Vertical shell & tube heat exchanger with larger tube diameters are designed for cooling air streams with large amounts of particulates, before it enters a bag house for final cleaning and discharge into the atmosphere. Hot, dirty air enters the top of the unit and goes down through the tubes. Most of the particulates fall through the tubes and are collected underneath the exchanger in a large material collection hopper.
Depending on the size, amounts and dryness of the particulate, the tubes may never have to be manually cleaned. When they do need cleaning, usually a simple running of a brush down through the tube will completely clean the tubes. Normally, large plenums are equipped with large access doors which allow cleaning personnel to enter the exchanger and clean the tubes while standing on the top tube sheet. Cleaning can be done with brushes, high pressure air, water, or steam, however keeping the system dry helps in the collection of the particulates. This method of particulate removal allows process air to come out of the tubes cool and cleaner before it enters the bag house. The air stream reduces the load on the bag houses and eliminates the possibility of destroying bags due to high temperatures.
The recovered heat can be re-used as building make-up-air, or process heating, which can result in huge energy savings. Units can be used to condense out moisture that can be reused in process, saving water usage. Units are also available with metallic single or double bellow expansion joints, or with our proprietary full or partial air seal expansion systems, which completely eliminate stress caused by tube expansion during heat up, and significantly increase the life of the exchanger.
Heat exchangers can be fabricated to withstand inlet air temperatures up to 1,800°F, air volumes from 1,000 SCFM to 100,000 SCFM. Tubes diameters are available from 1″ to 4″, with wall thickness from 0.049″ to 0.120″, and up to 40′ in length. All of which can be manufactured in materials from mild steel to all grades of Stainless Steel. Depending on application, 2″ to 8″ of internal insulation is available with various types of high temperature insulation with or without covers. Top hot air inlet plenums with access doors, with service platforms and ladders are also available. Other options include bottom, cooled air outlet plenum with material collection hoppers with access doors, service platforms, ladders and structural steel support framework.