Peculiar aplications for the pulsation dampers

I )  CIRCUITS THAT NEED TO BE CLEANED PERIODICALLY  AFTER FINISHING EACH PROCESS

All the pulsation dampeners whatever  was its form and because its own design, they have internal corners which are difficult to clean or to eliminate all particles of the product pumped; of course ones more than others.

According to our 26 years of experience the more secure and efficient solution is to use a quick bladder dismantling system from the inside dampener , and clean separately the bladder and the dampener internal body. This solution for applications where the charging gas value is lower than 10 Bar and if the dampener can be filled with compressed air, is the most effective.

II) CIRCUITS WHERE THE WORKING PRESSURE CHANGES

The Pulsation dampener application in this type of circuits has different  solutions. Also in this case the experience has shown us that the best solution is as always, the most simple one ,or at least is the solution that requires lower maintenance, any costs of energy and of course a low price.

Lets have an example. A circuit that must work at an initial pressure of 20 Bar and a final pressure of 200Bar
The “dv” = 10 c.c. and the residual pulsation accepted, in the case more disadvantage (at 200 bar ) ought to be :+,- 5%.
The pump is a single piston type and its capacity per stroke is:20 c.c.
To simplify the calculations we will consider that the gas volume variation is at constant temperature isothermal curve where, P x V = Constant
 
From:         PoxVo=P2xV2  ,   Po= 0.9x20= 18 bar ,    P2= 200 + 5%=210 bar

                  P2/Po = Vo/V2 = 210/18 = 11.66  (8)

We will calculate the hypothetical dampener volume for the maxi. pressure of 200 Bar

Vo(200) = (10 x 210) / 0.9 x ( 210 - 190 ) = 116,66 c.c.                                                                   

This volume is to be equal to ”V2” from the formula (8), then:

( Vo / 116.6 ) = ( 210 / 18 ) = 11,66     and    Vo = 116,6 x ( 210 / 18 ) = 1360,33 c.c.

this is in theory the total pulsation dampener volume necessary for this application , but the relation  , Vo / V2 can not be higher than 4 in order not to corrugate too much the bladder and damage it in a short time.

In this case because Vo / V2 is; 1360,33 / 116,66 = 11 nearly 3 times higher than the value of  4 that we recommended.

To achieve  that the volume bladder does not exceed the relation of 4:1 we will introduce a quantity of liquid inside the bladder mixed with the gas ( usually the same liquid of the circuit or any other which has not any reaction with the bladder material or with the circuit liquid ) 

The volume to be introduced into the bladder “VL” ( see sketch ) will be calculated 

                    ( 1360,3 + VL ) / ( 116,6 + VL ) =< 4 ; and operating , VL = 298 c.c.