Pegas 4000 MF Gas Mixer InstructionManual Columbus Instruments

Transcription

1 Pegas 4000 MF Gas Mixer InstructionManual

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3 Contents I Table of Contents Foreword Part I Introduction System overview Specifications... 3 Part II Installation 4 1 Rear panel connections Front panel controls Tubing connection Cable connections... 8 Part III Stand alone operation 9 1 Setting mixing... parameters 9 2 Static mixing Diagnostics Error messages Troubleshooting Part IV Software 15 1 Software intallation Running the... software 17 3 Configuration Index 0

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5 Foreword 1

6 2 Pegas 4000 MF 1 Introduction 1.1 System overview The Columbus Instruments Pegas 4000 MF is a gas blending system that uses mass flow controllers which are controlled by a microprocessor to blend precise mixtures of component gasses. The system can be operated stand alone or can be controlled by a computer via the RS-232 serial port. The system also has advanced features for allowing the use of different gasses. The systems are custom built to user specifications for the range of gas mixtures, flow and inlet and outlet pressures. The range of the flow controllers which can be used in the system can be from 5 sccm to over 500 slpm. The system can support between 2 and 4 different component gasses.

7 Introduction Specifications Power Consumption: 200 watts Dimensions: 13" x 11.5" x 7.5" (33 x 29 x 19 cm) Weight: 14 lbs (6.4 Kg) Available Flow Controller Ranges: 5 sccm sl/m Each mixer contains flow controllers with ranges to meet each application Flow controller accuracy and linearity: +/- 1% of full scale Flow controller repeatability: 0.2% of full scale Input pressure: 30 PSI* Outlet pressure: Atmospheric* *Alternative ranges and gasses are available, Contact Columbus Instruments for details Note: Pegas 4000MF can accommodate 2-4 gasses NOTE The flow controllers should not be used at less than 10% of their full scale range or accuracy will suffer and cannot be guaranteed Custom Specifications (for each mixer) Number of gases available Gas 1 type Gas 1 full scale flow SLPM SCCM Gas 2 type Gas 2 full scale flow SLPM SCCM Gas 3 type Gas 3 full scale flow SLPM SCCM Gas 4 type Gas 4 full scale flow SLPM SCCM

8 4 Pegas 4000 MF 2 Installation 2.1 Rear panel connections List of connections: 1 AC power connetor 2 Power switch 3 Fuse(s) 4 Mixed gas output 5-7 Input gas connections This is where the AC power cord connects to the instrument The power to the Pegas 4000 MF is switched on and off here Replace with 3A slow blow type if fuse blows, IF fuse continues to blow, contact Columbus Instruments for service. this is where the tubing connects for the output of mixed gasses The individual component gases connect here and the pressure must be regulated to the specified pressure (normally 30 PSIG)

9 Installation Front panel controls List of controls: Display screen 1 2 RS-232 Serial connector 3 Keypad 4 Flow meter Displays menus and operation parameters for the Pegas 4000 MF. The RS-232 connector allows the PEGAS 4000 MF to be connected to the serial port of a computer Input for parameters and controls when operating the gas mixer stand alone Indicates the flow of mixed gas. Keep in mind this is volumetric flow and the gas mixer output is mass flow normalize to 0 degrees C and 760 mmhg. So there can be a differnce in this flow meter reading and the gas mixer indicated flow

10 6 2.3 Pegas 4000 MF Tubing connection The PEGAS 4000 MF uses 2 different types of tubing connectors for the component gasses coming into and the mixed gas output on the mixer depending on pressure and flow rate used.. The proper use of the connectors is shown below. Also different sizes of tubing are used based upon the flow rates used. Swagelok Connectors All system are equipped with Swagelok fittings. These are compression fittings that use a 2 piece ferrule. The orientation of the ferrules is very important for a proper seal. The picture below shows the proper way to make the Swagelok connections. Be sure the nut faces towards the end of the tube that is going into the fitting. The nut should be tightened finger tight, then 1/2 turn tighter with a wrench. Be careful not to over tighten the fitting or it can be damaged. Be sure to use ferrules made of the same material as the tubing used to pervent leakage problems. If metal tubing is used, the ferrules must be changed to metal.

