Comparison of screw rotor pumps (rotating piston pumps) with other pump types and their own advantages
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1. The rotor consists of a pair of conjugate cams; when the cams rotate, the suction port becomes vacuum, and the liquid fills the entire pump chamber. The cam continues to rotate, sending the enclosed liquid to the outlet; there are no suction valve or discharge valve. 2. In China, it is called a spiral rotor pump or rotary piston pump, while abroad it is known as a cam rotor pump or rotary cam pump. 3. Compared with screw pumps: ① It saves one-third in energy consumption; ② Its maintenance cycle is longer than that of screw pumps. ③It can be maintained online; replacing spare parts requires no disassembly of any pipelines, enabling quick implementation. ④Non-squeezing working principle, few components require maintenance, **saving on spare parts costs. ⑤It can be operated in dry mode, which is especially important in case of sudden material interruption or operational errors, to prevent accidents. ⑥The installation volume is one-third that of a screw pump. 4. Comparison with centrifugal pumps: ① It can handle large-sized materials without clogging. ②No cavitation. ③It enables the mixed transportation of gas, liquid, and solid substances. 1. High efficiency: 75-85% 2. High self-priming capacity: 1-9m 3. High head: 1-200m; flow rate: 0.5-1400 4. Suitable for high viscosity fluids: 02-10 Pas 5. Clog-free, no need for a foot valve; resistant to dry grinding and high temperatures 6. Corrosion-resistant – suitable for media containing various chemical components 7. Capable of transporting both gas and liquid; can operate in forward and reverse directions. 8. Quick online repair, without the need to remove pipes or wires. Suitable for sludge treatment, wastewater, cleaning tanks from oil tankers, handling crude oil in gas-liquid-solid three-phase form, paraffin, suspensions, gasoline, diesel, lubricants, paints, toothpaste, crude oil, heavy oil, coal tar, asphalt, thick oil, as well as the transportation of various slurries, resins, solvents, and fibers. Rotor pumps, cam rotor pumps, piston rotor pumps, rotary piston pumps, bilge pumps, oil unloading bilge pumps, marine bilge pumps, dock cleaning pumps, methanol loading/unloading pumps, oil transfer pumps, petrochemical pumps, thick slurry pumps, crude oil pumps, heavy oil pumps, viscous oil pumps, residue oil pumps, oily wastewater pumps, sewage pumps, sludge pumps, oil-containing wastewater pumps, oily waste lifting pumps, river dredging pumps, feces transfer pumps, sewage and drainage pumps, self-priming pumps, imported rotor pumps, rubber-lined rotor pumps.
Maintenance is required frequently, especially the replacement of machine seals; there are a total of four sets of machine seals.
Hello! Conventional spiral rotor pumps are equipped with two sets of mechanical seals. The frequent failure of these seals, as you mentioned, is directly related to the medium being transported, as well as to the choice of mechanical seals used. You can leave a message describing your working conditions, so we can see if there is a suitable solution for you.
In our case, each end of a rotor is equipped with a set of mechanical seals. It is mainly used to transport sewage and slurry.
What are the disadvantages? For example, by how much is it more expensive than a centrifugal pump?
Four sets of mechanical seals are required due to the dual support. The pump shaft is too long; to achieve high pressure, dual support is necessary. Otherwise, if there is a gap of 5 threads or less in the pump shaft at the gearbox section, this gap increases by 10 times once it reaches the flow passage. If dual support is not used, once pressure builds up, the pump will vibrate, resulting in excessive wear of the rubber-coated rotor in the flow passage. With dual support, four sets of mechanical seals are definitely required. The reason for the complexity in maintenance lies in the use of non-modular mechanical seals; if modular mechanical seals were used, the maintenance costs would be reduced.