KR20080082697A - A screw type centrifugal pump - Google Patents

Abstract

A screw type centrifugal pump is provided to prevent damage to a delivered substance and wear of a casing by forming a gentle curved passage between a suction port and a discharge port. A screw type impeller(100) comprises a front part having a screw part(2) and a rear part having a centrifugal part(3). The screw part generates strong absorption force using Archimedes principle. The centrifugal part converts axial energy into centrifugal energy along a curved line formed by the impeller. The screw type impeller has a single screw type feature(1), so that floating matters and solid matters of sludge are directly delivered from a suction port to a discharge port without rotating between the impeller and a casing.

Description

Screw-type centrifugal pumps {A SCREW TYPE CENTRIFUGAL PUMP}

Figure 1. Cross-sectional view of a single helical screw 1 centrifugal pump impeller 100 composed of a screw portion 2 and a centrifugal portion 3

Figure 2. Sectional view in the direction of travel (4) of the solids contained in the fluid of the vane centrifugal pump.

Figure 3. Sectional view in the direction of travel of the solids contained in the fluid of the vortex pump.

Figure 4. Cross sectional view (6) in the direction of solids of a single helical screw centrifugal pump.

Figure 5. Spiral groove inside screw intake cover (7)

  Humanity has been interested in water supply and drainage facilities since ancient Roman times two thousand years ago, and has developed a transport system for the treatment of sewage and sludge discharged from industry and urban development. The development of pumps has been remarkable.

  Until now, the pump types have been generally classified into volume pumps and cost pumps, and they have been developed according to their own uses, but recently, two types of pumps have been reviewed since energy saving and operation cost reduction have been pursued.

  In the past, when designing pumps, sewage and sludge pumps largely excluded the efficiency and performance characteristics of pumps to prevent clogging in the casing. Developing.

  When transporting fluids, they often face difficulties due to the inclusion of solids. In general, when the solid content is less than 5%, single or double vane centrifugal pumps are used, but the heads / capacity and efficiency decrease as they are continuously used. If the solids content is 5% or more, the general centrifugal pump cannot be used despite the high efficiency. If it is 8% or more, the vortex pump is selected. At higher solids content than 8%, screw, diaphragm and piston pumps can be used to transfer high concentrations of material, but the pulsation output is less efficient and more difficult to maintain. When it is necessary to continuously transfer a fluid having a solids content of 8% or more at a moderately high discharge pressure, a mono pump modified from a screw pump is used. This method is also an uneconomical solution and has limited pump capacity.

  An object of the present invention is a single-screw centrifugal pump impeller (100) having a high performance solids transfer capability that can be used where a high efficiency, a large capacity, a high discharge head, a high feed limit volume, and a solids transfer pump having a reasonable price. )

The present invention relates to a screw centrifugal pump impeller (100). First, the most characteristic part of the structure is a pump impeller consisting of a single spiral structure (1) similar in shape to a cork screw as shown in Fig. [1]. to be. This impeller consists of a screw part 2 and a centrifugal part 3, as shown in Fig. [1], and follows the impeller itself curve of the screw part 2 and the latter part, which produce the Archimedes effect in the first half and create a strong suction force. Characterized in that divided into the centrifugal portion (3) for converting the axial energy into centrifugal energy. The first half, which is the screw part 1 of the impeller, produces the Archimedes effect and creates a strong suction force due to the turning lowering action, thereby increasing the suction capacity and lowering the suction head. And the second half, which is the centrifugal part 2, has an ideal hydraulic characteristic by converting the axial energy into centrifugal energy along the gentle slippery curve of the impeller itself.

