The impeller of a slurry pump is a rotating body with blades that transmits energy to the slurry and is the key component of a slurry pump.
There are various materials of the slurry pump impeller, commonly used are high chrome alloy impeller, rubber impeller and ceramic impeller
Centrifugal slurry pump impeller mainly has the following forms: closed impeller, semi-closed impeller, open impeller
Closed impeller: The impeller is a combination of a blade, a front cover and a rear cover. The front cover, the blade and the rear cover are joined together to form a casting.
This type of impeller is relatively efficient, but it is difficult to manufacture. It is most widely used in centrifugal pumps and is suitable for conveying clean water, solution and other non-particle cleaning liquids with small concentrations.
Semi-open impeller: generally consists of front and rear cover plates and blades, and the front and rear cover plates are separately cast. The efficiency of the impeller of this structure is generally low. In order to improve its working efficiency, it is necessary to add a sealing ring with adjustable clearance.
The semi-open impeller is generally suitable for conveying liquids containing suspended solids such as solid particles and fibers. Due to its low manufacturing difficulty, low cost and strong adaptability, it has been gradually applied in centrifugal pumps for chemical and non-ferrous industries in recent years.
Open impeller: low efficiency, mainly used to transport slurry liquid with high concentration. The blades of the impeller are mostly rearward, and the cover is usually a curved surface.
Corrosion has always been one of the most troublesome hazards of chemical equipment, the slightest inadvertence, light damage to equipment, serious accidents, or even lead to disaster. According to statistics, about 60% of the damage to chemical equipment is caused by corrosion. A large number of different equipment combinations are required each year globally in the manufacturing and handling process to address complex needs, and this includes pumps. Today we will discuss the selection of materials for chemical pumps
Chemical pumps are designed and manufactured from materials that can withstand varying degrees of viscosity, corrosiveness and abrasive substances. These substances require pumps that can handle them effectively without causing production downtime or pump failure. Before selecting a chemical pump, you need to have a firm grasp of the application requirements and chemical media properties and choose different materials based on the different media
Sulfuric acid is one of the strong corrosive media, sulfuric acid is a widely used and important industrial raw material. Different concentrations and temperatures of sulfuric acid on the corrosion of materials vary greatly, for concentrations of more than 80%, the temperature is less than 80 ℃ of concentrated sulfuric acid, carbon steel and cast iron have good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid, not suitable for pump and valve materials; ordinary stainless steel such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) for the use of sulfuric acid media is also very limited. Therefore, pump valves for conveying sulfuric acid are usually made of high silicon cast iron (casting and processing difficulties), and high alloy stainless steel (20 alloys). Fluorine plastic has good resistance to sulfuric acid, and the use of fluoroplastic centrifugal pumps is a more economical choice.
Hydrochloric acid most metal materials are not resistant to hydrochloric acid corrosion (including a variety of stainless steel), molybdenum high ferrosilicon can only be used for 50 ℃, hydrochloric acid below 30%. In contrast to metallic materials, the vast majority of non-metallic materials have good corrosion resistance to hydrochloric acid, so lined rubber pumps and plastic pumps (such as polypropylene, fluoroplastic, etc.) are the best choices for the delivery of hydrochloric acid.
Nitric acid Most metals are mostly corroded in nitric acid. Stainless steel is the most widely used nitric acid-resistant material and has good corrosion resistance to all concentrations of nitric acid at ambient temperature. It is worth mentioning that stainless steel contains molybdenum (such as 316, 316L) The corrosion resistance of nitric acid is not only not superior to ordinary stainless steel (such as 304,321), but sometimes even worse. For high-temperature nitric acid, usually titanium and titanium alloy materials.
Acetic acid is one of the most corrosive substances in organic acids. Ordinary steel is seriously corroded in all concentrations and temperatures of acetic acid. Stainless steel is an excellent acetic acid-resistant material. Molybdenum-containing 316 stainless steel is also suitable for high temperature and thinning Acetic acid steam. For high temperature and high concentration of acetic acid or other corrosive media and other harsh requirements, the choice of high alloy stainless steel pump or fluorine plastic pump.
Alkali (sodium hydroxide) steel is widely used in sodium hydroxide solution below 80 ℃, 30% concentration, there are many factories at 100 ℃, 75% below the ordinary steel is still used, although the corrosion increased, the economy is good. Ordinary stainless steel lye corrosion resistance and cast iron compared with no obvious advantages, as long as the medium allows a small amount of iron content is not recommended for incorporation of stainless steel. For high-temperature alkaline use titanium and titanium alloy or high alloy stainless steel.
Ammonia (ammonia hydroxide) Most metals and non-metals in liquid ammonia and ammonia (ammonia hydroxide) corrosion are minor, only copper and copper alloy should not be used.
Brine (seawater) Common steel corrosion rate in sodium chloride solution and seawater, saltwater is not too high, the general shall be used paint protection; all kinds of stainless steel also have a low uniform corrosion rate, but maybe due to chloride ions caused by localized corrosion, Usually 316 stainless steel is better.
