Simplex pumps

A one-piston double-action pump is called a double-acting simplex (since there are older single-action steam and pneumatic driven simplex pumps). 

The rate of fluid discharge from the cylinder is zero at the beginning of a piston stroke and increases to a maximum value when the piston reaches full speed. If only one discharge cylinder is used, the flow rate will pulsate. These pulsations can be reduced by placing an air chamber on the discharge line or by using a number of delivery cylinders compounded. Simplex pumps have only one delivery cylinder, duplex pumps have two cylinders, and triplex pumps have three cylinders. 

A simplex pump, sometimes referred to as a single pump, is a pump having a single liquid (pump) cylinder. A duplex pump is the equivalent of two simplex pumps placed side by side on the same foundation. 

The driving of the pistons of a duplex pump is arranged in such a manner that when one piston is on its upstroke, the other piston is on its downstroke and vice versa. This arrangement doubles the capacity of the duplex pump compared to a simplex pump of comparable design. 

Figure 9.14 Pulsation reduction (a) simplex pump, (b) pulsation dampener, (c) triplex pump.

Piston Pumps There are two ordinary types of piston pumps, simplex double-ac ting pumps and duplex double-acting pumps. 

Simplex Double-Acting Pumps These pumps may be direc t-acting (i.e., direct-connected to a steam cyhnder) or power-driven (through a crank and flywheel from the crosshead of a steam engine). 

Dupl ex Double-Acting Pumps These pumps differ primarily from those of the simplex type in having two cyhnders whose operation is coordinated. They may be direct-acting, steam-driven, or power-driven with crank and flywheel. 

Plunger pumps are available with one, two, three, four, five, or even more cylinders. Simplex and duplex units are often built in a horizontal design. Those with three or more cylinders are usually of vertical... 

The two independent variables (the axes) show the pump speeds for the two reagents required in the analysis reaction. The initial simplex is represented by the lowest triangle the vertices represent the spectro-photometrie response. The strategy is to move toward a better response by moving away from the worst response. Since the worst response is 0.25, conditions are selected at the vortex, 0.6, and, indeed, improvement is obtained. One can follow the experimental path to the optimum, 0.721. 

Plunger pumps are available with one, two, three, four, five, or even more cylinders. Simplex and duplex units are often built in a horizontal design. Those with three or more cylinders are usually of vertical design. The driver may be an electric motor, a steam or gas engine, or a steam turbine. This is the common type of power pump. An example, arranged for belt drive, is shown in Fig. 10-28 from which the action may be readily traced. 

Type of flow distribution. If nonpulsating flow is required, certain types of pumps, such as simplex reciprocating pumps, may be unsatisfactory. Similarly, if operation is intermittent, a self-priming pump may be desirable, and... 

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