steam reciprocating pump should have positions for extracting pistons and pull rods.
5. When a vertical pump is not located below the pipe gallery or frame, space should be left above it for installation and maintenance of the pump body.
What should I do if the metering pump malfunctions while adding medication?
When adding chemicals, precision requirements are quite important, so dosing pumps often use metering pumps, which can accurately control the amount of chemicals added. So when using a metering pump, what aspects and details should be carefully checked to avoid malfunctions?
Since not all metering pumps are equipped with a discharge valve, it is necessary to first check whether it exists, and then require it to be opened during the metering pump suction phase. If it is found that there may be gas leakage at the suction end of the metering pump, it is likely that the hydraulic end suction side connection may lack an O-ring or the suction valve connection may be loose, so it is also important to check here.
During use, it is important to avoid cleaning the hydraulic end of the metering pump with chemicals to prevent the ball and seat of the one-way valve from working properly. If there is indeed a malfunction in the metering pump, it must be promptly identified and resolved as soon as possible.
The first thing to do is to unscrew the screw fixing the pump head of the metering pump, and adjust the stroke length to 0% after the pump head is loose and before removing the pump head; At the same time, ensure that the electromagnetic shaft of the metering pump has sufficient pressure to maintain a stable connection, so that the diaphragm can be unscrewed.
Once the diaphragm is removed, check the safety diaphragm of the metering pump to ensure that it is intact and undamaged.
If there is any damage, it needs to be removed and replaced with a new one. Rotate the back plate and diaphragm clockwise until they are tightly attached; At the same time, it is necessary to adjust the back plate so that the leakage discharge hole is located at the bottom of the pump.
After the diaphragm in the metering pump is installed and the backplate leakage discharge hole is placed in a vertical position, install the pump head, ensuring that the suction valve is aligned with the leakage discharge hole, and the screws on the hydraulic end are aligned with the corresponding four holes. Then rotate to the position of 100% stroke length; Adjust the hydraulic end and diaphragm to the proper position during the operation of metering pump.
Installation methods and operating procedures for pneumatic diaphragm pumps
If the installation details of pneumatic diaphragm pumps are ignored, long-term careful planning, research, and selection may still lead to poor pumping performance and affect the pump's service life. Pneumatic diaphragm pumps are a new type of conveying machinery that uses compressed air as the power source. For various corrosive liquids, liquids with particles, high viscosity, volatile, flammable, and highly toxic liquids, they can be pumped and absorbed completely. The diameter of the suction pipe of the pneumatic diaphragm pump should not be smaller than the diameter of the pump inlet end. For example, when transporting high viscosity fluids, the diameter of the suction pipe should be greater than the diameter of the pump inlet. The suction piping at the inlet end must be durable and free from wrinkles in order to generate a high vacuum state. The diameter of the outlet piping should be at least equal to the outlet diameter, or slightly larger to reduce friction losses. All piping and joints must be sealed without leakage, otherwise it will reduce the self priming capacity of the pump. Pneumatic diaphragm pump is a commonly used machinery in the chemical industry. After purchasing this pump, if it is not installed by specialized technical personnel, it is likely to delay production. In the following article, I will briefly introduce the installation steps and operating procedures of pneumatic diaphragm pump.
Installation method of pneumatic diaphragm pump
1. Location: Noise, safety, and other logical factors usually have requirements for the location where the equipment should be installed. Parallel installation with conflicting requirements may cause blockage in the usage area and affect the installation of other pumps.
2. Usage: Firstly, the position of the pneumatic diaphragm pump must be easy to use, which will facilitate daily inspection and debugging by maintenance personnel.
3. Air supply: Each pneumatic diaphragm pump should have a ventilation pipe that can provide enough air to achieve the ideal pumping flow rate. The air pressure depends on different pumping needs, but should not exceed 7BAR.
4. Installation height: Please fully consider the self suction capacity of the pneumatic diaphragm pump to avoid the problem of reduced self suction.
5. Pipeline: The pump position can only be determined after considering each possible location where pipeline problems may occur.
The installation of pneumatic diaphragm pumps should be selected at the connection of a short and straight inlet and outlet pipeline, and additional bends and pipe fittings should be avoided as much as possible. The pump body should be able to independently support all pipelines. Moreover, the pipelines should be arranged in an orderly manner to avoid stress on the pump body pipeline device. Flexible hoses can be installed to eliminate the stress caused by the natural reciprocating movement of the pump. If the pump body is to be connected to a fixed base, placing a buffer pad between the pump body and the base will help reduce pump body vibration.