Alcohols, ketones, esters, and others are common alcohol mediums with methanol, ethanol, ethylene glycol, propanol, ketones have acetone, butanone, etc., ester medium has a variety of methyl ester, B Esters, ethers medium ether, ether, butyl ether, etc. They are basically non-corrosive, common materials are applicable, and the specific selection should be based on the media properties and related requirements to make a reasonable choice. It is also noteworthy that ketones, esters, and ethers are soluble in a wide variety of rubbers and avoid mistakes when selecting sealing materials.
Common malfunction and solution of mining slurry pump mainly summarizes the problems often encountered in the process of using mining slurry pump
Centrifugal slurry pumps are used in many industrial applications such as quarrying mining recycling and in large-scale manufacturing they are designed to pump abrasive fluids continuously and the wearing parts can simply be replaced when worn without having to replace the whole pump
At the back of the pump is the belt guard which protects operators from the pulleys and belts a perforated lightweight belt guard here is easily removed when required which makes for quicker and safer maintenance of the pump.
The pump is on a fixed base however slurry pumps can also be cited on sliding bases the advantage of a sliding base is it allows for easier and safer opening and closing of the pump during maintenance which in turn reduces downtime for the user
The shaft is powered by the motor and causes the impeller to rotate rapidly given the forces placed on the impeller and the shaft the role of the bearing assembly is to keep the shaft and impeller stable and correctly aligned for this reason slurry pumps have much larger and more robust bearing assemblies than water pumps
The cartridge can be adjusted backward and forwards to change the impeller clearance as it wears the volute casing houses the volute which houses the impeller this is designed to be a replaceable spare rather than wearing out the entire volute like water pumps do therefore it's easier and cheaper to maintain
The slurry enters the pump through the suction pipe the force of the rotating impeller pushes the fluid outwards into the discharge pipe at high pressure
The submersible sewage pump is a pump-motor integration working in a submersible way. Compared with common horizontal pumps or vertical sewage pumps, the submersible sewage pump has the following noticeable advantages:
Compact and space-effective: The submersible sewage pump works in a submersible way, so it can be mounted in the sewage sump directly, unnecessary for building a dedicated pump room to mount pumps and motors, thus saving a lot of expenses for land and capital construction.
Easy for installation and maintenance: A small-size submersible sewage pump can be installed freely while a large-size one is provided with an automatic coupling device generally for automatic installation, thus quite easy for installation and maintenance.
Available for long-time continuous operation: As for a submersible sewage pump, its pump and motor are coaxial, with a short shaft and a light rotary assembly, so that the load (radial) on the bearing is relatively small, thus its life is much longer than that of common pumps.
Free of such problems as cavitation pitting and pouring of diversion water. In particular, the latter facilitates operators a lot.
Low vibration noise, small motor temperature rise and being environment-friendly.
It's because of the above advantages that the submersible sewage pump has been catching more and more attention and applied in an increasingly bigger scope: transporting from clear water in the past simply too different kinds of domestic sewage, industrial effluent, drainage of construction sites, liquid feedstuff and others at present. It plays a vital role in all walks of life, like municipal works, industry, hospitals, buildings hotels and water conservancy construction.
However, every coin has two sides. As for the submersible sewage pump, the most critical question is its reliability: because it's used in a submersible way; some of media it transports are liquid mixtures containing solid materials; the pump is very close to the motor; and the pump adopts a vertical arrangement so that the weight of the rotary assembly has the same direction as the water pressure borne by the impeller. All of those issues result in higher requirements for the submersible sewage pump than common sewage pumps in such aspects as seal, motor bearing capacity, bearing arrangement and selection.
To improve the submersible sewage pump's life, at present most manufacturers, both at home and abroad, are seeking ways for the pump's protection system, that is, the system can alarm and stop the pump for repair automatically in case of such faults as leakage, overload and overtemperature. We think it's rather necessary to set a protection system for the submersible sewage pump because the system can protect the electric pump for safe operation effectively.
However, that's not the crux of the matter. The protection system is just a remedy after the pump goes wrong, which is a passive measure. The crux shall be focused on the cause to solve the pump's problems thoroughly in such aspects as seal and overload. That's an active way. Therefore, we applied the auxiliary impeller fluid power seal technology and the pump's overload-free design technology to the submersible sewage pump, thus improving the pump's seal reliability and bearing capacity substantially and extending its service life.
The slurry pump impeller is strictly prohibited from rotating in reverse, it is so important that all pump maintenance engineers need to know this.
If the impeller is reversed, it will fall off from the pump shaft, what is more, serious is that it will result in damage to the entire pump, so this problem must be paid enough attention to. Here are some serious consequences if the operating pump is in reverse rotation:
Slurry pump impeller falls off
Slurry pump impeller and shaft are connected by a one-way thread, when the normal operation, shaft screw threads will be able to get a good grip, slurry pump impeller will be tightened up, the more you use it, the more easy operation. But if the impeller is reversed, it will fall off at once.