11 Installation 7 Connecting the bottle Refer to the picture below for the tubing connection to the bottle. Make the same connection for all additional gas bottles. Once properly connected, Open the tank valve (1) adjust the pressure regulator knob (2) to achieve a pressure reading of 30 PSIG (or specified inlet pressure if controllers with inlet pressure other thant the standard 30 PSI have been ordered) on the pressure gauge (3). Open the flow control valve (4) (if the regulator is equipped with the valve) fully counterclockwise.

12 8 2.4 Pegas 4000 MF Cable connections The Pegas 4000 MF has only 2 cable connections. The AC power cord plugs into the AC power connector on the rear panel. If the PC software is used to control the mixer, then the included 9 pin serial cable is used to connect the Pegas 4000 to the RS-232 serial port on the computer. The picture below show proper connection the PC.

13 Stand alone operation 3 Stand alone operation 3.1 Setting mixing parameters 9 This section describes operating the Pegas 4000 MF stand alone. The user can set the concentration(s) and total flow for static (a single non changing mixture of gas) or cycling the mixer between 2 different mixtures for 2 different time durations which are configured on the PC computer and downloaded into the mixer. When the power to the mixer is first turned on, the following introduction screen if displayed. Push any of the front panel buttons to enter the main menu. The main menu contains selections for mixer settings and system functions. From the main menu, if you select Mixer settings by pressing the Enter button. You will go into the menu for setting the mixture. In the percent mode the total flow is specified, then the percentage of gas #1 and gas #2 and gas # 3 are specified (depending on how many different gasses the Pegas 4000 MF is configured for. The highest number gas is always used as the gas to creat the balance. For example a Mixer which is configured for 3 gasses having CO2 as gas #1, O2 for gas #2 and N2 for gas #3 The Mixer settings menu will be displayed as shown above. The Up arrow button is used to scroll through the different menu entries. The Enter button is used to select which menu entry to pick. The Set mixture parameter allows the user to set the values for the total flow of mixed gas and the

14 10 Pegas 4000 MF percentage of each gas components. The Static mixing selection start the mixing of a single static mixture,. When Set mixture is selected, the screen below is displayed: The first parameter to set is the total flow of gas. Pushing the up arrow button will increment the digit on which the cursor is placed each time the up arrow is pressed, If a lower value then the value displaed is desired the user must increase the value higher than 9 and it will then go to zero. If the user wishes to increase the value of any entry to another place left (increase by 10), then the digit must be set to 9, then accept the entry by pressing the Enter button, then re-enter the menu selection, and the cursor will be on another digit to the left of the digit which it was previously on as shown below: The next parameter to be set after the total flow of gas, is the concentration of gas #1 in percent: Then the concentration of gas #2 (if the Pegas 4000 MF is equipped with 3 gasses). and the concentration of gas #3 (if the Pegas is equipped for 4 gasses) After entering this information, the machine will go back to the mixer settings menu. Then when it is desired to start mixing the gas, the user puts the cursor on the selection for static mixing and press enter.

15 Stand alone operation Static mixing From the mixer settings menu, selecting Static mixing will start the flow of mixed gas Unless a flow rate that exceed the maximum flow rate of any controller. If the maximum flow rate of any controller is exceeded an error message will be displayed indicating the error and the system will return to the main menu. If a flow rate is selected for any controller that is less than 10% of the controller's maximum range, a warning message will be displayed indicating the accuracy will be degraded by operating the flow controllers at a flow that is too low. The display will show the flow of each gas as shown below: To stop the flow of gas, press the cancel key, the mixer will then prompt for confirmation of canceling the flow of gas as shown below, press the up button to change the entry from N to Y, then press enter, the mixing process will be stopped and the Pegas 4000 MF will return to the mixer settings menu. 3.3 Diagnostics The stand alone operation provides a basic diagnostics for checking the operation of the mixer. To run the diagnostics select Diagnostics from the main menu. The diagnostic test works as follows: The test

