What is instrumentation and how can it be applied to Membrane Electrode Cells or a UF machine? Instrumentation could be as simple as marking a wire with a Cell # so that an electrician can use a clamp on ammeter to measure the DC current flowing though it, an analog pressure gage, or something more sophisticated like a PLC controller that is used to select the best voltage output of the DC rectifier. It could also be a magnetic flow meter that keeps a close look at the flow of paint supplied to a UF machine.

UFS offers a wide variety of instrumentation products available to complement your E-coat paint system and enhance your understanding and control over its many process variables.

Here are some links to assist you with where to go or search. It could be by name of the instrument, name of the process (that is being measured), location in the e-coat system, etc.

 

Process Component

  • Paint
  • Anolyte
  • Permeate
  • Direct Current
  • Paint Film Thickness

Hardware

  • DC Shunt
  • PLC
  • Paint Feeder
  • Current Sensor
  • Current Sensor Panel

Process Variable

  • DC Current
  • DC Voltage
  • AC Ripple
  • Flow (Paint or Permeate)
  • Paint Pressure
  • Conductivity (Paint or Anolyte)
  • Paint Temperature
  • Turbidity (Permeate or Anolyte)

Equipment

  • UF Machine
  • DC Rectifier
  • Membrane Electrode Cells
  • E-coat lab

Paint

This is the water-based paint that fills the e-coat tank. Once a DC voltage is applied between the anode and cathode a thin protective is developed over the ware. Cathodic e-coat paint is the most popular and the other type is called anodic that is used for steel items used indoors. E-coat paint has many properties that can be measured. UFS provides some of these instruments.

Paint Conductivity

The conductivity of the paint is a measure of its relative resistance to the flow of the electrical current. The higher the conductivity the lower is its resistance and the lower the conductivity the higher is the resistance since conductivity and resistance are inversely related. UFS recommends JP Tech's Conductivity Monitors and Controllers. The JP Tech conductivity sensor is toroidal shaped and well-suitable for e-coat paint. The basic unit is a monitor function and the other versions can control pumps.

Paint Flow

Paint flow is a crucial process parameter for proper UF permeate production. Since the paint contains about 20% solids, normal flow meters (i.e. turbines or propellers) are of little use since they would quickly suffer component malfunction. Transit time and Doppler radar units can be used if there is sufficient space and the pipe has the proper orientation. The better solution is to use a magnetic flow meter. UFS is a distributor for Sparling Instruments, maker of the TigermagEP brand magnetic flow meters.

Another point to consider is that if your paint supply pumps are driven by a variable frequency motor drive system, then the output of the TigermagEP can be used as an input to the frequency drive system thereby allowing the frequency controller to adjust as required in order to keep the paint flow in an acceptable flow range.

Paint Pressure

Pressure is another critical process parameter for proper UF permeate production. Usually the minimum UF paint inlet pressure is 3.45 bar (50 psi). UFS offers large (3 inch) analog pressure gages filled with mineral oil and protected with a diaphragm type guard (also filled with mineral oil). Analog pressure gages are pre-tested and certified. Digital pressure gages are also available as an option, especially to those that want to record or set an alarm based upon the pressure at the inlet of the UF unit.

Paint Temperature

Temperature is the third important process parameter, especially for permeate production and UFS offers an analog gage as an option on all TruFlux UF Machines.

Paint Feeder

As parts leave the paint system they are removing paint solids. Thus replenishment paint must always be added to the bath to maintain the proper solids. A paint feeder can make the task easier and keep the bath at a more constant NV level. JP Tech's Amp Hour Pump Feeder is a versatile controller that offers a complete feature set. I t can control up to two different pumps and also communicate with your factory PLC.

Anolyte

Anolyte is an electrolytic fluid that is transported inside the Membrane Electrode (ME) Cell used in cathodic e-coat paint systems. A small percentage of e-coat paint systems use anodic type paint and in this situation the electrolyte is called catholyte. The purpose of the electrolyte fluid is to remove excess ionic components from the bath and also cool the surface of the Electrode that is located inside of the Membrane Electrode Cell. UFS provides instruments for the following —

Anolyte Conductivity

UFS is a distributor of Myron L Conductivity Monitors/Controllers. In the typical situation the conductivity range is from 0 to 20,000 micro Siemens/cm (0-20,000 micro Mho/cm). A contact type sensor measures the conductivity of the fluid. Since it is generally rising (i.e. the concentration of neutralizing agent is increasing), once the set point is reached a set of contacts closes. This generally opens a DI water or RO water valve. The fresh make-up water will then begin to dilute the electrolyte fluid and bring it several hundred micro Siemens/cm below the set point. Once this happens the make-up valve is turned off until the set point is reached again. Usually you would order the controller with the appropriate range and then also order the conductivity sensor for the controller.

