4results about How to "Reduce back flow" patented technology

The utility model belongs to the technical field of domestic water, and particularly relates to a diaphragm type balance valve core for a pipe-in-pipe and a balance valve. The balance valve is provided with a balance valve element and comprises a balance valve frame, a balance valve element and a balance valve element, the valve core seat is mounted on the balance valve frame; the diaphragm component is installed on the valve element seat or in the balance valve frame, and a balance channel is arranged between the valve element seat and the diaphragm component or between the balance valve frame and the diaphragm component; the diaphragm component can deform and change the sectional area of the balance channel according to the pressure of the first channel. The medium pressure is large, the deformation amount of the diaphragm component is large, and the backflow amount of the balance channel is small, so that the backflow amount of the branch away from the circulating pump is larger than or equal to the backflow amount of the branch close to the circulating pump, the effect that the backflow amount is small and large is achieved, and the circulating efficiency and the water quality of the branch at the far end are guaranteed.

A separation and recovery device for thiophene-containing BT oil includes a BT oil thiophene removal system, a first distillation column, and a second distillation column. The inlet of the BT oil thiophene removal system is connected to a BT oil source, and the outlet is fed to the first distillation column via a first pipeline. The outlet of the condenser at the top of the first distillation column forms a first benzene outlet, and a first reflux pipeline is provided connected to the reflux port of the first distillation column. The bottom of the first distillation column is fed to the second distillation column via a second pipeline. The top of the second distillation column is connected to the inlet of the reboiler heat exchange medium channel at the bottom of the first distillation column via a third pipeline. The outlet of the reboiler heat exchange medium channel at the bottom of the first distillation column forms a second benzene outlet, and a second reflux pipeline is provided connected to the reflux port of the second distillation column. This invention has a simple structure, is easy to operate, and can effectively separate and recover benzene and toluene from BT oil with high purity. It also effectively reduces the heat load of separating benzene and toluene, and can handle high-concentration thiophene petroleum benzene.

The application discloses an air conditioner indoor unit, and belongs to the technical field of air conditioners. The air conditioner indoor unit comprises a shell, an impeller, a heat exchanger, a volute and a volute tongue. The volute tongue and the shell form an air inlet air duct, and the volute and the volute tongue form an impeller mounting cavity and an air outlet air duct. The impeller is arranged at the impeller mounting cavity, and the impeller is used for driving airflow to sequentially pass through the air inlet air duct and the impeller mounting cavity to form outlet airflow. The outlet airflow comprises backflow airflow which flows back to the impeller after being divided at the volute tongue, and air outlet airflow which flows to the air outlet air duct. The air outlet airflow exchanges heat with the heat exchanger. A gap between a volute tongue windward surface of the volute tongue and the impeller forms a gap flow channel. A flow guide channel is arranged at the volute tongue, and the flow guide channel is used for guiding a part of the backflow airflow to the gap flow channel. The air conditioner indoor unit can improve the pressure resistance of the cross-flow fan.

A centrifugal fan comprises a machine shell, an impeller arranged in the machine shell, an air inlet pipe arranged on the machine shell and a front cover plate inserted in the impeller, and the center of a rear cover of the impeller is fixedly connected to a main shaft of a motor, and is characterized in that a plurality of radial ribs are arranged on the right side face of the rear cover plate, and a bearing seat is arranged in the air inlet pipe; a plurality of rib plates are symmetrically connected between the bearing seat and the air inlet pipe, a bearing is installed in the bearing seat, and the front end of the main shaft is connected in the bearing. The utility model has the beneficial effects that the ribs generate reverse centrifugal force when rotating to prevent gas in a high-pressure area from flowing towards the main shaft along the rear cover plate; the front end of the main shaft is connected in the bearing, so that the impeller can be prevented from shaking during rotation, a gap between a front cover plate of the impeller and a shell can be reduced, gas in a high-pressure area is prevented from converging to an inlet of the impeller, and non-contact sealing is realized; therefore, the problem that in the prior art, a sealing element needs to be replaced frequently due to abrasion is solved. Meanwhile, no friction force exists when the main shaft rotates, and mechanical loss of the fan can be reduced.