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1)When the slurry pump in gland sealed is in use, the gland seal water pressure and water volume should meet the requirements, and the tightness of the packing should be adjusted (or replaced) at any time, so as not to cause slurry leakage of the shaft seal, and the shaft sleeve shall be replaced in time. 2) When replacing the bearing, it is necessary to ensure that there is no dust in the bearing assembly and the lubricating oil is clean. Generally speaking, the bearing temperature during pump operation should not exceed 60-65 ℃ and the maximum should not exceed 75℃. 3) To ensure the coaxiality of the motor and the pump, to ensure that the elastic cusion in the coupling is complete and correct, and replace it in time after damage. 4) Ensure that the pump components and pipeline system are installed correctly, firmly and reliably. 5)Some parts of the slurry pump are wearing parts. Pay attention to the wearing of the wearing parts in daily use, and repair or replace them in time. During the repair or replacement of the consumable parts of the slurry pump, it is necessary to ensure that the assembly is correct, the clearance is adjusted reasonably, and the phenomenon of tight friction is avoided. 6) The suction pipeline system of the slurry pump must be free of air leakage. At the same time, pay attention to whether the suction port is blocked. The medium that the slurry pump needs to deal with often contains solid particles, so the grille placed in the pump pool should meet the requirements of the particles that the slurry pump can pass, reducing the possibility of blockage caused by excessively large particles or long fiber materials entering the pump body.

1. The design point of pump flow is generally designed according to the maximum flow requirements of the process. The actual operating point (C) of the pump is usually lower than the design point (B). If normal operation is to be maintained, bypass throttling or outlet valve adjustment is generally adopted to keep the pump running at the low flow point. This is bound to result in a waste of energy. 2. When the pump is selected, the design margin is left for safety reasons, which makes the centrifugal pump tend to be larger than the actual demand of the system, which makes the performance of the centrifugal pump tend to be higher than the actual demand of the system, thus leading to the centrifugal pump working in the area of large flow. The long-term off design operation not only can't give full play to the best efficiency of centrifugal pump, which leads to energy waste, but also greatly affects the operation reliability and service life of centrifugal pump. 3. According to the performance curve of the pump, the intersection of the pump curve and the piping system curve is the actual operation point of the pump (points A and B). After the speed adjustment, the actual flow of the pump can be adjusted stepless. When the pump speed n1 is adjusted to the speed n2, the actual flow point of the pump is adjusted from point A to the required point B, which reduces the fluid loss.

1. Direct drives Direct drive is the most common drive mode, which is often seen in the application of horizontal and vertical pumps. Pump, motor are directly connected. The speed of the motor is the rate of the pump. 2. Indirect drives Indirect drives are used for horizontal and vertical pumps, comprising motor (in various drive arrangements) and transmission (V-belt or gearbox.) V-belt Drives: A V-belt drive provides the most economical drive arrangement. There are several drive arrangements available for electric motors with belt drives, i.e. CV drive (overhead mounted), ZVz drive (reverse overhead mounted) and CRz drive (side mounted). CV drive and ZVz drive CRz drive The most common drive arrangements are CRz drive and CV drive. CV drive is generally the most economical and lifts the motor off the floor away from spillage. If the pump is of [back pull out" design and assembled on a [sliding maintenance base", servicing can be significantly simplified. Limitations CV drive: The size of the motor is limited by the size of the pump frame. If overhead mounting cannot be used, use side mounted motors (with slide rails for belt tensioning). V-belt transmissions (fixed speed drives) Impeller diameters of slurry pump (hard metal or elastomers) can not be easily altered, therefore, in order to change the performance, the speed must be changed. This is usually done with a V-belt drive. By changing one or both pulleys, the pump can be "fine-tuned" to achieve the duty point even when applications are changed. Provided the belts are tensioned correctly, modern V- belt drives are extremely reliable with a life expectancy of 40 000 hours and a power loss of less than 2%. V-belt transmissions – limitations When pump speed is too low (dredge pumping) or when the power is too high, V-belts are not suitable. In these cases gearboxes must be used. Variable speed drives For certain applications (varying flow conditions, long pipe lines, etc.), variable speed drives should be used. With variable speed drives the flow of a centrifugal pump can be closely controlled by tying the speed to a flow meter. Changes in concentration or particle size then have a minimal effect on flow rate. Should a pipe line start to block, the speed will increase to keep flow velocity constant and help prevent blockage. Modern electronic drives, particularly variable frequency drives have many advantages (can be used with standard motors) and are widely used.