16 12 Pegas 4000 MF sets the flow controllers at 0, 25, 50, 75 and 100% of the full scale range of each controller. The setpoint is incremented each time the ENTER key is pressed. The setpoint is displayed in the left column, and the actual flow is displayed in the right hand column. The two values should match each other for each gas. It starts with 0. Then with each press of the ENTER key the setpoint will increase 25% After the diagnostics reaches 100%, the tests are completed and press any key to return to the main menu.

17 Stand alone operation Error messages If the flow controllers are not operated within th proper range warning or error messages will be displayed. Error Warning message Cause Flow too low Warning message. The lowest flow at which the flow controlers should be operated is at 10% of the full scale range of the controller. If any gas is set below 10% of the flow controller's full scale range, this warning message will be generated for each controller. This is only a warning message and after a few second it will diappear, and normal operation will be allowed, buy the accuracy of the flow cannot be guaranteed. Error message. A flow has been selected which is greater than the range of the flow controller(s). Since it is not possible to operate the flow controller above it's maximum range, the system will stop and return to the previous menu. A lower flow must be selected to be able to continue gas flow > maximum range

18 Pegas 4000 MF Troubleshooting Symptom Possible Cause Possible solution Pegas 4000 MF will not turn on No power Check AC power to instrument Fuse blown Check with ohmeter or replace fuse Check flow settings are within specifications (for example is the system is configured for a flow rate of 1000 sccm and the flow is set to 2 sccm it will appear there is no flow becasue the value is so small When running the Pegas 4000 MF there is no flow. Incorrect settings of flow rate, No pressure from gas source. Not providing proper mixture Too low of flow rate has been selected Flow controller malfunction Referring to picture below check the following: tank valve (1) is opened fully counterclockwise Adjust regulator setpoint knob (2) to achieve the specified inlet pressure (30 psig / 2 bar for most systems) Open flow contol valve (3) if equipped fully counterclockwise. For accurate operation, the flow controller should not be used at a flow rate lower than 10% of the full scale range. The system will allow the use of flow rates less than 10% of full scale, but will issue a warning. The accuracy will be less than normal. Run diagnostics and verify flow is within 5% of set

19 Software 4 Software 4.1 Software intallation 15 To install the software insert the enclosed CD ROM into the CD ROM drive. On the windows desktop, double click the icon for My Computer. Then Double click the CD ROM icon. Select the Setup program.

20 16 Pegas 4000 MF The following screen will me displayed. From here, click the button to install the software. It is recommended to install the program in the default location. This will copy all of the needed files to run the program In some instances Windows will come up with a message(s) that a file on the computer is newer than the one being installed, do you wish too keep the newer file. Always answer yes, to keep the newer file.

21 Software Running the software To run the software, go to the start menu and click on Gas Mixer System, this will start the program and the following splash screen will be shown. After a few seconds, the software will attempt to communicate with the Pegas 4000 MF. If the software can communicate with the mixer it will display this message.

22 18 Pegas 4000 MF If the software is unable to communicate with the Pegas 4000 MF this message will be displayed. If this happens first check the serial cable connection between the computer and the Pegas 4000 MF. If the connection is ok, check to see that there are no other programs running that might be using the same serial port. If the problem still persists, have a qualified technician test the function of the serial communication port. Once the software connects to the Pegas 4000 MF, the main menu will be displayed. To set the parameters for controlling the mixer, select experiment and then set mixer parameters.

