What is the Digital Flow Control Valve Working Principle
The digital diaphragm control valve is an electrically and hydraulically operated multi-functional control valve. It can be used for local and remote batching operations with electronic unit controllers. The valve also has a built-in flow control feature. In this particular post, we will discuss the working principles of digital flow control valve.
Digital Control Valve:
The digital flow control valve basically consists of a diaphragm-operated main valve and two solenoid valves. A normally open (NO) solenoid connects the valve cover chamber to upstream pressure. At the same time, a normally closed (NC) solenoid connects the valve bonnet chamber to downstream pressure. When using a digital diaphragm control valve with an electronic batch controller, It can be controlled digitally using a solenoid valve through these three steps:
- When the NO and NC solenoids are actuated, the valve gradually opens.
- When the NC solenoid is de-energized (Not energizing the solenoid), the valve locks in its current position.
- When the NO and NC solenoids lose power, the valve will gradually close.
The digital flow control valve operates simply and is describe below. The total batch amount delivere and controlled through the valve is divide into seven steps (reference chart) for convenience. Initially, the NO and NC solenoid valves were in an energized state. The NO valve applied high pressure upstream on the diaphragm. At the same time, the NC valve prevents this pressure from draining to the downstream side. The valve remains closed for this reason. A manage valve regulates the fee of fluid go with the drift as the placement of the valve plug or disk is modified via way of means of an actuator. Control valves are used to keep a procedure variable as near as feasible to the preferred set point. Controller set factors are generally go with the drift fee, pressure, and temperature.
Both NO and NC solenoids are energize. Currently, there are no valves that limit the entry of high pressure upstream to the closing chamber. The NC valve allows the pressure on the relief diaphragm to be low downstream. This creates different pressures across the diaphragm. High upstream pressure acting from the lower diaphragm opens the main valve and allows initial flow through the digital flow control valve.
when the flow rate reaches the preset value (Set in the batch controller to “Low Flow Start”), the NC valve de-energizes. This prevents drainage of the culture chamber and locks the digital flow control valve at this flow rate. Low-speed first delivery prevents the product from splashing and also prevents static electricity.
When a sufficient quantity is delivered at low speed, the NC pneumatic needle valves is activated again. This will allow more water to drain from the grow chamber and thus increase the flow.
When the flow reaches its maximum level (set in the batch controller), the NC solenoid is de-energize. This maintains a constant high flow rate for the remaining batches. During this process, the flow control is carry out by a group controller. When multiple flow meters are connect to the same pump, stopping (or starting) one or more meters will increase (or decrease) the flow rate in the remaining meters.
When the flow rate increases, the solenoid does NOT cut off momentarily. This injects high pressure into the closed chamber and causes the flow control solenoid valve to speed up to maintain the set flow rate. If the flow decreases, the NC solenoid is momentarily energize. This allows for slight drainage of the grow chamber and allows the liquid flow control valve to continue to open to maintain the set flow rate.
At the end of the batch, the solenoid is NOT deactivate. This injects high pressure upstream into the closing chamber and throttless high-pressure flow control valve.
When the throttle electronic flow control valve is sufficient to achieve a predetermined slow-closing flow rate. (configured in the batch controller) NO solenoids will be energize. This will maintain a constant flow rate.
When batch quantities are delivere, the solenoid is NOT de-energize (the NC solenoid has been de-energize). This applies a high upstream pressure in the closed chamber. This causes the main valve to close completely until it is fully close.