As shown in the figure, this is a clear water performance curve of a slurry pump with an impeller diameter of245mmand model SMAH75-C(D) at different speeds.The performance curve (or characteristic curve) of a centrifugal slurry pump is an external manifestation of the law of liquid movement in the pump, which can only be measured in practice at present. Characteristic curves include: The Flow/Head curve (Q-H pump curve) (shown in Figure 1); The Flow/Efficiency curve (Q/η pump curve) (shown in Figure 2); The Flow/Net Positive Suction Head required by the pump curve (Q-NPSHr pump curve) (shown in Figure 3). Figure 4 represents The Flow/Head curve at a speed of 2000 r/min. The function of the performance curve is to find a set of relative head (H), efficiency (η) and NPSHr on the curve at any flow point of the pump. This set of parameters is called the working state, referred to as the working condition or working condition point. The working condition of the higher efficiency point of the centrifugal pump is called the better working condition point, and the preferred working condition point is generally the design working condition point. Generally, the rated parameters of the centrifugal pump, that is, the design operating point and the preferred operating point coincide or are close. In practice, the efficiency interval is selected, that is, energy saving, and the pump can be guaranteed to work normally. The basic curve for performance is The Flow/ Head (Q-H) curve, showing the relation between the discharge head of the slurry and the capacity (volume flow) at constant impeller speed. NPSHr: The Net Positive Suction Head required by a centrifugal pump, at any given point on it`s The Flow/Head characteristic curve, is the minimum net positive suction head value which the liquid pumped must posses at a point close to the pump suction flange, in order to avoid pump cavitation.

We have obtained a new patent --- The utility model relates to a sealing cover sealing structure of shaft seal of slurry pump

The conditions encountered in the selection of slurry pumps vary widely. Here are some general methods and ideas for selection. Ⅰ. Selection Conditions 1. Physical and Chemical Properties of Transport Medium The physical and chemical properties of the conveying medium directly affect the performance, material and structure of the pump, which are important factors to be considered in the selection of the pump. The physical and chemical properties of the medium include: medium name, medium characteristics (corrosion, corrosion resistance, etc.), the content, the size, the density, the viscosity, the vaporization pressure of the solid particles, and the like. 2. Process Parameters Process parameters are the most important basis for pump selection. (1) Flow Q, which refers to the medium quality required by the pump in the process equipment, and the normal, minimum and maximum flow are generally given. In general, the customer needs to select according to the maximum flow. (2) Head H, which refers to head value required by the process device. The head loss of the pipeline when conveying clean water and slurry is not the same. The head value should be calculated according to the length, the diameter, the number of elbows and vertical height of pipeline. (3)Inlet pressure and outlet pressure, which refers to the pressure at the flange of the pump inlet and outlet connection, the size of which affects the pressure resistance of the shell and the requirements of the shaft seal. (4) Temperature, which refers to the inlet medium temperature of the pump, generally gives the normal, minimum and maximum temperatures of the medium. The temperature sometimes determines the overall structure of the pump and the seal flushing scheme. (5)Net Positive Suction Head available from the system NPSHa must not be less than NPSHr (required by the pump) to avoid cavitation. (6) Operating state, divided into continuous operation and intermittent operation. (7)Site conditions Including pump installation location (indoor, outdoor), environmental temperature, relative humidity, atmospheric pressure, atmospheric corrosion and the classification of dangerous areas and other conditions. Ⅱ. How to Select a Slurry Pump? The selection of a slurry pump should be based on the technological parameters of the device, physical and chemical properties of the conveying medium, operation period and structural characteristics of the pump. 1. According to the site installation conditions, choose horizontal pump, vertical pump and sump pump. 2. Select low-speed or high-speed pump according to the flow rate, medium concentration and particle size. For the Warman pump, the L series pump is generally used for light-abrasion medium, the AH pump for heavy duty, and the HH pump for heavy duty high-head pumps. 3. According to the head, single-stage pump, two-stage or multi-stage series connection is selected. Because the speed of the slurry pump is inversely related to the service life of the pump. When the medium concentration is large and the abrasion is strong, two stages and multiple stages can be used in series. 4. Determine the material of the pump according to the characteristics of the medium. There are many materials available for slurry pump wet parts, which should be based on the physical (particle composition, particle size, shape, hardness, concentration) and chemical (acid, alkali, oil) characteristics of the slurry conveyed. Metal wear resistant material KmTBCr26 has good abrasion resistance to fine particles and good corrosion resistance to PH=5-11 slurries; KMTBCr15Mo3 has Brinell hardness up to 650-750 and good abrasion resistance to coarse particles; high chromium alloy A49 is suitable for acidic mixed slurry with PH=4-6; natural rubber is suitable for conveying weak acid, weak alkaline slurry, round particles (such as river sand) or fine particles( D ≤0.5mm) slurry. Ⅲ. Selection of Matching Power of Motor. Pump shaft power: Pa=ρQH/102η(KW)(Pa, pump shaft power; ρ, slurry density, kg/m3; Q,flow rate, l/s; H, head, m; η, efficiency). When the pump shaft power is calculated, the standard motor should be selected with a certain safety factor in consideration of factors such as pump startup and flow fluctuation. The safety factor generally takes 1.1-1.2, and the high power takes a small value and the small power takes a large value. Ⅳ. Selection of Shaft Seal Type. The shaft seal is a sealing device that prevents the pump shaft from leaking from the housing. Commonly utilized shaft seal types include packing seal, mechanical seal, and expeller seal. 1. Packing seal is simple, cheap and leaky. Shaft seal water should be added and sufficient water pressure and quantity should be ensured. 2. Mechanical seal has good sealing effect, less leakage and high requirements for installation and maintenance. 3. Expeller seal is generally reliable, cheap, easy to maintain, no shaft sealing water. Generally the slurry supply level is above pump centerline. The expeller seal is only effective when the pump is running.

