Aggregate batcher discharge gates are operated by a pneumatic cylinder. The cylinder receives air from a double acting solenoid valve that operates from an electrical signal from the batch control. To operate a double acting (inching) solenoid valve, two signals are required to turn on and off, both signals need to be momentary. Flow controls are installed on the solenoid valve or cylinder that regulates the air flow to the cylinder, and are installed allowing the operator to regulate the speed of the cylinder movement in order to precisely control of the gate.
During normal operation of the plant the batch control will control the operation of the gates and the discharge rates. The batch control does need to be programmed properly to operate the gate efficiently. Below are some settings that may affect the operation of the gate. Note: These settings may be labeled differently depending on the manufacturer of the control. Aggregate batcher in the one-batch concrete plant
Flow Rate (Minimum and Maximum)-Most batch controls try to obtain a flow rate when discharging; they will typically try to stay in a range and work off of a minimum and maximum setting. The settings for this need to be determined for each plant individually.
Initial Open-The initial open setting is used to get the gate opened at the start of discharge. Typically the initial open setting should get the gate ¼ - 1/3 of the way open for the first pulse or to get a good flow rate started.
Open and Close Pulse-After the discharge gate has been opened with the initial open pulse, the open and close pulse takes over for the remainder of discharge. If the batch control determines the flow rate needs to be adjusted a pulse will be sent to the open or close the gate depending on if the discharge rate needs to increase or decrease. Each open or close pulse should move the cylinder 1/8 of its overall travel.