|  Why 2nd generation of submersible sewage pumps?
A concept for 20th century Europe - a pump for 21st century World !
The 1st generation submersible non clog pumps used in India were either designed for European conditions or based on these European pumps (either through inspirations or collaborations). However the Indian (& for that matter most developing countries) have operating conditions that are drastically different (much harsher on pumps), like:
| Condition |
Effect on Pump |
Result |
| Poor Electrical Supply |
Motor Insulation Stressing |
Premature motor burnout |
| Higher Ambient Temperature |
| Poor liquid level sensing & operation by often unskilled staff leading to frequent Dry Running |
Excessive heating leading to motor insulation burn out, bearings grease leakage & possibly seizure; Mechanical seal overheating |
Immediate motor, bearing & mechanical seal failure |
| Poor or defunct Solid Screening leading to high concentration of solids, especially fibrous ones |
Dangerous cocktail of large solids & fibrous waste plait up & choke conventional non clog impellers leading to motor stall |
Immediate Motor
Insulation burnout |
| Higher content of sand, silt & ash in sewage |
accelerated erosive wear of impeller Leakage Clearance |
Drop of pressure & efficiency |
hence their performance in India was below the mark. Our engineers were amongst the first to realize this mismatch between design & operating conditions. Here the concept of ANS was born - ANS is the First 2nd second generation of submersible sewage pump specifically redesigned / upgraded for operating conditions of developing countries; some of its salient features are :
-
Heavy duty motors (with large reserve margins) rated at 50 C ambient temperature
-
Superior Non Clogging hydraulics with vastly improved Fibrous solid handling abilities
-
Abrasion resistant pump portion due to elimination of all soft metal parts (support rings,bushes, etc)
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High Temperature, Dry Run Resistant bearings
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Dry Run Fail resistant Mechanical Shaft Seals
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Multi stage Cable Gland Sealing resists water ingress in motor winding thereby preventing burnout
-
Simple & cost effective Efficiency Restoration System
Design
1.Cable Gland
is specially designed to prevent moisture ingress (into the motor windings via capillary action) even in case of cable’s protective outer sheath puncture.
2.Reliable Shaft sealing
Two, Independent Mechanical Shaft Seals allow a longer useful life even in case of failure of one seal. Both the seals are bidirectional permitting safe Reverse rotation in case of accidental reverse rotation or intentional pipeline back-flow (to flush out bottom sedimentation at suction side). The primary seal is of Silicon Carbide faces while all “O” rings are of FKM for enhanced dry run fail safe characteristics.
3.Self Centering Lifting Hook
enables the pump to be “fished out” in the event of chain breakage (without the need of the operator going down to the sump floor).
4.Heavy Duty Motor
Instead of using off the shelf standard motors; we design & build our own motors with higher reserve margin, Class “F” insulation (class “H” insulation optional) & Vacuum Pressure Impregnate them (for air bubble free varnishing).
Larger motors can be offered with Dual Cage Copper Bar rotors for Higher efficiency, Lower Operating temperature, Increased Safety (against burnout) & Easy On site repairs.
Note : for VFD applications it is strongly recommended that the the motor insulation is Class “H”, the rotor is of Dual Cage Copper Bar & one of the bearings is Current Insulated.
5.Motor Thermal Overload Protection
Bi-Mettalic switches are embedded into each phase of winding to detect accidental overheating & thereby trip off the power. Optionally Thermistors (PTCT ) or PT 100 transducers can also be offered.
6.Shaft
Is always made from rust free stainless steel & designed without any sleeves for long maintenance free life.
7.Seal Condition Monitoring
Standard fitted, in the event of primary seal leakage the same is detected by the inbuilt moisture sensor & displayed in the control panel. Optionally moisture detectors in motor chamber can also be provided.
8.Pump Casing
CA Designed Casing withstands impacts (during handling especially with portable emergency duties).
Full In Volute profile (as opposed to simple concentric design) increases pump efficiency.
Impellers
Advanced CA Designed impellers are optimized for raw unscreened sewage – they can handle large solids as well as fibrous wastes (which generally plait up & clog up conventional non clog impellers). To obviate the leakage losses (due to erosion of wearing rings), our pumps don't have any soft metal wearing rings / bushes. Restoration of the pump’s efficiency is simple, easy & quick.
Semi Open Impeller |
Selection :
Vortex impellers are preferred for small pumps (upto 100mm discharge size) operating in heavily solid laden unscreened sewage or gassy crude sludge.
Semi Open, Single / Double Channel type impellers are preferred for medium sized pumps ( from 125mm to 250mm discharge size ) operating in unscreened sewage.
Fully Enclosed Double / Triple Channel impellers can be fitted on larger pumps ( discharge sizes exceeding 250mm) for screened sewage, storm water, industrial waste water & effluents with lower fibrous waste content |
Vortex Impeller |
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