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How should corrosion-resistant pumps be selected? Here is a brief explanation: Sulfuric acid As one of the highly corrosive media, sulfuric acid is an important industrial raw material with a wide range of uses. Sulfuric acid of different concentrations and temperatures has a large difference in the corrosion of materials. For concentrated sulfuric acid with a concentration of more than 80% and a temperature of less than 80°C, carbon steel and cast iron have good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid and is not suitable for use as pump valve materials; ordinary stainless steel such as 304 and 316 are also limited in use for sulfuric acid media. Hydrochloric acid: Most metal materials are not resistant to hydrochloric acid corrosion, and molybdenum-containing high-silicon iron can only be used for hydrochloric acid below 50°C and 30%. In contrast to metal materials, most non-metallic materials have good corrosion resistance to hydrochloric acid, so lined rubber pumps and plastic pumps are good choices for transporting hydrochloric acid.   Nitric acid: Most general metals are quickly corroded and destroyed in nitric acid. Stainless steel is a widely used nitric acid-resistant material with good corrosion resistance to nitric acid of all concentrations at room temperature. It is worth mentioning that the corrosion resistance of molybdenum-containing stainless steel to nitric acid is not only not better than that of ordinary stainless steel, but sometimes even worse. Acetic acid: It is one of the most corrosive substances in organic acids. Ordinary steel will be severely corroded in acetic acid of all concentrations and temperatures. Stainless steel is an excellent acetic acid resistant material. Molybdenum-containing 316 stainless steel can also be used for high temperature and dilute acetic acid vapor. For demanding requirements such as high temperature and high concentration acetic acid or other corrosive media, high alloy stainless steel or fluoroplastic pumps can be selected. Alkali is generally not very corrosive, but general alkaline solutions will produce crystals. Ammonia Most metals and non-metals are slightly corroded in liquid ammonia and ammonia water (ammonia hydroxide), only copper and copper alloys are not suitable for use.   The selection of corrosion-resistant pumps also needs to pay attention to: Salt water (seawater) Ordinary steel has a low corrosion rate in sodium chloride solution, seawater, and salt water, and generally needs to be protected by coatings; various types of stainless steel also have a very low uniform corrosion rate, but may cause local corrosion due to chloride ions, and 316 stainless steel is usually better. Alcohols, ketones, esters, ethers Common alcohol media include methanol, ethanol, ethylene glycol, propanol, etc., ketone media include acetone, butanone, etc., ester media include various methyl esters, ethyl esters, etc., ether media include methyl ether, ethyl ether, butyl ether, etc., they are basically not very corrosive, so ordinary stainless steel can be used. When selecting, reasonable choices should be made based on the properties of the media and related requirements. It is also worth noting that ketones, esters, and ethers are soluble in many types of rubber, so avoid mistakes when choosing sealing materials.

What are the structural characteristics of forced circulation pumps? Today, our editor from Shanhe Pump Industry will explain to you: The forced circulation pump has a low speed, generally within 980r/min, which meets the requirements of the crystallization process and runs smoothly. Excellent hydraulic performance, efficiency 〉70%, wide high-efficiency zone, and good anti-cavitation performance. Considering that the flow direction of the pump medium is vertically downward and horizontally out. Due to the huge impact of the water flow force on the pump shaft, a pump shaft jacket protection device is added to the pump body.   The diving force of the medium is transferred to the pump body, thereby ensuring the stable operation of the pump, greatly reducing the impact of the medium on the mechanical seal force, and extending the service life of the machine seal. The improvement of this structure has taken a big step forward among similar domestic products. In addition, the pump body adopts integral casting with good rigidity and stable connection of the intermediate support structure. The horizontal axial flow pump has no guide vanes. The bearing box of the forced circulation pump is a square long-span heavy-duty structure with good stability, strong bearing capacity, reliable operation, and easy installation compared with similar domestic products (the original domestic bearing box is split). The front and rear ends use short radial cylindrical bearings and heavy-duty paired bearings respectively. The bearings are all NSK (SKF) or domestic high-quality bearings.   The forced circulation pump has an advanced seal shaft, which uses a combination of auxiliary impeller dynamic seal and Burgman quick-install double-end mechanical seal, external cooling and flushing water, improves the working conditions of the shaft seal, and prolongs the service life of the mechanical seal. The outer diameter of the sleeve is enlarged, and the wall thickness is thicker and the deformation is small compared with similar domestic products. Then, I will introduce the structural characteristics of the forced circulation pump to you here, and I hope it will be of some help to you. Of course, if you have other questions about the forced circulation pump, you can also contact us by phone at any time!