  Comparing the vane, vortex, screw-type centrifugal pump can clearly see the difference of the above characteristics. Single vane or double vane centrifugal pumps and vortex pumps are used to transfer sludge or solids containing fluids with moderately fast flow and high lift. [2] and [3] show cross-sectional views of typical vane-type centrifugal pumps and vortex pumps that can handle solids. [4] is a cross-sectional view of the screw-type centrifugal pump to be shown in the present invention. When transporting sludge containing solids, the shape of the solids raceway inside the pump is very important. Figures [2] and [3] show that the vane pumps have a moving direction (4) and a vortex pump. It can be seen that the direction of travel 5 of the solids contained in the fluid changes drastically, but the change in the direction of travel of the solids is suppressed by inertia, which causes a large amount of solids to contact the back of the impeller. However, the moving path of the solids in the screw-type centrifugal pump is line OB 6 of FIG. In summary, since the impeller used in the vortex pump used up to now has a sudden change in the direction of fluid flow in the impeller and the casing, the suspended matter and the solid collide in the impeller and the casing, thereby causing Promote breakage and casing wear. On the other hand, as shown in Figs. [1] and [4], the screw centrifugal pump impeller is a single helical structure (1), so that suspended solids and solids of sludge are transferred from the inlet to the outlet without being strongly rotated in the impeller and the casing. The impeller 100 is a device. This structure is characterized by a gentle curve, which slows down the breakage of the conveying material and wear of the casing.

  The performance characteristics of the single helical screw centrifugal pump impeller 1 show a high efficiency as a non-clog pump. However, depending on the point of use, the same performance can be achieved even when using a lower electric motor than a vortex pump. When transporting fluids, it often faces difficulties due to the inclusion of solids. Screw-type centrifugal pumps can transfer speed and kinetic energy to solids due to the characteristics of the screw impeller (2). At lower fluid concentrations, almost constant head flow rates can be maintained, but in vanes and vortex pumps, most of this energy is lost in the centrifuge.

  In addition, all pumps are clogged with heavy operation for no closure, and screw centrifugal pumps can achieve the most complete no-clogging operation of all centrifugal pumps. This problem is solved by a large suction through the screw-type impeller with a single helical structure (1), which obstructs the blockage that can be caused by a soft solid object in a vane or vortex pump.

  And the screw type centrifugal pump of the present invention [5] is provided with a spiral groove (7) on the inner surface of the suction cover to prevent the adhesion of the fibers between the impeller 100 and the suction cover and to smoothly transport the solids have. This feature allows the spiral groove 7 of the screw suction cover to cut the fibers and solids, thereby preventing the adhesion of the fibers, and to prevent the twisting in the impeller by allowing the long object to pass through the impeller in a single pass method. do.

 As described above, according to the present invention, a screw centrifugal pump impeller having a single spiral structure 1 having a cork screw shape, unlike the impeller used in the conventional pump, creates a strong suction force of the Archimedes effect and the screw part 2 and the impeller itself. It consists of a centrifugal part (3) which converts axial energy into centrifugal energy along the curve, and forms a gentle curve from the inlet to the outlet, so that high concentration sludge suspended solids and solids do not rotate in the impeller and casing. As it is transferred immediately, it can reduce the damage of the conveyed material and the casing wear due to the clogging phenomenon, and maintain a constant head flow rate with the change of the fluid concentration. In addition, the spiral groove 7 between the impeller and the suction cover is characterized in that it can prevent the adhesion of the fiber and smoothly transport the solids.

Claims (4)

 Single spiral impeller (100) shaped like a cork screw. The method of claim 1,    It consists of a screw part (2) which produces the Archimedes effect in the first half and creates a strong suction force, and a centrifugal part (3) which converts the axial energy into centrifugal energy along the impeller itself curve in the second half. The method of claim 1,     An impeller device, characterized in that the float and solids of the sludge are conveyed directly from the inlet to the outlet without rotating in the impeller and casing because of a single spiral structure (1). The method of claim 1,     Screw-type centrifugal pump, characterized in that the spiral groove (7) is provided on the inner surface of the suction cover to prevent the adhesion of fibers between the impeller and the suction cover and to smoothly transport the solids.

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