Slurry pump wet end parts damage
When the slurry pump operates, the impeller rotates at a very high speed, and the weir slurry pumps impeller is very heavy, and made of high chrome alloy, so once the impeller reverses and falls off, it will slam into the slurry pump volute liner, you need to replace new slurry pump wet parts.
Slurry pump mechanical seal damage
The mechanical seal is made of 316 stainless steel, rigid substances, and non-flexible materials. When reversal occurs and the impeller falls off, the opposite acting force will move the shaft back to the motor, resulting in a stationary ring and dynamic ring collision. The moment of impact is very large, it can directly damage the huge split mechanical seal.
Slurry pump shaft bend
Once the pump reversal occurs, impeller reaction force may directly impact the shaft, if there is a lack of rigidity and strength, will directly cause shaft bend, an unbalanced pump shaft will cause excessive shaft vibration, and result in lots of big noise.
Slurry pump bearing overheat
Slurry pump shaft which is not straight may cause abnormal wear on all its bearings, and the bearing temperature will rise sharply, which could reduce the service life of the bearing.
Reverse rotation often occurs during the commissioning of new pumps or new motors, we must determine the correct direction of rotation before the motor is connected to the slurry pump.
Irrigation of farmland is an indispensable part of agriculture, especially in the absence of rain. This work has become more frequent. In general, farmland irrigation is carried out by drawing water out of rivers and ditches and sending it to the farmland for irrigation, or spraying the water under a rated pressure into the air.
The amount of water discharged from the farmland irrigation pump depends on the size of the farmland, soil conditions, and climatic conditions. The customer needs to determine the hourly water demand according to the actual working conditions, but it is generally 1 to 5 L/s.
Irrigation equipment pressure is less than 10 meters, you can choose an axial pump or low head single-stage double suction centrifugal pump. If the pressure is greater than 10 meters, single-stage single-suction centrifugal pumps, submersible pumps or self-priming pumps may be selected as the irrigation pump. If the required pressure is large, a small-flow high-lift multi-stage pump or a high-lift submersible pump may be selected.
No matter what type of pump, as long as it is used in agricultural irrigation, we generally call it an irrigation pump. When selecting a type of pump, it is not only necessary to consider the structure and installation of the pump, but also the actual local conditions selected.
AN PUMP Machinery is a professional irrigation water pump manufacturer, our high-efficiency pumping solutions work seamlessly with modern irrigation systems for agricultural and non-agricultural applications. We offer a full range of reliable pumps and systems designed for minimal maintenance with low operation costs and long operation life.
Model AHW pump is a horizontal single stage single suction volute mixed flow pump and suitable for transporting pure water or the other liquid with both physical and chemical natures similar to those of water, with the temperature of the liquid to be transported not over 50, for the farmland irrigation, industrial and city water supply and drainage, etc. multiple places.
Following is the use and maintenance of our AHW series mixed flow pump:
Trial:
Take a trial of movement after the pump is installed to check its moving direction of it and remove the defect in the installation.
The sequence of trial:
Close the outlet gate valve or check the valve.
Fill leading water: first, start the pump and fill water into it through the screw hole on the top of it or open the check valve to let the water in the water-out pool back primed in or directly use a vacuum pump to lead water by means of exhausting (when the vacuum pump exhausts the air inside of the pump completely and gets water out, start the pump and stop the vacuum pump).
When the mover reaches the normal speed, open the gate valve fully and adjust the packing tightness. Have the pump go on moving in case of a normal movement and bearing temperature and a slight vibration (when the check valve is used, lift the bonnet when water goes out so as to reduce resistance).
Use and maintenance:
When the bearing uses thin oil for lubricating, often check and control the oil level with the bearing body in between two marking lines on the oil leveler rod; and when it uses dry oil (lubricating grease), supplement a proper amount of oil in a periodic time by means of removing both front and rear covers for model 150~350AHW pump and the oil cup for model 400~800AHW pump.
Often check the bearing's temperature rise, which should not be over the ambient one by 35 generally and by 75 to the utmost extent.
Pay attention to both frictional and collided sounds that may occur during the pump movement. In case of friction between both pump cover and impeller, add a paper pad in between both pump cover and casing. The applicable interval in the actual use is 0.3~0.7mm
Adjust the packing properly to have the liquid intermittently leak in drops from the packing gland. Too tight packing will cause the shaft to heat and the power increase while too loose will cause an excessive liquid leak and a lowered efficiency.
In the case of the direct link between both pump and motor, have the axial lines of both on the same straight line.
Check if there is the air that leaks from the water-in pipeline.
Pay attention to the power to see if it is suddenly enlarged or lowered and if the flow is suddenly reduced, stop the pump to troubleshoot if it is.
Often check if the bolts get loose due to vibration.
For any other help, please feel free to contact us.