WARMAN PUMP MAXIMUM ALLOWABLE BEARING SPEEDS The maximum allowable bearing speeds are listed are below for each frame and for standard lubrication utilising Warman recommended greases and oils. G=Greases and O=Oil. For Recommended Maximum Allowable Pump Speeds, refer to the Information Sheet which takes into consideration the impeller and liner materials and the maximum allowable impeller peripheral velocity. Allowable bearing speed is influenced by the type of lubrication, loads(radial and axial) and the bearing assembly operating temperature. At higher operating temperatures, re-lubrication intervals should to be shorter. WARNING:Pump operating within 25% of the maximum bearing speed should generally be reserved for [lightly loaded" applications (eg single stage pumps) to avoid possible lubrication or over temperature problems. High speed multistage applications involving high axial thrust loads should generally be limited to 50~75% of the tabulated maximum speeds. For further recommendations refer to Warman Head Office-Artarmon. FRAME LUBE TYPE SPEED(r/min) FRAME LUBE TYPE SPEED(r/min) A G 6100 CY O 4775 B G 4400 RY O 2425 C G 3450 SY O 1940 D G 2750 TY O 1385 E G 2000 PD O 4775 F G 1600 PE O 3245 G G 1150 PF O 2625 H G 800 PG O 2150 CC G 3170 2/2 TC G 4400 DD G 2750 3/3 TC G 3450 EE G 1830 4/4 to 10/8 TC G 2500 FF G 1400 250/250 TC G 2000 GG G 1000 VERTICAL FRAMES N,NP G 3900 PV G 3000 P,PQ G 3170 QV G 2350 Q,QR G 2750 RV G 1750 R,RS G 1830 RVH G 1800 S,ST G 1400 SV G 1400 T,TU G 1000 SVH G 1600 U,UV G 700 TV G 1000 CB G 4000 VC G 4000 DC G 3400 VCH G 3400 ED G 2200 VD G 3400 FE G 1900 VDH G 2200 VE G 2200 A4-100-7-125618:ISSUE DATE:August 1991 VEH G 1900