A mud pump is a machine that uses centrifugal force (rotation of the pump impeller) to increase the energy of the solid-liquid mixed medium and converts electrical energy into kinetic energy and potential energy of the medium. It is mainly applicable to: mining, power plants, dredging, metallurgy, chemical industry, building materials, petroleum and other industries. The mud pump transports a mixture of solid particles containing scum and water. But in principle, the mud pump is a type of centrifugal pump, which is mainly used for slurry transportation of converter dust removal water, blast furnace gas washing water, continuous casting turbid circulating water and rolling turbid circulating water in steel enterprises.   Working principle of the mud pump: Under the action of centrifugal force, the liquid is thrown out from the center of the impeller to the outer edge and gains energy, leaving the outer edge of the impeller and entering the volute pump casing at high speed. In the volute pump casing, the liquid slows down due to the gradual expansion of the flow channel, and part of the kinetic energy is converted into static pressure energy, flowing into the discharge pipe at a higher pressure and sent to the This is necessary. When the liquid flows from the center of the impeller to the outer edge, a certain vacuum is formed in the center of the impeller. Since the pressure above the tank liquid level is greater than the pressure at the pump inlet, the liquid is continuously pressed into the impeller.   The following checks should be carried out when installing the mud pump: the size, position, and elevation of the foundation should meet the design requirements, the anchor bolts must be properly and correctly fixed on the concrete foundation, and the machine must not be missing, damaged, or rusted; according to the characteristics of the mud pump conveying medium, check the materials of the main components, shaft seals, and gaskets when necessary; the leveling and alignment of the mud pump should comply with the technical regulations of the equipment. If there are no regulations, the current national standard "General Specifications for Construction and Acceptance of Mechanical Equipment Installation Engineering" shall be implemented; the installation of all pipes and pipe fittings connected to the mud pump and the cleaning requirements of the lubricating oil pipeline shall comply with relevant national standards.

How to select a submersible pump: The medium can be used to preliminarily determine the type! For example, a slurry pump or a water pump! Whether the medium is corrosive or not, choose the appropriate material. The depth and operating conditions of the pool determine the length and structure of the submersible pump! For example, the pump head at the bottom of the pool should be properly supplemented with a suction tube! The flow rate determines the diameter of the delivery pipe, and the distance and height difference determine the head! The motor power is the last! The selection of a submersible pump should be based on the process flow, water supply and drainage requirements, and should be considered from five aspects: liquid delivery volume, device head, liquid properties, pipeline layout, and operating conditions.   Flow rate is one of the important performance data for selecting a submersible pump, which is directly related to the production capacity and delivery capacity of the entire device. When selecting a pump, the large flow rate is used as the basis, taking into account the normal flow rate. When there is no large flow rate, 1.1 times the normal flow rate can usually be taken as the large flow rate. The head required by the device system is another important performance data for selecting a submersible pump. Generally, the head after enlarging the margin by 5%-10% is used for selection. The piping layout conditions of the submersible pump system refer to the liquid delivery height, liquid delivery distance, and liquid delivery direction, so as to calculate the system head and check the cavitation margin.   The selection of submersible pumps should also pay attention to the properties of the liquid, including the name of the liquid medium, physical properties, chemical properties and other properties. The physical properties include temperature c, density d, viscosity u, solid particle diameter and gas content in the medium, etc. This involves the system head, effective cavitation margin calculation and the type of suitable pump: chemical properties, mainly referring to the chemical corrosiveness and toxicity of the liquid medium, are important bases for selecting submersible pump materials and which type of shaft seal to choose. There are many operating conditions for submersible pumps, such as the liquid's operating T, saturated steam force P, suction side pressure PS, discharge side container pressure PZ, altitude, ambient temperature, whether the operation is intermittent or continuous, and whether the pump position is fixed or movable.

