SEQUENCE CONTROLLERS

What is dust collector & how timer Board Interfaces with it ?

The pulse jet design have group of bags enclosed in housing. Dirty air enters the housing and travels through the filter bags. Filtered air is vented to the atmosphere. High pressure (4-6 kg/sq cm) air pulse dislodges the dust, which falls into the hopper for disposal or recovered for use. Cleaning cycle is initiated from remote timer (Continuous Cycle) or pressure switch (on demand pulsing) Signal actuates diaphragm solenoid valves which permits momentary jet of high pressure air to each venturi and filter bag. Only one row of bags is cleaned at pre-selected intervals, while the system is in operation.

Timer Board Operating Modes....

• Continuous Cycle Mode : The boards have two operating modes available for different applications. Starting with the most vital mode, it is capable of operating in a continuous cleaning cycle. This can be started by putting a jumper (shorting link) between the pressure switch input to the terminal strip connection. Two setup parameters control operation: off time, on time. on Time and off time specifically deal with the solenoid on time and the time interval between the end of the on pulse and the start of the next.


• On Demand Mode (Air save mode) : Demand mode operation can be configured using the high limit and low limit inputs. A simple on-off system can be setup with a single pressure switch connected to the high limit input. Better control can be achieved with a high and low limit switch set such as is provided in the Photohelic® (DWYER Make) pressure gage. In this on demand mode, on time and off time may be programmed to define the cleaning cycle. Meaning there by Pulsing will start when DP (Delta "P") is high & continue till it reaches low set point.


• No. of Channels Selection : A jumper (Flying lead wire) connector is provided to select the last channel used. Place the jumper on the pins corresponding to the last channel to be used in the Operation .


• Off Time and On Time Setup : Off Time defines the period of time between solenoid activations when no channels are enabled. This value may be set between 2 second and 120 seconds. On Time defines the solenoid Firing time. The value may be set between 20 m/sec and 200 m/sec . If adjustments are made while the system is in operation, the new setting will take effect in the following next Channel solenoid operation. Do not use excessive force to rotate the potentiometers. This will damage the Timer unit.

Timer cards

The use of micro controllers in in bag house sequencers has seen a change in emphasis from unit cost considerations alone back towards emission performance & bag house maintenances. This recent change has been brought about by several factors including better automation provisions, dust collection accountability / process reporting as well as fulfillments of certification requirements.

A small, but vital, item of Bag House equipment. controls the sequencing of solenoid valves. The duration of the Valve opening can be varied between 20 -200 milliseconds, and the time interval between the activation is adjustable from 2- 60 Seconds. The controllers are micro controller design, developed over a number of years through extensive and exacting site testing All controllers are fully (100%) tested before being sent to site and they have been proved reliable over the whole field of dust control applications. Only the best quality electronic components are used, so that the reliability of the whole is to a very high standard Consequently on site failures all which have occurred within first week of operation are less than 0. 5 %.

All the Timer boards are compact and based on ATMEL 89C2051 based micro controller. A manual pulsing to test the timer is a standard feature. These timers are Underwriter Laboratories (UL) listed and can be integrated into a NEMA box for ease of operation.

Standard features of the timer boards

• UL Listing : Yes
• Power : 230v / 110v, 50 / 60Hz
• Pulse freq. : 2-120 sec (int. time) [Different Timings On request]
• Pulse Duration : 20-200 m sec. [Different Timings On request]
• Output Glands : PG 9 for solenoids--- Input Glands : PG13.5 for power
• On Demand Pulsing : Standard on all models
• Red Clock Led : Yes Power On Led : Yes
• Feed back relay : Yes
• Sequence Function Indicators Leds : Yes
• Manual Pulsing for Testing : Yes
• Conformal Coat: Yes (Loctite)

Significant Features of all Timer Boards

• Ex-stock Available Timer Boards 5, 10, 15, 20 outputs
• Delivery with in 48 hrs for Quantities up to 25 Boards
• Proven product for last 20 years
• Excellent performance, extremely low failure rates
• 100% testing of all Sequential Timers on Simulated Air Headers with all types of Solenoids

Below are some of the examples of our products

Applications:- These timer boards can be interfaced with any pulse jet valves, filter bags to create a properly timed sequence of burst of air that can be used in an industrial dust collector systems. Such dust collector systems are necessary in food industries, mining industries and pharmaceutical industries. We supply all the necessary mechanical parts, valves, control electronics, filter bag accessories, and to make a complete system as per customer’s requirements as shown below