If you need a solenoid valve is required then order PN 360035, which is a 110 VAC 1” x 1” NPT female connections.

Anolyte Turbidity

Turbidity is the relative measure of opaqueness. If you think of three clear glasses: one with water, apple juice, and milk. The water would have the lowest turbidity measurement and milk would have the highest. Anolyte is generally somewhere between water and apple juice. However, if there is an upset and paint (it does not take much paint) enters the anolyte, then the turbidity measurement can increase very quickly. Turbidity meters can be several thousand dollars and some have to be cleaned every time there is an upset. The purpose of the measurement is to alert the operator that paint has entered the anolyte fluid and the source of the contamination should be sought and stopped. UFS is developing a low cost digital sensor technology that will be introduced in 2006. This item is available at the time when a Cell Circulation System is ordered or can be added on to an existing cell circulation system.

Permeate

Permeate is the fluid that is able to pass through the UF membrane and is mostly water and other small molecular objects such as ions and salts. The permeate fluid is used as a rinse fluid and sometimes it is purged from the system to remove contaminates. UFS provides instruments for the following—

Permeate Flow

Permeate is produced in UF modules, which typically contain a '7640' or '7940' type UF Element. The typical range of the analog flow meter is 0 — 20 lpm (0 — 5 gpm) with 1/2” NPT male connections. UFS is a distributor of BlueWhite brand flow meters and offer the F440 polysulfone for service with permeate. Newer 8” Spiral UF systems may now use 0 - 40 lpm (0 - 10 gpm) with 3/4” NPT connections. UFS PN 22502 is the 0 - 5 gpm and PN 225025 is the 0 — 2 gpm flowmeter. Both of these have 1/2” male NPT fittings. If you need 3/4” NPT fittings then order PN 225034 for the 0 -10 gpm range.

If you are looking for a totalizing flowmeter then ask UFS for guidance in the selection.

Permeate Turbidity

See section on Anolyte Turbidity fluid above. Generally permeate is even more like water than anolyte, but if paint enters, then the alarm should sound and the source of the contamination (i.e. one of the UF Elements has developed a leak and is passing paint into the permeate) should be located. UFS is developing a low cost digital sensor technology that will be introduced in 2006.

Direct Current

DC current is the life's blood of e-coat and without the process just would not have a chance to work. Thus knowing the distribution of current amongst all the Membrane Electrode Cells is a cornerstone of good maintenance practices. It is best to keep a record of the individual current draw when the system was brand new. This record will become the baseline and all future measurements can be compared to the baseline.

How is this type of equipment justified? If the current distribution becomes uneven (some Cells no longer deliver the same current as when they were new due to: high electrical resistance; a loose connection; trapped air in the Cell; etc) will tend to cause the operator to increase voltage to compensate. The increased voltage will tend to alleviate the problem (i.e. low film thickness on a portion of the ware), but the 'price' will be increased paint consumption elsewhere. What does a 10%, 15%, or 20% increase in paint consumption meant for your plant? Many current monitoring systems can be installed for less than $25k, which could be less than 2 year payback for many plants.

UFS offers several different instrumentation products specific for DC Current, DC voltage, and AC Ripple as shown below -

DC Current

This is most commonly used to monitor the DC current delivered by each Membrane Electrode Cell in an E-coat paint system. If your safety protocol will allow, then a clamp on ammeter can be used reliability. You may want to reroute all the load cables to the ME Cells through a small enclosure and label each wire.

JP Tech's offers the Anode Monitor, which can be connected through an RS232 connection or Ethernet (option) to provide real time data. If you already have an existing current monitor then it may be possible to upgrade to the Anode Monitor since you already have the DC current sensors in place. This unit is well suited for hoist systems as it can measure all the Cells in a very short period of time and report the peak values for each paint cycle.

The UFS Current Monitor is a safe and secure method to see the current flowing to each Cell and it has one switch for every two Cells. You can quickly see the current in the digital meter. If is better suited for monorail systems than hoist systems since all the Cells of the hoist system reach the peak at about the same time.

