General Discussion of PULSAIR Pneumatic Controllers
Tank Shape | Multiple Tank Mixing | Simultaneous Mixing | Remote Control Options
PULSAIR builds pneumatic controllers for three general shapes of tanks including flat bottomed tanks (FT series), horizontal tanks (HT series) an v-bottomed tanks (VTS series). Although PULSAIR pneumatic controllers have many similarities, each system varies to the degree that the number and configuration of accumulator plates, injection valves, filters and regulators changes for different tank shape and size.
The basic PULSAIR Pneumatic Controller, without remote control options, places all of the controls at the mixing tank. PULSAIR Pneumatic Controllers allow tank operators to control several control functions:
|V or Cone bottom tanks, because of the steep sides, can usually be mixed by installing one accumulator plate just above the drain. Thus a PULSAIR VTS Controller generates one signal that opens and closes one injection valve.||
|PULSAIR systems for Flat Bottom (or shallow V, cone or dish bottom) tanks alternately pulse a center accumulator plate and an outer ring of six accumulator plates. Larger tanks require a third ring of accumulator plates to be pulsed in sequence with the center and middle ring of plates. The nomenclature for these systems is FT Controllers.|
|Horizontal tanks are rectangular, square or round (a cylinder on its side). PULSAIR systems for these tanks utilize a design that has a series of accumulator plates in a row down the center of the tank. Every other plate is plumbed together and alternately pulsed, maximizing tank coverage, a difficult task for mechanical mixers. Horizontal systems are referred to as HT Controller.|
Multiple Tanks PULSAIR builds control systems designed to mix single tanks, two tanks, or three tanks. It is not cost effective to build a pneumatic controller for four tanks because the circuitry and installation is complicated. It is more economical to purchase two FT-2 systems instead of one FT-4. The tank count is denoted in the model number by a dash followed by the number. For example, a single flat tank controller is an FT-1, a controller for two cone tanks is VTS-2, and so forth.
Simultaneous Mixing The PULSAIR multiple controller must be switched from one tank to the other. In other words, the FT-2 controller mixes one tank at a time. However, PULSAIR builds FT & HT (VTS is capable of running up to four tanks simultaneously) systems, denoted by a "D" in the model number, that will mix two tanks simultaneously. An additional Injection Pressure control is installed on D models so that the operator can adjust the pulse pressure for each tank, therefore adjusting the mixer to meet the specific demands of each tank. The Injection Time and Dwell settings on the D models are shared by both tanks. Model numbers are FT-2D, HT-2D or VTS-2D.
It is not always necessary to have a D model because liquids mixed by PULSAIR gain momentum, which causes mixing to continue even after the system is shut off. An FT-2 system, running one tank at a time, can be designed with the RC option and a timing device that causes the system to switch back and forth between tanks. When two tanks are filled to equal levels with similar compounds, the pre-selected on-off cycle can balance the system such that continual mixing is achieved in both tanks, even though the PULSAIR is on in only one tank. When the system is balanced, two mixes can often be made for the price of one in terms of expended energy and production time. The advantages of PULSAIR liquid momentum follows Newtons law that "things at rest tend to stay at rest, and things in motion tend to stay in motion". See Intermittent Mixing.
Internal Injection Valves Sometimes a PULSAIR system is put into an especially harsh environment. In such cases, it is advantageous to put the injection valves inside the Pneumatic Controller housing. This requires a larger enclosure. PULSAIR designates by adding an "X" to the model number. For example, PULSAIR sold a VTS-3X to the Grays Harbor Paper Company in Hoquium, WA. The V-bottomed tank system mixes in three cone tanks and the three injection valves are housed inside the controller.
Remote Control Options PULSAIR makes a remote control "RC" option for all pneumatically controlled models. A solenoid valve is added to the controller, which is capable of receiving on/off signals that are sent electrically. Although tank selection and on/off can be operated remotely with the RC option, Injection Pressure, Injection Time and Dwell continue to be maintained on the PULSAIR pneumatic controller at the tank. Unlike a lamp that is plugged into an outlet wired to a switch, the RC system can not be shut off at the tank unless the remote switch is also off. Furthermore, like the lamp analogy, the system cannot be energized remotely if the pneumatic controller at the tank is switched off. It is important to note that mixing can always be shut down by turning the Injection Pressure knob on the pneumatic controller to zero.
The remote control option is denoted by the letters RC at the end of the model number. Thus a VTS-2 RC is system that mixes to cone tanks and can be turned on or off from a remote location.
See Programmable PULSAIR Controller (PPC), Remote Station Controller (RSC) and Programmable Remote Station Controller (PRSC).
Electro-Pneumatic Interface (EPI)
Customers can move the control of multiple PULSAIR mixers to a central location replacing each pneumatic controller with an Electro-Pneumatic Interface (EPI). An EPI has no controls on the panel. The only control left at the tank is the injection pressure regulator. The EPI converts electrical signals from Programmable PULSAIR Controller (PPC) into pneumatic signals that open and close the injection valves.
PULSAIR also sells a DCS package that includes a license to use the technology and the Programming Guidelines. The DCS system includes EPIs, accumulator plates, injection valves, filters, regulators, installation drawings etc. The customer installs the system, programs their PLC and then links the two together to complete the licensed DCS PULSAIR package.