The composition of the sludge in petroleum and petrochemical storage tanks is mainly a mixture of sewage, dirty oil, hydrocarbons and particulate matter. In general, the sludge in the storage tank is separated from oil and water, and the precipitated sludge is transported to the dewatering machine via a pump, after which the treated sludge is destroyed or subsequently treated. In this process, the requirements for the transfer pump are as follows.
1. Because the sludge will be deposited at the bottom of the container, the pump needs to have a good self-priming capability.
2. Because of the complex composition of oil sludge, which is corrosive and abrasive, the pump needs to be wear-resistant and corrosion-resistant at the same time.
3、Ensure the economy of use of the pump, low cost of use and extended service life.
After research and analysis by the relevant technical staff, we recommend the use of rotary lobe pumps in order to meet the above 3 technical requirements.
I. Self-priming 8.5m, no pumping required
The self-priming capacity of the rotary lobe pump can reach 8.5 m. Because of the external reducer setting, the process selection for tank bottom sludge cleaning is kept between 200-250 rpm outlet speed to ensure a balance of self-priming capacity as well as resistance to wear and tear and corrosion.
II. Wear and corrosion resistant rubber covered rotor
With a fully rubber covered rotor, there is basically no gap between the rotor and the inner wall of the pump cavity. During operation, the pump cavity forms a vacuum and the medium is conveyed through the principle of atmospheric pressure.
The rubber rotor made of fluoroelastomer is insensitive to dirty oil, weak acids, weak alkalis and oily effluent with particulate matter as the main body, and can meet the requirements of corrosion and wear resistance.
III. Positive displacement, high efficiency
The rotary lobe pump is a positive displacement pump with a straight performance curve, the higher the speed, the higher the efficiency and is not affected by pressure, which is where it differs from centrifugal pumps.
IV. Design with mobile trolley
For tank cleaning and emergency dewatering, high efficiency, easy to move pumps are required. The rotary lobe pump is designed with a mobile trolley and can be operated by one person.
V. Online maintenance, simple and convenient
Easy in-line access for removal and replacement of wearing parts without dismantling the pipework.
To solve the problem of tank sludge cleaning, a rotary lobe pump can be used. The resistance to wear and tear, corrosion resistance and low comprehensive use cost of the positive displacement pump can also be applied in other processes such as loading, unloading and sweeping of oil tanks.