Volumetric piston and rock pumps.The principle of operation of the piston pump is to move the liquid (or gas ) under the action of the piston performing reciprocating motion . In this case, there is an alternation of two successive processes : suction and discharge . Suction is a process where the movement of the piston in the pump cylinder creates a vacuum and the liquid enters the cylinder . Injection-the process of ejecting liquid from the cylinder under the pressure of the piston Combination of these two processes in one stroke of the piston is called the multiplicity of action . On the multiplicity of the actions distinguish simple pumps , the differential !! oro, double and multiple action Pump of simple action in two stroke of the piston, or in one rotation of the shaft produces once suction and once naked . Tanya . These pumps are characterized by the greatest unevenness of suction and liquid supply compared to other piston pumps . The scheme of the device of such a pump . The valve chest 6 are total 5 suction and discharge valves 4 . When the piston moves up, the valve 4 closes and the fluid is pressurized by the external environment.it enters the cavity of the cylinder 1, where vacuum is formed . When the piston 3 moves downwards, the valve 4 closes, and the liquid through the valve 4 opened under its pressure enters the pipeline . Thus, the liquid will be supplied with shocks at each discharge stroke of the piston Differential Pumps provide a more uniform suction of the liquid supply . They are . they are characterized by the presence of two groups of discharge valves 1 and 4 . as well as the size of the piston rod 2, having a cross-sectional area equal to half the area of the piston . The suction process occurs when the piston moves up , and the injection process for each stroke of the piston when the piston moves down half of the water entering the cylinder is pushed into the discharge
tubing through the top valve 1. The other half of the liquid enters the cylinder cavity above the piston . When the piston moves up, the lower cavity of the qilin is sucked in . DRA and ejection of fluid from the upper cavity with the lower discharge valve closed . Double-acting pumps are single-cylinder or made up of two pumps of simple action , the scheme of the device single-cylinder double-acting pump . Both cavities of the pump cylinder are working , and each of them has 2 suction and 1 discharge valves . For each stroke of the piston is suction in one injection in another cavity of the cylinder, t . e . the pump performs two working actions in one stroke of the piston . Multiple-acting pumps are simple or double-acting pumps connected in one unit . To reduce the unevenness of the supply caused by the uneven speed of the piston , air caps are installed on the pipelines , in which the air occupying 2/3 of the volume of the cap plays the role of a buffer , equalizing the speed of the liquid movement . Steam piston pumps are still used on ships . According to the method of actuation , they are divided into direct acting and driving, and by the form of the piston into piston and rocky . In the direct acting piston pumps, the pistons of the steam and water cylinders are fixed to a common rod . Drive pumps have a crank or crankshaft from which the piston or rolling pin of the pump is driven . Rocky drive pumps are different from piston piston piston elongated cylindrical shape (rolling pin ) , loosely adjacent to the walls of the water cylinder . The displacement of the liquid from the cylinder of such a pump is not due to the pressure on it by the piston ,and as a result of changes in the volume of the cylinder during the working course of the rolling pin . The most common direct acting pumps, as the most simple in design and reliable in operation . Often these pumps are made double, with two steam and two water cylinders of double action . drive pumps come both as standalone and hung . The design of the mounted rock feed pump is shown in the figure
The pump is vertical, simple action, mounted flanges d to the body of the air pump condenser . The pump piston 2 is rigidly attached by the rod to the crossbar of the balancer } 1 Oro drive (ia figure not shown ) of the steam engine . The output of the rolling pin from the water cylinder 4 is equipped with a stuffing device with the push sleeve To cylinder 4 valve box 5 is attached , and it attached on the side of the air discharge cap . The suction 8 and discharge 9 valves are located in the valve box . Above the valves are the roofs of CI 6, having bolts 7 in the center, which allow you to adjust the height of the lifting of the valves . To prevent hydraulic shock inside the pump and to replenish the air leakage in the air cap on the side of the valve box is installed air valve 10, Pumps with folded pistons are compact, simple in design and reliable in operation but have low performance.