CHEMICAL DOSING PUMPBy MILTON ROY
A dosing pump, or often referred to as a metering pump, is a device used to accurately deliver a precise amount of liquid or substance under controlled conditions. While similar to generic dosing pumps, the chemical dosing pump differs in its type of application within specific industries and its usage in the process.
For example, in wastewater plants, chemical metering pumps are used to apply a specific amount of chemicals accurately, and to control the pressure and pH of the liquid. Other typical applications include utilisation of the pumps industries such as food processing, water processing and other industries where the precise flow rate is essential.
Other popular applications for liquid dosing pumps are the food, cosmetic and manufacturing industries where ingredients need to be added into a mixture on a production line.
As accuracy is a vital aspect of a liquid metering pump, a smooth, constant and low pulsating flow is required making pumps such as a piston, progressive cavity and flexible impeller pumps suitable. Chemical dosing pumps are also used to handle tasks such as the chemical treatment of water in boilers for use in cooling towers, or when working potable water.
Milton Roy’s range of chemical metering pumps is designed for high out applications. Robust in design and construction, these dosing pumps are highly suitable for applications such as water treatment chemicals, process additives, acids, out-gassing fluids, slurries and much more.
Dosing Pumps suitable for an extensive range of applications
Chemical Dosing Pumps
The drive incorporates a variable eccentric design which ensures smooth output and reduces system shock. The mechanically actuated diaphragm reduces the possibility of hydraulic oil contamination of process liquid which makes this an ideal pump to handle all types of water treatment applications. DC variable speed drives are available for external control and automation.
Series G™ dosing pumps are electric motor-driven pumps with mechanical diaphragm liquid ends. Simple, economical and rugged, they offer great flexibility and a wide selection of liquid ends compatible with most chemicals. With a corrosion-resistant plastic or aluminium housing, depending on the model, they are based on two technologies previously only used for intensive-use industrial pumps: variable eccentric drive and stroke adjustment.
Series G™ is made up of three dosing pump models, covering a very wide flow range (up to 2,000 l/h) at an excellent quality-price ratio.
These pumps are recommended for use at low discharge pressures, mainly in service applications such as water treatment and surface treatment, but also in the food processing industry, agriculture, etc.
The MAXROY® pump is specially designed for pumping specific products, including viscous products. With its industrial design and absence of any dead volume, it can pump and dose products with a viscosity of 3,500 cP and meets the specific requirements of food type applications. Guaranteeing a dosing accuracy of ±1%, even at low pressure, and a controlled life cycle cost (service lives in excess of 20 years have been recorded), the MAXROY® is the ideal pump for numerous dosing operations.
- Chemical industry: Fertiliser manufacture: dosing of amines or paraffin + amines
- Water treatment in explosive atmospheres: Pumping of flocculants, neutralising agents
- Food industry: Injection of starter in cheese-making
mRoy MRA & MRB
mRoy series Models A & B metering pumps are controlled-volume, hydraulically-actuated diaphragm pumps that are designed for consistent chemical delivery. Its compact design contains a plunger that reciprocates at a fixed stroke, displacing a fixed volume of hydraulic fluid and thereby actuating a flexible, chemically inert PTFE diaphragm to create the pumping action. This field-proven design enables metering with repetitive steady-state accuracy at a ±1% range. Designed to meet global industry standards, Models A & B provide accurate dosing of a broad spectrum of fluids. Like all mRoy metering pumps, Models A & B are built to run constantly all year long with preventative maintenance, leading to decades of consistent performance.
Injection of chemicals such as coagulants, biocides, disinfectants, polymers, softening agents, acids and bases for pH control, scale and corrosion inhibitors, oxygen scavengers, process additives, and many more for the following areas of application:
- Chemical and petrochemical processing
- Cooling towers and boilers
- Drinking water treatment
- Oil and gas production
- Food and beverages industry
- Industrial water and wastewater treatment
- Pharmaceuticals production
- Power generation
Features and Benefits
- Hydraulically-balanced PTFE diaphragm, designed for 96,000 hours operating life, does not use seals and eliminates
plunger packing maintenance.
- Liquid end bleed system makes it easier to commission a new or a newly maintained pump.
- Worm and pinion drive operating in an oil bath lubrication produces a smooth mechanical motion that eliminates wear and tear of mechanical lost motion designs and assures long gear and bearing life.
