Purpose

• Describe the design, principles, components and operating procedures for the Prominent chlorine dosing pump system.
• Generate the calibration graphs for the Gamma X pump ran at different settings of pumping frequency and volume displacement.
• Measure the chemical feed rate.

Introduction

A pump is a device that moves fluids, or sometimes slurries, by mechanical action. Pumps can be classified into two groups: positive displacement and dynamic. The schematics below shows different types of pumps used in industry.

Figure 1: Pump Classification

Pumps in the ProMinent gamma/X product range are microprocessor-controlled solenoid metering pumps.  Watch the following Prominent short video clips before the experiment. The pump is a part of the chlorine dosing assembly as shown in Figure 1.

• Video 1 (Pump Description)
  
• Video 2 (Pump Operation):
  
• Video 3 (Pump Control):
  

Chemical processes can be designed in batch, continuous or fed-batch modes. The selection of the specific type of process depends on the product being formed. Using biotechnology as an example, two different process modes are explained below:

•  When primary metabolites are the goal of the process, we need to keep high concentration of substrate so that there is a continuous surplus of substrate enabling the microbes to stay in exponential growth phase.
• When secondary metabolites are the goal of the process, we want to keep strict control of the substrate and this is why the fed-batch mode of the process is often selected by the engineers. In that mode, we need to accurately control the feed rate of substrate in order to keep microbial cells in the stationary phase.

In this experiment students will have an opportunity to work with the gamma X pump which is a part of the chemical feed system. Students will be generating calibration graphs for the pump and monitoring the feed rate of a chemical in the process.

Experimental Setup

In the lab you will be working with the Prominent chlorine dossing system utilizing a Gamma X pump. The system consists of a pump, hand valves, pressure relief valves, calibration column and associated piping components. Refer to Figure 2 below for a photo of the set-up with most elements highlighted.

Figure 2: Gamma X Pump experiment set-up with major components identified.

Procedure

The video of the Calibration Check part of the experimental procedure can be found in this link: Lab Video

Pump operation

The pump needs to be connected to the power outlet first. With the LCD display on, the user can move between the set up screens by rotating the orange dial. To set certain conditions for the process the dial needs to be pushed in. Rotation of the dial allows for increasing or decreasing given process parameter. To enter the desired set point, the dial needs to be depressed again.
The parameters that can be adjusted by the user include:

• Volume displacement of the single stroke
• Pulse (stroke) frequency

Practice with hypothetical setting of the process parameters before starting your actual runs. For more information students need to refer to the video of the experimental procedure and the pump manual residing beside the unit.

Start-up and Pressure Test

Upon initial start-up, the system must be primed and pressure tested prior to use. Testing the system as described below confirms the system is ready for use. Refer to Figure 1 for component details and locations; this procedure is used for pressure testing the system with water prior to using any chemical.

1. Connect the pump suction line (TP-01) to a tank or container with water.
2. Visually check all the pipe work and components for signs of damage; call your instructor if any are noticed.
3. Manually check the connections and tighten if necessary.
4. Set the three way valve HV-03 with arrow pointing up. This will allow the water to be discharged through the discharge line TP-02. Make sure that this tubing is directed back to the intake tank.
5. Close HV-02 and HV-04. Open HV-01, double check if HV-03 three way valve is set with black arrow on the handle facing up.
6. Press and hold the button on the pump with the double arrow pointing to the right for 4 seconds until the pump is turned on for priming.
7. With the dial rotation set the time 60 seconds for the priming mode. The pump will automatically set the maximum stroke length and pulsation frequency.
8. Wait until water fills the lines. As the pump runs you will see the pressure increasing on the gauge (PG-01) until the Back Pressure Valve (BPV-01) setting is achieved. At this point you should see the water going down the line past the BPV-01. If air bubbles are visible inside the lines loosen up the bleed valve on the back of the pump BV-01 to remove air from the lines. Close the bleed valve.
9. With water coming out the TP-02 the pump is primed and you can stop it by pressing the stop button or wait until the timer automatically stops the pump when it reaches zero.

Calibration Check

This calibration process is done to verify the actual capacity of the pump at the normal operating pressure. The back pressure valve BPV-01 is adjusted properly to ensure an accurate calibration. Refer to Figure 1 for component details and locations.  Verify that the TP-02 line tubing is going back to the water tank.

1. Make sure the pump is primed and the Feed tank full.
2. HV-02 and HV-04 should be closed.
3. Set the three way valve HV-03 with black arrow on the handle to point down. With this setting the pump will feed water into calibration cylinder CC-01.
4. With the pump setting of your choice (volume displacement/stroke length and frequency) fill the CC-01. Stop the pump once the water level in the CC-01 reaches the 0 level on the scale.
5. With the pump stopped and level in the calibration column at zero, you are ready to start your calibration runs.
6. Close HV-01. Make sure HV-04 is closed, open HV-02. This might drop the level of water in CC-01 if the system was not primed properly earlier. If this is the case record the new level on CC-01.
7. Reset the three way valve HV-03 so that the pump will discharge the fluid into the water tank through TP-02. The black arrow on the HV-03 is to be set up.
8. Set the pump to maximum stroke length and maximum frequency.
9. With pump stopped and level in the calibration column at zero, start the pump and a stopwatch. Run it until the water in the calibration cylinder reaches the 250 mL level and immediately close HV-02 and stop your stopwatch.
10. Use the pump volume (volume removed from the calibration cylinder) and your elapsed time in the stopwatch to calculate the volumetric flow rate of the pump at your selected pump stroke and frequency settings.
11. Repeat the process of steps 4 to 10 for different pump stroke and frequency settings.  You will be required to perform 6 runs in total:
    1. three runs with fixed stroke length and different frequency.
    2. three runs with fixed frequency and different stroke % displacement.
12. After completing the lab session drain the water from the system and shut down the pump.
13. Make sure you leave clean the lab area after the experiment.

REPORT

1. Draw the schematic of the system (hand drawing is acceptable).
2. Tabulate all the results.
3. Generate the calibration graphs, one for different frequency runs and one for different stroke length. Is the trend linear?
4. Discuss your results:
   1. Compare the feed rates with stroke length adjustments to the feed rate at maximum feed rate setting (i.e. describe the feed rate vs. stroke length % graph)
   2. Compare the feed rates with frequency adjustments to the feed rate at maximum frequency setting (i.e. describe the feed rate vs. pump frequency graph)
   3. Is there any difference in adjusting the stroke rate or frequency?
   4. Compare the maximum feed rate established in the lab at the maximum pump settings with the information from the sticker on the side of the pump (visible on the experimental procedure video at approximately 1:35).
   5. What would cause wear and tear on internal components of the pump?