What kind of pump is a good pump? For the user of the pump, it is generally considered that the pump with high efficiency, low price and good effect is a good pump. But in the practical application, only in the case of achieving the same useful effect, the lowest comprehensive use cost (including pump manufacturing cost, pump shutdown cost, operation cost, power consumption cost etc.) of the pump is a good pump. An example is as follows: The use of the first phase of A Power Plant and the second phase of the ash slag pump are as follows: Engineering Staging Weight Concentration Pump Parameters Service Life of Wet Parts(month) Cw(%) Outlet Diameter (mm) Flow(m3/h) Head(m) Pump Series Phase 1 5.7% 250 1200 240 1 0.5 250 1200 120 2 2 Phase 2 14.3% 200 650 57.5 4 18 According to the service life of the pump (parts) in the table above, the economic comparison is listed in the following table: Engineering Staging Pump Series Pump Wet Parts Total Comprehensive Cost(￥) Purchase Price(￥) Annual Consumption(sets) Annual Total Costs(￥) Phase 1 1 100,000 24 1,008,000 1,108,000 2 200,000 12 504,000 704,000 Phase 2 4 304,000 2.67 78,700 382,700 It can be viewed on the above two tables that the four-stage series pumps have the least annual spare parts (12/18 4=2.67 sets) and the maximum economic benefits in long-term operation. Due to the low speed and low head, the operating reliability is higher. Depending on this idea, in view of the slurry pump design and use, combined with the use of experience, we suggest the following aspects. 1. Design parameters of slurry pump 1.1 Relationship between flow rate and the inlet and outlet of slurry pump When the design flow Q is determined, the paramount consideration is the diameter of the outlet of the pump. It is recommended to determine the outlet diameter and inlet diameter of the pump: Do≈6.1Q0.53 mm Di=Do+Ck mm Where: Q-Pump design flow, m3/h Do-Pump outlet diameter, rounded to standard diameter after calculation Ck -Experience constant, generally Ck=20~50 mm 1.2 Relationship between pump head and speed: Hn/1000≤KHn Where: H- Pump head, m n - Pump speed, r/min KHn- Empirical coefficient related to the service life of the pump, whose value is as follows: Slurry Abrasion Characteristics Heavy Duty Moderate Duty Light Duty KHn 20-60 60-90 90-120 2. Use the right pump material In the use of the slurry pump, it is also important to correctly select the material of the wet parts suitable for the working condition. If the material of the wet parts is not properly selected, the pump service life will be greatly shortened. At present, there are two kinds of materials commonly used in slurry pump wet parts: metal material and non-metal material. 2.1 Commonly used metal materials include KmTBCr26, KmTBCr15Mo3, etc. When solid particles are coarse, KmTBCr15Mo3 should be utilized, and KmTBCr26 should be used for fine particles. 2.2 Non-metallic materials: 2.2.1 Rubber materials: natural rubber, butyl rubber, etc., suitable for conveying round particles (such as river sand) and fine particles (d≤0.5mm) abrasive slurry. 2.2.2 Polyurethane material: the abrasion resistance is the same as the metal material, and it can be used as the part with weak bearing capacity. It is not a substitute for rubber. 2.2.3 Ceramic materials: suitable for slurry with corrosion, abrasion and low impact toughness.

