LEWA pumps

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LEWA pumps I. Pump types: 1. P-3103A/B: Horizontal triple-plunger positive-displacement reciprocating pump. Model: G3F 2, P-3105A/B: Horizontal opposed-piston diaphragm pump. Model: ESB1. II. Working principle of LEWA pumps: LEWA pumps are reciprocating positive-displacement pumps. Volumetric flow rate is generated by periodically repeating a predetermined stroke displacement determined by the plunger area and stroke length. The volume and flow rate can be changed by altering the stroke length (such as P-3105A/B) or the stroke frequency (such as P-3103A/B), or by changing both. 1. The P-3103A/B pumps consist of ① a drive unit for the assembly, ② a pump transmission mechanism, ③ a pump head (plunger), and ④ inlet and outlet valves and other accessories. The power required to increase the pressure of the fluid transported from the inlet to the outlet is provided by the driver (motor). Model: ED-Ⅱ-T3) is available. The rotation of the driver is converted, through a transmission mechanism, into a swinging (back-and-forth) motion of the plunger to perform work. 1.1 Plunger pump heads: Φ60×494, 3 units; material: 316Ti coated with NiC2. 1.2 Pump casing: 560×360×510, 3 units; material: 316Ti (DW1.4571). 1.3 Inlet/outlet valves: Composed of a valve seat, valve disc, valve spring, and internal valve components. ⑴Inlet/Outlet valve seats: Φ96.5×32, 6 pieces; material: Hastelloy C. (2) Inlet/Outlet valve discs: Φ52×16, 6 pieces; material: Hastelloy C. (3) Valve springs: Φ52.5×40.9, 6 pieces; material: Hastelloy C 1.4. Transmission mechanism: A single-shell three-stage transmission mechanism, with an eccentric shaft supported at both ends and an internal turbine reducer. The three cams on the eccentric shaft alternate evenly with one another, resulting in smooth operation and low pulse output. The transmission system operates on the principle of the crank crosshead; the rotational motion of the turbine connected to the drive motor is transmitted directly to the eccentric shaft through the turbine (3), which in turn drives the plunger rod via a connecting rod. ⑴Screw: Φ94.8×542, 1 piece; material: DIN1.7131 (CrMo steel). Gear transmission ratio I=9.25.
(2) Turbine: Φ344×61, 1 piece; material: DW2.1052(); gear transmission ratio I=9.25.
(3) Eccentric shaft: Φ280×1240, 1 piece; material: DW0.7040(); displacement: 00/1200/2400.
(4) Connecting rods: 531×278×50, 3 pieces.
(5) Piston rods: Φ110×423, 3 pieces; thrust capacity: 45 KW.
(6) Transmission device housing: 1205×1000×663, 1 piece; material: DIN0.625. Bearings: The two ends of the screw are supported by bearings: (1) The front bearing (at the drive motor end) is a tapered roller bearing, Φ355×Φ125×37, 1 piece; (2) The bearing on the other side is a short cylindrical roller bearing, model NU211.E.M1. For 1 eccentric shaft, the bearings at both ends are as follows: (1) Front bearing (turbine side): Tapered roller bearing, TDO 780 Φ181×105, 1 piece; (2) Rear bearing: Short cylindrical roller bearing, NU2320E.M1. Φ215×73, 1 piece. Lubrication for the transmission units: 1.6.1 Amount of lubricating oil per transmission unit: 135 liters. The starting oil temperature of the transmission is 00°C; the maximum temperature of the transmission is 700°C; the normal operating temperature range for the transmission is -20 to +500°C. 1.6.2 Check the level of the lubricating oil once a week. The oil level should reach the scale mark on the glass tube gauge or the center. After 8,000 hours of operation, the lubricating oil should be replaced at least every two years. 1.6.3 The oil cooler is of the large-end and small-end type; the dimensions of the large end are 985×165×165, while those of the small end are 41×47.3×55. The material used is 1.4571. A flexible ROTEX coupling is employed to connect the pump to the motor. 1.8 Shaft seal: Packed seal is used. It consists of 13 packing rings and 3 bushings, divided into 2 groups. One set is used to seal process media, and the other set is used to seal oil. One set of packing rings: GR.60 HS 8×8×228, made of material P1.0; 9 pieces in total. The packing gland bolts are of size M20. Another set of packing rings: GR.60 ALΦ72×6, made of material P0.2; 4 pieces in total. The packing gland bolts for this set are of size M12. The liquid that leaks out is discharged through a 3/4″ pipe at the bottom. 1.9 The pump head is equipped with an integral heating jacket. The steam is low-pressure steam at 1650°C and 6 bar.g. The process parameters for pumps P-3103A/B are as follows: Medium: molten urea; Outlet pressure: 81 bar.g; Pump speed: 16–159 rpm; Plunger speed: 0.47 m/s (max) at 159 rpm; Stroke: 90 mm; Motor speed: 3. The operation of pumps P-3105A/B involves the transmission mechanism converting rotational motion into oscillatory motion, driven by the motor. The transmission operates on the principle of a linear thrust crankshaft. The worm shaft is connected to the motor, transmitting rotation directly to the eccentric wheel via the turbine and the hollow shaft. The eccentric block rotates within the slider, which is controlled by the yoke. The collar and slider convert rotation into the reciprocating motion of the plunger rod. The plunger stroke length is adjusted by turning the handwheel. The reciprocating plunger transmits motion to the control push rod, which acts on the diaphragm; the diaphragm in turn acts on the fluid being measured, thereby creating a suction action. 3.1 Diaphragm pump heads: Specification: GR.60/70 ESM511. Dimensions: 320×690×480. Material: DW1.4571-3B. There are 2 diaphragm pump heads, which are divided into three functional chambers: the operating chamber (in contact with the fluid to be measured), the hydraulic chamber, and the hydraulic system oil tank. Diaphragm specifications: GR.70/85 HS; dimensions 330×330×120. It is a jacketed diaphragm, made of P.T.F.E. Between the hydraulic chamber and the hydraulic system tank are a plunger and control rods, as well as a hydraulic double-function valve (comprising a pressure reduction valve and a vent valve), a hydraulic jet valve, and control rods. These valves are used to control the displacement of the diaphragm, preventing the pump from being overloaded or misoperated. The amount discharged by the diaphragm is always less than that of the plunger, because with each stroke, a small amount of hydraulic fluid is discharged from the hydraulic chamber into the hydraulic system tank through the relief valve and the plunger seal. This excretion can only be replenished through a jet valve. The function of the air release valve is to eliminate measurement errors caused by gas accumulation in the hydraulic chamber. It is located at the highest point of the hydraulic chamber. The hydraulic valve protects the pump from accidental operation, and it also serves as a safety valve for the entire system when the pump generates process pressure on its own. A hydraulic jet valve opens to supply liquid from the hydraulic system’s tank into the hydraulic chamber when a vacuum is created in that chamber and the pressure drops below a predetermined value. 3.2 Inlet/Outlet Valve: Valve seat: 440 (DIN 1.4122); Cone valve: KERF40ES; Dimensions: Φ87×94. Valve spring: 316Ti (DIN 1.4571FH); Dimensions: Φ35.6×30.8. 3.3 Drive mechanism: Single-casing, two-cylinder opposed type. 3.3.1 Worm: Φ75.6×486, material DIN 1.7131; gear transmission ratio I=10.0, 1 piece.