DC Voltage

AC Ripple

AC Ripple is a carry over from the process used to convert AC power into DC power. Normally, there are filters on the output of the rectifier to clean this AC ripple from the DC power. If the filters fail then the AC Ripple can increase and paint defects can occur. Usually the AC Ripple should be less than 5% and less than 1% is considered ideal. JP Tech offers a low cost AC Ripple meter to offer real time information so you do not have to bother the plant electrician to take the measurement.

Paint Film Thickness

Anode Monitor

The DC current information is only worth something if it can be made available in the future and serve as a basis for comparison. This favors the Anode Monitor product line that is made by JP Tech. UFS is the exclusive distributor for JP Tech's products for the e-coat market. The Anode Monitor is an intelligent choice since it uses a DC shunt to measure the current, fuse to protect the load wiring, and on board RS232 type communications so you can connect a Serial cable from your lab PC to the Anode Monitor. Once this is done, you can receive real time current draw information and record the data to file for safe keeping. Data can be exported to an Excel spreadsheet and saved to create history.

If you have more than one Electrical Zone, then you will need one Anode Monitor for each Zone since only one anode bus can be connected to an Anode Monitor.

The rating of the Anode Monitor is reviewed by looking at the rating of the max current that the unit can handle as well as the maximum for any individual Membrane Electrode Cell (sometimes referred to as a 'point'). The Anode Monitor is available in a 50 amp max per point or a 100 amp max per point. When you get ready to ask for a quote make sure and specify the max current per point (i.e. 50 amps or 100 amps) and specify the max amps of your rectifier(s).

Special note for hoist type e-coat paint systems. Since all the Cells achieve a maximum value all about the same time it is not practical to use a handheld DC current clamp on ammeter. If you do use a handheld device you can only get the max reading for one each during a cycle. So if you have 20 Cells, it will take you most of the morning to get a reading from each Cell. The Anode Monitor is able to gather information very quickly and can poll all of the cells quickly enough that it can get the maximum value for each Cell for each cycle. Thus if you have a hoist system you should strongly consider the Anode Monitor.

How do you know what is the maximum amps per Cell (i.e. point)? You can ask an electrician to sample the current draws using a DC clamp on ammeter (make sure it's the largest ware that is painted). You can also take the anode area (SF) of your Membrane Electrode Cell and multiply by 10 amps/SF. This would typically be the highest current expected.

Click here to view the Specification Sheet. Please contact UFS for a price quote. If you are interested in an estimate of the entire project cost including installation and start-up assistance please contact UFS Technical.

Current Monitor

If your budget is tight and you do not want to send an electrician into the e-coat enclosure every time a measurement is required, then you should consider the Current Monitor from UFS. This uses a DC shunt as the DC current sensor for each ME Cell. The output from each sensor is sent to an enclosure and the output sent to the meter is selected by a series of switches on the front of the enclosure. This panel does not have any type of connectivity built-in and so the operator must manually record current draw data and save it in an Excel spreadsheet.

The Current Monitor Panel is available in 16, 32, 48, and 64 point versions. The Current Sensor is available in a 100 amp and 150 amp versions.

The addition of a Current Monitoring System in combination with a preventative maintenance program can help to avoid production problems. Electrical current data, when viewed over a period of time, is an excellent service tool. Performance problems and likely replacement periods for ME Cells become apparent to the user. As the authorized sales and service distributor of JP Tech E-coat paint market products, UFS offers several alternatives for monitoring ME Cell's electrical performance.

For the latest technology to view electrical current draw from each ME Cell on a PC in the E-coat lab, the Anode Monitor System is for you.

Hoist type E-coat systems benefit additionally with the Anode Monitor System in that that all Cells are polled in a fraction of a second. The E-coat operator can view data on a remote control screen mounted near the E-coat tank as well as on a PC in their lab via an RS232 port. Ethernet capabilities can be added as an option.

Hoist or Monorail customers that already have UFS Current Monitoring installed can upgrade to theCurrent Monitor Plus which offers the features of an Anode Monitor System without having to purchase an entirely new system.

If budgetary constraints require purchase of a more standard monitoring system, UFS offers a Current Monitor Panel installed with either Current Sensor Modules (designed for monorail ED system) or a Current Sensor Panel (suited for hoist ED System). Easy monitoring of individual ME Cells can be performed by pressing the appropriate switch on the front of the panel. The standard system can be easily upgraded at a later date.