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Chemical Feed Applications are Driven by Metering Pumps


Many commercial and industrial sites rely on the addition of chemicals in various processes throughout the facility to prevent water quality issues. Prevention of water quality issues is important because poor water quality can easily lead to scale build up, corrosion, and biological fouling. All of these conditions are much more cost effective to prevent than remedy.

LMI Diaphragm Metering Pumps or Chemical Feed Pumps, are defined by ANSI 7.1, as “reciprocating positive displacement pumps typically used for the injection of chemical additives, proportional blending of multiple components, or metered transfer of a single liquid. These types of pumps are used in applications requiring accurate, repeatable, and an adjustable rate of flow.”

LMI metering pumps and LMI controllers utilized in chemical feed systems are simple ways commercial and industrial sites can improve their processes. Robust and reliable chemical feed equipment can yield substantial advantages in a wide range of industrial and commercial water applications, including:

Boiler Feeds:

To increase steam generation efficiency, it is important to use clean water. Clean water with corrosion inhibitors and anti-scalants also protect the boiler and piping infrastructure within the plant. These chemicals injected at the proper rate enable boiler systems to run for a longer period of time with higher levels of efficiency. Furthermore, by properly dosing the chemical and not over-feeding, chemical usage can be optimized to reduce chemical costs.

A Typical Boiler Installation includes the following LMI equipment:
- (1) Metering pump
- (1) Boiler probe and Cross assembly
- (1) Conductivity Controller
- (1) Flow control valve or (1) Orifice plate assembly


A Typical Chemical Feed System Illustration in Boiler Applications

Cooling Towers:

Cooling Towers – LMI products help reduce energy costs and maximize performance by preventing scale build up and corrosion. Simultaneously, proper dosage of biocides prevents microbiological fouling which reduces the risk of building occupants developing Legionaire’s disease.

Typical Cooling Tower installations include the following LMI equipment :
- (1) Conductivity Controller
- (3) Metering pumps for Biocides, Anti Scalants, Corrosion Inhibitor
- (1) Manifold assembly consisting of Conductivity probe, Flow switch, Sample valve


Chemical Feed Illustration in Cooling Towers

pH Control:

pH Neutralization / pH Process Control

Many industrial and water treatment applications require pH control in process and/or waste water. For instance, some applications may be required to neutralize pH on discharge water. In other cases, there may be a chemical process that requires process fluid to be more alkaline or acidic.

LMI Chemical Metering pumps in conjunction with a pH controller (such as the LMI DP5000), a desired pH can be easily achieved by the user. The controller will trigger the pumps to simply meter acid or base solutions to ensure the process fluid can meet the required conditions.

Typical Cooling Tower installations include the following LMI equipment :
- (1) Conductivity Controller
- (3) Metering pumps for Biocides, Anti Scalants, Corrosion Inhibitor
- (1) Manifold assembly consisting of Conductivity probe, Flow switch, Sample valve


pH Adjustment Illustration with Chemical Feed Equipment

Common Chemical Feed Applications:

Some other common chemical feed applications in which metering pumps are heavily relied on are:

Water and Wastewater – It is critical to properly treat process water prior to discharge into the environment. Industrial wastewater operators need to evaluate and adjust many different water parameters with the proper combination of chemicals. Prior to discharge, water will undergo pH adjustment, removal of large particles via coagulation, flocculation, and filtration, antifoam agent addition, and disinfection.

Disinfection – Disinfection is common in many chemical treatment processes. Chlorinating a pool or fountain and disinfection for municipal potable and wastewater treatment are common applications.

The addition of sodium hypochlorite (commonly referred to as chlorine or bleach) is one of the more common chemical feed processes today. There are many strict controls on chemical amounts to both properly disinfect the water and minimize adverse health effects. It is important to neither underdose or overdose this chemical because of these limits.

Utilities – Treating water properly in re-circulating water systems helps to avoid expensive unplanned outages and plant de-rates. Furthermore, properly injecting chemicals keeps equipment running longer at higher efficiency levels.

Process Water – Accurately metering chemicals helps remove dissolved minerals and other impurities, increasing overall water quality. Additionally, with chemical costs increasing, it is important to accurately meter chemicals to reduce overall chemical expenditures while providing properly treated water

Highly accurate and reliable products are critical in supporting these mission critical applications. By using reliable, repeatable, and accurate chemical feed products not only optimize capital equipment longevity, but also enhance reliability and reduce energy consumption. In applications where microbiological fouling is of concern, metering pumps are used to protect public health.