How to select valves for black water system in coal gasification?
Coal water slurry gasification is one of the world’s most advanced technology on the coal gasification, which is widely used in the coal chemical enterprise. The working condition of the coal water slurry is very hard, as well as valve is in the key process of the pipeline, thus the valve selection becomes a headache problem for many valve procurement engineer.
Coal water slurry is a mixture of liquid and solid powder. When the medium flow into the circular type orifice, the flow speed is very high. The valve of this system faces the following problems :
1.The coal water slurry reaches a very high flow rate in the valve orifice, at the same time the coal slurry has a certain degree of hardness, so the erosion damage to the valve is quite serious.
2. The coal slurry is easy to be deposited to block the valve cavity, so the valve flow channel is required to be clear without dead space, the coal slurry particle is quite fine, is very easy to penetrate into the valve ball gap and make the valve disc to be jammed.
3.The coal slurry has a certain adhesive force, is very easy to form scales on the sealing face of the valve disc and valve seat, when the valve is fully closed, the leakage level is affected, so the valve is required to automatically remove the scaling.
So there are three special requirements to the valve applying on the black water system ：Erosion resistance, Anti-scaling, self-cleaning. The black water almost has no corrosion, so valve body and valve cover are selected with WCB material, the valve disc and valve seat are selected with general austenitic stainless steel which is hot compressed with a layer of hard alloy on the surface to anti erosion, and the adhesion of the of the ash water scaling is smaller than the coking deposit layer, the torque of the actuators is not required to be large.
How to select the valve for this system ?
QUANSHUN R&D team carefully researched the working condition as follows：
Application position：Feed pump inlet and outlet of settling tank for methanol gasification plant;
Medium: black water (ammonia, H2S and a small amount of pulverized coal particles);
Density: 1g/cm3; Pressure: 0.3MPa;
Temperature: 80 ℃ Viscosity: 0.6 Pa.s;
Initially ,Metal sealing ball valves is installed on the system . One valve is in operating condition while two other valves are in preparing stage .
Because the pump have to be changed every 3 months , the valve will be operated . As everyone knows , valve ball and valve seat are always in contact stage whether in opening or in closing stage . so the medium is very easy to deposited to the sealing face between the valve ball and valve seat, resulting in valve blocking .
That is why the metal sealing ball valve is blocked . QUANSHUN R&D team analyzed the reason, and developed the new Y-type anti –abrasive valve. After trial and inspection on site , the valve structure is proved to be reasonable, and the performance is reliable .It not only solved the valve blocking problem, but also has longer working life than metal sealing ball valve. The trouble of valve procurement engineer is solved.
QUANSHUN VALVES , focused on industrial valves for more than ten years, provided the best solutions for the harsh working conditions in the black water system. QUANSHUN VALVES , becomes the best choice for more and more valve procurement engineer.
Coal water slurry is a mixture of liquid and solid powder. When the medium flow into the circular type orifice, the flow speed is very high. The valve of this system faces the following problems :
1.The coal water slurry reaches a very high flow rate in the valve orifice, at the same time the coal slurry has a certain degree of hardness, so the erosion damage to the valve is quite serious.
2. The coal slurry is easy to be deposited to block the valve cavity, so the valve flow channel is required to be clear without dead space, the coal slurry particle is quite fine, is very easy to penetrate into the valve ball gap and make the valve disc to be jammed.
3.The coal slurry has a certain adhesive force, is very easy to form scales on the sealing face of the valve disc and valve seat, when the valve is fully closed, the leakage level is affected, so the valve is required to automatically remove the scaling.
So there are three special requirements to the valve applying on the black water system ：Erosion resistance, Anti-scaling, self-cleaning. The black water almost has no corrosion, so valve body and valve cover are selected with WCB material, the valve disc and valve seat are selected with general austenitic stainless steel which is hot compressed with a layer of hard alloy on the surface to anti erosion, and the adhesion of the of the ash water scaling is smaller than the coking deposit layer, the torque of the actuators is not required to be large.
How to select the valve for this system ?
QUANSHUN R&D team carefully researched the working condition as follows：
Application position：Feed pump inlet and outlet of settling tank for methanol gasification plant;
Medium: black water (ammonia, H2S and a small amount of pulverized coal particles);
Density: 1g/cm3; Pressure: 0.3MPa;
Temperature: 80 ℃ Viscosity: 0.6 Pa.s;
Initially ,Metal sealing ball valves is installed on the system . One valve is in operating condition while two other valves are in preparing stage .
Because the pump have to be changed every 3 months , the valve will be operated . As everyone knows , valve ball and valve seat are always in contact stage whether in opening or in closing stage . so the medium is very easy to deposited to the sealing face between the valve ball and valve seat, resulting in valve blocking .
That is why the metal sealing ball valve is blocked . QUANSHUN R&D team analyzed the reason, and developed the new Y-type anti –abrasive valve. After trial and inspection on site , the valve structure is proved to be reasonable, and the performance is reliable .It not only solved the valve blocking problem, but also has longer working life than metal sealing ball valve. The trouble of valve procurement engineer is solved.
QUANSHUN VALVES , focused on industrial valves for more than ten years, provided the best solutions for the harsh working conditions in the black water system. QUANSHUN VALVES , becomes the best choice for more and more valve procurement engineer.
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