Air Pollution Control Equipment
Electro-Static Precipitators (E.S.P.),
Baghouses, Scrubbers, etc.
Printable or Viewable Sample ESP Diagram
Printable or Viewable ESP Key Interlock System Ordering Aid
Superior Interlock has been working with original equipment manufacturers
(O.E.M.), rebuilders, and end users for over 50 years in the safe-guarding of personnel and
equipment throughout the world. Drawing from this experience, the following information is a
general guideline in the proper interlock sequence for E.S.P.'s. For your specific needs,
please feel free to contact our engineers for a free proposal without obligation. Please see
our precipitator cost estimator to help provide all required information for an accurate
proposal. Superior Interlock can recondition, update, add, or replace your system. We
understand the costs associated with outages and with our flexibility we will strive to meet
your schedule requirements.
Over the years we have found that the harsh environments of air pollution
control equipment, petrol-chemical equipment, food processing, and many other caustic
industrial climates require more resistant interlocks. We have developed the majority of our
product line in stainless steel for this reason. We have formed a relationship with the
Abloy Corporation to use their keys and locks in our products in areas where problems with
common pin-tumbler locks arise. The Abloy keys are of an I-beam profile, providing great
strength and break resistance. The Abloy locks are a non pin-tumbler type which is
positively actuated by the key. This positive actuation requires no springs that may stick
in industrial climates such as the ones found in precipitators. These locks are available
in our standard product line as an option, and are standard in our stainless steel product
line. Systems may be mixed and matched with our standard pin-tumbler locks and Abloy locks
in standard or stainless steel housings to suit any application.
Precipitator Interlocking
Precipitators are being used in more and more industries due to
environmental concerns and government regulations. A precipitator is used to remove
particulate (dust and soot) and prevent it from entering the atmosphere. The particulate
is removed by passing a gas containing the particulate past a series of high voltage
plates. The particulate is attracted to these plates by the high voltage static charge.
Rappers are used to knock the dust off the plates into the hoppers below for collection
and disposal. The high voltage static charge is produced by a transformer rectifier (T.R.).
This takes A.C. power from the facility, boosts the voltage and rectifies it to produce
D.C. This is used to charge the plates. The plates' potential can be in excess of 50,000
volts. For this reason, access must be restricted until safe. The power must be locked off
and the plates grounded to remove residual charges.
The first part of the process in interlocking the precipitator is to lock
off the power in the control cabinet that feeds the T.R. This can be done by locking of the
switch or circuit breaker supplying power to the control cabinet or using a panel mount key
switch that may be used to control the internal electronics of the cabinet.
Circuit Breaker with Interlock |
Disconnect Switch with Interlock |
Once the cabinet has been safely locked off and keys obtained, giving
evidence that the cabinet has been locked off, they are then taken to the T.R. The T. R.
is a non-load break capable switch. For this reason, it can only be operated when the
control power is shut off. The key from the control cabinet is inserted into the lock that
locks the T.R. in the high voltage or operate position. When the key is inserted and the
lock unlocked, the T.R. switch may now be put into the off and ground position. When in
the ground position, a second lock will lock it grounded, releasing another key. When the
plates are all grounded, it is safe to access the precipitator.
Transformer Rectifier with Superior Interlock
When all control cabinets are locked off and all the T.R.'s are locked
in the ground position, all of the ground position keys are released. All these keys are
then taken to the transfer interlock and inserted. When all of the ground keys are
inserted, this will release all of the access interlock keys. These keys may be taken
to all of the entry point interlocks, and the precipitator may now be opened up for
maintenance and repair.
Transfer Interlock |
Access Interlock |
If nuclear level detectors are used within the hoppers, or any equipment,
they must also be incorporated into the interlock system. This prevents operators from being
exposed to radiation. It is recommended that all level detectors are locked in a shielded,
safe position. When the keys are released they are taken to the transfer interlock and
inserted, along with the ground keys, prior to releasing any access interlock keys. Specific
facility grounding procedures may also be incorporated into the interlock sequence.
Nuclear Level Detector Interlock
Superior Interlock's access interlocks have a key retaining feature that
prevents an access key from being removed from an interlock when the access way is open. For
this reason, to reverse the above procedure to restore the equipment to its original
operating position, all access ways will be safely locked closed.
Some T.R.'s have multiple positions for greater flexibility for a facility.
For this reason, more complex interlock schemes will be provided to maintain the greatest of
flexibility for this equipment. Superior Interlock's engineers will work with their
counterparts to provide a safe and flexible custom designed system.
Sample electro-static precipitator key flow diagram.
Printable or Viewable Sample ESP Diagram
Printable or Viewable ESP Key Interlock System Ordering Aid
| 
Home
