Advantages of Direct-Inject, Boosted Pressure Chemical Dispensing Systems
July 16, 2014
By: Gary Brown | Hydra-Flex, Inc.
As featured in SECWA’s Wash Street Journal Summer 2014
Recent innovations have brought to the vehicle wash industry a chemical dispensing solution that will deliver improved vehicle coverage and enhance your chemical performance while using less water, taking up less space, and requiring less maintenance and operating costs than traditional mixing and pumping systems. Direct-inject chemical dispensing systems are an equipment upgrade that can contribute to the success of your car wash in a big way, with results that are better for your customers, the environment, and your bottom line.
Revolutionizing the Industry
The science behind direct-inject chemical dispensing systems is far from new. Giovanni Battista Venturi, an Italian physicist, wrote about the eponymous discovery of the Venturi effect in 1797. The fundamental technology has been used in vehicle care with relative success over the last 50+ years, but only recently have innovative manufacturers learned how to apply the technology with techniques and components that can solve the unique needs of the car wash industry.
PDQ Vehicle Wash Systems is recognized as one of the first in the industry to package a direct-inject system with their line of in-bay automatic equipment. Manufacturers such as Hydra-Flex, Carolina Pride, and SAS specialize in this technology, while many other OEMs and distributors offer this feature as an upgrade. With thousands of sites now in operation, car wash owners have clearly signaled that this is the wave of the future.
Today’s direct-inject chemical dispensing systems combine water with chemicals using a regulated Venturi injector to deliver consistent and accurate mixed solution to the applicator(s) in the car wash. After chemical is mixed, air may be introduced into the solution line to generate foam at the arch or gantry. Complete systems include booster pumps, injectors, metering tips, manifolds, electronic controls, gauges, and regulators pre-mounted, and pre-plumbed for easy installation.
- Small Footprint. Most systems can be wall mounted, and these dispensing systems accurately deliver RTU (ready to use) solution without cumbersome mixing tanks. Compare the wall space required to hang a bank of 12+ mixing tanks to the less than 20 sq ft. required for the equivalent direct-inject system at the national average build cost of $313.48/sq foot and you can see the savings add up.
- Consistency. Because these systems use pumps to pressurize and regulate the water, you don’t have to worry about changes in local water pressure changing your dilution ratios. The precisely diluted chemical is delivered to the arch, every time.
- Better Vehicle Coverage. Water is used to carry the chemicals. Using the same dilution ratio, but increasing the delivery pressure allows for less solution used with better coverage and stunning visual results. (See water droplet images.)
- Precision. These systems have the ability to work with super-concentrated chemicals. Color-coded injectors (by flow rate) and metering tips (by dilution ratio) offer precise optimization and easy maintenance of your chemical delivery system.
- Reliability. Less moving parts means less downtime and reduced operational costs. Some manufacturers offer systems that are constructed with chemically resistant materials that will last longer and stand up to the rigorous demands of the car wash industry.
- Environmentally Friendly. Because solution is applied to the vehicle at higher pressure, less solution is used, which can often result in significant reductions in water and chemical usage. Additionally, the use of super concentrated chemicals can reduce packaging waste and shipping costs.
Selecting Your Equipment
Not all direct-inject dispensing equipment is the same. Look for these features when selecting your equipment provider.
- Compatibility with Chemicals Used. Injectors are available in a number of materials, from brass and stainless to Kynar®, a very chemically resistant plastic.
- Reliable Components. Make sure your system has been tested for reliability.
- Customization: Some manufacturers offer kits for triple foam, lava arches, and bug prep applications, etc.
- Testimonials. Ask your equipment provider for testimonials from installations done in your area.
Venturi Injectors – How they work
A Venturi can be used to infuse a small amount of one fluid into the flow of another fluid. In vehicle wash applications, Venturi injectors work by forcing water through a cone-shaped nozzle, creating a pressure differential between the inlet and outlet. The constricted flow in the center of the injector creates a vacuum, pulling in the undiluted chemistry, mixing it with water, and delivers the precisely diluted solution from the injector outlet directly to the car wash applicator.
Want to learn more? Watch videos at www.YouTube.com/HydraFlexInc
 Reed Construction Data 2013, U.S. National Average for Car Wash Square Foot Cost Assuming Brick with Concrete Block Back-Up / Bearing Walls.