23 Software 19 The screen below will be displayed. The way the software works, it will cycle through the rows on the grid from top to bottom, The time column sets the amount of time that the gas will flow with the concentrations selected in that row. If time is set to zero it will continuously flow the amount of gas specified in the first row The flow column selects the total flow. And the % gas columns set the concentration of each component gas, with the last gas comprising the balance. The number of mixing points control sets how many different mixtures (rows) are available in the grid. When more than one is selected, it will cycle from top to bottom and deliver the mixture for the time specified in the boxes in the time column. Start starts the mixing and stop stops the mixing Number of mixing points. This controls how many discrete points are used when cyling the mixer through the different concentrattions Status window. This indicates when data is being sent to the Pegas 4000 Start button. This button starts the cycling of the mixer. Stop button. This button stops the flow of gas when the mixer is running under computer control. Time column. The entry controls the amount time that the mixture listed in the corresponding row is flowing. Flow column. This entry determines the total flow rate during the current interval. % Gas 1. This column sets the concentration of Gas 1 for the current interval. % Gas 2. This column sets the concentration of Gas 1 for the current interval. Control From file: when this box is checked, the Pegas 4000 can be controlled

24 20 Pegas 4000 MF Below is an example of multiple mixing points spaced 1 minute apart. Control from file allows the user to control the mixtures from a file called mixer.txt. The advantage of this is the gas mixer can be easily incorporated into process controls The file must be written to the gas mixer software directory and must be in the following format : #.##,#.##,#.##,#.## (How many numbers is determined by how many gasses installed in the Pegas The first number will be the total flow the following are concentrations of each gas with the final gas being the balance. Here is an example of a file which could be used In this example a total flow of 10 liters (or cc's) per min would be used, depending of the configuration of the system and the concentration of gas # 1 would be 5.0 % and the concentration of gas # 2 would be 21.0%. The file is checked approximately once every second.

25 Software Configuration The configuration screen allow changing the operating parameters of the mixer including the gasses being used in the mixer, whether the system is in the flow mode (where the flow of each controller is set individually), or percentage mode (where total flow is selected and the percentage of each component gas is set). Also different types of gases can be used and liters or cc's can be selected. The configuration screen can be accessed from the main menu under setup:

26 22 Pegas 4000 MF List of configuration screen slections: Max N2 flow: This column contains the basic flow calibration for each controller based on nitrogen flowing through the controller. This value is used in all calculations and is specific to the controllers and entered at the factory. These values should never change Gas type: This column selcts and displays the chemical formula of gas used with the corresponding flow controller. Alternate gasses can be selected to use, Changing the type of gas used will change full scale range of the corresponding flow controller. Gas name: This column selcts and displays the name of the gas used with the corresponding flow controller. Alternate gasses can be selected to use, Changing the type of gas used will change full scale range of the corresponding flow controller. Coefficient: The coefficient is used to calculate the full scale range of the corresponding controller. Depending on which gas is selected, the corresponding coefficient will be displayed used. Max flow: This column diplays the Max flow rate for each controller. based on the gas used. 8 Units: This button selects whether cc/min units are used or l/min are used. This is set at the factory based on the contoller used. If you wish to change between liters/min and cc/min please contact Columbus Instrumnets. Mode: This button selects between flow mode and percent mode. In flow mode, the flow rate of each individual controller is set individually. In percent mode, the user enters a total flow rate and the percentage of each componenet gas. Cancel: This button exits the configuration screen without saving the parameters 9 Save: This button saves all of the configuration variables into the Pegas 4000 MF 10 Number of gasses: This pulldown selects how many different gasses (flow controllers) are installed in the pegas 4000 MF 7

27 Software 23 Changing the system to use different gases All mass flow controllers used in the Pegas 4000 MF are calibrated to a maximum flow when Nitrogen is flowing through the controller. Each gas other than N2 which is used has an associated coefficient which is used to determine the maximjum flow possible with the gas being used. The system is configured to the user specifications from the factory and the basic Maximum N2 flow cannot be changed. The system can be configured to operate with a different gasses, however the value of the coefficient will control what the maximum available flow of the alternate gas will be. See the example below where the system is change from using carbon dioxide to using propane. In this example the maximum flow rate was previously.8195 and it has changed to.4092

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