What are chemical injection pumps?
Chemical injection pumps are designed to improve water treatment plant production and pipeline flow and reduce corrosion. They operate to specific chemical and fluid requirements depending on the temperature and pressure at which the injection pump will operate. Ultimately, chemical injection pumps deliver specific chemicals into the production system at specific rates. These procedures are required for the safe application of chemicals and for oilfield systems to operate efficiently. Chemical injection pumps are common systems in the Canadian oil and gas industry. Some of the chemicals used include solvents, desalting agents, corrosion inhibitors, biocides, softeners, scale inhibitors, hydrate inhibitors, oxygen scavengers, surfactants, and more. Sometimes methanol is used to reduce antifreeze that causes clogged pipelines. This can be a complex topic, but it is important to understand the various applications, limitations, and conditions that contribute to the efficiency and overall performance of these systems.
Mechanism of operation of injection pumps
These dosing pumps work by taking a certain amount of liquid into a chamber and introducing the chemical into the tubes or tanks containing the liquid being dosed. The pump is activated primarily by electric motors or a ventilation operating element and uses a controller that cycles the pumps (controls the flow rate) and turns the power on and off.
Uses or applications of injection pumps
- Agriculture
- Manufacturing and chemical processing
- Oil and gas production
- Cryogenics
- The cars
- The pulp and paper industry
- Food processing
- Semiconductors
Types of pumps
There are different types of pumps used as chemical injection pumps. In general, chemical injection pumps fall into two categories, gas-powered or electrically-powered.
Gas-powered pumps are also called pneumatic CIPs and are classified as either piston type or diaphragm type. They both work in the same way but differ in the mechanism that drives the chemicals.
Pneumatic or gas injection pumps
Positive displacement pumps and diaphragm chemical pumps: They operate by gas pressure and have a single head. The amount of gas injected is directly related to the length of the stroke.
Metering pumps can be used for chemical and water injection. They can operate under high pressures and allow constant average flow rates over time. The best way to avoid leaks is to use metering diaphragm pumps. Diaphragm pumps are better in that they are precise and have no leaks, resulting in a more efficient pump with longer product life.
AC or DC electric injection pumps
Electric chemical injection pump designs are similar because they are piston-driven, but the motor and power are different. Piston-driven injection pumps contribute to operations by preventing the system from venting gas. Direct current electric chemical injection pumps have emerged in places where air conditioning is not available, often in remote areas. It is a great alternative to pneumatic chemical injection pumps in terms of cost and environment.
The main advantages of using chemical pumps
- Very precise
- Simple in design and relatively easy to install, adjust, or repair
- Operates under high pressures
- Long pump life
- Increase work safety
- Reduce greenhouse gas emissions and odors
- Efficient systems will reduce fire risks as well
Maintenance of injection pumps:
As in any other process in oil and gas production, high levels of inspection and control are needed. To operate and maintain chemical injection systems efficiently, operators must track and record all activities. The most important details to keep records of are the number of chemical injection pumps used, data for the different types of injection pumps, fuel, and gas consumption levels, any change or upgrade made, and MSDS data for all chemicals used.