- Dust-tight cast iron housing provides a rugged enclosure for operation in the harshest plant and field environments.
- Micrometre capacity adjustment enables accurate output flow control.
- Internal hydraulic pressure relief valve automatically protects the pump’s hydraulic system from overpressure conditions.
- High-performance, adjustable, cartridge-type check valves provide positive, repeatable sealing on every pump stroke.
- Metallic and non-metallic liquid end materials, available for corrosion resistance in any chemical application.
- The pump is capable of withstanding a wide range of fluid and ambient temperatures with options for extremely low and high-temperature requirements.
- Simplex and duplex versions available.
- The pump meets standards for CE, ATEX, and API 675.
- Extensive motor mount and pipe connection options are available for process compatibility and simple integration into
chemical injection systems.
- Process compatibility options are easily selected such as heating/cooling liquid end jackets, configurations for slurries or
viscous fluids, unique material combinations, etc.
The DSD technology has been developed to pump fluids at very low flow rates.
Launched in 2012 with the DSD 71, the DSD technology is now available with 3 sizes of liquid ends to handle flow rates from 0.06 l/h (at 100% of capacity) to 40 l/h and pressures up to 130 bar.
The efficiency of this technology is based on the properties of its diaphragm, which is unbreakable. That is why the DSD technology is also available with a single diaphragm diaphragm: the double diaphragm is no longer needed. This is a real game changer. Both configurations guarantee safe operation with the best efficiency, but the single DSD diaphragm option expends the higher hydraulic performance..;
MILROYAL® D pumps are particularly rugged and can operate in the severest of conditions, such as on offshore platforms, in the desert, etc., and the oil bath gives moving parts an exceptionally long service life.
Oil and Gas
Extraction: injection of corrosion inhibitor in the wellhead or in pipelines
Gas treatment: gas odorization, injection of mercaptan, or THT
Refineries: injection of additives into fuel, injection of catalysts
Boiler water treatment: of make-up, circuit and discharge water (injection of corrosion inhibiter, biocides, anti-foaming agent, scale inhibitor, etc.)
Water treatment in utilities: Injection of corrosion inhibitor (phosphate), hydrazine, ammonia
During the development of the PRIMEROY® dosing pump, our eco-design initiative culminated in the 2007 launch of the PRIMEROY®, a dosing pump with incontestable environmental benefits (*):
- Raw materials: 40% reduction in energy consumption and 160 kg CO2 equivalent reduction in greenhouse gas emissions per pump, and 37% reduction in impact on human toxicity
- Transport: it is difficult to put a figure on this due to the wide variety of destinations, but there is a definite impact due to a 43% weight reduction and 46% volume reduction
- Consumables (oil): over the 20-year service life of the pump, the user will use half as much oil, a saving of around 500 litres per pump
- Recycling: the PRIMEROY® is approximately 95% recyclable by weight (no glued parts) and has almost 30% less painted surface area
Although eco-design is a new initiative, these few figures show just how relevant it is; and, while protecting the planet, there are economic benefits for the manufacturer and user.
Oil and Gas
Gas processing: Gas odorization – our modular pumps can be adapted to environments with temperatures of -50 °C
Refineries and Petrochemical industry
Process: Injection of sulphuric acid into water to produce diluted sulphuric acid
Storage: Injection of paraffin inhibitor into fuel storage tanks
Pressure maintenance pump for filter press supply
The combination of their design, which enables them to operate in extreme conditions, and their modularity makes PRIMEROYAL® dosing pumps suitable for a large number of industrial processes. Comprising 6 types of mechanism, the PRIMEROYAL® range provides accurate dosing of all types of fluids at flow rates that can reach more than 70,000 l/h. With over 50 years’ experience in dosing equipment for industry, Milton Roy Europe’s industrial dosing pumps provide you with Safety, Reliability and High performance.
Oil and Gas
Extraction – Process: Injection of methanol at pressures of 500 bar and more in the extraction well
FPSO – Water treatment: Injection of sodium hypochlorite, biocides, scale inhibitor, oxygen reducing agent, etc.
Refineries – process: Pumping of hydrocarbons
Chemical and Petrochemical industries
Process: Dosing catalysts for polymerization of polyethylene
Process: Injection of supercritical CO2. Two possible solutions: metal liquid end with metal diaphragm or metal liquid end with PTFE diaphragm equipped with a system combining continuous degassing and diaphragm rupture detection (Milton Roy Europe patent)