Abstract: Vacuum trucks are utilized for collecting liquids and solids capable of fluidization, via a hose or pipe connected to a holding tank in which a vacuum has been induced via an air mover such as a blower. The air stream drawn from the holding tank must be discharged to the atmosphere; environmental laws may require treatment of the exhaust stream prior to discharge. Vacuum trucks used in industrial settings like petroleum refineries and chemical plants may require a large charge of materials to remove pollutants discharged from the vacuum truck holding tank. The embodiments disclosed herein include modularized “control units,” containing adsorbents and/or absorbents to reduce the organic content of the exhaust gas, including VOCs as well as specific organic compounds of concern. These materials must be replaced when they are no longer effective in removing pollutants. Embodiments herein include a system for efficient change out of control units to allow continued operation.

Abstract: An apparatus and a method for removing volatile organic compounds from air that is vented from tanks and vessels containing hydrocarbon material. This invention also relates to a self-propelled vehicle on which the apparatus is mounted.

Abstract: First and second C-shaped clamping members are provided to engage a ladder and a roof rack. One of the clamping members is mounted on an actuator rod, the other on an actuator housing. A pistol grip handle and trigger mechanism enable the two clamping members to be ratcheted into secure clamping engagement with the two items. A quick release plate allows the clamp to be easily opened for disengagement. In a second embodiment, a compression spring draws the two clamping members together when the quick release plate is engaged.

Abstract: In modem circuitry in which an angle modulated carrier signal is clipped and demodulated, and the demodulated signal is filtered and compared with a threshold value to produce an output signal, the invention features, in one aspect, a delay line whose length and shifting frequency are both programmable and, in another aspect, the combination of a differential detector, having a programmable delay line and a digital filter, having a programmable sampling frequency.

Abstract: Modem circuitry for processing data signals, featuring a digital filter whose tap coefficients are all scaled by a common factor such that the most significant bits of the filter output are indicative of the digital data.