Ash Disposal Centrifugal Single Suction Mixer Sewage Pumps

Coal ash slurry pump & Slurry Pump and ash pump

If clean water is important to you and your family, you need to know about a silent danger to our waterways and public health.

Coal ash, the waste left over after coal is burned to generate power, contains concentrated amounts of heavy metals, such as lead, mercury, arsenic, chromium, and selenium, which are hazardous to human health, and to wildlife.

Thermal power plants generate more than half of the world’s electric power by burning millions of tonnes of coal and simultaneously produce large quantity of coal ash. Slurry pipelines are commonly used across the world for the transportation of coal ash (fly ash and bottom ash) from the plant to the ash ponds in thermal power plants. These systems are very energy intensive and also lead to excessive wear of pipeline and wastage of water.

Further, the present enhanced consciousness towards the imbalance in the eco-system and related stringent government policies are forcing the thermal power plants to adopt environment friendly transportation systems. Thus, high concentration slurry disposal (HCSD) system has emerged as preferred option to transport coal ash in thermal power plants as it is economical and environmentally friendly.

Concentration of 50% by weight was the limit of safe pumping of coal ash using a centrifugal pump and positive displacement pumps may become necessary to pump coal ash slurries above this concentration.

Pumps Used for Pumping of Sewage

Centrifugal pumps are most commonly used for pumping sewage, because these pumps can be easily installed in pits and sumps, and can easily transport the suspended matter present in the sewage. A centrifugal pump consists of a revolving wheel called impeller which is enclosed in an air tight casing to which suction pipe and delivery pipe or rising main are connected.

The impellers of centrifugal pumps have backward curved vanes which are either open or have shrouds. Open impellers have no shrouds. Semi-open impellers have only a back shroud. Closed impellers have both the front and the back shrouds. For pumping sewage either open or semi-open type impellers are commonly used.

The clearance between the vanes of the impeller is kept large enough to allow any solid matter entering the pump to pass out with the liquid so that the pump does not get clogged. As such for handling sewage with large-size solids, the impellers are usually designed with fewer vanes. The pumps with fewer vanes in the impeller or having large clearance between the vanes are called non-clog pumps. However, pumps with fewer vanes in the impeller are less efficient.

A spiral shaped casing called volute casing is provided around the impeller. At the inlet to the pump at the centre of the casing a suction pipe is connected, the lower end of which dips into the liquid in the tank or sump from which the liquid is to be pumped or lifted up.

At the outlet of the pump a delivery pipe or rising main is connected which delivers the liquid to the required height. Just near the outlet of the pump on the delivery pipe or rising main a delivery valve is provided. A delivery valve is a sluice valve or gate valve which is provided in order to control the flow of liquid from the pump into the delivery pipe or rising main.

Sewage Disposal Single Stage Plastic Centrifugal Pump For Chemical

1. Self-flushing: washing with chemical centrifugal pump medium, the internal circulation and the external circulation can be used as two methods of cirsulation, the internal circulation refers to the chemical centrifugal pump medium from the outlet of the impeller to the chemical centrifugal pump cover through the hole to the sealing surface and then along the chemical centrifugal pump shaft into the chemical centrifugal pump body. The external circulation refers to the medium being fed from the outlet of chemical centrifugal pump from the pipeline to the sealing gland and into the sealing chamber. The external circulation can be equipped with heat exchanger, suspension separator and other auxiliary equipment, and orifice plate should be added when the external circulation is needed.

2. Flushing: The seal is immersed in the chemical centrifugal pumping medium during operation without the circulation of washing liquid. If the temperature of the chemical centrifugal pumping medium is high, a cooling jacket shall be added; if the freezing point of the chemical centrifugal pumping medium is high, a heat preservation jacket shall be added.

3. External supply source flushing: pour the liquid from the external liquid source into the sealing chamber. The external supply liquid must have the appropriate pressure, the temperature must be less than the chemical centrifugal pump medium temperature is not less than 5℃, and must choose the suitable sealing flushing liquid source to exclude the potential probability of the flushing liquid into vaporization, and prevent the chemical centrifugal pump medium from being polluted by the flushing liquid. Thermometers, flow indicator meters, flow controllers, etc. should be installed when necessary