The New Slurry Pump Transport System 1. Introduction Centrifugal slurry pumps such as metal pumps, rubber-lined pumps, ceramic pumps etc. are widely used in mining, electric power, metallurgy ,dredge, coal and other industries. The market share of the metal slurry pumps has been ranked the first for decades, and its market capacity is reaching 10 billion. With the technology development of all industries, the newer and higher requirement has been put forward in the new era of social development. The existing slurry pump delivery systems need to be updated for solving the following problem during use: A. Customize products for use conditions are needed. B. The MTBF should be expanded more regularly, and the service life of all vulnerable parts should be as same as possible. C. The product can be adaptive to changing performance point. D. The product seal should be leak-free to achieve environmental protection. E. The product is highly efficient and energy-saving throughout its life cycle. 2. The design idea of the new slurry pump system. The Goal of the new slurry pump system:High efficiency, energy saving, stable operation, safe and reliable, long life and convenient control. For this goal, we put forward new design ideas. 2.1 [Four Parts Three Match" The design is optimized taking pipe installation, slurry pump, motor, control system as a whole system. We have fully considered the role of pressure, flow, pipe line, slurry, equipment and other factors to make [four parts three match " perfect. 2.2 Reasonable selection and optimization design of slurry pump must be needed. 2.3 High efficiency permanent magnet motor is preferred. 2.4 Optimize the design of automatic control to realize adaptive working of system, and realize the real-time monitoring and the control of mobile phones, computers. 3. The core of the new slurry pump: "Four Parts Three Match" 3.1 Four Parts As shown in above picture, the slurry pump system consists of pipe line, slurry pump, motor, control system four parts. 3.2 Three Match The matching between the four parts of the slurry pump conveying system, the slurry pump, the motor and the control system determines the operation effect of the system. We conducted in-depth investigation and research, and obtained a good result by analyzing a large amount of experimental data, and proposed a new slurry pump delivery system. No. 1 Match-The match between pump and pipe line In above picture, A-----Q-H curve of pump B---Q-H curve of pipe line C---NPSHr D-NPSHa m----working point d--- Pump cavitation critical point In the new slurry pump system, the performance of the pump and the piping are automatically matched perfectly. The pump is always operating at the optimum point of efficiency, extending pump life and reducing operating costs of the conveyor system. No. 2 Match As shown in the picture above:In the new slurry delivery system , the working curve of the motor and the power curve of the pump are matched perfectly. The load rate of the motor is maintained within a certain range, the torque meets the pump torque requirement, and the motor ensures safe operation in the high efficiency zone to achieve energy saving effect. The high-efficient load rate of rare earth permanent magnet motor is higher ordinary motor, and it is easy to match to pump. No. 3 match-The match between motor and control system The Variable frequency control system changes the frequency of the motor according to a certain rule to ensure that the motor can smoothly and efficiently operate whether it is starting or adjusting the speed during operation. Each part of the new slurry pump delivery system installs flow, pressure, vibration, voltage, current and other sensors according to the requirements. According to the feedback signals of the sensors, the Variable frequency control system changes the operating parameters of the system according to the optimal scheme, so as to achieve the slurry pump delivery system running at its best. The variable frequency control system can transport the real-time data to the server and analyze the data. It has certain guiding significance for equipment maintenance, vulnerable parts replacement and construction technology. The new slurry pump system we designed has been tested in coal, desulfurization, mining and other industries, and has achieved good results in energy saving and reliability. New project: provide the newest idea design scheme Renovation project: provide the best technological transformation scheme according to real working conditions

In the process of slurry pump selection, transport of solid materials is an important factor, which affects the slurry transmission concentration, pipe friction coefficient, determination of parameters, such as settling velocity. 1 The density of Common Solid Material metallurgy Mine Power Coal Cement Other Material t/m3 material t/m3 material t/m3 material t/m3 material t/m3 ore sand 2.5~4 ash 2~2.2 Iron ore powder 4.8~5 limestone 2.64 silica sand 2.1 Tailings 2.7~3.2 cinder 2.2~2.4 coal slime 1.6 clay 1.35~2 river sand 2.36 ore concentrate 4.8~5 Liquid cinder 2.4~2.7 2 The Median particle size of solid -d50 The Median particle size of solid d50, is the sieve diameter when the material weight on the sieve is same as under the sieve by sieving method to be Grading of material particle size. The value of d50 is usually determined by the production process of materials. For natural materials, on-site investigation is required. The d50 of medium and coarse sand in the river and sea is usually calculated as 0.231mm. 3 Solid material particle size millimeter mesh comparison table millimeter mesh comparison table in GB2476 mesh millimeter mesh millimeter mesh millimeter 8 2.5~3.15 30 0.5~0.63 120 0.1~0.125 10 2.0~2.5 36 0.4~0.5 150 0.08~0.1 12 1.6~2.0 46 0.315~0. 180 0.063~0.08 14 1.25~1.6 60 0.25~0.315 240 0.05~0.063 16 1.0~1.25 70 0.2~0.25 280 0.04~0.05 20 0.8~1.0 80 0.16~0.2 24 0.63~0.8 100 0.125~0.16 millimeter mesh comparison table in US standards mesh millimeter mesh millimeter mesh millimeter 8 2.38 30 0.595 100 0.149 12 1.68 45 0.352 140 0.105 16 1.19 60 0.21 200 0.074 20 0.841 80 0.177 270 0.053 Based on the above two tables, it can be estimated according to "mm =20/ sieve size" without a comparison table to meet the needs of slurry pump selection. (Shijiazhuang Soarho Mechinary LTD., internal technical materials)

In August 2018, our company obtained four utility model technology invention patents.