Online Self Cleaning Online Dry Coke Disge Filter

Process Description

1. The quench oil enters the cyclone via the inlet and rotates in high velocity. As the specific gravity of coke is larger than the quench oil, the coke is driven to the outer edge(the edge of cyclone section). After removal of coke, the cleaned quench oil is in the center of the rotation flow, which flow out via outlet of cyclone (N2) through the center pipe of the cyclone.

2. In the cyclone, the quench oil with high content of cokes gathers at the lower part of the vortex section, and flows out of the cyclone via the underflow drain (N³ at the bottom of cyclone). Hence we can see that:
a) The higher the rotation velocity, the better the separation efficiency. Our cyclone could separate the material with 5% density difference.
b) The high velocity rotating liquid and coke could have great abrasion on the vortex section, we adopt different wear resistance designs for sections with different velocity. For example, we use wear resistance alloy for the high velocity section.
c) To reduce the wear and tear, we have the flow reducing measure at the nozzle of the underflow.
d) The underflow must be capable of discharging the quench oil with high content of coke (herein after referred to as dirty quench oil) with high reliability, or else the coke will be entrained with the cleaned quench oil via the center pipe in the cyclone, in that way the removal of the coke is meaningless.
3.The underflow (dirty quench oil) of the cyclone containing all the solid particles removed with HSE etc. from the cyclone, enters the underflow filter.
4.The dirty quench oil enters the underflow filter via the inlet, after filtration by the Johnson Screen (with different filtering rating options available), the cleaned quench oil flow back to the quench tower via the filter outlet (N²).

5.The removed solid dirt like coke etc. are temporally stored in the filter. 

a)Generally the capacity of the filter could retain thecokes for several months, when the coke reach certain volume, the filter could be temporally stopped, open the coke removal port below the filter and discharge the coke onto the coke tank of the truck(e.g.,2m*3m*2.5m tank).
b)The filter could also be constructed into two parts, one part for filtration and the other for coke storage, in this way the filter could discharge the coke without temporally shutting down the filter, but this will increase the installation height and need additional valves, it will increase the investment.

Features and advantages
The filter could remove the filter cake online automatically The coke could stick to the Johnson Screen and form filter cake, when the filter cake accumulates to a certain thickness, pressure drop will be created, causing the reduction in flow rate, or even no flow rate and the filtration process would be stopped. Thus it is necessary to remove the filter cake in time. When entering into the filter, as the content of coke in the viscous quench oil is very high, the automatic removal of filter cake without shutting down is essential. In our design, the automatic removal of filter cake will be started once the pressure drop reaches 0.05 MPa, or the system could be operated with continuous removal of filter cake.

Our filter design could achieve the discharge of dry coke or semi-dry semi wet coke, of course this requires some consumption of nitrogen etc. on site, this eliminates the needs of operators to load and unload the cokes with spades, that will hurt the operators, it is not in conformity with HSE standard.

Our quench oil cyclone + filtration system is advanced, features in high precision, high reliability, easier operation, less maintenance, without clogging problem, in compliance with HSE etc.