Design Considerations for Dry Scrubbers

This paper presents comments and recommenda­ tions regarding conceptual design specifications for dry scrubbers (also known as wet/dry scrubbers) for use on waste-to-energy facilities. These recommendations would be used to develop minimum acceptable design parameters for requests for proposals for full-service or turnkey waste-to-energy contractors. The reason for presenting these comments and recommendations is that the authors perceive a general overestimation within the waste-to-energy industry as to the extent of applicable experience with the dry scrubber technology on waste-to-energy facilities. These recommendations, however, are more conservative than what certain full­ service and turnkey contractors are willing to guar­ antee. Upon examination, the dry scrubber technology experience-base is actually quite limited (as of the time of writing of this paper in September 1987 and the time of responding to reviewers' comments in February 1988). Based on this limited experience, the authors are reluctant to consider or recommend dry scrubber designs that deviate significantly from this experience because of a concern that unsuccessful operation will result. Unsuccessful operation of a dry scrubber can be defined in several ways. Foremost is the situation in which the required removal efficiencies are not achieved, thereby potentially resulting in facility shut­ down, reduction in throughput, or equipment replace­ ment. Although this scenario is uppermost in our