Using liquid de-icers is an effective method to both remove and prevent the buildup of snow and ice on roads, sidewalks, and equipment. Airlines have used it for years to remove ice on planes, and of course, government road departments have been using it on highways to keep roads safe, but de-icing liquids can also be used by about anyone on parking lots, driveways, and sidewalks.
If you are a turfcare professional, property manager, or even a homeowner who wants to know what equipment they need to apply liquid de-icer this article will cover the types of de-icers, the equipment needed to store it, and the sprayers needed to apply it.
What is the Difference Between “De-Ice & Anti-Ice”
“De-icing” and “anti-icing” are two different techniques used to combat icy and snowy road conditions. The intent of both is to improve road safety, however, they differ in timing, what liquid is used, and how it is applied.
De-icing is simply the act of removing ice and snow after they have already formed on the road or other surfaces. De-icing liquids are applied to penetrate the ice and snow to get down to the road surface where it can melt the existing ice. This method works faster because it separates the ice/snow from the road surface and allows sunlight (when present) to work on melting from the top.
This application method requires specific equipment and sprayer nozzles to penetrate the ice and snow, rather than simply spraying the liquid over the surface where it would only melt from the top.
Anti-icing is a proactive approach with the intention of preventing ice from bonding to the road surface in the first place. This typically involves pre-treating roads or surfaces with material or liquids that work to lower the freezing point of water thus keeping it from freezing. This preventative measure is intended to maintain safer road conditions during and after winter weather.
Using rock salt or liquid salt-brine is a common anti-ice method used to pretreat major city roads, highways, and bridges
De-icing and anti-icing methods have the same common goal of improving road safety during icy conditions. Both techniques will often utilize salt or salt brine though the amount of liquid and the method of application may be different.
De-Icing & Anti-Ice liquids
There are various liquids are used on roads and highways to enhance safety by preventing or mitigating the formation of ice. Each liquid has unique characteristics. Let’s examine the commonly used liquids, their characteristics, typical applications, and relative costs:
Salt Brine – Sodium Chloride Solution (NaCl)
- Freezing Point: A typical salt brine used for deicing roads, with a concentration of about 23.3% NaCl by weight, the freezing point is approximately 20°F (-6.7°C).
- Characteristics: Salt brine is a solution made by dissolving sodium chloride in water. It is a cost-effective de-icing agent that lowers the freezing point of water. It is typically applied as a pre-wetting agent or used in spray applications.
- Salinity is a significant factor in making salt brine for de-icing. Salinity refers to the concentration of dissolved salt in water.
- Typical applications: Salt brine is commonly used for anti-icing and de-icing purposes. It is often applied as a pre-treatment before a winter storm to prevent ice bonding to the road. It can also be sprayed directly on icy surfaces to accelerate the melting process.
- Relative cost: Salt brine is relatively inexpensive compared to other de-icing liquids.
Liquid Magnesium Chloride (MgCl2)
- Freezing Point: This varies depending on the concentration of the solution. 30% solution has a freezing point of about 3 degrees F.
- Characteristics: Liquid magnesium chloride works at lower temperatures than salt brine alone. It is highly effective in preventing ice bonding and accelerating ice melting.
- Typical applications: Liquid magnesium chloride is used for anti-icing and de-icing applications as well as dust control. It is often applied as a pre-treatment to prevent ice formation.
- Relative cost: Liquid magnesium chloride is generally more expensive than salt brine but offers increased effectiveness at lower temperatures.
- Characteristics: It has a very low freezing point, being effective in temps well below freezing.
- Uses: Potassium acetate is used in locations where salt is not allowed. Airports, parking garages, etc.
- Relative Costs: It is one of the most costly de-icing liquids available.
- Characteristics: Beet juice is a natural and biodegradable liquid derived from sugar beets. It has a vibrant color and is sticky. It also has moderate acidity.
- Typical applications: Beet juice is often used as an additive to salt brine or other de-icing liquids. Beet juice helps salt brine stick to the road and lower the freezing point of the brine.
- Relative cost: The cost of beet juice as an additive can vary, but it is generally inexpensive compared to other agents although the amount required might be more than other types of de-ice liquids.
Calcium Chloride (CaCl2)
- Characteristics: Calcium chloride is a highly effective de-icing agent that releases heat as it dissolves in water, allowing it to melt ice at lower temperatures. Its liquid form is most commonly used on roads and highways.
- Typical applications: Calcium chloride is used for de-icing and anti-icing applications, especially in northern regions with extremely cold winters. It is usually used as an additive rather than the primary de-icing liquid due to cost.
- Relative cost: Calcium chloride is typically going to be more expensive when compared to de-icing liquids due to its effectiveness at lower temperatures.
The specific liquids used for de-icing and anti-icing vary depending on regional preferences, climates, and budget restrictions. Different regions and municipalities may have their own preferred liquid or combinations based on their unique needs and available resources.
Equipment for Applying De-Ice and Anti-Ice Liquids
Using the correct liquid for your de-ice needs is important, but the other half of the battle is applying and handling the liquid. A specialized sprayer is required for different de-ice applications. The liquids need to be applied at a consistent rate, in the right location, and the equipment needs to be compatible with the liquids and winter weather conditions it will be used in.
D-Ice & Anti-Ice Sprayers
There are many variations of sprayers used to apply de-ice and anti-ice liquids. They vary primarily in size and the type of surfaces they are designed to treat. There are de-ice sprayers for sidewalks, driveways, parking lots, and highways. They are often made so they can be put into the back of a pickup or dump truck.