Shaft breakage may occur in filter press pumps during use, but this is rare, with a probability of almost one in a thousand. There are probably several reasons for this: poor material quality. The pump shaft of the filter press pump is generally made of chrome-vanadium steel or chrome-molybdenum-vanadium steel. Poor material quality is the main cause of pump shaft damage. Unreasonable selection. Among the four parallel feed pumps on the third floor of the old factory building, one has a power and flow greater than the other three, and this feed pump has never had a broken shaft. Imprecise installation. Among them, R is the pipeline constant, which is inversely proportional to the pipeline diameter, and is related to factors such as the material size of the pipeline, the opening degree of the pipeline gate, the straight pipe length and the resistance coefficient. When the pipeline is constant, R is a constant.   H is the head of the filter press pump, and H is the total energy loss of the material in the pipeline. Compared with the feed pipe of the quick-open filter press, the feed pipe of the chamber filter press has more elbows and short straight pipes, and the diameter is thin. The different opening degrees of the discharge gate valve cause large energy loss in the pipeline. The feed pump of the chamber filter press is outside the working range, resulting in large flow and low head. It is necessary to ensure the feed pressure of 0.8MPa, which increases the pump load. The discharge valve is always open. The operation of the filter press pump has always been to open the discharge valve to start the pump, causing the motor to overload and increase the load on the shaft. The use of closing the feed valve to control the flow will cause cavitation. The oxygen formed by cavitation will chemically corrode the metal and cause fatigue damage to the shaft and impeller. Correct operation should start the discharge valve slowly at normal speed. Because the discharge valve is manual, it takes more than 30 minutes to open and close each time, causing the pump discharge valve to always be open. An electric gate should be installed at the discharge point for operation. Fatigue damage.   The filter press pump is proportional to the flow rate of the pump and the speed. By changing the diameter of the pump's belt wheel to change the speed, the pump flow rate is reduced, the head is increased, and the pump operates within the efficient working range, which improves work efficiency and reduces the torque on the shaft, reducing the degree of fatigue damage. The flow rate deviates from the working range. From the performance curve of the filter press pump, it can be seen that the flow rate, head, power, and efficiency of the filter press pump are within the efficient working range. This range is within the efficient area of ​​the filter press pump and is also the theoretical working area of ​​the pump. However, the actual operation is to determine the other parameters on the basis of satisfying the feed pressure of the pump. At this time, the flow value is not within the working range, which causes the power and other parameters of the filter press pump to deviate from the efficient working range.

With the wide application of pipeline pumps in chemical, pharmaceutical, food delivery and other industries, the maintenance of pipeline pumps has received more and more attention. Today, the editor will introduce you to the maintenance tips of pipeline pumps, as follows: Pipeline pump maintenance: Scrub all parts to be installed. Install the mechanical seal on the motor main shaft, and add a small amount of clean turbine oil or No. 20 engine oil to the surface where the dynamic and static rings of the mechanical seal match.   Pipeline pump maintenance tips: Install the impeller and tighten it with the impeller nut. Pipeline pump fault maintenance: Fault maintenance during pipeline pump operation: The inlet pipeline must be filled with liquid, and the hot water pipeline pump is prohibited from running for a long time under cavitation conditions. Check the motor current value regularly, and it must not exceed the rated current of the motor. After the hot water pipeline pump has been running for a long time, due to mechanical wear, when the noise and vibration of the unit increase, it should be stopped for inspection. If necessary, the vulnerable parts and bearings can be replaced. The overhaul period of the unit is generally one year.   Mechanical seal fault maintenance of pipeline pump: Mechanical seal lubrication should be clean and free of solid particles. It is strictly forbidden for mechanical seals to work under dry grinding conditions. Before starting, you should turn the Triumph hot water pipeline pump (motor) for a few turns to avoid graphite ring breakage caused by sudden starting. The seal leakage tolerance is 3 drops/minute. Otherwise, it should be checked. In the process of using pipeline pumps, it is impossible to be smooth sailing, and various problems will often be encountered. Therefore, this requires us to do a good job of maintenance of pipeline pumps when using them, which can not only ensure the normal operation of the equipment, but also extend its service life.

The advantages of using sealless self-priming pumps in the field of traditional fermentation can be roughly divided into several energy-saving points: sealless self-priming pumps have energy-saving advantages over the current traditional steam heating. Environmental protection: sealless self-priming pumps have no toxic and harmful combustion emissions, and no greenhouse gas emissions. The noise meets environmental protection requirements. Safety: microcomputer control, water and electricity separation, no leakage risk, no poisoning, and no explosion risk. It can use the original site, process, and equipment, with a small footprint, light weight, and can be moved. Boilers have many faults and high repair costs. The use of sealless self-priming pumps does not use boilers in the fermentation process, which can greatly reduce the cost of boiler operation.   The existing power supply system of the sealless self-priming pump can meet the requirements, and no line modification is required. The sealless self-priming pump does not require steam and circulating water, and the original water and steam pipelines do not need to be repaired. It complies with the policy of energy saving and consumption reduction. The application of sealless self-priming pumps in traditional fermentation has a good alternative energy saving and consumption reduction value, and is a new energy technology worth developing. The application range of sealless self-priming pumps is very wide, especially in some harsh environments, some problems will arise, which requires negotiation with the manufacturer, and then the manufacturer's after-sales service will be tested. Nowadays, there are countless manufacturers of self-priming pumps. Users choose not only quality, but also after-sales service, thereby reducing customer troubles.   No matter how good the quality of the sealless self-priming pump is, there will be some problems in the early stage of running-in, especially when customers do not understand, the manufacturer's after-sales service is very critical. To a certain extent, after-sales service is even more decisive than the product. Therefore, it is particularly important in product marketing to provide good after-sales service, comprehensively improve the quality of one's own service, win customers by service, and expand product sales. Then, the relevant knowledge about the sealless self-priming pump will be introduced here today. I hope it will be helpful to everyone. If you have other questions, you can also call us at any time!