Large Current Fluctuations In Vacuum Pumps For Reasons And Solutions
Disassembly of gear pump
The structure of a gear pump is simpler than that of a centrifugal pump, but the disassembly work is more laborious and mainly zero
The components are heavy and require high installation accuracy. They are also suspended on the beam and must be disassembled
Attention must be paid to safety. The disassembly of the components of the water pump can be divided into two parts, now using vertical axial flow
Take the pump as an example to illustrate its disassembly process
]Dismantling of the upper base
Firstly, remove the screws of the elastic coupling, loosen the screws connecting the motor to the base, and remove the motor. Support the rigid coupling of the pumping unit with wooden blocks to prevent the pump shaft from falling down, and then remove it
The connecting screws of the cap nut and bearing gland on the transmission uranium are used to seal the coupling and tighten the transmission
Lift the shaft up to a certain height, then remove the joint cap and thread of the rigid coupling, and remove the elastic
The coupling can be used to extract the transmission shaft from the upper base. Remove the elastic coupling again and roll it
Remove the bearing from the transmission shaft using a special tool. At this point, all the upper machine seats have been disassembled
2. Removal of the lower pump body
First remove the water inlet bell mouth, and then use a special tool to lift the impeller at the lower end of the pump
Open it to remove the entire impeller. For the water pump equipped with a movable blade field, remove the water inlet valve
After the bell mouth is opened, disassemble the rotating blade ring and then disassemble the impeller.
Will stainless steel sewage pumps rust?
Customers usually believe that stainless steel centrifugal pumps will not rust, and rust is not a stainless steel pump. When brown rust spots (spots) appear on the surface of the stainless steel pump, the customer believes that there is a problem with the steel. In fact, this is a misconception about a lack of understanding of stainless steel. In some cases, stainless steel can also rust. There are many forms of damage to such surface facial mask. The following are common phenomena in daily life:
1. The surface of stainless steel contains dust or other metal particles attached to other metal elements. In humid air, the condensed water between the attached material and stainless steel connects the two to form a miniature battery, leading to a chemical reaction that generates electricity. The destruction of the protective film is called electrochemical corrosion.
As shown in Figure 2, in the presence of water and oxygen, the surface of stainless steel adheres to organic juices (such as melons, noodle soup, glutinous rice, etc.), forming organic acids that corrode the metal surface for a long time.
3. The surface of stainless steel adheres to acid, alkali, and salt substances (such as alkaline water and lime water splashed onto the wall), causing local corrosion.
4. In polluted air (such as atmospheres containing large amounts of sulfides, carbon oxides, and nitrogen oxides), liquid points of sulfuric acid, nitric acid, and acetic acid can form in the presence of condensed water, leading to chemical corrosion.
All of the above situations can cause corrosion and rusting of the protective film on the surface of stainless steel.
Therefore, to ensure that the metal surface is bright and does not rust, we recommend:
1. The surface of decorative stainless steel must be regularly cleaned and scrubbed to remove deposits and eliminate external factors that cause modification.
2. Coastal areas should use 316 stainless steel, which can resist seawater corrosion.
3. Some chemical components of stainless steel pipes on the market cannot meet the corresponding national standards and cannot meet the requirements of 304 materials. Therefore, it can also cause rusting, which requires users to carefully select products from reputable manufacturers.
Differences in self priming centrifugal pumps
In order to better discharge the gas in the suction pipeline and generate a certain vacuum value during the operation of general centrifugal pumps, exhaust pipe measures must be adopted. For small pumps, the pump casing and water inlet must be filled with water before starting. In order to better avoid water jumping, a single side water pump bottom valve is installed at the bottom of the water inlet that opens when water flows up and closes when it flows down; Generally, centrifugal pumps with large water seepage specifications above 300mm are not equipped with bottom valves, but only use professional vacuum equipment to vacuum drinking water. There is no doubt that starting the water supply pump will cause inconvenience and lead to hasty consumption.
Principle: Centrifugal pumps operate by using the rotation of the impeller to generate centrifugal motion of water. Before starting the water pump, it is necessary to fill the pump casing and suction pipe with water. Then, start the electric motor to push the impeller and water to perform high-speed running fitness exercise. The water produces centrifugal motion and is thrown towards the edge of the impeller. It is then injected into the pressurized water pipeline of the water pump through the gate of the volute pump casing.
Structure: A centrifugal pump operates by using the rotation of the impeller to generate centrifugal motion of water. The main structure of a centrifugal pump is composed of six parts: impeller, pump casing, pump shaft, rolling bearing, sealing ring, and sleeve joint.
The structural type of self priming centrifugal pumps has been improved, overcoming the shortcomings of general pipeline centrifugal pumps. The advantage of a self priming centrifugal pump is that the pump casing is a double vortex shell structure. The detergent outlet is located on the edge of the water pump impeller, and there is a large capacity vapor liquid separation chamber above the outlet. Other structures are similar to single pole single suction centrifugal pumps, including sealing rings, machine seals, shafts, and rolling bearings. When starting the self priming pump for the first time during operation, it is necessary to introduce a diversion channel into the pump casing, and the amount of introduction should exceed the centerline of the pump within the pump casing. Afterwards, the fully automatic suction pipe can be started anytime and anywhere, without the need to introduce water into the diversion channel, making the application more convenient than pipeline centrifugal pumps.
Principle: The design principle of a self priming water pump is to fill the pump casing with water (or the pump casing itself has water) before starting the pump. After startup, the high-speed operation of the impeller causes the water in the impeller channel to flow towards the vortex shell. At this time, a vacuum pump is generated in the channel, causing the water seepage check valve to open. The gas in the suction pipe enters the pump and reaches the edge through the impeller channel.