Handheld De-Ice Sprayers
Your basic handheld pump sprayer or backpack sprayer can also be used to spray most de-icing or anti-icing liquids. These work best for small driveways and sidewalks.
Pickup De-Ice Sprayers
Contractors and Lawn Maintenance companies often use skid sprayers or spray rigs that will slide into the bed of a pickup truck. These de-ice sprayers offer the ideal capacity and flexibility to apply snow and ice melt liquids to parking lots, roads, large sidewalks, etc.
They are typically pretty similar to the equipment used by turf care professionals to apply fertilizers and herbicides. The major difference may be in the pump type on the sprayer and the type of nozzles used on the spray boom.
A centrifugal sprayer pump is preferable to a roller or diaphragm pump that are typically used on lawn care sprayers. De-ice applications typically require higher volumes of liquid that some diaphragm pumps can’t achieve. Diaphragm pumps and roller pumps are also less resilient to the liquids used for de-icing. Whatever type of pump you use, it is important to rinse with fresh water and make sure it is drained, winterized, or stored in a climate-controlled building to avoid freezing.
The nozzles used are often larger capacity nozzles. With de-ice liquids a fine droplet is not as necessary as with many herbicides, or pesticides, so flood nozzles and boomless nozzles can work fine.
If you want to build your own de-ice sprayer or convert some existing sprayer, check out this article on what it takes to make a de-ice or anti-ice sprayer.
Snow Plow/Dump Truck Sprayers
Municipalities and road maintenance departments charged with clearing and treating highways and city streets will use large sprayers with spray bars or booms that can cover a single lane of traffic or multiple lanes at once.
These sprayers need to hold large volumes of the de-icing liquid that is being used. The amount of liquid applied is often 30, 40, or more gallons of liquid per lane mile. This means most de-ice sprayers used on freeways will have a tank capacity of 1000 gallons or greater.
They use high-volume centrifugal pumps, typically powered by a hydraulic system on the truck. These pumps are usually made from cast iron or stainless steel. They can transfer liquids at 100 gallons per minute or more.
The spray bar is made up of a piece of stainless steel pipe that has spray nozzles evenly spaced about 8-10 inches apart. The spray nozzles are typically stainless steel as well and they produce a solid stream of liquid.
De-Ice Sprayer Nozzles
There are two main reasons for using solid stream nozzles. First, after snowfall or Ice has accumulated on the road, a solid stream nozzle is used to try and penetrate the surface of the ice/snow. The aim here is to speed up the melting process. A flat fan nozzle, while it would cover the surface, only gets the top layer melting and takes longer.
The second reason for solid stream nozzles is to leave a gap between the treated areas on the street. This is done specifically with salt brine only and not other products like made chloride calcium chloride that have lower freezing points.
Salt brine in cold climates can still freeze depending on the mixture. So when pre-treating in extremely cold temperatures, where there is a risk of freezing after it is applied, they don’t want to coat the entire surface because if it does freeze it becomes a sheet of ice.
The approach of using solid stream nozzles will ideally leave strips of dry surface on the road between the areas where the brine has been applied. This would then provide some surface that is free from ice for any drivers that may venture out.
De-Ice Sprayer Rate Controls
The regulation of the sprayer output in de-ice and anti-ice sprayers is a critical aspect of their operation. De-ice applicators that work on public roads and freeways must be able to change their output as they speed up and slow down. This is achieved with electronic meters, regulating valves, and either automatic or manual controls.
The system uses a sensor to monitor the vehicle’s speed and adjusts a regulating valve accordingly to maintain a consistent application rate. A rate control console is programmed with the desired application rate and nozzle size so it knows how to adjust the regulating valve based on input from the speed/GPS sensor and a flow meter on the discharge side of the pump.
For example, if the vehicle slows down, the control system will close the regulating valve to prevent over-application. Conversely, if the vehicle speeds up, the control system will open the valve more to ensure that the application rate remains consistent.
This system can be manually overridden by the operator if necessary. However, in normal operation, it allows for precise control of the de-icing liquid application, ensuring efficient use of materials and consistent road conditions.
These rate control systems are similar to the ones used for agricultural sprayers but instead of gallons per acre, they operate on gallons per lane mile. You can see a full guide to the different rate control setups in this post on electronic sprayer controls.
Salt brine (NaCl) can be purchased if you only need a small amount for sidewalks or driveways. DOTs, Contractors, and municipalities use a device called a brine maker to produce their brine solution.
A brine maker typically consists of a tank or container where water is mixed with salt to create the solution. Typically they will have controls to regulate the salt-to-water ratio. The brine maker can be designed to handle different volumes of water and salt, depending on the specific requirements of a specific application.
De-Ice Liquid Storage and Transfer Equipment
Salt brine can be made ahead of time and stored for use when needed. To effectively store brine, a large polyethylene tank is used. Centrifugal transfer pumps are used to load the brine sprayers and to recirculate the brine.
Polypropylene and stainless steel hoses, fittings, and pumps are best suited for de-icing liquids. Stainless is often the best option but it is significantly more expensive than polypropylene which is more than adequate.
Camlock couplings are effective couplers used to quickly connect to storage tanks and load brine sprayers. If you are not familiar with these couplers, be sure to check out this article that breaks down the different camlock coupler types and how they work.
Liquid anti-ice/de-icing application is an effective means of preventing hazardous winter road conditions. It does require specialty equipment to apply it effectively. Hopefully, this provides you with a good start to the basic requirements of spraying salt-brine and other de-ice liquids.