Pipeline pump pipeline mismatch: Some pipeline pump users believe that this can increase the actual head. In fact, the actual head of the water pump = total head ~ loss head. When the water pump model is determined, the total head is certain; the loss head mainly comes from the pipeline resistance. The smaller the pipe diameter, the greater the resistance, and thus the greater the loss head. Therefore, after reducing the pipe diameter, the actual head of the water pump will not increase, but will decrease, resulting in a decrease in the efficiency of the water pump. Similarly, when a small-diameter water pump uses a large water pipe to pump water, it will not reduce the actual head of the water pump. On the contrary, the loss head will be reduced due to the reduction of pipeline resistance, so that the actual head will be increased.   Some operators also believe that when a small-diameter water pump uses a large water pipe to pump water, the motor load will inevitably increase greatly. They believe that after the pipe diameter increases, the water in the outlet pipe will put greater pressure on the pump impeller, which will greatly increase the motor load. High-lift water pumps are used for low-lift pumping: Some pipeline centrifugal pump users believe that the lower the pumping head, the smaller the motor load. Under the misleading of this misunderstanding, when purchasing a water pump, the head of the water pump is often selected to be very high. In fact, for a centrifugal water pump, when the water pump model is determined, the size of its power consumption is proportional to the actual flow rate of the water pump. The flow rate of the water pump will decrease with the increase of the head, so the higher the head, the smaller the flow rate, and the smaller the power consumption. Conversely, the lower the head, the greater the flow rate, and the greater the power consumption.   There are many elbows on the water inlet pipe of the pipeline pump: If there are many elbows on the water inlet pipe, the local water flow resistance will increase. And the elbows should turn in the vertical direction, and are not allowed to turn in the horizontal direction to avoid air accumulation. When installing the water inlet pipe, the horizontal section is horizontal or tilted upward: Doing so will cause air to gather in the water inlet pipe, reduce the vacuum of the water pipe and the water pump, reduce the water suction head of the water pump, and reduce the water output. The correct approach is: its horizontal section should be slightly inclined in the direction of the water source, should not be horizontal, and must not be tilted upward.

The unique process design of forced circulation pump, regarding this aspect, the editor of our Shanhe Pump Industry will give you an introduction below: In the forced circulation pump outlet pipeline, due to high pressure, the diffusion speed of liquid molecules increases, the penetration ability is enhanced, and electrochemical corrosion is forced to occur more easily. The axial clearance of the bearing generally does not need to be adjusted. As long as it is assembled in the correct assembly order, its axial clearance has been guaranteed by the forced circulation pump. For ground pipeline anti-corrosion, it must be implemented. Under normal circumstances, we recommend that the pressure gauge is connected to the outlet end of the shaft seal water and a saving valve is installed.   The purpose of this is to prevent the pressure of the shaft seal water in the sealing cavity from being relieved, and the pressure gauge at the outlet end can truly reflect the pressure of the shaft seal water in the sealing cavity. Forced pump bracket structure This type of bracket pump shaft has good diameter, rigidity, and short cantilever, and will not bend or vibrate under harsh working conditions. The double-end face machine seal is mainly used as a matching, and the two machine seal structures are the same, and the forced thickness is thicker. Although the double-end face machine seal has its superiority in the circulation pump, the circulation pump also has many problems in actual use.   The forced circulation pump is manifested in the following: the pressure of the shaft seal water does not meet the design requirements. Environmentally friendly forced circulation pump, environmentally friendly forced circulation pump, referred to as forced circulation pump, is a new generation of series of forced circulation pumps carefully developed based on the experience of successful design and manufacture of slurry pumps, targeting the characteristics of industrial flue gas desulfurization pumps in my country, and accepting advanced technologies of similar products at home and abroad. Finally, it is placed on the bracket body. For the anti-corrosion protection of flue gas desulfurization, oil bath lubrication is adopted, and the lower part of the bearing is immersed in the lubricating oil. The standby pump should rotate the shaft a quarter of a turn every week to allow the bearing to evenly withstand static loads and external vibrations. The relevant knowledge about forced circulation pumps will be introduced here today. If you have any other questions, please feel free to call us!