Construction
February 5, 2003

Introduction

Thought and consideration to the construction of an acid plant must done even in the early stages of bidding a project.  Aspect to be considered are in terms of construction are schedule, site access, labour, transportation, housing, site services, weather, availability of equipment (i.e. cranes), ground conditions, tie-points, etc.  Some of these have minimal impact on construction and cost but others are more critical and a preliminary plan must be drawn up to determine how the problem will be resolved.

Transportation

The transportation of equipment from the point of manufacturer to the acid plant site must be considered in the early stages of the project.  

The cost of freight/transportation is on average 8 to 10% of the capital cost of equipment for the overall project.  However, the freight cost for a large piece of equipment can easily exceed the average cost of 8 to 10% of the equipment capital cost depending on the route, method of shipment and schedule. 

Erection Sequences

• Sulphuric Acid Storage Tank Erection
• Heat Exchanger Erection
• Stack Erection
• Tower Shell

Insulation

Insulation is one of the last activities to be performed in the construction of an acid plant.  Sometimes due schedule, insulation is being applied to equipment as the plant is being preheated.  It is important that insulation be applied to prior to the equipment reaching normal operating temperatures to avoid injury to personnel and damage to the equipment.

Preheater ducting	Ducting between to heat exchangers	Ducting and heat exchanger
Smelter gas ducting at inlet of quench tower	Smelter gas ducting	Finished heat exchanger with cladding
Installation of insulation is a very labour intensive process.   Scaffolding and man lifts are used extensively to get access to the areas to be insulated.  In some cases ducting can be insulated on the ground prior to being lifted in place saving a lot of time.