Apparatus for controlling operational parameters in polymerization equipment

Clemmer et al.

[45] Feb. 15, 1977

[54] APPARATUS FOR CONTROLLING OPERATIONAL PARAMETERS IN POLYMERIZATION EQUIPMENT

[75] Inventors: Clyde C. Clemmer; Ward C. Alcorn, III, both of Odessa, Tex.

[73] Assignee: Dart Industries Inc., Los Angeles, Calif.

[22] Filed: Oct. 30, 1972 [21] Appl. No.: 302,309

Related U.S. Application Data

[62] Division of Ser. No. 53,355, July 9, 1970, abandoned.

[52] U.S. CI 23/288 H; 23/253 A;

23/288 E; 23/288 K; 23/289; 73/341; 260/695; 260/700; 307/235 A; 307/310;

328/3; 526/61; 526/64; 526/82

[51 ] Int. CI.2 B01J 3/04; C08F 110/02;

C08G 85/00

[58] Field of Search 260/94.9 R, 94.9 P,

260/95 A, 695, 698, 700; 23/289, 288 E, 288 H, 288 K, 284, 253 A, 230 A, 253 R; 235/151.12 R, 151.12 MO, 151.12 MI

[56] References Cited

UNITED STATES PATENTS

2,852,501 9/1958 Richard, Jr. et al 260/94.9 R

3,079,372 2/1963 Fulknier et al 260/94.9 R

3,293,233 12/1966 Erchak, Jr. et al 260/94.9 R

3,294,773 12/1966 Gans et al 260/94.9 R

3,427,138 2/1969 Donnelly et al 23/253 AX

3,475,392 10/1969 McCoy et al 23/253 AX

3,506,715 4/1970 Clark 23/230 AX

3,582,629 6/1971 Ross 235/151.12 X

3,654,447 4/1972 Bradley 23/253 AX

Primary Examiner—Joseph Scovronek

Attorney, Agent, or Firm—Arthur S. Collins; Fred S.

Valles

[57] ABSTRACT

In apparatus for polymerizing high-pressure ethylene to produce polyethylene, a tubular reactor is connected to a source of high pressure ethylene. An intensifier supplies an initiator solution to the tubular reactor. This solution includes one or more catalysts which promote the polymerization reaction. Within the tubular reactor, a peak temperature occurs in proximity of the point at which the catalysts are introduced. If the catalysts are introduced at more than one point, peak temperatures will result downstream of each of such points. For various reasons, the peak temperatures are displaced along the tubular reactor and a plurality of thermocouples are distributed at spaced positions in the tubular reactor to measure the temperatures at the positions at which the peak temperature might occur. These thermocouples generate signals which are fed into a gating arrangement which selects the peak signal which is compared in a comparator circuit with an adjustable or selectable signal representative of the peak temperature which is desired. A difference signal is generated which relates to the difference between the selected signal and the peak signal with which it is compared. This difference signal is converted by a transducer into a pressure signal which is fed to a control valve which controls the speed of operation of a pump feeding the catalysts into the reactor. If two or more pumps are employed for feeding the catalysts into different zones in the reactor, separate controls are provided for each of the pumps.