6 CIRCULAR 4 5 7. U. 5. DEPARTMENT OF AGRICULTURE 



In any method the important thing is to get a? complete combustion 

 in as short a time as possible. Keeent experiments have shown that 

 it is very unusual to get complete combustion by any method of 

 burning sulfur within the houses, and that the time required for 

 bui-ning averages about 3 hours. In burning sulfur vrithin the 

 houses a uniform concentration is rarely if ever obtained, as the 

 hot sulfur dioxide gas from the pans rises to the top of the house. 

 By the time the gas has cooled sufficiently to settle to the floor the 

 total concentration of sulfur dioxide gas vdthin the house has reached 

 a point too low to be of much value. There is also considerable 

 hazard of fire and danger to human beings in btirning sulfur within 

 the houses by the methods now commonly used. 



AS HFTZCTIVE DEVICE FOB BTTE2vCsG STTLFCB 



The use of the sulfur burner described below has been found by 

 experimentation to be an improvement over the methods now in com- 

 mon use for fumigating mushroom houses with sulfur. It produces 

 a highly concentrated gas in the house with less than one-third of 

 the quantity of sulfur required by the pan method, burns the sul- 

 fur completely vdthin about 30 minutes, reduces the fire hazard, and 

 gives completely uniform distribution of the gas within the house. 

 The details of construction are shown in figure 2. C. 



The apparatus consists of a rectangular box 2 feet square and 3 feet 

 long, of IS-gage galvanized sheet iron on a frame of 1%-inch angle 

 iron. At each end is a cone IS inches long, terminating in an open 

 pipe, the intake pipe being 5 inches and the outlet pipe 6 inches in 

 diameter. TTithin the box. shcling on supports of 1%-ineh angle iron 

 riveted to the frame, are three trays, each 23 by 34^ by 2 inches, and 

 each capable of holding about 15 pounds of sulfur. The sides of the 

 trays are strengthened by pieces of 1%-inch strap iron, and a piece 

 of the same material is run from these crosswise beneath the center 

 of each pan to prevent sagging. The door at the side is secured by 

 bolts and wing nuts. To prevent the gas from escaping, a gasket of 

 asbestos cloth is placed between the door and the body of the burner. 

 All seams and connections are strongly crimped or riveted, as the heat 

 of the burning sulfur will quickly melt any solder work. 



In preliminary tests it was found that the sulfur in the middle 

 tray burned faster than that in the top and bottom trays, owing to 

 uneven distribution of air. This condition was corrected by using 

 baffles in the intake funnel. The baffles are of IS-gage galvanized sheet 

 iron cut to fit the intake cone, with a piece of % 2 - by li 4 -ineh strap 

 iron riveted to the center of each, longitudinally. The ends of the 

 strap iron are pierced with holes and project into the intake pipe, being 

 held in place by bolts, the nuts of which are outside on top of the intake 

 pipe j fig. 2. ) . to allow adjustment of the baffles. The bases of the 

 baffles rest on the tray supports. The spacing of the baffles must be 

 determined by testing, or by the use of an anemometer, so that each 

 pan receives air at the same rate. 



The fan used is of the centrifugal type in a steel housing, connected 

 directly to a 1 20 horsepower electric motor running at 1.750 revolu- 

 tions per minute, and with a horizontal 5-inch discharge and 6-inch 

 sinofle suction. This fan delivers 150 cubic feet of air per minute. 

 Since the outlet from the burner is an inch greater in diameter than 



