For the most precise systems available today, electronic direct injection proportioners are the best option. Foam concentration is injected directly into the foam manifold by these electrically controlled devices. A variety of criteria are used to calculate how much concentration to use in the water, which is then used to produce the right amount of foam solution.
Paddle wheel flow meters are used in all systems to measure water flow volume. The quicker the wheel rotates, the more water there is to move it. It generates an electrical signal when the paddle wheel moves in a clockwise direction. In certain cases, temperature sensors may be added to proportioners. Foaming concentrate is simpler to combine with warm water than cold water; thus, the temperature is a consideration.
A more precise approach to determine the solution % may be found in other proportioners that detect conductivity. Foam solution production may also be improved by controlling the variables in water and foam concentrates. The conductivity of the water entering the proportioner and the conductivity of the foam solution leaving the proportioner are both measured by conductivity-measuring equipment. They then verify that the percentage is accurate by comparing the figures. This information is sent to a computer, which determines how much foam concentrate to add to the mixture. The injection pump’s speed is then controlled by the computer. Increased concentration may be injected with a quicker pump speed. Percentage accuracy is maintained through a closed-loop system that continually monitors and adjusts.
Achieving A Decision
A proportioner’s flow capacity is measured in gallons per minute of foam concentrate. From 1.5 GPM to over 12 GPM, they’re all over the place. It is important to keep in mind that bigger isn’t necessarily better. In order to figure out what’s necessary, there are two things to keep in mind. The amount of foam solution required is the first consideration. A low-gpm proportioner is all that’s needed for a brush truck with a modest volume of flow. When the proportioner is too big, the low-flow precision is reduced, and the system might at times be intermittently low-flow. To be able to flow foam master streams, a structural pumper will need a significantly larger concentration flow capacity. To keep up with the concentration need of high water flows, a large-capacity proportioner will be required.
The second aspect to consider is the sort of concentrate to be used. When using Class A concentrates, the maximum percentage is 1%; when using Class B concentrates, the maximum percentages are 3% or 6%. To treat a given amount of water, a greater volume of concentrate is needed the higher the percentage. Three gallons of concentrate will treat 1,000 gallons of water when using Class A foam at a concentration of 0.3 percent. Only 100 gallons of water may be treated using 3 gallons of concentrated Class B foam at a concentration of 3.0 percent. You should also think about other factors while making your proportioner selection. For starters, there’s a switch that lets you choose between two different tanks. You’ll need a selector switch to switch between different concentrates if you intend to utilize more than one sort of concentrate. Both manual and electric tank selector switches are readily accessible.
A single tank and an overboard pick-up may both be operated via a dual tank selection switch. For significant incidents, the overboard pick-up may be used to switch to a different kind of concentrate or draw from a huge supply. The proportioner you’re employing must be able to draw from an external source if you want an overboard pickup. A foam refill mechanism is a second option to keep in mind. The onboard foam tank may be refilled from the ground using this system, which comprises a pick-up tube, pump, and associated equipment. Using foam buckets to climb on top of a firefighter’s gear may lead to a number of injuries, including slips, trips, and falls.
Proportioning Method For Electronic Foam
When flammable substances need to be extinguished, a water extinguishing system like a sprinkler system is used. A layer of foam emerges from the nozzles, covering the liquid and putting an end to the burning process. Foam concentration may be used to extinguish solid items as well as liquids. In addition lessens surface tension, enabling more of the extinguishing water into the core. There are cases when an extremely small proportioning percentage is needed. As a result, it is necessary to make the appropriate adjustments to the dividing percentage in order to eliminate the threat.
Using an electronic foam proportioning system, InnoVfoam has created a large-area foam dosing system that is both efficient and precise. As a result, it is suited for a sprinkler system in which one or more sprinklers open, and the flow might be erratic and unpredictable throughout the fire fighting process. An adjustable speed gear pump ensures that the foam concentrate is always dispensed in a precise quantity. This entire, ready-to-use plug-and-play system is provided on a metal frame!
Electronic control systems and flow meters in the pipes for water and foam concentrate ensure that the right foam proportioning is achieved for every given application. Whenever there is a change in the water flow, the foam concentrate flow is adjusted promptly and without any time to adapt. In the test mode, the foam concentrate flow may be adjusted at any moment via the electronic control system. Testing the system in compliance with relevant requirements without side effects such as foam concentrate consumption or discharge responsibilities of leftover liquid is an essential feature.
In this case, the flow of water causes an increase in water pressure, which in turn elevates the water cone. Water from the normal pressure side of the pump is returned to the pump’s suction side by opening the drive water line. The proportioning rate is then set by opening the relevant ball valve. As a result, water and foam compounds are mixed together on the suction side of the cone. There are two ways to choose the proportioning rates: manually (for a single proportioning rate) or pneumatically.
Before purchasing an electronic direct-injection proportioner, do some study. Your department’s money will be better spent, and the system will satisfy your department’s requirements and expectations if this is done.