3.3.2 Worm gear: Φ276×46, material DIN 2.1052; gear transmission ratio I=10.0, 1 piece.
3.3.3 Hollow shaft: Φ180×313, material DIN 0.7040, 1 piece.
3.3.4 Sliding shaft: Φ90×242, material DIN 1.7131, 1 piece.
3.3.5 Adjustment rod: Φ57×294, material DIN 1.4021, 1 piece.
3.3.6 Eccentric block: Φ220×118, material DIN 0.7040, 1 piece.
3.3.7 Slider: 250×250×40, 1 piece.
3.3.8 Plunger rod: Φ106×393, 2 pieces.
3.3.9 Guide rails: 250×250×270, 2 pieces; material DIN 0.6025.
3.3.10 Grooved plunger: Φ60×266, material DIN 1.7131.
3.3.11 Plunger ring: GR60, material DIN 70910; dimensions Φ60×2.5, 2 pieces.
3.3.12 Control push rod: specification 85D EH.EZ.ES G3F; dimensions Φ85×77, 1 piece.
3.4 Bearings:
3.4.1 Bearings at both ends of the worm: the front and rear bearings are tapered roller bearings, dimensions Φ55×95×30, 2 pieces.
3.4.2 Bearings at both ends of the hollow shaft: the front and rear bearings are tapered roller bearings, dimensions Φ110×170×38, 2 pieces.
3.4.3 Axial roller bearings for the sliding shaft: dimensions Φ40×60×13, 2 pieces.
3.5 The pump and motor are connected by a flexible coupling, ROJEX.
3.6 Shaft seals are the same as those in P-3103A/B.
3.7 Lubrication is achieved through splash lubrication.
4. Maintenance of LEWA pumps:
4.1 Loosen the oil drain plug and stopcock at the bottom of the drive mechanism to drain the oil.
4.2 Remove the pump head and detach the plunger from the plunger rod.
4.3 Remove the manual stroke adjustment mechanism and loosen the control lever.
4.4 Unscrew the hex screws and remove the dial. Push the scale ring upward until the snap ring is removed. 4.5 Turn the handwheel in the direction of \"increasing stroke\" (clockwise). Until the entire manual adjustment mechanism is removed: 4.6 Remove the bearing flange; 4.7 Take out the two spring plates. Move the eccentric block to the 0 position by pulling the adjustment rod upward, and insert an appropriate spring plate into the inclined groove of the sliding shaft. Remove the yoke and sliding shaft from the transmission mechanism. 4.8 Pull out the plunger rod guide, as well as the plunger rod with its flange. 4.9 Lift the hollow shaft on the worm gear’s central axis until the teeth of the worm gear are no longer in contact; then remove the hollow shaft, the entire worm gear set, and the adjustment mechanism. 4.10 Remove the hub from the worm gear. 4.11 Disassemble the adjustment mechanism, take out the retaining ring, and use a wooden hammer to push out the screws with edges. The adjustment rod, along with the bearings and sliding shaft, can be pulled out together. Screw out the threaded sleeve from the sliding shaft, and pull out the adjustment rod along with the axial bearings. 4.12 Use a lifting pulley to remove the axial thrust washer and the inner ring of the clamp-type roller bearing from the hollow shaft, and then remove the eccentric block. 4.13 Remove the turbine. 4.14 Disassemble the inlet and outlet flanges. 4.15 First remove the two hex head screws and replace them with two longer bolts; then remove the remaining hex head screws and slide the diaphragm body over the bolts. 4.16 Remove the plug at the bottom of the oil tank to drain the hydraulic fluid. 4.17 Remove the hydraulic double-action valve and the hydraulic jet valve. 4.18 Remove the piston seal; for seals with piston rings, use a sharp tool to push them out of the groove. 4.19 Remove the control rod; reinstall it in the reverse order. 5. Process parameters for P-3105A/B: Medium: Ammonia. Outlet pressure: 94 bar. Pump speed: 142 rpm. Stroke: 60 mm. Piston speed: 0.32 m/s (max). Inlet and outlet flanges: 1 1⁄2” 1500# RF