What is a dosing pump?
Dosing pump or injection pump is a family of positive reciprocating displacement pumps. These pumps are used to transfer a certain amount of liquids and chemicals. These liquids include a variety of disinfectants such as chlorine, acids, antiscalants (flavors), flavorings and additives in the food and beverage industry, coagulants (flocculants) in wastewater treatment, chemicals, and more. . Injection pumps (dosing pumps) have two main parameters of pressure and flow. In these pumps, the constant pressure and flow are usually adjusted by the reciprocating course of the piston or diaphragm. This course is manually controlled by a micrometer screw (volume) or automatically by probes and control panels. Head, diaphragm and piston material in dosing pumps Dosing pumps are selected according to the type of liquid being pumped. The head part is usually made of PP polypropylene, PVC PVC, KINAR PVDF, stainless steel 304 and 316 and the diaphragm part is made of PTFE Teflon or NBR natural rubber.
Types of dosing pumps
Dosing pumps Metering pumps are designed and manufactured in terms of compression mechanism in piston, plunger and diaphragm models. Also, these pumps are available in motorized or solenoid types based on the power transmission generator, which we will introduce in the following.
Solenoid dosing pump
Dorsing solenoid pump is made entirely of polymer and is usually used to move fluids with low temperature and viscosity. In fact, a solenoid is an iron wire or core that is wound around it. This set is also called a magnet, whose job is to move the shaft. The shaft is connected to the diaphragm, which pumps the fluid with its reciprocating motion. The maximum pressure of solenoid pumps is 20 times and their maximum output flow is 100 liters per hour.
Dosing pump Motorized diaphragm dosing pump
In order to better understand how dosing pumps with motorized diaphragm pumps, we will first introduce their main components: This model of dosing pumps consists of an electric motor, gearbox and diaphragm. The gearbox converts the rotational motion of the electromotor into reciprocating motion and then transmits it to the aperture. With the reciprocating motion of the diaphragm, the action of suction and discharge of fluid occurs.
Dosing pump Motorized piston dosing pump
- Piston dosing pumps belong to the family of positive displacement pumps with motor.
- In these pumps, the rotation of the cam off-center causes the reciprocating motion of the piston.
- By moving the piston backwards, suction is done and the cylinder chamber is filled with liquid
- and then by moving the piston forward, the liquid is directed to the outlet.
- The inlet and outlet valves of these pumps are one-way.
- These valves are designed to prevent fluid from entering the low pressure section and vice versa during suction and compression of the piston.
Piston dosing pumps have less wear
- and longer life compared to diaphragm models due to diaphragm removal.
- The dosing material of piston pumps should be selected according to the type of fluid and its temperature,
- which can be SS, PP, PVC and PVDF.
- Piston dosing pumps used in petrochemical and refinery units are designed in accordance with API675 and API676 standards.
- Note: Due to the positive displacement of the dosing piston pumps,
- the outlet path should never be closed when the pump is operating,
- as this will damage the pump, fittings or piping system.
Peristaltic dosing pump Hose pump
- These pumps, also known as hose pumps or roller pumps, transfer fluid by rotating the roller on the hose.
- Peristaltic dosing pumps are usually used for low pressures up to 6 bar.
- The hose material in peristaltic pumps is usually made of silicon or centoprene,
- which is selected according to the type of fluid and its temperature.
- Peristaltic pumps are mostly used in medical, laboratory, washing machine and pool purifiers, etc.
- It should be noted that their laboratory samples have a high accuracy of milliliters.
Dosing pump accessories
Usually the accessories that are used with dosing pumps include the following, which we will give a brief description of each of them in the following:
- Safety valve: The safety valve is used in the liquid outlet path.
- This valve automatically drains a certain amount of liquid without manual intervention
- to prevent the pressure from exceeding the specified amount. When the pressure returns to normal,
- the valve closes and prevents fluid from escaping.
- Injection valve: The injection valve is one-way and is used to prevent the liquid from returning to the pump.
- This valve is usually installed on storage tanks or the main pipeline.
- Strainer: The strainer prevents solid particles from entering the pump. The filter installation location is usually in the pumped liquid storage tank.
- Damper pulsation or accumulator: Since the dosing pumps are positive displacement pumps,
- their output current is with the pulse and is not uniform.
- The use of a damper pulse or accumulator equalizes the output current and also increases the life of the pump.
Important points in choosing dosing pumps
- Flow rate: The most important factor to consider when choosing the right dosing pumps is flow rate. For example,
- if a dosing pump is used to inject chlorine into pool water and too much injection is required,
- it may endanger the health of swimmers. Therefore,
- adjusting the flow rate of dosing pumps is one of the important issues that should be considered.
- Pressure: Injection pumps are capable of producing a wide range of outlet pressures.
- Therefore, when buying a dosing pump (according to what you want to do), you should also pay attention to the issue of outlet pressure.
- Corrosion: To choose the right dosing pump, you must consider the amount of liquid corrosion,
- because the material used in the injection pump is selected based on the fluid specifications.
- Suppose a dosing pump with polypropylene (PP) material is used to inject 80% sulfuric acid.
- Hydraulic parts corrode and damage over time.
