Check valve for desulfurization Roots blower

Generally, a check valve is installed on the inlet side, and a flap device is used on the outlet side. After a power outage, wind flows in the reverse direction; the flap drops automatically to prevent this reverse flow, and the fan gradually stops due to inertia. The check valve prevents backflow, thereby reducing the likelihood of damage to the fan.

It is essential for the safe operation of the device to install check valves at the inlet and flap valves at the outlet.

Will installing a check valve on the inlet increase additional resistance? We installed a homemade flap valve at the outlet, and it worked very well. The flap is easy to manufacture, but what’s important is to minimize resistance as much as possible, as well as prevent coal tar from sticking to it and rendering it ineffective. Another crucial aspect is how to reduce vibration and noise. The one we made ourselves has worked very well for two years now; it allows for adjustment of the flap’s opening angle, and its noise level is even lower than that when no flap valve is used.

. Extracting an article might be helpful to you. To eliminate the noise generated by the check valve, in the desulfurization section of the gas production workshop, when installing the outlet pipeline for the Roots blower, due to space constraints in the area, a check valve is installed directly on the outlet flange of the Roots blower, with a elbow following immediately after the valve. When the Roots blower operates under pressurized conditions, the gas passes through the check valve and then creates vortices as it moves through the elbow; this causes the valve disc to swing back and forth with the pulses of air from the blower, resulting in significant vibration. The pin sleeves of the valve disc strike the valve body, causing indentations to form. The opening angle of the valve disc increases from the normal 60° to around 75°, and the edges of the valve disc strike the inner walls of the pipes, posing a serious threat to the safe operation of those pipes. Improvement measures: (1) Thicken the pin of the valve plate to reduce the gap between the pin and the hole in the valve plate. (2) When the valve plate is opened by 60°, a groove of 100mm×30mm×30mm is milled on the contact surface between the valve body and the valve plate, into which nylon PTFE is inserted and fixed. (3) A spring-loaded piston is installed behind the check valve, that is, in a direction perpendicular to the 60° opening angle of the valve plate. When the valve plate moves due to pulses and eddies, the spring-loaded piston controls the impact force at the maximum opening angle of the valve plate, transforming a hard collision into a gentle contact, thereby effectively preventing noise and vibration. As shown in Figure 4.

We once broke the blower due to backpressure from the export of rotary machines, so we have now installed check valves as well. If it’s equipped for export, isn’t it unnecessary for import? We installed a silencer on the inlet side when importing it. At first I thought the silencer would be placed on the outlet side; I wasn’t sure myself why it was installed on the inlet side, as the noise should mainly come from the outlet side!

A safety water seal can be added to the cleaning tower; if the compressor trips and gas flows back, causing pressure to rise, this pressure can then break through the safety water seal. The disadvantages include slow water replenishment after the water seal is broken (the desulfurization pressurizer must be stopped), gas loss, high electricity consumption due to the start-up and shutdown of the pressurizer, and difficulty in adjusting the liquid levels in the desulfurization tower and circulation tank, which increases the workload. The advantage is that it reduces resistance.