Out of the reactor and into the fire.
The treatment of industrial waste products is today a major concern for all companies who’s by-products cannot be commercially disposed of in traditional landfill sites. The legislative measures being enforced today mean that harmful media should be treated, disposed of or handled with the environment in mind.
A specialist waste management company is handling such media, with disposal techniques including the latest incineration technology, operating at extremely high temperatures, up to 2500 °F. One such process stream that they were required to handle was a “Hydrocracked Oily Crude Sludge” which had been pre-thickened by a centrifuge.
The starting situation
The non flowable highly viscous media arrives from a local refinery in skips via lorries. It was requested to use an existing hopper from which media would be pumped directly into the incinerator. This requires accurate dosing to ensure appropriate burn rates and uninterrupted feed from the reception hopper. But the product was difficult to handle and did not flow readily.
The solution
Seepex specialises in handling highly viscous or non flowable products and had previous experience in handling such media.
The waste management companies engineering team had recognised the flexible approach to problem solving adopted by seepex. Initial discussions led to a trial being set up, which proved that the media could be easily conveyed with a seepex progressive cavity pump. The next hurdle was to ensure efficient bulk handling could be achieved. On test it was observed that the media had a tendency to hang up or bridge when held in the small trial hopper. Experiences of similar applications showed us that this would need to be dealt with carefully.
A pump solution to address this was required. The opening at the bottom of the existing silo was 6.5 ft x 6.5 ft. So as to reduce the risk of arching or bridging, this 6.5 ft x 6.5 ft outlet area was fully utilised with two seepex BTEI range pumps, each auger feed screw and integral bridge breaker paddle shaft next to each other, thus offering a vast moving bottom to the silo.
The dry cake is pumped by the two pumps into a common line, which runs with a total length of 196 ft with a static rise of 66 ft. The dry cake flows in the pipeline with some high friction losses which are reduced by using a seepex boundary layer injection system fed by a smaller seepex MD range dosing pump. The boundary layer injection liquid further utilised a waste stream product.
The benefit
The combination of seepex standard pumping and feeding technology, with innovative use of special engineered designs has meant that an otherwise unattainable result has been achieved. The benefits speak for them selves, the pumps provide accurate metered flow of product to the incinerator. The silo and hopper feed arrangement means that product always flows into the pump hopper providing reliable pumping and sustainable equipment life. The two pump systems provide a level of equipment back up when one pump is not available. The seepex material selection of these pumps means they can handle virtually any oily sludge cake the site can throw at them.