- One of the important factors in choosing the material of effective injection pumps is liquid temperature. For example,
- for high temperature liquids, dosing pumps of steel or PVDF are usually used.
- Flammability: In order to inject flammable or explosive materials,
- care must be taken to use explosion-proof (anti-spark) dosing pumps. Usually,
- these pumps are made of steel and have an engine according to the ATEX standard.
- Liquid concentration: Usually,
- dosing reciprocating pumps are used for injecting dilute liquids
- and screw dosing pumps are used for injecting concentrated liquids.
Chemical Injection Pump Introduction
- One of the devices available in all hospitals is very vital if there
- are injection pumps that are of different types. The syringe pump is one
- of the devices that helps to inject the patient with a smaller volume than the precision.
- As the injection site is not controlled, some specific drugs in the body can
- cause and pose a risk to the patient. The device you become familiar with becomes a hospital
- staff member who has the ability to inject your desired drug into the patient’s
- body at a constant rate over a very long and accurate time.
What is an injection pump
- It is a small device that weighs about 2 kg and can be installed on a stand or for you.
- This device is able to inject very small amounts of 1 ml per hour to 450 ml per
- hour with full accuracy. The device is equipped with a smart computer
- that by reducing or increasing the pressure, you can accurately power a continuous current.
- Patient distance to the pump or reduction of normal column height, flow pressure and injection speed
- can not be created. The smallest volume of air inside the column
- is detected by the device and normally shuts off its flow in the off state.
- If a substance with a different volumetric mass is injected,
- the device has the ability to be calibrated with it. So that the volume of the decorated material
- is calculated exactly. Any resistance to fluid flow, such as blockage
- of a vessel or movement of an angiocatheter
- (a device that attaches to a patient’s artery
- and is injected into the patient’s body through a variety of injection sites and drugs)
- from the vessel to under the skin, is triggered by alarms. That particular device is reported.
- After injecting the volume of mine from the desired material,
- the machine automatically shuts off the flow and remains in kno mode.
- If other authorized devices are able to send pressure to
- positive pressure inside the vessel, so that it can increase the infusion rate up to
- 5 cc / min. The device is able to work without electricity for two hours,
- which is the case when moving the patient.
Injection pump Principles of operation
- A plastic syringe containing the middle is inserted into the holder,
- a tube with a holding set is attached to the patient’s vein either directly into
- the stomach or through a cannula or cannula. If the flow rate is variable,
- it is determined that the pump is a plunger (piston) that is pressed to find a
- wide flow. The injection speed (planer movement) depends on the syringe
- diameter and the regulated flow for the pump. Chemical Injection Pump
- When the pump is currently running, it reduces the flow rate, measures
- its pressure and pressure, and shows the operator’s devices to
- your store whenever these or other parameters occur.
High or low injection of a particular drug
- may be very dangerous for each patient, the plastic produced
- by the manufacturer is not exactly the same, so the pump is designed
- to work with a specific type (brand) of the specified type
- (syringe types Can be used if the label is used on a specified protection device, in which case
- possible errors due to reduced flow and its volume are not usable if not allowed.
- The result of using a high pressure pump, closing with an alarm And the obstruction (occlusion) of the injection tube comes with you.
Unit of measurement: ml per hour (ml per hour)
Typical and common values: 0 to 250 ml per hour (0-250 ml per hour)
Internal device mechanism of syringe injection pump
Syringe injection pump
- A 50 ° C syringe pump has a specific characteristic.
- The observed syringe pump has a different speed from 5 ml
- per hour to 255 ml per hour depending on the speed required in different types of drugs.
- After setting the desired speed for injecting the drug under the supervision
- of a doctor, the injection is started by pressing the RUN key.
- The low-speed syringe pump is used for poisonings that require the injection of a drug
- gradually but very slowly but at a constant rate, for work in the river,
- or for the injection of anesthetics during surgery, which must be injected continuously.
Internal device mechanism
- The movement of material in the syringe pump is controlled by Step-motor.
- The first step Chemical Injection Pump is to control the speed and
- movement before determining the type of syringe and its load,
- which is done by the optocoupler mechanism. This mechanism has an infrared
- transmitter and an infrared receiver that is started by a diode that is emitted
- with a specific infrared voltage. This transceiver receives a
- packet that Opto Coptler deals with. Each moment the height of each
- OptoCoptler stand is determined by the measurement that your motion can not be in front
- of the OptoCoptler and prevents infrared emission. Through
- a receiver that infrared can not calculate the height of the syringe
- and determine the type of syringe. Inside the package is a microcontroller that
- controls the operation of the Optocoptler. The next step is allowed if you select
- quickly Chemical Injection Pump on the microcontroller screen to convert
- it to m / s and generate the desired voltage to move. The next step
- is to create the right feedback for your device. There should be a
- feedback from the speed of the device because for any reason there may be a problem
- in the device that stops the injection of the drug, or the engine may have a problem.
- These should be detected by feedback and in other cases an alarm will be sounded.
- This alert is also given by Optocoptler. OCCL alarm means that there is a
- blockage in the movement path. This device and this mechanism are due to the sensitivity of Optocoptlers